diff --git a/ext/json.hpp b/ext/json.hpp index 48d797d..51f16de 100644 --- a/ext/json.hpp +++ b/ext/json.hpp @@ -1,11 +1,12 @@ /* __ _____ _____ _____ __| | __| | | | JSON for Modern C++ -| | |__ | | | | | | version 2.1.1 +| | |__ | | | | | | version 3.1.2 |_____|_____|_____|_|___| https://github.com/nlohmann/json Licensed under the MIT License . -Copyright (c) 2013-2017 Niels Lohmann . +SPDX-License-Identifier: MIT +Copyright (c) 2013-2018 Niels Lohmann . Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal @@ -29,41 +30,104 @@ SOFTWARE. #ifndef NLOHMANN_JSON_HPP #define NLOHMANN_JSON_HPP -#include // all_of, copy, fill, find, for_each, none_of, remove, reverse, transform -#include // array +#define NLOHMANN_JSON_VERSION_MAJOR 3 +#define NLOHMANN_JSON_VERSION_MINOR 1 +#define NLOHMANN_JSON_VERSION_PATCH 2 + +#include // all_of, find, for_each #include // assert #include // and, not, or -#include // lconv, localeconv -#include // isfinite, labs, ldexp, signbit #include // nullptr_t, ptrdiff_t, size_t -#include // int64_t, uint64_t -#include // abort, strtod, strtof, strtold, strtoul, strtoll, strtoull -#include // memcpy, strlen -#include // forward_list -#include // function, hash, less +#include // hash, less #include // initializer_list -#include // hex -#include // istream, ostream -#include // advance, begin, back_inserter, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator -#include // numeric_limits -#include // locale -#include // map -#include // addressof, allocator, allocator_traits, unique_ptr +#include // istream, ostream +#include // iterator_traits, random_access_iterator_tag #include // accumulate -#include // stringstream -#include // getline, stoi, string, to_string -#include // add_pointer, conditional, decay, enable_if, false_type, integral_constant, is_arithmetic, is_base_of, is_const, is_constructible, is_convertible, is_default_constructible, is_enum, is_floating_point, is_integral, is_nothrow_move_assignable, is_nothrow_move_constructible, is_pointer, is_reference, is_same, is_scalar, is_signed, remove_const, remove_cv, remove_pointer, remove_reference, true_type, underlying_type -#include // declval, forward, make_pair, move, pair, swap +#include // string, stoi, to_string +#include // declval, forward, move, pair, swap + +// #include +#ifndef NLOHMANN_JSON_FWD_HPP +#define NLOHMANN_JSON_FWD_HPP + +#include // int64_t, uint64_t +#include // map +#include // allocator +#include // string #include // vector +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ +/*! +@brief default JSONSerializer template argument + +This serializer ignores the template arguments and uses ADL +([argument-dependent lookup](https://en.cppreference.com/w/cpp/language/adl)) +for serialization. +*/ +template +struct adl_serializer; + +template class ObjectType = + std::map, + template class ArrayType = std::vector, + class StringType = std::string, class BooleanType = bool, + class NumberIntegerType = std::int64_t, + class NumberUnsignedType = std::uint64_t, + class NumberFloatType = double, + template class AllocatorType = std::allocator, + template class JSONSerializer = + adl_serializer> +class basic_json; + +/*! +@brief JSON Pointer + +A JSON pointer defines a string syntax for identifying a specific value +within a JSON document. It can be used with functions `at` and +`operator[]`. Furthermore, JSON pointers are the base for JSON patches. + +@sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + +@since version 2.0.0 +*/ +template +class json_pointer; + +/*! +@brief default JSON class + +This type is the default specialization of the @ref basic_json class which +uses the standard template types. + +@since version 1.0.0 +*/ +using json = basic_json<>; +} + +#endif + +// #include + + +// This file contains all internal macro definitions +// You MUST include macro_unscope.hpp at the end of json.hpp to undef all of them + // exclude unsupported compilers -#if defined(__clang__) - #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400 - #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers" - #endif -#elif defined(__GNUC__) - #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900 - #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers" +#if !defined(JSON_SKIP_UNSUPPORTED_COMPILER_CHECK) + #if defined(__clang__) + #if (__clang_major__ * 10000 + __clang_minor__ * 100 + __clang_patchlevel__) < 30400 + #error "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers" + #endif + #elif defined(__GNUC__) && !(defined(__ICC) || defined(__INTEL_COMPILER)) + #if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900 + #error "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers" + #endif #endif #endif @@ -89,7 +153,7 @@ SOFTWARE. #endif // allow to disable exceptions -#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && not defined(JSON_NOEXCEPTION) +#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION) #define JSON_THROW(exception) throw exception #define JSON_TRY try #define JSON_CATCH(exception) catch(exception) @@ -99,6 +163,20 @@ SOFTWARE. #define JSON_CATCH(exception) if(false) #endif +// override exception macros +#if defined(JSON_THROW_USER) + #undef JSON_THROW + #define JSON_THROW JSON_THROW_USER +#endif +#if defined(JSON_TRY_USER) + #undef JSON_TRY + #define JSON_TRY JSON_TRY_USER +#endif +#if defined(JSON_CATCH_USER) + #undef JSON_CATCH + #define JSON_CATCH JSON_CATCH_USER +#endif + // manual branch prediction #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) #define JSON_LIKELY(x) __builtin_expect(!!(x), 1) @@ -108,185 +186,540 @@ SOFTWARE. #define JSON_UNLIKELY(x) x #endif +// C++ language standard detection +#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 + #define JSON_HAS_CPP_17 + #define JSON_HAS_CPP_14 +#elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1) + #define JSON_HAS_CPP_14 +#endif + +// Ugly macros to avoid uglier copy-paste when specializing basic_json. They +// may be removed in the future once the class is split. + +#define NLOHMANN_BASIC_JSON_TPL_DECLARATION \ + template class ObjectType, \ + template class ArrayType, \ + class StringType, class BooleanType, class NumberIntegerType, \ + class NumberUnsignedType, class NumberFloatType, \ + template class AllocatorType, \ + template class JSONSerializer> + +#define NLOHMANN_BASIC_JSON_TPL \ + basic_json + /*! -@brief namespace for Niels Lohmann -@see https://github.com/nlohmann -@since version 1.0.0 +@brief Helper to determine whether there's a key_type for T. + +This helper is used to tell associative containers apart from other containers +such as sequence containers. For instance, `std::map` passes the test as it +contains a `mapped_type`, whereas `std::vector` fails the test. + +@sa http://stackoverflow.com/a/7728728/266378 +@since version 1.0.0, overworked in version 2.0.6 */ +#define NLOHMANN_JSON_HAS_HELPER(type) \ + template struct has_##type { \ + private: \ + template \ + static int detect(U &&); \ + static void detect(...); \ + public: \ + static constexpr bool value = \ + std::is_integral()))>::value; \ + } + +// #include + + +#include // not +#include // size_t +#include // numeric_limits +#include // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type +#include // declval + +// #include + +// #include + + namespace nlohmann { - /*! -@brief unnamed namespace with internal helper functions +@brief detail namespace with internal helper functions -This namespace collects some functions that could not be defined inside the -@ref basic_json class. +This namespace collects functions that should not be exposed, +implementations of some @ref basic_json methods, and meta-programming helpers. @since version 2.1.0 */ namespace detail { -//////////////// -// exceptions // -//////////////// +///////////// +// helpers // +///////////// -/*! -@brief general exception of the @ref basic_json class +template struct is_basic_json : std::false_type {}; -Extension of std::exception objects with a member @a id for exception ids. +NLOHMANN_BASIC_JSON_TPL_DECLARATION +struct is_basic_json : std::true_type {}; -@note To have nothrow-copy-constructible exceptions, we internally use - std::runtime_error which can cope with arbitrary-length error messages. - Intermediate strings are built with static functions and then passed to - the actual constructor. +// alias templates to reduce boilerplate +template +using enable_if_t = typename std::enable_if::type; -@since version 3.0.0 -*/ -class exception : public std::exception +template +using uncvref_t = typename std::remove_cv::type>::type; + +// implementation of C++14 index_sequence and affiliates +// source: https://stackoverflow.com/a/32223343 +template +struct index_sequence { - public: - /// returns the explanatory string - virtual const char* what() const noexcept override + using type = index_sequence; + using value_type = std::size_t; + static constexpr std::size_t size() noexcept { - return m.what(); + return sizeof...(Ints); } +}; - /// the id of the exception - const int id; +template +struct merge_and_renumber; - protected: - exception(int id_, const char* what_arg) - : id(id_), m(what_arg) - {} +template +struct merge_and_renumber, index_sequence> + : index_sequence < I1..., (sizeof...(I1) + I2)... > {}; - static std::string name(const std::string& ename, int id) - { - return "[json.exception." + ename + "." + std::to_string(id) + "] "; - } +template +struct make_index_sequence + : merge_and_renumber < typename make_index_sequence < N / 2 >::type, + typename make_index_sequence < N - N / 2 >::type > {}; - private: - /// an exception object as storage for error messages - std::runtime_error m; -}; +template<> struct make_index_sequence<0> : index_sequence<> {}; +template<> struct make_index_sequence<1> : index_sequence<0> {}; -/*! -@brief exception indicating a parse error +template +using index_sequence_for = make_index_sequence; + +/* +Implementation of two C++17 constructs: conjunction, negation. This is needed +to avoid evaluating all the traits in a condition -This excpetion is thrown by the library when a parse error occurs. Parse -errors can occur during the deserialization of JSON text as well as when -using JSON Patch. +For example: not std::is_same::value and has_value_type::value +will not compile when T = void (on MSVC at least). Whereas +conjunction>, has_value_type>::value will +stop evaluating if negation<...>::value == false -Member @a byte holds the byte index of the last read character in the input -file. +Please note that those constructs must be used with caution, since symbols can +become very long quickly (which can slow down compilation and cause MSVC +internal compiler errors). Only use it when you have to (see example ahead). +*/ +template struct conjunction : std::true_type {}; +template struct conjunction : B1 {}; +template +struct conjunction : std::conditional, B1>::type {}; -@note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). +template struct negation : std::integral_constant {}; -Exceptions have ids 1xx. +// dispatch utility (taken from ranges-v3) +template struct priority_tag : priority_tag < N - 1 > {}; +template<> struct priority_tag<0> {}; -name / id | example massage | description ------------------------------- | --------------- | ------------------------- -json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. -json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. -json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. -json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. -json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. -json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number wihtout a leading `0`. -json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. -json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. -json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. -json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. -json.exception.parse_error.111 | parse error: bad input stream | Parsing CBOR or MessagePack from an input stream where the [`badbit` or `failbit`](http://en.cppreference.com/w/cpp/io/ios_base/iostate) is set. -json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xf8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. -json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. +//////////////////////// +// has_/is_ functions // +//////////////////////// -@since version 3.0.0 -*/ -class parse_error : public exception -{ - public: - /*! - @brief create a parse error exception - @param[in] id the id of the exception - @param[in] byte_ the byte index where the error occured (or 0 if - the position cannot be determined) - @param[in] what_arg the explanatory string - @return parse_error object - */ - static parse_error create(int id, size_t byte_, const std::string& what_arg) - { - std::string w = exception::name("parse_error", id) + "parse error" + - (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + - ": " + what_arg; - return parse_error(id, byte_, w.c_str()); - } +// source: https://stackoverflow.com/a/37193089/4116453 - /*! - @brief byte index of the parse error +template +struct is_complete_type : std::false_type {}; - The byte index of the last read character in the input file. +template +struct is_complete_type : std::true_type {}; - @note For an input with n bytes, 1 is the index of the first character - and n+1 is the index of the terminating null byte or the end of - file. This also holds true when reading a byte vector (CBOR or - MessagePack). - */ - const size_t byte; +NLOHMANN_JSON_HAS_HELPER(mapped_type); +NLOHMANN_JSON_HAS_HELPER(key_type); +NLOHMANN_JSON_HAS_HELPER(value_type); +NLOHMANN_JSON_HAS_HELPER(iterator); - private: - parse_error(int id_, size_t byte_, const char* what_arg) - : exception(id_, what_arg), byte(byte_) - {} +template +struct is_compatible_object_type_impl : std::false_type {}; + +template +struct is_compatible_object_type_impl +{ + static constexpr auto value = + std::is_constructible::value and + std::is_constructible::value; }; -/*! -@brief exception indicating errors with iterators +template +struct is_compatible_string_type_impl : std::false_type {}; -Exceptions have ids 2xx. +template +struct is_compatible_string_type_impl +{ + static constexpr auto value = + std::is_same::value and + std::is_constructible::value; +}; -name / id | example massage | description ------------------------------------ | --------------- | ------------------------- -json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. -json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. -json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. -json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. -json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. -json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. -json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. -json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. -json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. -json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. -json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compated, because JSON objects are unordered. -json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). +template +struct is_compatible_object_type +{ + static auto constexpr value = is_compatible_object_type_impl < + conjunction>, + has_mapped_type, + has_key_type>::value, + typename BasicJsonType::object_t, CompatibleObjectType >::value; +}; -@since version 3.0.0 -*/ -class invalid_iterator : public exception +template +struct is_compatible_string_type { - public: - static invalid_iterator create(int id, const std::string& what_arg) - { - std::string w = exception::name("invalid_iterator", id) + what_arg; - return invalid_iterator(id, w.c_str()); - } + static auto constexpr value = is_compatible_string_type_impl < + conjunction>, + has_value_type>::value, + typename BasicJsonType::string_t, CompatibleStringType >::value; +}; - private: - invalid_iterator(int id_, const char* what_arg) - : exception(id_, what_arg) - {} +template +struct is_basic_json_nested_type +{ + static auto constexpr value = std::is_same::value or + std::is_same::value or + std::is_same::value or + std::is_same::value; }; -/*! -@brief exception indicating executing a member function with a wrong type +template +struct is_compatible_array_type +{ + static auto constexpr value = + conjunction>, + negation>, + negation>, + negation>, + has_value_type, + has_iterator>::value; +}; -Exceptions have ids 3xx. +template +struct is_compatible_integer_type_impl : std::false_type {}; -name / id | example massage | description ------------------------------ | --------------- | ------------------------- +template +struct is_compatible_integer_type_impl +{ + // is there an assert somewhere on overflows? + using RealLimits = std::numeric_limits; + using CompatibleLimits = std::numeric_limits; + + static constexpr auto value = + std::is_constructible::value and + CompatibleLimits::is_integer and + RealLimits::is_signed == CompatibleLimits::is_signed; +}; + +template +struct is_compatible_integer_type +{ + static constexpr auto value = + is_compatible_integer_type_impl < + std::is_integral::value and + not std::is_same::value, + RealIntegerType, CompatibleNumberIntegerType > ::value; +}; + +// trait checking if JSONSerializer::from_json(json const&, udt&) exists +template +struct has_from_json +{ + private: + // also check the return type of from_json + template::from_json( + std::declval(), std::declval()))>::value>> + static int detect(U&&); + static void detect(...); + + public: + static constexpr bool value = std::is_integral>()))>::value; +}; + +// This trait checks if JSONSerializer::from_json(json const&) exists +// this overload is used for non-default-constructible user-defined-types +template +struct has_non_default_from_json +{ + private: + template < + typename U, + typename = enable_if_t::from_json(std::declval()))>::value >> + static int detect(U&&); + static void detect(...); + + public: + static constexpr bool value = std::is_integral>()))>::value; +}; + +// This trait checks if BasicJsonType::json_serializer::to_json exists +template +struct has_to_json +{ + private: + template::to_json( + std::declval(), std::declval()))> + static int detect(U&&); + static void detect(...); + + public: + static constexpr bool value = std::is_integral>()))>::value; +}; + +template +struct is_compatible_complete_type +{ + static constexpr bool value = + not std::is_base_of::value and + not is_basic_json::value and + not is_basic_json_nested_type::value and + has_to_json::value; +}; + +template +struct is_compatible_type + : conjunction, + is_compatible_complete_type> +{ +}; + +// taken from ranges-v3 +template +struct static_const +{ + static constexpr T value{}; +}; + +template +constexpr T static_const::value; +} +} + +// #include + + +#include // exception +#include // runtime_error +#include // to_string + +namespace nlohmann +{ +namespace detail +{ +//////////////// +// exceptions // +//////////////// + +/*! +@brief general exception of the @ref basic_json class + +This class is an extension of `std::exception` objects with a member @a id for +exception ids. It is used as the base class for all exceptions thrown by the +@ref basic_json class. This class can hence be used as "wildcard" to catch +exceptions. + +Subclasses: +- @ref parse_error for exceptions indicating a parse error +- @ref invalid_iterator for exceptions indicating errors with iterators +- @ref type_error for exceptions indicating executing a member function with + a wrong type +- @ref out_of_range for exceptions indicating access out of the defined range +- @ref other_error for exceptions indicating other library errors + +@internal +@note To have nothrow-copy-constructible exceptions, we internally use + `std::runtime_error` which can cope with arbitrary-length error messages. + Intermediate strings are built with static functions and then passed to + the actual constructor. +@endinternal + +@liveexample{The following code shows how arbitrary library exceptions can be +caught.,exception} + +@since version 3.0.0 +*/ +class exception : public std::exception +{ + public: + /// returns the explanatory string + const char* what() const noexcept override + { + return m.what(); + } + + /// the id of the exception + const int id; + + protected: + exception(int id_, const char* what_arg) : id(id_), m(what_arg) {} + + static std::string name(const std::string& ename, int id_) + { + return "[json.exception." + ename + "." + std::to_string(id_) + "] "; + } + + private: + /// an exception object as storage for error messages + std::runtime_error m; +}; + +/*! +@brief exception indicating a parse error + +This exception is thrown by the library when a parse error occurs. Parse errors +can occur during the deserialization of JSON text, CBOR, MessagePack, as well +as when using JSON Patch. + +Member @a byte holds the byte index of the last read character in the input +file. + +Exceptions have ids 1xx. + +name / id | example message | description +------------------------------ | --------------- | ------------------------- +json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member @a byte indicates the error position. +json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the `\uxxxx` format to describe Unicode characters. Code points above above 0xFFFF are split into two `\uxxxx` entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. +json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. +json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | [RFC 6902](https://tools.ietf.org/html/rfc6902) requires a JSON Patch document to be a JSON document that represents an array of objects. +json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. +json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)) may be `0` or any number without a leading `0`. +json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a `/` character. +json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only `~0` and `~1` are valid escape sequences. +json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. +json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. +json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xF8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. +json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. + +@note For an input with n bytes, 1 is the index of the first character and n+1 + is the index of the terminating null byte or the end of file. This also + holds true when reading a byte vector (CBOR or MessagePack). + +@liveexample{The following code shows how a `parse_error` exception can be +caught.,parse_error} + +@sa @ref exception for the base class of the library exceptions +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class parse_error : public exception +{ + public: + /*! + @brief create a parse error exception + @param[in] id_ the id of the exception + @param[in] byte_ the byte index where the error occurred (or 0 if the + position cannot be determined) + @param[in] what_arg the explanatory string + @return parse_error object + */ + static parse_error create(int id_, std::size_t byte_, const std::string& what_arg) + { + std::string w = exception::name("parse_error", id_) + "parse error" + + (byte_ != 0 ? (" at " + std::to_string(byte_)) : "") + + ": " + what_arg; + return parse_error(id_, byte_, w.c_str()); + } + + /*! + @brief byte index of the parse error + + The byte index of the last read character in the input file. + + @note For an input with n bytes, 1 is the index of the first character and + n+1 is the index of the terminating null byte or the end of file. + This also holds true when reading a byte vector (CBOR or MessagePack). + */ + const std::size_t byte; + + private: + parse_error(int id_, std::size_t byte_, const char* what_arg) + : exception(id_, what_arg), byte(byte_) {} +}; + +/*! +@brief exception indicating errors with iterators + +This exception is thrown if iterators passed to a library function do not match +the expected semantics. + +Exceptions have ids 2xx. + +name / id | example message | description +----------------------------------- | --------------- | ------------------------- +json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator @a pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. +json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function @ref erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. +json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (@ref begin(), @ref end()), because this is the only way the single stored value is expressed. All other ranges are invalid. +json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. +json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. +json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. +json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. +json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid. +json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. +json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. +json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. +json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to @ref begin(). + +@liveexample{The following code shows how an `invalid_iterator` exception can be +caught.,invalid_iterator} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors + +@since version 3.0.0 +*/ +class invalid_iterator : public exception +{ + public: + static invalid_iterator create(int id_, const std::string& what_arg) + { + std::string w = exception::name("invalid_iterator", id_) + what_arg; + return invalid_iterator(id_, w.c_str()); + } + + private: + invalid_iterator(int id_, const char* what_arg) + : exception(id_, what_arg) {} +}; + +/*! +@brief exception indicating executing a member function with a wrong type + +This exception is thrown in case of a type error; that is, a library function is +executed on a JSON value whose type does not match the expected semantics. + +Exceptions have ids 3xx. + +name / id | example message | description +----------------------------- | --------------- | ------------------------- json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a @ref basic_json object with @ref get_ref, the type of the reference must match the value type. For instance, for a JSON array, the @a ReferenceType must be @ref array_t&. @@ -298,33 +731,46 @@ json.exception.type_error.308 | cannot use push_back() with string | The @ref pu json.exception.type_error.309 | cannot use insert() with | The @ref insert() member functions can only be executed for certain JSON types. json.exception.type_error.310 | cannot use swap() with number | The @ref swap() member functions can only be executed for certain JSON types. json.exception.type_error.311 | cannot use emplace_back() with string | The @ref emplace_back() member function can only be executed for certain JSON types. +json.exception.type_error.312 | cannot use update() with string | The @ref update() member functions can only be executed for certain JSON types. json.exception.type_error.313 | invalid value to unflatten | The @ref unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. json.exception.type_error.314 | only objects can be unflattened | The @ref unflatten function only works for an object whose keys are JSON Pointers. json.exception.type_error.315 | values in object must be primitive | The @ref unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. +json.exception.type_error.316 | invalid UTF-8 byte at index 10: 0x7E | The @ref dump function only works with UTF-8 encoded strings; that is, if you assign a `std::string` to a JSON value, make sure it is UTF-8 encoded. | + +@liveexample{The following code shows how a `type_error` exception can be +caught.,type_error} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref out_of_range for exceptions indicating access out of the defined range +@sa @ref other_error for exceptions indicating other library errors @since version 3.0.0 */ class type_error : public exception { public: - static type_error create(int id, const std::string& what_arg) + static type_error create(int id_, const std::string& what_arg) { - std::string w = exception::name("type_error", id) + what_arg; - return type_error(id, w.c_str()); + std::string w = exception::name("type_error", id_) + what_arg; + return type_error(id_, w.c_str()); } private: - type_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} + type_error(int id_, const char* what_arg) : exception(id_, what_arg) {} }; /*! @brief exception indicating access out of the defined range +This exception is thrown in case a library function is called on an input +parameter that exceeds the expected range, for instance in case of array +indices or nonexisting object keys. + Exceptions have ids 4xx. -name / id | example massage | description +name / id | example message | description ------------------------------- | --------------- | ------------------------- json.exception.out_of_range.401 | array index 3 is out of range | The provided array index @a i is larger than @a size-1. json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index `-` in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. @@ -332,52 +778,85 @@ json.exception.out_of_range.403 | key 'foo' not found | The provided key was not json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. +json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON only supports integers numbers up to 9223372036854775807. | +json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following `#`) of an UBJSON array or object exceeds the maximal capacity. | + +@liveexample{The following code shows how an `out_of_range` exception can be +caught.,out_of_range} + +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref other_error for exceptions indicating other library errors @since version 3.0.0 */ class out_of_range : public exception { public: - static out_of_range create(int id, const std::string& what_arg) + static out_of_range create(int id_, const std::string& what_arg) { - std::string w = exception::name("out_of_range", id) + what_arg; - return out_of_range(id, w.c_str()); + std::string w = exception::name("out_of_range", id_) + what_arg; + return out_of_range(id_, w.c_str()); } private: - out_of_range(int id_, const char* what_arg) - : exception(id_, what_arg) - {} + out_of_range(int id_, const char* what_arg) : exception(id_, what_arg) {} }; /*! -@brief exception indicating other errors +@brief exception indicating other library errors + +This exception is thrown in case of errors that cannot be classified with the +other exception types. Exceptions have ids 5xx. -name / id | example massage | description +name / id | example message | description ------------------------------ | --------------- | ------------------------- json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. +@sa @ref exception for the base class of the library exceptions +@sa @ref parse_error for exceptions indicating a parse error +@sa @ref invalid_iterator for exceptions indicating errors with iterators +@sa @ref type_error for exceptions indicating executing a member function with + a wrong type +@sa @ref out_of_range for exceptions indicating access out of the defined range + +@liveexample{The following code shows how an `other_error` exception can be +caught.,other_error} + @since version 3.0.0 */ class other_error : public exception { public: - static other_error create(int id, const std::string& what_arg) + static other_error create(int id_, const std::string& what_arg) { - std::string w = exception::name("other_error", id) + what_arg; - return other_error(id, w.c_str()); + std::string w = exception::name("other_error", id_) + what_arg; + return other_error(id_, w.c_str()); } private: - other_error(int id_, const char* what_arg) - : exception(id_, what_arg) - {} + other_error(int id_, const char* what_arg) : exception(id_, what_arg) {} }; +} +} +// #include +#include // array +#include // and +#include // size_t +#include // uint8_t + +namespace nlohmann +{ +namespace detail +{ /////////////////////////// // JSON type enumeration // /////////////////////////// @@ -406,17 +885,17 @@ value with the default value for a given type @since version 1.0.0 */ -enum class value_t : uint8_t -{ - null, ///< null value - object, ///< object (unordered set of name/value pairs) - array, ///< array (ordered collection of values) - string, ///< string value - boolean, ///< boolean value - number_integer, ///< number value (signed integer) - number_unsigned, ///< number value (unsigned integer) - number_float, ///< number value (floating-point) - discarded ///< discarded by the the parser callback function +enum class value_t : std::uint8_t +{ + null, ///< null value + object, ///< object (unordered set of name/value pairs) + array, ///< array (ordered collection of values) + string, ///< string value + boolean, ///< boolean value + number_integer, ///< number value (signed integer) + number_unsigned, ///< number value (unsigned integer) + number_float, ///< number value (floating-point) + discarded ///< discarded by the the parser callback function }; /*! @@ -425,13234 +904,16787 @@ enum class value_t : uint8_t Returns an ordering that is similar to Python: - order: null < boolean < number < object < array < string - furthermore, each type is not smaller than itself +- discarded values are not comparable @since version 1.0.0 */ inline bool operator<(const value_t lhs, const value_t rhs) noexcept { - static constexpr std::array order = {{ - 0, // null - 3, // object - 4, // array - 5, // string - 1, // boolean - 2, // integer - 2, // unsigned - 2, // float + static constexpr std::array order = {{ + 0 /* null */, 3 /* object */, 4 /* array */, 5 /* string */, + 1 /* boolean */, 2 /* integer */, 2 /* unsigned */, 2 /* float */ } }; - // discarded values are not comparable - if (lhs == value_t::discarded or rhs == value_t::discarded) - { - return false; - } - - return order[static_cast(lhs)] < - order[static_cast(rhs)]; + const auto l_index = static_cast(lhs); + const auto r_index = static_cast(rhs); + return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index]; +} +} } +// #include -///////////// -// helpers // -///////////// -// alias templates to reduce boilerplate -template -using enable_if_t = typename std::enable_if::type; - -template -using uncvref_t = typename std::remove_cv::type>::type; - -/* -Implementation of two C++17 constructs: conjunction, negation. This is needed -to avoid evaluating all the traits in a condition - -For example: not std::is_same::value and has_value_type::value -will not compile when T = void (on MSVC at least). Whereas -conjunction>, has_value_type>::value will -stop evaluating if negation<...>::value == false - -Please note that those constructs must be used with caution, since symbols can -become very long quickly (which can slow down compilation and cause MSVC -internal compiler errors). Only use it when you have to (see example ahead). -*/ -template struct conjunction : std::true_type {}; -template struct conjunction : B1 {}; -template -struct conjunction : std::conditional, B1>::type {}; +#include // transform +#include // array +#include // and, not +#include // forward_list +#include // inserter, front_inserter, end +#include // map +#include // string +#include // tuple, make_tuple +#include // is_arithmetic, is_same, is_enum, underlying_type, is_convertible +#include // unordered_map +#include // pair, declval +#include // valarray -template struct negation : std::integral_constant < bool, !B::value > {}; +// #include -// dispatch utility (taken from ranges-v3) -template struct priority_tag : priority_tag < N - 1 > {}; -template<> struct priority_tag<0> {}; +// #include +// #include -////////////////// -// constructors // -////////////////// +// #include -template struct external_constructor; -template<> -struct external_constructor +namespace nlohmann { - template - static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept +namespace detail +{ +template +void from_json(const BasicJsonType& j, typename std::nullptr_t& n) +{ + if (JSON_UNLIKELY(not j.is_null())) { - j.m_type = value_t::boolean; - j.m_value = b; - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be null, but is " + std::string(j.type_name()))); } -}; + n = nullptr; +} -template<> -struct external_constructor +// overloads for basic_json template parameters +template::value and + not std::is_same::value, + int> = 0> +void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) { - template - static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) + switch (static_cast(j)) { - j.m_type = value_t::string; - j.m_value = s; - j.assert_invariant(); + case value_t::number_unsigned: + { + val = static_cast(*j.template get_ptr()); + break; + } + case value_t::number_integer: + { + val = static_cast(*j.template get_ptr()); + break; + } + case value_t::number_float: + { + val = static_cast(*j.template get_ptr()); + break; + } + + default: + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); } -}; +} -template<> -struct external_constructor +template +void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept + if (JSON_UNLIKELY(not j.is_boolean())) { - j.m_type = value_t::number_float; - j.m_value = val; - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(j.type_name()))); } -}; + b = *j.template get_ptr(); +} -template<> -struct external_constructor +template +void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s) { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept + if (JSON_UNLIKELY(not j.is_string())) { - j.m_type = value_t::number_unsigned; - j.m_value = val; - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name()))); } -}; + s = *j.template get_ptr(); +} -template<> -struct external_constructor +template < + typename BasicJsonType, typename CompatibleStringType, + enable_if_t < + is_compatible_string_type::value and + not std::is_same::value, + int > = 0 > +void from_json(const BasicJsonType& j, CompatibleStringType& s) { - template - static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept + if (JSON_UNLIKELY(not j.is_string())) { - j.m_type = value_t::number_integer; - j.m_value = val; - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name()))); } -}; -template<> -struct external_constructor + s = *j.template get_ptr(); +} + +template +void from_json(const BasicJsonType& j, typename BasicJsonType::number_float_t& val) { - template - static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) + get_arithmetic_value(j, val); +} + +template +void from_json(const BasicJsonType& j, typename BasicJsonType::number_unsigned_t& val) +{ + get_arithmetic_value(j, val); +} + +template +void from_json(const BasicJsonType& j, typename BasicJsonType::number_integer_t& val) +{ + get_arithmetic_value(j, val); +} + +template::value, int> = 0> +void from_json(const BasicJsonType& j, EnumType& e) +{ + typename std::underlying_type::type val; + get_arithmetic_value(j, val); + e = static_cast(val); +} + +template +void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr) +{ + if (JSON_UNLIKELY(not j.is_array())) { - j.m_type = value_t::array; - j.m_value = arr; - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + arr = *j.template get_ptr(); +} - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleArrayType& arr) +// forward_list doesn't have an insert method +template::value, int> = 0> +void from_json(const BasicJsonType& j, std::forward_list& l) +{ + if (JSON_UNLIKELY(not j.is_array())) { - using std::begin; - using std::end; - j.m_type = value_t::array; - j.m_value.array = j.template create(begin(arr), end(arr)); - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } + std::transform(j.rbegin(), j.rend(), + std::front_inserter(l), [](const BasicJsonType & i) + { + return i.template get(); + }); +} - template - static void construct(BasicJsonType& j, const std::vector& arr) +// valarray doesn't have an insert method +template::value, int> = 0> +void from_json(const BasicJsonType& j, std::valarray& l) +{ + if (JSON_UNLIKELY(not j.is_array())) { - j.m_type = value_t::array; - j.m_value = value_t::array; - j.m_value.array->reserve(arr.size()); - for (bool x : arr) - { - j.m_value.array->push_back(x); - } - j.assert_invariant(); + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); } -}; + l.resize(j.size()); + std::copy(j.m_value.array->begin(), j.m_value.array->end(), std::begin(l)); +} -template<> -struct external_constructor +template +void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0> /*unused*/) { - template - static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + using std::end; + + std::transform(j.begin(), j.end(), + std::inserter(arr, end(arr)), [](const BasicJsonType & i) { - j.m_type = value_t::object; - j.m_value = obj; - j.assert_invariant(); - } + // get() returns *this, this won't call a from_json + // method when value_type is BasicJsonType + return i.template get(); + }); +} - template::value, - int> = 0> - static void construct(BasicJsonType& j, const CompatibleObjectType& obj) +template +auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1> /*unused*/) +-> decltype( + arr.reserve(std::declval()), + void()) +{ + using std::end; + + arr.reserve(j.size()); + std::transform(j.begin(), j.end(), + std::inserter(arr, end(arr)), [](const BasicJsonType & i) { - using std::begin; - using std::end; + // get() returns *this, this won't call a from_json + // method when value_type is BasicJsonType + return i.template get(); + }); +} - j.m_type = value_t::object; - j.m_value.object = j.template create(begin(obj), end(obj)); - j.assert_invariant(); +template +void from_json_array_impl(const BasicJsonType& j, std::array& arr, priority_tag<2> /*unused*/) +{ + for (std::size_t i = 0; i < N; ++i) + { + arr[i] = j.at(i).template get(); } -}; +} +template < + typename BasicJsonType, typename CompatibleArrayType, + enable_if_t < + is_compatible_array_type::value and + not std::is_same::value and + std::is_constructible < + BasicJsonType, typename CompatibleArrayType::value_type >::value, + int > = 0 > +void from_json(const BasicJsonType& j, CompatibleArrayType& arr) +{ + if (JSON_UNLIKELY(not j.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + + std::string(j.type_name()))); + } -//////////////////////// -// has_/is_ functions // -//////////////////////// + from_json_array_impl(j, arr, priority_tag<2> {}); +} -/*! -@brief Helper to determine whether there's a key_type for T. +template::value, int> = 0> +void from_json(const BasicJsonType& j, CompatibleObjectType& obj) +{ + if (JSON_UNLIKELY(not j.is_object())) + { + JSON_THROW(type_error::create(302, "type must be object, but is " + std::string(j.type_name()))); + } -This helper is used to tell associative containers apart from other containers -such as sequence containers. For instance, `std::map` passes the test as it -contains a `mapped_type`, whereas `std::vector` fails the test. + auto inner_object = j.template get_ptr(); + using value_type = typename CompatibleObjectType::value_type; + std::transform( + inner_object->begin(), inner_object->end(), + std::inserter(obj, obj.begin()), + [](typename BasicJsonType::object_t::value_type const & p) + { + return value_type(p.first, p.second.template get()); + }); +} -@sa http://stackoverflow.com/a/7728728/266378 -@since version 1.0.0, overworked in version 2.0.6 -*/ -#define NLOHMANN_JSON_HAS_HELPER(type) \ - template struct has_##type { \ - private: \ - template \ - static int detect(U &&); \ - static void detect(...); \ - public: \ - static constexpr bool value = \ - std::is_integral()))>::value; \ - } - -NLOHMANN_JSON_HAS_HELPER(mapped_type); -NLOHMANN_JSON_HAS_HELPER(key_type); -NLOHMANN_JSON_HAS_HELPER(value_type); -NLOHMANN_JSON_HAS_HELPER(iterator); - -#undef NLOHMANN_JSON_HAS_HELPER - - -template -struct is_compatible_object_type_impl : std::false_type {}; - -template -struct is_compatible_object_type_impl +// overload for arithmetic types, not chosen for basic_json template arguments +// (BooleanType, etc..); note: Is it really necessary to provide explicit +// overloads for boolean_t etc. in case of a custom BooleanType which is not +// an arithmetic type? +template::value and + not std::is_same::value and + not std::is_same::value and + not std::is_same::value and + not std::is_same::value, + int> = 0> +void from_json(const BasicJsonType& j, ArithmeticType& val) { - static constexpr auto value = - std::is_constructible::value and - std::is_constructible::value; -}; + switch (static_cast(j)) + { + case value_t::number_unsigned: + { + val = static_cast(*j.template get_ptr()); + break; + } + case value_t::number_integer: + { + val = static_cast(*j.template get_ptr()); + break; + } + case value_t::number_float: + { + val = static_cast(*j.template get_ptr()); + break; + } + case value_t::boolean: + { + val = static_cast(*j.template get_ptr()); + break; + } -template -struct is_compatible_object_type -{ - static auto constexpr value = is_compatible_object_type_impl < - conjunction>, - has_mapped_type, - has_key_type>::value, - typename BasicJsonType::object_t, CompatibleObjectType >::value; -}; + default: + JSON_THROW(type_error::create(302, "type must be number, but is " + std::string(j.type_name()))); + } +} -template -struct is_basic_json_nested_type +template +void from_json(const BasicJsonType& j, std::pair& p) { - static auto constexpr value = std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value or - std::is_same::value; -}; + p = {j.at(0).template get(), j.at(1).template get()}; +} -template -struct is_compatible_array_type +template +void from_json_tuple_impl(const BasicJsonType& j, Tuple& t, index_sequence) { - static auto constexpr value = - conjunction>, - negation>, - negation>, - negation>, - has_value_type, - has_iterator>::value; -}; - -template -struct is_compatible_integer_type_impl : std::false_type {}; + t = std::make_tuple(j.at(Idx).template get::type>()...); +} -template -struct is_compatible_integer_type_impl +template +void from_json(const BasicJsonType& j, std::tuple& t) { - // is there an assert somewhere on overflows? - using RealLimits = std::numeric_limits; - using CompatibleLimits = std::numeric_limits; - - static constexpr auto value = - std::is_constructible::value and - CompatibleLimits::is_integer and - RealLimits::is_signed == CompatibleLimits::is_signed; -}; + from_json_tuple_impl(j, t, index_sequence_for {}); +} -template -struct is_compatible_integer_type +template ::value>> +void from_json(const BasicJsonType& j, std::map& m) { - static constexpr auto value = - is_compatible_integer_type_impl < - std::is_integral::value and - not std::is_same::value, - RealIntegerType, CompatibleNumberIntegerType > ::value; -}; + if (JSON_UNLIKELY(not j.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); + } + for (const auto& p : j) + { + if (JSON_UNLIKELY(not p.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(p.type_name()))); + } + m.emplace(p.at(0).template get(), p.at(1).template get()); + } +} +template ::value>> +void from_json(const BasicJsonType& j, std::unordered_map& m) +{ + if (JSON_UNLIKELY(not j.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name()))); + } + for (const auto& p : j) + { + if (JSON_UNLIKELY(not p.is_array())) + { + JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(p.type_name()))); + } + m.emplace(p.at(0).template get(), p.at(1).template get()); + } +} -// trait checking if JSONSerializer::from_json(json const&, udt&) exists -template -struct has_from_json +struct from_json_fn { private: - // also check the return type of from_json - template::from_json( - std::declval(), std::declval()))>::value>> - static int detect(U&&); - static void detect(...); + template + auto call(const BasicJsonType& j, T& val, priority_tag<1> /*unused*/) const + noexcept(noexcept(from_json(j, val))) + -> decltype(from_json(j, val), void()) + { + return from_json(j, val); + } + + template + void call(const BasicJsonType& /*unused*/, T& /*unused*/, priority_tag<0> /*unused*/) const noexcept + { + static_assert(sizeof(BasicJsonType) == 0, + "could not find from_json() method in T's namespace"); +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); +#endif + } public: - static constexpr bool value = std::is_integral>()))>::value; + template + void operator()(const BasicJsonType& j, T& val) const + noexcept(noexcept(std::declval().call(j, val, priority_tag<1> {}))) + { + return call(j, val, priority_tag<1> {}); + } }; +} -// This trait checks if JSONSerializer::from_json(json const&) exists -// this overload is used for non-default-constructible user-defined-types -template -struct has_non_default_from_json +/// namespace to hold default `from_json` function +/// to see why this is required: +/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html +namespace { - private: - template < - typename U, - typename = enable_if_t::from_json(std::declval()))>::value >> - static int detect(U&&); - static void detect(...); +constexpr const auto& from_json = detail::static_const::value; +} +} - public: - static constexpr bool value = std::is_integral>()))>::value; -}; +// #include -// This trait checks if BasicJsonType::json_serializer::to_json exists -template -struct has_to_json -{ - private: - template::to_json( - std::declval(), std::declval()))> - static int detect(U&&); - static void detect(...); - public: - static constexpr bool value = std::is_integral>()))>::value; -}; +#include // or, and, not +#include // begin, end +#include // tuple, get +#include // is_same, is_constructible, is_floating_point, is_enum, underlying_type +#include // move, forward, declval, pair +#include // valarray +#include // vector +// #include -///////////// -// to_json // -///////////// +// #include -template::value, int> = 0> -void to_json(BasicJsonType& j, T b) noexcept -{ - external_constructor::construct(j, b); -} +// #include -template::value, int> = 0> -void to_json(BasicJsonType& j, const CompatibleString& s) -{ - external_constructor::construct(j, s); -} -template::value, int> = 0> -void to_json(BasicJsonType& j, FloatType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} +#include // size_t +#include // string, to_string +#include // input_iterator_tag -template < - typename BasicJsonType, typename CompatibleNumberUnsignedType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} +// #include -template < - typename BasicJsonType, typename CompatibleNumberIntegerType, - enable_if_t::value, int> = 0 > -void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept -{ - external_constructor::construct(j, static_cast(val)); -} -template::value, int> = 0> -void to_json(BasicJsonType& j, EnumType e) noexcept +namespace nlohmann { - using underlying_type = typename std::underlying_type::type; - external_constructor::construct(j, static_cast(e)); -} - -template -void to_json(BasicJsonType& j, const std::vector& e) +namespace detail { - external_constructor::construct(j, e); -} - -template < - typename BasicJsonType, typename CompatibleArrayType, - enable_if_t < - is_compatible_array_type::value or - std::is_same::value, - int > = 0 > -void to_json(BasicJsonType& j, const CompatibleArrayType& arr) +/// proxy class for the items() function +template class iteration_proxy { - external_constructor::construct(j, arr); -} + private: + /// helper class for iteration + class iteration_proxy_internal + { + public: + using difference_type = std::ptrdiff_t; + using value_type = iteration_proxy_internal; + using pointer = iteration_proxy_internal*; + using reference = iteration_proxy_internal&; + using iterator_category = std::input_iterator_tag; -template < - typename BasicJsonType, typename CompatibleObjectType, - enable_if_t::value, - int> = 0 > -void to_json(BasicJsonType& j, const CompatibleObjectType& arr) -{ - external_constructor::construct(j, arr); -} + private: + /// the iterator + IteratorType anchor; + /// an index for arrays (used to create key names) + std::size_t array_index = 0; + /// last stringified array index + mutable std::size_t array_index_last = 0; + /// a string representation of the array index + mutable std::string array_index_str = "0"; + /// an empty string (to return a reference for primitive values) + const std::string empty_str = ""; -template ::value, - int> = 0> -void to_json(BasicJsonType& j, T (&arr)[N]) -{ - external_constructor::construct(j, arr); -} + public: + explicit iteration_proxy_internal(IteratorType it) noexcept : anchor(it) {} -/////////////// -// from_json // -/////////////// + iteration_proxy_internal(const iteration_proxy_internal&) = default; + iteration_proxy_internal& operator=(const iteration_proxy_internal&) = default; -// overloads for basic_json template parameters -template::value and - not std::is_same::value, - int> = 0> -void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val) -{ - switch (static_cast(j)) - { - case value_t::number_unsigned: + /// dereference operator (needed for range-based for) + iteration_proxy_internal& operator*() { - val = static_cast( - *j.template get_ptr()); - break; + return *this; } - case value_t::number_integer: + + /// increment operator (needed for range-based for) + iteration_proxy_internal& operator++() { - val = static_cast( - *j.template get_ptr()); - break; + ++anchor; + ++array_index; + + return *this; } - case value_t::number_float: + + /// equality operator (needed for InputIterator) + bool operator==(const iteration_proxy_internal& o) const noexcept { - val = static_cast( - *j.template get_ptr()); - break; + return anchor == o.anchor; } - default: + + /// inequality operator (needed for range-based for) + bool operator!=(const iteration_proxy_internal& o) const noexcept { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); + return anchor != o.anchor; } - } -} -template -void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b) -{ - if (not j.is_boolean()) - { - JSON_THROW(type_error::create(302, "type must be boolean, but is " + j.type_name())); - } - b = *j.template get_ptr(); -} + /// return key of the iterator + const std::string& key() const + { + assert(anchor.m_object != nullptr); -template -void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s) -{ - if (not j.is_string()) - { - JSON_THROW(type_error::create(302, "type must be string, but is " + j.type_name())); - } - s = *j.template get_ptr(); -} + switch (anchor.m_object->type()) + { + // use integer array index as key + case value_t::array: + { + if (array_index != array_index_last) + { + array_index_str = std::to_string(array_index); + array_index_last = array_index; + } + return array_index_str; + } -template -void from_json(const BasicJsonType& j, typename BasicJsonType::number_float_t& val) -{ - get_arithmetic_value(j, val); -} + // use key from the object + case value_t::object: + return anchor.key(); -template -void from_json(const BasicJsonType& j, typename BasicJsonType::number_unsigned_t& val) -{ - get_arithmetic_value(j, val); -} + // use an empty key for all primitive types + default: + return empty_str; + } + } -template -void from_json(const BasicJsonType& j, typename BasicJsonType::number_integer_t& val) -{ - get_arithmetic_value(j, val); -} + /// return value of the iterator + typename IteratorType::reference value() const + { + return anchor.value(); + } + }; -template::value, int> = 0> -void from_json(const BasicJsonType& j, EnumType& e) -{ - typename std::underlying_type::type val; - get_arithmetic_value(j, val); - e = static_cast(val); -} + /// the container to iterate + typename IteratorType::reference container; -template -void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr) -{ - if (not j.is_array()) - { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); - } - arr = *j.template get_ptr(); -} + public: + /// construct iteration proxy from a container + explicit iteration_proxy(typename IteratorType::reference cont) noexcept + : container(cont) {} -// forward_list doesn't have an insert method -template::value, int> = 0> -void from_json(const BasicJsonType& j, std::forward_list& l) -{ - if (not j.is_array()) + /// return iterator begin (needed for range-based for) + iteration_proxy_internal begin() noexcept { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + return iteration_proxy_internal(container.begin()); } - for (auto it = j.rbegin(), end = j.rend(); it != end; ++it) + /// return iterator end (needed for range-based for) + iteration_proxy_internal end() noexcept { - l.push_front(it->template get()); + return iteration_proxy_internal(container.end()); } +}; } - -template -void from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<0>) -{ - using std::begin; - using std::end; - - std::transform(j.begin(), j.end(), - std::inserter(arr, end(arr)), [](const BasicJsonType & i) - { - // get() returns *this, this won't call a from_json - // method when value_type is BasicJsonType - return i.template get(); - }); } -template -auto from_json_array_impl(const BasicJsonType& j, CompatibleArrayType& arr, priority_tag<1>) --> decltype( - arr.reserve(std::declval()), - void()) + +namespace nlohmann { - using std::begin; - using std::end; +namespace detail +{ +////////////////// +// constructors // +////////////////// - arr.reserve(j.size()); - std::transform(j.begin(), j.end(), - std::inserter(arr, end(arr)), [](const BasicJsonType & i) - { - // get() returns *this, this won't call a from_json - // method when value_type is BasicJsonType - return i.template get(); - }); -} +template struct external_constructor; -template::value and - std::is_convertible::value and - not std::is_same::value, int> = 0> -void from_json(const BasicJsonType& j, CompatibleArrayType& arr) +template<> +struct external_constructor { - if (not j.is_array()) + template + static void construct(BasicJsonType& j, typename BasicJsonType::boolean_t b) noexcept { - JSON_THROW(type_error::create(302, "type must be array, but is " + j.type_name())); + j.m_type = value_t::boolean; + j.m_value = b; + j.assert_invariant(); } +}; - from_json_array_impl(j, arr, priority_tag<1> {}); -} - -template::value, int> = 0> -void from_json(const BasicJsonType& j, CompatibleObjectType& obj) +template<> +struct external_constructor { - if (not j.is_object()) + template + static void construct(BasicJsonType& j, const typename BasicJsonType::string_t& s) { - JSON_THROW(type_error::create(302, "type must be object, but is " + j.type_name())); + j.m_type = value_t::string; + j.m_value = s; + j.assert_invariant(); } - auto inner_object = j.template get_ptr(); - using std::begin; - using std::end; - // we could avoid the assignment, but this might require a for loop, which - // might be less efficient than the container constructor for some - // containers (would it?) - obj = CompatibleObjectType(begin(*inner_object), end(*inner_object)); -} + template + static void construct(BasicJsonType& j, typename BasicJsonType::string_t&& s) + { + j.m_type = value_t::string; + j.m_value = std::move(s); + j.assert_invariant(); + } -// overload for arithmetic types, not chosen for basic_json template arguments -// (BooleanType, etc..); note: Is it really necessary to provide explicit -// overloads for boolean_t etc. in case of a custom BooleanType which is not -// an arithmetic type? -template::value and - not std::is_same::value and - not std::is_same::value and - not std::is_same::value and - not std::is_same::value, - int> = 0> -void from_json(const BasicJsonType& j, ArithmeticType& val) -{ - switch (static_cast(j)) + template::value, + int> = 0> + static void construct(BasicJsonType& j, const CompatibleStringType& str) { - case value_t::number_unsigned: - { - val = static_cast(*j.template get_ptr()); - break; - } - case value_t::number_integer: - { - val = static_cast(*j.template get_ptr()); - break; - } - case value_t::number_float: - { - val = static_cast(*j.template get_ptr()); - break; - } - case value_t::boolean: - { - val = static_cast(*j.template get_ptr()); - break; - } - default: - { - JSON_THROW(type_error::create(302, "type must be number, but is " + j.type_name())); - } + j.m_type = value_t::string; + j.m_value.string = j.template create(str); + j.assert_invariant(); } -} +}; -struct to_json_fn +template<> +struct external_constructor { - private: - template - auto call(BasicJsonType& j, T&& val, priority_tag<1>) const noexcept(noexcept(to_json(j, std::forward(val)))) - -> decltype(to_json(j, std::forward(val)), void()) + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_float_t val) noexcept { - return to_json(j, std::forward(val)); + j.m_type = value_t::number_float; + j.m_value = val; + j.assert_invariant(); } +}; - template - void call(BasicJsonType&, T&&, priority_tag<0>) const noexcept +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_unsigned_t val) noexcept { - static_assert(sizeof(BasicJsonType) == 0, - "could not find to_json() method in T's namespace"); + j.m_type = value_t::number_unsigned; + j.m_value = val; + j.assert_invariant(); } +}; - public: - template - void operator()(BasicJsonType& j, T&& val) const - noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) +template<> +struct external_constructor +{ + template + static void construct(BasicJsonType& j, typename BasicJsonType::number_integer_t val) noexcept { - return call(j, std::forward(val), priority_tag<1> {}); + j.m_type = value_t::number_integer; + j.m_value = val; + j.assert_invariant(); } }; -struct from_json_fn +template<> +struct external_constructor { - private: - template - auto call(const BasicJsonType& j, T& val, priority_tag<1>) const - noexcept(noexcept(from_json(j, val))) - -> decltype(from_json(j, val), void()) + template + static void construct(BasicJsonType& j, const typename BasicJsonType::array_t& arr) { - return from_json(j, val); + j.m_type = value_t::array; + j.m_value = arr; + j.assert_invariant(); } - template - void call(const BasicJsonType&, T&, priority_tag<0>) const noexcept + template + static void construct(BasicJsonType& j, typename BasicJsonType::array_t&& arr) { - static_assert(sizeof(BasicJsonType) == 0, - "could not find from_json() method in T's namespace"); + j.m_type = value_t::array; + j.m_value = std::move(arr); + j.assert_invariant(); } - public: - template - void operator()(const BasicJsonType& j, T& val) const - noexcept(noexcept(std::declval().call(j, val, priority_tag<1> {}))) + template::value, + int> = 0> + static void construct(BasicJsonType& j, const CompatibleArrayType& arr) { - return call(j, val, priority_tag<1> {}); + using std::begin; + using std::end; + j.m_type = value_t::array; + j.m_value.array = j.template create(begin(arr), end(arr)); + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, const std::vector& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->reserve(arr.size()); + for (const bool x : arr) + { + j.m_value.array->push_back(x); + } + j.assert_invariant(); + } + + template::value, int> = 0> + static void construct(BasicJsonType& j, const std::valarray& arr) + { + j.m_type = value_t::array; + j.m_value = value_t::array; + j.m_value.array->resize(arr.size()); + std::copy(std::begin(arr), std::end(arr), j.m_value.array->begin()); + j.assert_invariant(); } }; -// taken from ranges-v3 -template -struct static_const +template<> +struct external_constructor { - static constexpr T value{}; + template + static void construct(BasicJsonType& j, const typename BasicJsonType::object_t& obj) + { + j.m_type = value_t::object; + j.m_value = obj; + j.assert_invariant(); + } + + template + static void construct(BasicJsonType& j, typename BasicJsonType::object_t&& obj) + { + j.m_type = value_t::object; + j.m_value = std::move(obj); + j.assert_invariant(); + } + + template::value, int> = 0> + static void construct(BasicJsonType& j, const CompatibleObjectType& obj) + { + using std::begin; + using std::end; + + j.m_type = value_t::object; + j.m_value.object = j.template create(begin(obj), end(obj)); + j.assert_invariant(); + } }; -template -constexpr T static_const::value; -} // namespace detail +///////////// +// to_json // +///////////// +template::value, int> = 0> +void to_json(BasicJsonType& j, T b) noexcept +{ + external_constructor::construct(j, b); +} -/// namespace to hold default `to_json` / `from_json` functions -namespace +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleString& s) { -constexpr const auto& to_json = detail::static_const::value; -constexpr const auto& from_json = detail::static_const::value; + external_constructor::construct(j, s); } +template +void to_json(BasicJsonType& j, typename BasicJsonType::string_t&& s) +{ + external_constructor::construct(j, std::move(s)); +} -/*! -@brief default JSONSerializer template argument +template::value, int> = 0> +void to_json(BasicJsonType& j, FloatType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} -This serializer ignores the template arguments and uses ADL -([argument-dependent lookup](http://en.cppreference.com/w/cpp/language/adl)) -for serialization. -*/ -template -struct adl_serializer +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberUnsignedType val) noexcept { - /*! - @brief convert a JSON value to any value type + external_constructor::construct(j, static_cast(val)); +} - This function is usually called by the `get()` function of the - @ref basic_json class (either explicit or via conversion operators). +template::value, int> = 0> +void to_json(BasicJsonType& j, CompatibleNumberIntegerType val) noexcept +{ + external_constructor::construct(j, static_cast(val)); +} - @param[in] j JSON value to read from - @param[in,out] val value to write to - */ - template - static void from_json(BasicJsonType&& j, ValueType& val) noexcept( - noexcept(::nlohmann::from_json(std::forward(j), val))) - { - ::nlohmann::from_json(std::forward(j), val); - } +template::value, int> = 0> +void to_json(BasicJsonType& j, EnumType e) noexcept +{ + using underlying_type = typename std::underlying_type::type; + external_constructor::construct(j, static_cast(e)); +} - /*! - @brief convert any value type to a JSON value +template +void to_json(BasicJsonType& j, const std::vector& e) +{ + external_constructor::construct(j, e); +} - This function is usually called by the constructors of the @ref basic_json - class. +template::value or + std::is_same::value, + int> = 0> +void to_json(BasicJsonType& j, const CompatibleArrayType& arr) +{ + external_constructor::construct(j, arr); +} - @param[in,out] j JSON value to write to - @param[in] val value to read from - */ - template - static void to_json(BasicJsonType& j, ValueType&& val) noexcept( - noexcept(::nlohmann::to_json(j, std::forward(val)))) - { - ::nlohmann::to_json(j, std::forward(val)); - } -}; +template::value, int> = 0> +void to_json(BasicJsonType& j, const std::valarray& arr) +{ + external_constructor::construct(j, std::move(arr)); +} +template +void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr) +{ + external_constructor::construct(j, std::move(arr)); +} -/*! -@brief a class to store JSON values +template::value, int> = 0> +void to_json(BasicJsonType& j, const CompatibleObjectType& obj) +{ + external_constructor::construct(j, obj); +} -@tparam ObjectType type for JSON objects (`std::map` by default; will be used -in @ref object_t) -@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used -in @ref array_t) -@tparam StringType type for JSON strings and object keys (`std::string` by -default; will be used in @ref string_t) -@tparam BooleanType type for JSON booleans (`bool` by default; will be used -in @ref boolean_t) -@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by -default; will be used in @ref number_integer_t) -@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c -`uint64_t` by default; will be used in @ref number_unsigned_t) -@tparam NumberFloatType type for JSON floating-point numbers (`double` by -default; will be used in @ref number_float_t) -@tparam AllocatorType type of the allocator to use (`std::allocator` by -default) -@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` -and `from_json()` (@ref adl_serializer by default) +template +void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj) +{ + external_constructor::construct(j, std::move(obj)); +} -@requirement The class satisfies the following concept requirements: -- Basic - - [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible): - JSON values can be default constructed. The result will be a JSON null - value. - - [MoveConstructible](http://en.cppreference.com/w/cpp/concept/MoveConstructible): - A JSON value can be constructed from an rvalue argument. - - [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible): - A JSON value can be copy-constructed from an lvalue expression. - - [MoveAssignable](http://en.cppreference.com/w/cpp/concept/MoveAssignable): - A JSON value van be assigned from an rvalue argument. - - [CopyAssignable](http://en.cppreference.com/w/cpp/concept/CopyAssignable): - A JSON value can be copy-assigned from an lvalue expression. - - [Destructible](http://en.cppreference.com/w/cpp/concept/Destructible): - JSON values can be destructed. -- Layout - - [StandardLayoutType](http://en.cppreference.com/w/cpp/concept/StandardLayoutType): - JSON values have - [standard layout](http://en.cppreference.com/w/cpp/language/data_members#Standard_layout): - All non-static data members are private and standard layout types, the - class has no virtual functions or (virtual) base classes. -- Library-wide - - [EqualityComparable](http://en.cppreference.com/w/cpp/concept/EqualityComparable): - JSON values can be compared with `==`, see @ref - operator==(const_reference,const_reference). - - [LessThanComparable](http://en.cppreference.com/w/cpp/concept/LessThanComparable): - JSON values can be compared with `<`, see @ref - operator<(const_reference,const_reference). - - [Swappable](http://en.cppreference.com/w/cpp/concept/Swappable): - Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of - other compatible types, using unqualified function call @ref swap(). - - [NullablePointer](http://en.cppreference.com/w/cpp/concept/NullablePointer): - JSON values can be compared against `std::nullptr_t` objects which are used - to model the `null` value. -- Container - - [Container](http://en.cppreference.com/w/cpp/concept/Container): - JSON values can be used like STL containers and provide iterator access. - - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer); - JSON values can be used like STL containers and provide reverse iterator - access. +template::value, int> = 0> +void to_json(BasicJsonType& j, T (&arr)[N]) +{ + external_constructor::construct(j, arr); +} -@invariant The member variables @a m_value and @a m_type have the following -relationship: -- If `m_type == value_t::object`, then `m_value.object != nullptr`. -- If `m_type == value_t::array`, then `m_value.array != nullptr`. -- If `m_type == value_t::string`, then `m_value.string != nullptr`. -The invariants are checked by member function assert_invariant(). +template +void to_json(BasicJsonType& j, const std::pair& p) +{ + j = {p.first, p.second}; +} -@internal -@note ObjectType trick from http://stackoverflow.com/a/9860911 -@endinternal +// for https://github.com/nlohmann/json/pull/1134 +template::iteration_proxy_internal>::value, int> = 0> +void to_json(BasicJsonType& j, T b) noexcept +{ + j = {{b.key(), b.value()}}; +} -@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange -Format](http://rfc7159.net/rfc7159) +template +void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence) +{ + j = {std::get(t)...}; +} -@since version 1.0.0 +template +void to_json(BasicJsonType& j, const std::tuple& t) +{ + to_json_tuple_impl(j, t, index_sequence_for {}); +} -@nosubgrouping -*/ -template < - template class ObjectType = std::map, - template class ArrayType = std::vector, - class StringType = std::string, - class BooleanType = bool, - class NumberIntegerType = std::int64_t, - class NumberUnsignedType = std::uint64_t, - class NumberFloatType = double, - template class AllocatorType = std::allocator, - template class JSONSerializer = adl_serializer - > -class basic_json +struct to_json_fn { private: - template friend struct detail::external_constructor; - /// workaround type for MSVC - using basic_json_t = basic_json; - - public: - using value_t = detail::value_t; - // forward declarations - template class iter_impl; - template class json_reverse_iterator; - class json_pointer; - template - using json_serializer = JSONSerializer; - + template + auto call(BasicJsonType& j, T&& val, priority_tag<1> /*unused*/) const noexcept(noexcept(to_json(j, std::forward(val)))) + -> decltype(to_json(j, std::forward(val)), void()) + { + return to_json(j, std::forward(val)); + } - //////////////// - // exceptions // - //////////////// + template + void call(BasicJsonType& /*unused*/, T&& /*unused*/, priority_tag<0> /*unused*/) const noexcept + { + static_assert(sizeof(BasicJsonType) == 0, + "could not find to_json() method in T's namespace"); - /// @name exceptions - /// Classes to implement user-defined exceptions. - /// @{ +#ifdef _MSC_VER + // MSVC does not show a stacktrace for the above assert + using decayed = uncvref_t; + static_assert(sizeof(typename decayed::force_msvc_stacktrace) == 0, + "forcing MSVC stacktrace to show which T we're talking about."); +#endif + } - /// @copydoc detail::exception - using exception = detail::exception; - /// @copydoc detail::parse_error - using parse_error = detail::parse_error; - /// @copydoc detail::invalid_iterator - using invalid_iterator = detail::invalid_iterator; - /// @copydoc detail::type_error - using type_error = detail::type_error; - /// @copydoc detail::out_of_range - using out_of_range = detail::out_of_range; - /// @copydoc detail::other_error - using other_error = detail::other_error; + public: + template + void operator()(BasicJsonType& j, T&& val) const + noexcept(noexcept(std::declval().call(j, std::forward(val), priority_tag<1> {}))) + { + return call(j, std::forward(val), priority_tag<1> {}); + } +}; +} - /// @} +/// namespace to hold default `to_json` function +namespace +{ +constexpr const auto& to_json = detail::static_const::value; +} +} +// #include - ///////////////////// - // container types // - ///////////////////// - /// @name container types - /// The canonic container types to use @ref basic_json like any other STL - /// container. - /// @{ +#include // assert +#include // size_t +#include // strlen +#include // istream +#include // begin, end, iterator_traits, random_access_iterator_tag, distance, next +#include // shared_ptr, make_shared, addressof +#include // accumulate +#include // string, char_traits +#include // enable_if, is_base_of, is_pointer, is_integral, remove_pointer +#include // pair, declval - /// the type of elements in a basic_json container - using value_type = basic_json; +// #include - /// the type of an element reference - using reference = value_type&; - /// the type of an element const reference - using const_reference = const value_type&; - /// a type to represent differences between iterators - using difference_type = std::ptrdiff_t; - /// a type to represent container sizes - using size_type = std::size_t; +namespace nlohmann +{ +namespace detail +{ +/// the supported input formats +enum class input_format_t { json, cbor, msgpack, ubjson }; - /// the allocator type - using allocator_type = AllocatorType; +//////////////////// +// input adapters // +//////////////////// - /// the type of an element pointer - using pointer = typename std::allocator_traits::pointer; - /// the type of an element const pointer - using const_pointer = typename std::allocator_traits::const_pointer; +/*! +@brief abstract input adapter interface + +Produces a stream of std::char_traits::int_type characters from a +std::istream, a buffer, or some other input type. Accepts the return of +exactly one non-EOF character for future input. The int_type characters +returned consist of all valid char values as positive values (typically +unsigned char), plus an EOF value outside that range, specified by the value +of the function std::char_traits::eof(). This value is typically -1, but +could be any arbitrary value which is not a valid char value. +*/ +struct input_adapter_protocol +{ + /// get a character [0,255] or std::char_traits::eof(). + virtual std::char_traits::int_type get_character() = 0; + virtual ~input_adapter_protocol() = default; +}; - /// an iterator for a basic_json container - using iterator = iter_impl; - /// a const iterator for a basic_json container - using const_iterator = iter_impl; - /// a reverse iterator for a basic_json container - using reverse_iterator = json_reverse_iterator; - /// a const reverse iterator for a basic_json container - using const_reverse_iterator = json_reverse_iterator; +/// a type to simplify interfaces +using input_adapter_t = std::shared_ptr; - /// @} +/*! +Input adapter for a (caching) istream. Ignores a UFT Byte Order Mark at +beginning of input. Does not support changing the underlying std::streambuf +in mid-input. Maintains underlying std::istream and std::streambuf to support +subsequent use of standard std::istream operations to process any input +characters following those used in parsing the JSON input. Clears the +std::istream flags; any input errors (e.g., EOF) will be detected by the first +subsequent call for input from the std::istream. +*/ +class input_stream_adapter : public input_adapter_protocol +{ + public: + ~input_stream_adapter() override + { + // clear stream flags; we use underlying streambuf I/O, do not + // maintain ifstream flags + is.clear(); + } + explicit input_stream_adapter(std::istream& i) + : is(i), sb(*i.rdbuf()) + {} - /*! - @brief returns the allocator associated with the container - */ - static allocator_type get_allocator() + // delete because of pointer members + input_stream_adapter(const input_stream_adapter&) = delete; + input_stream_adapter& operator=(input_stream_adapter&) = delete; + + // std::istream/std::streambuf use std::char_traits::to_int_type, to + // ensure that std::char_traits::eof() and the character 0xFF do not + // end up as the same value, eg. 0xFFFFFFFF. + std::char_traits::int_type get_character() override { - return allocator_type(); + return sb.sbumpc(); } - /*! - @brief returns version information on the library + private: + /// the associated input stream + std::istream& is; + std::streambuf& sb; +}; - This function returns a JSON object with information about the library, - including the version number and information on the platform and compiler. +/// input adapter for buffer input +class input_buffer_adapter : public input_adapter_protocol +{ + public: + input_buffer_adapter(const char* b, const std::size_t l) + : cursor(b), limit(b + l) + {} - @return JSON object holding version information - key | description - ----------- | --------------- - `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). - `copyright` | The copyright line for the library as string. - `name` | The name of the library as string. - `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. - `url` | The URL of the project as string. - `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). + // delete because of pointer members + input_buffer_adapter(const input_buffer_adapter&) = delete; + input_buffer_adapter& operator=(input_buffer_adapter&) = delete; - @liveexample{The following code shows an example output of the `meta()` - function.,meta} + std::char_traits::int_type get_character() noexcept override + { + if (JSON_LIKELY(cursor < limit)) + { + return std::char_traits::to_int_type(*(cursor++)); + } - @complexity Constant. + return std::char_traits::eof(); + } - @since 2.1.0 - */ - static basic_json meta() - { - basic_json result; + private: + /// pointer to the current character + const char* cursor; + /// pointer past the last character + const char* const limit; +}; - result["copyright"] = "(C) 2013-2017 Niels Lohmann"; - result["name"] = "JSON for Modern C++"; - result["url"] = "https://github.com/nlohmann/json"; - result["version"] = - { - {"string", "2.1.1"}, {"major", 2}, {"minor", 1}, {"patch", 1} - }; +template +class wide_string_input_adapter : public input_adapter_protocol +{ + public: + explicit wide_string_input_adapter(const WideStringType& w) : str(w) {} -#ifdef _WIN32 - result["platform"] = "win32"; -#elif defined __linux__ - result["platform"] = "linux"; -#elif defined __APPLE__ - result["platform"] = "apple"; -#elif defined __unix__ - result["platform"] = "unix"; -#else - result["platform"] = "unknown"; -#endif + std::char_traits::int_type get_character() noexcept override + { + // check if buffer needs to be filled + if (utf8_bytes_index == utf8_bytes_filled) + { + if (sizeof(typename WideStringType::value_type) == 2) + { + fill_buffer_utf16(); + } + else + { + fill_buffer_utf32(); + } -#if defined(__clang__) - result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; -#elif defined(__ICC) || defined(__INTEL_COMPILER) - result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; -#elif defined(__GNUC__) || defined(__GNUG__) - result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; -#elif defined(__HP_cc) || defined(__HP_aCC) - result["compiler"] = "hp" -#elif defined(__IBMCPP__) - result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; -#elif defined(_MSC_VER) - result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; -#elif defined(__PGI) - result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; -#elif defined(__SUNPRO_CC) - result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; -#else - result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; -#endif + assert(utf8_bytes_filled > 0); + assert(utf8_bytes_index == 0); + } -#ifdef __cplusplus - result["compiler"]["c++"] = std::to_string(__cplusplus); -#else - result["compiler"]["c++"] = "unknown"; -#endif - return result; + // use buffer + assert(utf8_bytes_filled > 0); + assert(utf8_bytes_index < utf8_bytes_filled); + return utf8_bytes[utf8_bytes_index++]; } + private: + void fill_buffer_utf16() + { + utf8_bytes_index = 0; - /////////////////////////// - // JSON value data types // - /////////////////////////// + if (current_wchar == str.size()) + { + utf8_bytes[0] = std::char_traits::eof(); + utf8_bytes_filled = 1; + } + else + { + // get the current character + const int wc = static_cast(str[current_wchar++]); - /// @name JSON value data types - /// The data types to store a JSON value. These types are derived from - /// the template arguments passed to class @ref basic_json. - /// @{ + // UTF-16 to UTF-8 encoding + if (wc < 0x80) + { + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + else if (wc <= 0x7FF) + { + utf8_bytes[0] = 0xC0 | ((wc >> 6)); + utf8_bytes[1] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 2; + } + else if (0xD800 > wc or wc >= 0xE000) + { + utf8_bytes[0] = 0xE0 | ((wc >> 12)); + utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[2] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 3; + } + else + { + if (current_wchar < str.size()) + { + const int wc2 = static_cast(str[current_wchar++]); + const int charcode = 0x10000 + (((wc & 0x3FF) << 10) | (wc2 & 0x3FF)); + utf8_bytes[0] = 0xf0 | (charcode >> 18); + utf8_bytes[1] = 0x80 | ((charcode >> 12) & 0x3F); + utf8_bytes[2] = 0x80 | ((charcode >> 6) & 0x3F); + utf8_bytes[3] = 0x80 | (charcode & 0x3F); + utf8_bytes_filled = 4; + } + else + { + // unknown character + ++current_wchar; + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + } + } + } - /*! - @brief a type for an object + void fill_buffer_utf32() + { + utf8_bytes_index = 0; - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: - > An object is an unordered collection of zero or more name/value pairs, - > where a name is a string and a value is a string, number, boolean, null, - > object, or array. + if (current_wchar == str.size()) + { + utf8_bytes[0] = std::char_traits::eof(); + utf8_bytes_filled = 1; + } + else + { + // get the current character + const int wc = static_cast(str[current_wchar++]); - To store objects in C++, a type is defined by the template parameters - described below. + // UTF-32 to UTF-8 encoding + if (wc < 0x80) + { + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + else if (wc <= 0x7FF) + { + utf8_bytes[0] = 0xC0 | ((wc >> 6) & 0x1F); + utf8_bytes[1] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 2; + } + else if (wc <= 0xFFFF) + { + utf8_bytes[0] = 0xE0 | ((wc >> 12) & 0x0F); + utf8_bytes[1] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[2] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 3; + } + else if (wc <= 0x10FFFF) + { + utf8_bytes[0] = 0xF0 | ((wc >> 18 ) & 0x07); + utf8_bytes[1] = 0x80 | ((wc >> 12) & 0x3F); + utf8_bytes[2] = 0x80 | ((wc >> 6) & 0x3F); + utf8_bytes[3] = 0x80 | (wc & 0x3F); + utf8_bytes_filled = 4; + } + else + { + // unknown character + utf8_bytes[0] = wc; + utf8_bytes_filled = 1; + } + } + } - @tparam ObjectType the container to store objects (e.g., `std::map` or - `std::unordered_map`) - @tparam StringType the type of the keys or names (e.g., `std::string`). - The comparison function `std::less` is used to order elements - inside the container. - @tparam AllocatorType the allocator to use for objects (e.g., - `std::allocator`) + private: + /// the wstring to process + const WideStringType& str; - #### Default type + /// index of the current wchar in str + std::size_t current_wchar = 0; - With the default values for @a ObjectType (`std::map`), @a StringType - (`std::string`), and @a AllocatorType (`std::allocator`), the default - value for @a object_t is: + /// a buffer for UTF-8 bytes + std::array::int_type, 4> utf8_bytes = {{0, 0, 0, 0}}; - @code {.cpp} - std::map< - std::string, // key_type - basic_json, // value_type - std::less, // key_compare - std::allocator> // allocator_type - > - @endcode + /// index to the utf8_codes array for the next valid byte + std::size_t utf8_bytes_index = 0; + /// number of valid bytes in the utf8_codes array + std::size_t utf8_bytes_filled = 0; +}; - #### Behavior +class input_adapter +{ + public: + // native support - The choice of @a object_t influences the behavior of the JSON class. With - the default type, objects have the following behavior: + /// input adapter for input stream + input_adapter(std::istream& i) + : ia(std::make_shared(i)) {} - - When all names are unique, objects will be interoperable in the sense - that all software implementations receiving that object will agree on - the name-value mappings. - - When the names within an object are not unique, later stored name/value - pairs overwrite previously stored name/value pairs, leaving the used - names unique. For instance, `{"key": 1}` and `{"key": 2, "key": 1}` will - be treated as equal and both stored as `{"key": 1}`. - - Internally, name/value pairs are stored in lexicographical order of the - names. Objects will also be serialized (see @ref dump) in this order. - For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored - and serialized as `{"a": 2, "b": 1}`. - - When comparing objects, the order of the name/value pairs is irrelevant. - This makes objects interoperable in the sense that they will not be - affected by these differences. For instance, `{"b": 1, "a": 2}` and - `{"a": 2, "b": 1}` will be treated as equal. + /// input adapter for input stream + input_adapter(std::istream&& i) + : ia(std::make_shared(i)) {} - #### Limits + input_adapter(const std::wstring& ws) + : ia(std::make_shared>(ws)) {} - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. + input_adapter(const std::u16string& ws) + : ia(std::make_shared>(ws)) {} - In this class, the object's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON object. + input_adapter(const std::u32string& ws) + : ia(std::make_shared>(ws)) {} - #### Storage + /// input adapter for buffer + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b, std::size_t l) + : ia(std::make_shared(reinterpret_cast(b), l)) {} - Objects are stored as pointers in a @ref basic_json type. That is, for any - access to object values, a pointer of type `object_t*` must be - dereferenced. + // derived support - @sa @ref array_t -- type for an array value + /// input adapter for string literal + template::value and + std::is_integral::type>::value and + sizeof(typename std::remove_pointer::type) == 1, + int>::type = 0> + input_adapter(CharT b) + : input_adapter(reinterpret_cast(b), + std::strlen(reinterpret_cast(b))) {} + + /// input adapter for iterator range with contiguous storage + template::iterator_category, std::random_access_iterator_tag>::value, + int>::type = 0> + input_adapter(IteratorType first, IteratorType last) + { + // assertion to check that the iterator range is indeed contiguous, + // see http://stackoverflow.com/a/35008842/266378 for more discussion + assert(std::accumulate( + first, last, std::pair(true, 0), + [&first](std::pair res, decltype(*first) val) + { + res.first &= (val == *(std::next(std::addressof(*first), res.second++))); + return res; + }).first); - @since version 1.0.0 + // assertion to check that each element is 1 byte long + static_assert( + sizeof(typename std::iterator_traits::value_type) == 1, + "each element in the iterator range must have the size of 1 byte"); - @note The order name/value pairs are added to the object is *not* - preserved by the library. Therefore, iterating an object may return - name/value pairs in a different order than they were originally stored. In - fact, keys will be traversed in alphabetical order as `std::map` with - `std::less` is used by default. Please note this behavior conforms to [RFC - 7159](http://rfc7159.net/rfc7159), because any order implements the - specified "unordered" nature of JSON objects. - */ - using object_t = ObjectType, - AllocatorType>>; + const auto len = static_cast(std::distance(first, last)); + if (JSON_LIKELY(len > 0)) + { + // there is at least one element: use the address of first + ia = std::make_shared(reinterpret_cast(&(*first)), len); + } + else + { + // the address of first cannot be used: use nullptr + ia = std::make_shared(nullptr, len); + } + } - /*! - @brief a type for an array + /// input adapter for array + template + input_adapter(T (&array)[N]) + : input_adapter(std::begin(array), std::end(array)) {} + + /// input adapter for contiguous container + template::value and + std::is_base_of()))>::iterator_category>::value, + int>::type = 0> + input_adapter(const ContiguousContainer& c) + : input_adapter(std::begin(c), std::end(c)) {} + + operator input_adapter_t() + { + return ia; + } - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: - > An array is an ordered sequence of zero or more values. + private: + /// the actual adapter + input_adapter_t ia = nullptr; +}; +} +} - To store objects in C++, a type is defined by the template parameters - explained below. +// #include - @tparam ArrayType container type to store arrays (e.g., `std::vector` or - `std::list`) - @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) - #### Default type +#include // localeconv +#include // size_t +#include // strtof, strtod, strtold, strtoll, strtoull +#include // snprintf +#include // initializer_list +#include // char_traits, string +#include // vector - With the default values for @a ArrayType (`std::vector`) and @a - AllocatorType (`std::allocator`), the default value for @a array_t is: +// #include - @code {.cpp} - std::vector< - basic_json, // value_type - std::allocator // allocator_type - > - @endcode +// #include - #### Limits - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the maximum depth of nesting. +namespace nlohmann +{ +namespace detail +{ +/////////// +// lexer // +/////////// - In this class, the array's limit of nesting is not constraint explicitly. - However, a maximum depth of nesting may be introduced by the compiler or - runtime environment. A theoretical limit can be queried by calling the - @ref max_size function of a JSON array. +/*! +@brief lexical analysis - #### Storage +This class organizes the lexical analysis during JSON deserialization. +*/ +template +class lexer +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; - Arrays are stored as pointers in a @ref basic_json type. That is, for any - access to array values, a pointer of type `array_t*` must be dereferenced. + public: + /// token types for the parser + enum class token_type + { + uninitialized, ///< indicating the scanner is uninitialized + literal_true, ///< the `true` literal + literal_false, ///< the `false` literal + literal_null, ///< the `null` literal + value_string, ///< a string -- use get_string() for actual value + value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value + value_integer, ///< a signed integer -- use get_number_integer() for actual value + value_float, ///< an floating point number -- use get_number_float() for actual value + begin_array, ///< the character for array begin `[` + begin_object, ///< the character for object begin `{` + end_array, ///< the character for array end `]` + end_object, ///< the character for object end `}` + name_separator, ///< the name separator `:` + value_separator, ///< the value separator `,` + parse_error, ///< indicating a parse error + end_of_input, ///< indicating the end of the input buffer + literal_or_value ///< a literal or the begin of a value (only for diagnostics) + }; - @sa @ref object_t -- type for an object value + /// return name of values of type token_type (only used for errors) + static const char* token_type_name(const token_type t) noexcept + { + switch (t) + { + case token_type::uninitialized: + return ""; + case token_type::literal_true: + return "true literal"; + case token_type::literal_false: + return "false literal"; + case token_type::literal_null: + return "null literal"; + case token_type::value_string: + return "string literal"; + case lexer::token_type::value_unsigned: + case lexer::token_type::value_integer: + case lexer::token_type::value_float: + return "number literal"; + case token_type::begin_array: + return "'['"; + case token_type::begin_object: + return "'{'"; + case token_type::end_array: + return "']'"; + case token_type::end_object: + return "'}'"; + case token_type::name_separator: + return "':'"; + case token_type::value_separator: + return "','"; + case token_type::parse_error: + return ""; + case token_type::end_of_input: + return "end of input"; + case token_type::literal_or_value: + return "'[', '{', or a literal"; + default: // catch non-enum values + return "unknown token"; // LCOV_EXCL_LINE + } + } - @since version 1.0.0 - */ - using array_t = ArrayType>; + explicit lexer(detail::input_adapter_t&& adapter) + : ia(std::move(adapter)), decimal_point_char(get_decimal_point()) {} - /*! - @brief a type for a string + // delete because of pointer members + lexer(const lexer&) = delete; + lexer& operator=(lexer&) = delete; - [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: - > A string is a sequence of zero or more Unicode characters. + private: + ///////////////////// + // locales + ///////////////////// - To store objects in C++, a type is defined by the template parameter - described below. Unicode values are split by the JSON class into - byte-sized characters during deserialization. + /// return the locale-dependent decimal point + static char get_decimal_point() noexcept + { + const auto loc = localeconv(); + assert(loc != nullptr); + return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point); + } - @tparam StringType the container to store strings (e.g., `std::string`). - Note this container is used for keys/names in objects, see @ref object_t. + ///////////////////// + // scan functions + ///////////////////// - #### Default type + /*! + @brief get codepoint from 4 hex characters following `\u` - With the default values for @a StringType (`std::string`), the default - value for @a string_t is: + For input "\u c1 c2 c3 c4" the codepoint is: + (c1 * 0x1000) + (c2 * 0x0100) + (c3 * 0x0010) + c4 + = (c1 << 12) + (c2 << 8) + (c3 << 4) + (c4 << 0) - @code {.cpp} - std::string - @endcode + Furthermore, the possible characters '0'..'9', 'A'..'F', and 'a'..'f' + must be converted to the integers 0x0..0x9, 0xA..0xF, 0xA..0xF, resp. The + conversion is done by subtracting the offset (0x30, 0x37, and 0x57) + between the ASCII value of the character and the desired integer value. - #### Encoding + @return codepoint (0x0000..0xFFFF) or -1 in case of an error (e.g. EOF or + non-hex character) + */ + int get_codepoint() + { + // this function only makes sense after reading `\u` + assert(current == 'u'); + int codepoint = 0; - Strings are stored in UTF-8 encoding. Therefore, functions like - `std::string::size()` or `std::string::length()` return the number of - bytes in the string rather than the number of characters or glyphs. + const auto factors = { 12, 8, 4, 0 }; + for (const auto factor : factors) + { + get(); - #### String comparison + if (current >= '0' and current <= '9') + { + codepoint += ((current - 0x30) << factor); + } + else if (current >= 'A' and current <= 'F') + { + codepoint += ((current - 0x37) << factor); + } + else if (current >= 'a' and current <= 'f') + { + codepoint += ((current - 0x57) << factor); + } + else + { + return -1; + } + } - [RFC 7159](http://rfc7159.net/rfc7159) states: - > Software implementations are typically required to test names of object - > members for equality. Implementations that transform the textual - > representation into sequences of Unicode code units and then perform the - > comparison numerically, code unit by code unit, are interoperable in the - > sense that implementations will agree in all cases on equality or - > inequality of two strings. For example, implementations that compare - > strings with escaped characters unconverted may incorrectly find that - > `"a\\b"` and `"a\u005Cb"` are not equal. + assert(0x0000 <= codepoint and codepoint <= 0xFFFF); + return codepoint; + } - This implementation is interoperable as it does compare strings code unit - by code unit. + /*! + @brief check if the next byte(s) are inside a given range - #### Storage + Adds the current byte and, for each passed range, reads a new byte and + checks if it is inside the range. If a violation was detected, set up an + error message and return false. Otherwise, return true. - String values are stored as pointers in a @ref basic_json type. That is, - for any access to string values, a pointer of type `string_t*` must be - dereferenced. + @param[in] ranges list of integers; interpreted as list of pairs of + inclusive lower and upper bound, respectively - @since version 1.0.0 + @pre The passed list @a ranges must have 2, 4, or 6 elements; that is, + 1, 2, or 3 pairs. This precondition is enforced by an assertion. + + @return true if and only if no range violation was detected */ - using string_t = StringType; + bool next_byte_in_range(std::initializer_list ranges) + { + assert(ranges.size() == 2 or ranges.size() == 4 or ranges.size() == 6); + add(current); + + for (auto range = ranges.begin(); range != ranges.end(); ++range) + { + get(); + if (JSON_LIKELY(*range <= current and current <= *(++range))) + { + add(current); + } + else + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return false; + } + } + + return true; + } /*! - @brief a type for a boolean + @brief scan a string literal - [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a - type which differentiates the two literals `true` and `false`. + This function scans a string according to Sect. 7 of RFC 7159. While + scanning, bytes are escaped and copied into buffer token_buffer. Then the + function returns successfully, token_buffer is *not* null-terminated (as it + may contain \0 bytes), and token_buffer.size() is the number of bytes in the + string. - To store objects in C++, a type is defined by the template parameter @a - BooleanType which chooses the type to use. + @return token_type::value_string if string could be successfully scanned, + token_type::parse_error otherwise - #### Default type + @note In case of errors, variable error_message contains a textual + description. + */ + token_type scan_string() + { + // reset token_buffer (ignore opening quote) + reset(); - With the default values for @a BooleanType (`bool`), the default value for - @a boolean_t is: + // we entered the function by reading an open quote + assert(current == '\"'); - @code {.cpp} - bool - @endcode + while (true) + { + // get next character + switch (get()) + { + // end of file while parsing string + case std::char_traits::eof(): + { + error_message = "invalid string: missing closing quote"; + return token_type::parse_error; + } - #### Storage + // closing quote + case '\"': + { + return token_type::value_string; + } - Boolean values are stored directly inside a @ref basic_json type. + // escapes + case '\\': + { + switch (get()) + { + // quotation mark + case '\"': + add('\"'); + break; + // reverse solidus + case '\\': + add('\\'); + break; + // solidus + case '/': + add('/'); + break; + // backspace + case 'b': + add('\b'); + break; + // form feed + case 'f': + add('\f'); + break; + // line feed + case 'n': + add('\n'); + break; + // carriage return + case 'r': + add('\r'); + break; + // tab + case 't': + add('\t'); + break; + + // unicode escapes + case 'u': + { + const int codepoint1 = get_codepoint(); + int codepoint = codepoint1; // start with codepoint1 - @since version 1.0.0 - */ - using boolean_t = BooleanType; + if (JSON_UNLIKELY(codepoint1 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } - /*! - @brief a type for a number (integer) + // check if code point is a high surrogate + if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) + { + // expect next \uxxxx entry + if (JSON_LIKELY(get() == '\\' and get() == 'u')) + { + const int codepoint2 = get_codepoint(); - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + if (JSON_UNLIKELY(codepoint2 == -1)) + { + error_message = "invalid string: '\\u' must be followed by 4 hex digits"; + return token_type::parse_error; + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + // check if codepoint2 is a low surrogate + if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) + { + // overwrite codepoint + codepoint = + // high surrogate occupies the most significant 22 bits + (codepoint1 << 10) + // low surrogate occupies the least significant 15 bits + + codepoint2 + // there is still the 0xD800, 0xDC00 and 0x10000 noise + // in the result so we have to subtract with: + // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 + - 0x35FDC00; + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF"; + return token_type::parse_error; + } + } + else + { + if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) + { + error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF"; + return token_type::parse_error; + } + } - To store integer numbers in C++, a type is defined by the template - parameter @a NumberIntegerType which chooses the type to use. + // result of the above calculation yields a proper codepoint + assert(0x00 <= codepoint and codepoint <= 0x10FFFF); - #### Default type + // translate codepoint into bytes + if (codepoint < 0x80) + { + // 1-byte characters: 0xxxxxxx (ASCII) + add(codepoint); + } + else if (codepoint <= 0x7FF) + { + // 2-byte characters: 110xxxxx 10xxxxxx + add(0xC0 | (codepoint >> 6)); + add(0x80 | (codepoint & 0x3F)); + } + else if (codepoint <= 0xFFFF) + { + // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx + add(0xE0 | (codepoint >> 12)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } + else + { + // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx + add(0xF0 | (codepoint >> 18)); + add(0x80 | ((codepoint >> 12) & 0x3F)); + add(0x80 | ((codepoint >> 6) & 0x3F)); + add(0x80 | (codepoint & 0x3F)); + } - With the default values for @a NumberIntegerType (`int64_t`), the default - value for @a number_integer_t is: + break; + } - @code {.cpp} - int64_t - @endcode + // other characters after escape + default: + error_message = "invalid string: forbidden character after backslash"; + return token_type::parse_error; + } - #### Default behavior + break; + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. + // invalid control characters + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + { + error_message = "invalid string: control character must be escaped"; + return token_type::parse_error; + } - #### Limits + // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) + case 0x20: + case 0x21: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + { + add(current); + break; + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + // U+0080..U+07FF: bytes C2..DF 80..BF + case 0xC2: + case 0xC3: + case 0xC4: + case 0xC5: + case 0xC6: + case 0xC7: + case 0xC8: + case 0xC9: + case 0xCA: + case 0xCB: + case 0xCC: + case 0xCD: + case 0xCE: + case 0xCF: + case 0xD0: + case 0xD1: + case 0xD2: + case 0xD3: + case 0xD4: + case 0xD5: + case 0xD6: + case 0xD7: + case 0xD8: + case 0xD9: + case 0xDA: + case 0xDB: + case 0xDC: + case 0xDD: + case 0xDE: + case 0xDF: + { + if (JSON_UNLIKELY(not next_byte_in_range({0x80, 0xBF}))) + { + return token_type::parse_error; + } + break; + } - When the default type is used, the maximal integer number that can be - stored is `9223372036854775807` (INT64_MAX) and the minimal integer number - that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers - that are out of range will yield over/underflow when used in a - constructor. During deserialization, too large or small integer numbers - will be automatically be stored as @ref number_unsigned_t or @ref - number_float_t. + // U+0800..U+0FFF: bytes E0 A0..BF 80..BF + case 0xE0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF + // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xEE: + case 0xEF: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - As this range is a subrange of the exactly supported range [INT64_MIN, - INT64_MAX], this class's integer type is interoperable. + // U+D000..U+D7FF: bytes ED 80..9F 80..BF + case 0xED: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x9F, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - #### Storage + // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF + case 0xF0: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - Integer number values are stored directly inside a @ref basic_json type. + // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF + case 0xF1: + case 0xF2: + case 0xF3: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - @sa @ref number_float_t -- type for number values (floating-point) + // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF + case 0xF4: + { + if (JSON_UNLIKELY(not (next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF})))) + { + return token_type::parse_error; + } + break; + } - @sa @ref number_unsigned_t -- type for number values (unsigned integer) + // remaining bytes (80..C1 and F5..FF) are ill-formed + default: + { + error_message = "invalid string: ill-formed UTF-8 byte"; + return token_type::parse_error; + } + } + } + } - @since version 1.0.0 - */ - using number_integer_t = NumberIntegerType; + static void strtof(float& f, const char* str, char** endptr) noexcept + { + f = std::strtof(str, endptr); + } - /*! - @brief a type for a number (unsigned) + static void strtof(double& f, const char* str, char** endptr) noexcept + { + f = std::strtod(str, endptr); + } - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + static void strtof(long double& f, const char* str, char** endptr) noexcept + { + f = std::strtold(str, endptr); + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + /*! + @brief scan a number literal + + This function scans a string according to Sect. 6 of RFC 7159. + + The function is realized with a deterministic finite state machine derived + from the grammar described in RFC 7159. Starting in state "init", the + input is read and used to determined the next state. Only state "done" + accepts the number. State "error" is a trap state to model errors. In the + table below, "anything" means any character but the ones listed before. + + state | 0 | 1-9 | e E | + | - | . | anything + ---------|----------|----------|----------|---------|---------|----------|----------- + init | zero | any1 | [error] | [error] | minus | [error] | [error] + minus | zero | any1 | [error] | [error] | [error] | [error] | [error] + zero | done | done | exponent | done | done | decimal1 | done + any1 | any1 | any1 | exponent | done | done | decimal1 | done + decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] + decimal2 | decimal2 | decimal2 | exponent | done | done | done | done + exponent | any2 | any2 | [error] | sign | sign | [error] | [error] + sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] + any2 | any2 | any2 | done | done | done | done | done + + The state machine is realized with one label per state (prefixed with + "scan_number_") and `goto` statements between them. The state machine + contains cycles, but any cycle can be left when EOF is read. Therefore, + the function is guaranteed to terminate. + + During scanning, the read bytes are stored in token_buffer. This string is + then converted to a signed integer, an unsigned integer, or a + floating-point number. + + @return token_type::value_unsigned, token_type::value_integer, or + token_type::value_float if number could be successfully scanned, + token_type::parse_error otherwise + + @note The scanner is independent of the current locale. Internally, the + locale's decimal point is used instead of `.` to work with the + locale-dependent converters. + */ + token_type scan_number() + { + // reset token_buffer to store the number's bytes + reset(); - To store unsigned integer numbers in C++, a type is defined by the - template parameter @a NumberUnsignedType which chooses the type to use. + // the type of the parsed number; initially set to unsigned; will be + // changed if minus sign, decimal point or exponent is read + token_type number_type = token_type::value_unsigned; - #### Default type + // state (init): we just found out we need to scan a number + switch (current) + { + case '-': + { + add(current); + goto scan_number_minus; + } - With the default values for @a NumberUnsignedType (`uint64_t`), the - default value for @a number_unsigned_t is: + case '0': + { + add(current); + goto scan_number_zero; + } - @code {.cpp} - uint64_t - @endcode + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - #### Default behavior + default: + { + // all other characters are rejected outside scan_number() + assert(false); // LCOV_EXCL_LINE + } + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in integer literals lead to an interpretation as octal - number. Internally, the value will be stored as decimal number. For - instance, the C++ integer literal `010` will be serialized to `8`. - During deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. +scan_number_minus: + // state: we just parsed a leading minus sign + number_type = token_type::value_integer; + switch (get()) + { + case '0': + { + add(current); + goto scan_number_zero; + } - #### Limits + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - [RFC 7159](http://rfc7159.net/rfc7159) specifies: - > An implementation may set limits on the range and precision of numbers. + default: + { + error_message = "invalid number; expected digit after '-'"; + return token_type::parse_error; + } + } - When the default type is used, the maximal integer number that can be - stored is `18446744073709551615` (UINT64_MAX) and the minimal integer - number that can be stored is `0`. Integer numbers that are out of range - will yield over/underflow when used in a constructor. During - deserialization, too large or small integer numbers will be automatically - be stored as @ref number_integer_t or @ref number_float_t. +scan_number_zero: + // state: we just parse a zero (maybe with a leading minus sign) + switch (get()) + { + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } - [RFC 7159](http://rfc7159.net/rfc7159) further states: - > Note that when such software is used, numbers that are integers and are - > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense - > that implementations will agree exactly on their numeric values. + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - As this range is a subrange (when considered in conjunction with the - number_integer_t type) of the exactly supported range [0, UINT64_MAX], - this class's integer type is interoperable. + default: + goto scan_number_done; + } - #### Storage +scan_number_any1: + // state: we just parsed a number 0-9 (maybe with a leading minus sign) + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any1; + } - Integer number values are stored directly inside a @ref basic_json type. + case '.': + { + add(decimal_point_char); + goto scan_number_decimal1; + } - @sa @ref number_float_t -- type for number values (floating-point) - @sa @ref number_integer_t -- type for number values (integer) - - @since version 2.0.0 - */ - using number_unsigned_t = NumberUnsignedType; - - /*! - @brief a type for a number (floating-point) - - [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: - > The representation of numbers is similar to that used in most - > programming languages. A number is represented in base 10 using decimal - > digits. It contains an integer component that may be prefixed with an - > optional minus sign, which may be followed by a fraction part and/or an - > exponent part. Leading zeros are not allowed. (...) Numeric values that - > cannot be represented in the grammar below (such as Infinity and NaN) - > are not permitted. + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - This description includes both integer and floating-point numbers. - However, C++ allows more precise storage if it is known whether the number - is a signed integer, an unsigned integer or a floating-point number. - Therefore, three different types, @ref number_integer_t, @ref - number_unsigned_t and @ref number_float_t are used. + default: + goto scan_number_done; + } - To store floating-point numbers in C++, a type is defined by the template - parameter @a NumberFloatType which chooses the type to use. +scan_number_decimal1: + // state: we just parsed a decimal point + number_type = token_type::value_float; + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } - #### Default type + default: + { + error_message = "invalid number; expected digit after '.'"; + return token_type::parse_error; + } + } - With the default values for @a NumberFloatType (`double`), the default - value for @a number_float_t is: +scan_number_decimal2: + // we just parsed at least one number after a decimal point + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_decimal2; + } - @code {.cpp} - double - @endcode + case 'e': + case 'E': + { + add(current); + goto scan_number_exponent; + } - #### Default behavior + default: + goto scan_number_done; + } - - The restrictions about leading zeros is not enforced in C++. Instead, - leading zeros in floating-point literals will be ignored. Internally, - the value will be stored as decimal number. For instance, the C++ - floating-point literal `01.2` will be serialized to `1.2`. During - deserialization, leading zeros yield an error. - - Not-a-number (NaN) values will be serialized to `null`. +scan_number_exponent: + // we just parsed an exponent + number_type = token_type::value_float; + switch (get()) + { + case '+': + case '-': + { + add(current); + goto scan_number_sign; + } - #### Limits + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - [RFC 7159](http://rfc7159.net/rfc7159) states: - > This specification allows implementations to set limits on the range and - > precision of numbers accepted. Since software that implements IEEE - > 754-2008 binary64 (double precision) numbers is generally available and - > widely used, good interoperability can be achieved by implementations - > that expect no more precision or range than these provide, in the sense - > that implementations will approximate JSON numbers within the expected - > precision. + default: + { + error_message = + "invalid number; expected '+', '-', or digit after exponent"; + return token_type::parse_error; + } + } - This implementation does exactly follow this approach, as it uses double - precision floating-point numbers. Note values smaller than - `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` - will be stored as NaN internally and be serialized to `null`. +scan_number_sign: + // we just parsed an exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - #### Storage + default: + { + error_message = "invalid number; expected digit after exponent sign"; + return token_type::parse_error; + } + } - Floating-point number values are stored directly inside a @ref basic_json - type. +scan_number_any2: + // we just parsed a number after the exponent or exponent sign + switch (get()) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + add(current); + goto scan_number_any2; + } - @sa @ref number_integer_t -- type for number values (integer) + default: + goto scan_number_done; + } - @sa @ref number_unsigned_t -- type for number values (unsigned integer) +scan_number_done: + // unget the character after the number (we only read it to know that + // we are done scanning a number) + unget(); - @since version 1.0.0 - */ - using number_float_t = NumberFloatType; + char* endptr = nullptr; + errno = 0; - /// @} + // try to parse integers first and fall back to floats + if (number_type == token_type::value_unsigned) + { + const auto x = std::strtoull(token_buffer.data(), &endptr, 10); - private: + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - /// helper for exception-safe object creation - template - static T* create(Args&& ... args) - { - AllocatorType alloc; - auto deleter = [&](T * object) + if (errno == 0) + { + value_unsigned = static_cast(x); + if (value_unsigned == x) + { + return token_type::value_unsigned; + } + } + } + else if (number_type == token_type::value_integer) { - alloc.deallocate(object, 1); - }; - std::unique_ptr object(alloc.allocate(1), deleter); - alloc.construct(object.get(), std::forward(args)...); - assert(object != nullptr); - return object.release(); - } + const auto x = std::strtoll(token_buffer.data(), &endptr, 10); - //////////////////////// - // JSON value storage // - //////////////////////// + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - /*! - @brief a JSON value + if (errno == 0) + { + value_integer = static_cast(x); + if (value_integer == x) + { + return token_type::value_integer; + } + } + } - The actual storage for a JSON value of the @ref basic_json class. This - union combines the different storage types for the JSON value types - defined in @ref value_t. + // this code is reached if we parse a floating-point number or if an + // integer conversion above failed + strtof(value_float, token_buffer.data(), &endptr); - JSON type | value_t type | used type - --------- | --------------- | ------------------------ - object | object | pointer to @ref object_t - array | array | pointer to @ref array_t - string | string | pointer to @ref string_t - boolean | boolean | @ref boolean_t - number | number_integer | @ref number_integer_t - number | number_unsigned | @ref number_unsigned_t - number | number_float | @ref number_float_t - null | null | *no value is stored* + // we checked the number format before + assert(endptr == token_buffer.data() + token_buffer.size()); - @note Variable-length types (objects, arrays, and strings) are stored as - pointers. The size of the union should not exceed 64 bits if the default - value types are used. + return token_type::value_float; + } - @since version 1.0.0 + /*! + @param[in] literal_text the literal text to expect + @param[in] length the length of the passed literal text + @param[in] return_type the token type to return on success */ - union json_value + token_type scan_literal(const char* literal_text, const std::size_t length, + token_type return_type) { - /// object (stored with pointer to save storage) - object_t* object; - /// array (stored with pointer to save storage) - array_t* array; - /// string (stored with pointer to save storage) - string_t* string; - /// boolean - boolean_t boolean; - /// number (integer) - number_integer_t number_integer; - /// number (unsigned integer) - number_unsigned_t number_unsigned; - /// number (floating-point) - number_float_t number_float; - - /// default constructor (for null values) - json_value() = default; - /// constructor for booleans - json_value(boolean_t v) noexcept : boolean(v) {} - /// constructor for numbers (integer) - json_value(number_integer_t v) noexcept : number_integer(v) {} - /// constructor for numbers (unsigned) - json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} - /// constructor for numbers (floating-point) - json_value(number_float_t v) noexcept : number_float(v) {} - /// constructor for empty values of a given type - json_value(value_t t) + assert(current == literal_text[0]); + for (std::size_t i = 1; i < length; ++i) { - switch (t) + if (JSON_UNLIKELY(get() != literal_text[i])) { - case value_t::object: - { - object = create(); - break; - } - - case value_t::array: - { - array = create(); - break; - } - - case value_t::string: - { - string = create(""); - break; - } - - case value_t::boolean: - { - boolean = boolean_t(false); - break; - } - - case value_t::number_integer: - { - number_integer = number_integer_t(0); - break; - } + error_message = "invalid literal"; + return token_type::parse_error; + } + } + return return_type; + } - case value_t::number_unsigned: - { - number_unsigned = number_unsigned_t(0); - break; - } + ///////////////////// + // input management + ///////////////////// - case value_t::number_float: - { - number_float = number_float_t(0.0); - break; - } + /// reset token_buffer; current character is beginning of token + void reset() noexcept + { + token_buffer.clear(); + token_string.clear(); + token_string.push_back(std::char_traits::to_char_type(current)); + } - case value_t::null: - { - break; - } + /* + @brief get next character from the input - default: - { - if (JSON_UNLIKELY(t == value_t::null)) - { - JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 2.1.1")); // LCOV_EXCL_LINE - } - break; - } - } - } + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a + `std::char_traits::eof()` in that case. Stores the scanned characters + for use in error messages. - /// constructor for strings - json_value(const string_t& value) + @return character read from the input + */ + std::char_traits::int_type get() + { + ++chars_read; + if (next_unget) { - string = create(value); + // just reset the next_unget variable and work with current + next_unget = false; } - - /// constructor for objects - json_value(const object_t& value) + else { - object = create(value); + current = ia->get_character(); } - /// constructor for arrays - json_value(const array_t& value) + if (JSON_LIKELY(current != std::char_traits::eof())) { - array = create(value); + token_string.push_back(std::char_traits::to_char_type(current)); } - }; + return current; + } /*! - @brief checks the class invariants + @brief unget current character (read it again on next get) - This function asserts the class invariants. It needs to be called at the - end of every constructor to make sure that created objects respect the - invariant. Furthermore, it has to be called each time the type of a JSON - value is changed, because the invariant expresses a relationship between - @a m_type and @a m_value. + We implement unget by setting variable next_unget to true. The input is not + changed - we just simulate ungetting by modifying chars_read and + token_string. The next call to get() will behave as if the unget character + is read again. */ - void assert_invariant() const + void unget() { - assert(m_type != value_t::object or m_value.object != nullptr); - assert(m_type != value_t::array or m_value.array != nullptr); - assert(m_type != value_t::string or m_value.string != nullptr); + next_unget = true; + --chars_read; + if (JSON_LIKELY(current != std::char_traits::eof())) + { + assert(token_string.size() != 0); + token_string.pop_back(); + } + } + + /// add a character to token_buffer + void add(int c) + { + token_buffer.push_back(std::char_traits::to_char_type(c)); } public: - ////////////////////////// - // JSON parser callback // - ////////////////////////// + ///////////////////// + // value getters + ///////////////////// - /*! - @brief JSON callback events + /// return integer value + constexpr number_integer_t get_number_integer() const noexcept + { + return value_integer; + } - This enumeration lists the parser events that can trigger calling a - callback function of type @ref parser_callback_t during parsing. + /// return unsigned integer value + constexpr number_unsigned_t get_number_unsigned() const noexcept + { + return value_unsigned; + } - @image html callback_events.png "Example when certain parse events are triggered" + /// return floating-point value + constexpr number_float_t get_number_float() const noexcept + { + return value_float; + } - @since version 1.0.0 - */ - enum class parse_event_t : uint8_t + /// return current string value (implicitly resets the token; useful only once) + string_t& get_string() { - /// the parser read `{` and started to process a JSON object - object_start, - /// the parser read `}` and finished processing a JSON object - object_end, - /// the parser read `[` and started to process a JSON array - array_start, - /// the parser read `]` and finished processing a JSON array - array_end, - /// the parser read a key of a value in an object - key, - /// the parser finished reading a JSON value - value - }; + return token_buffer; + } + + ///////////////////// + // diagnostics + ///////////////////// + + /// return position of last read token + constexpr std::size_t get_position() const noexcept + { + return chars_read; + } + + /// return the last read token (for errors only). Will never contain EOF + /// (an arbitrary value that is not a valid char value, often -1), because + /// 255 may legitimately occur. May contain NUL, which should be escaped. + std::string get_token_string() const + { + // escape control characters + std::string result; + for (const auto c : token_string) + { + if ('\x00' <= c and c <= '\x1F') + { + // escape control characters + char cs[9]; + snprintf(cs, 9, "", static_cast(c)); + result += cs; + } + else + { + // add character as is + result.push_back(c); + } + } + + return result; + } + + /// return syntax error message + constexpr const char* get_error_message() const noexcept + { + return error_message; + } + + ///////////////////// + // actual scanner + ///////////////////// /*! - @brief per-element parser callback type + @brief skip the UTF-8 byte order mark + @return true iff there is no BOM or the correct BOM has been skipped + */ + bool skip_bom() + { + if (get() == 0xEF) + { + if (get() == 0xBB and get() == 0xBF) + { + // we completely parsed the BOM + return true; + } + else + { + // after reading 0xEF, an unexpected character followed + return false; + } + } + else + { + // the first character is not the beginning of the BOM; unget it to + // process is later + unget(); + return true; + } + } - With a parser callback function, the result of parsing a JSON text can be - influenced. When passed to @ref parse(std::istream&, const - parser_callback_t) or @ref parse(const CharT, const parser_callback_t), - it is called on certain events (passed as @ref parse_event_t via parameter - @a event) with a set recursion depth @a depth and context JSON value - @a parsed. The return value of the callback function is a boolean - indicating whether the element that emitted the callback shall be kept or - not. + token_type scan() + { + // initially, skip the BOM + if (chars_read == 0 and not skip_bom()) + { + error_message = "invalid BOM; must be 0xEF 0xBB 0xBF if given"; + return token_type::parse_error; + } - We distinguish six scenarios (determined by the event type) in which the - callback function can be called. The following table describes the values - of the parameters @a depth, @a event, and @a parsed. + // read next character and ignore whitespace + do + { + get(); + } + while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); + + switch (current) + { + // structural characters + case '[': + return token_type::begin_array; + case ']': + return token_type::end_array; + case '{': + return token_type::begin_object; + case '}': + return token_type::end_object; + case ':': + return token_type::name_separator; + case ',': + return token_type::value_separator; + + // literals + case 't': + return scan_literal("true", 4, token_type::literal_true); + case 'f': + return scan_literal("false", 5, token_type::literal_false); + case 'n': + return scan_literal("null", 4, token_type::literal_null); + + // string + case '\"': + return scan_string(); + + // number + case '-': + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + return scan_number(); + + // end of input (the null byte is needed when parsing from + // string literals) + case '\0': + case std::char_traits::eof(): + return token_type::end_of_input; + + // error + default: + error_message = "invalid literal"; + return token_type::parse_error; + } + } - parameter @a event | description | parameter @a depth | parameter @a parsed - ------------------ | ----------- | ------------------ | ------------------- - parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded - parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key - parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object - parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded - parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array - parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value + private: + /// input adapter + detail::input_adapter_t ia = nullptr; - @image html callback_events.png "Example when certain parse events are triggered" + /// the current character + std::char_traits::int_type current = std::char_traits::eof(); - Discarding a value (i.e., returning `false`) has different effects - depending on the context in which function was called: + /// whether the next get() call should just return current + bool next_unget = false; - - Discarded values in structured types are skipped. That is, the parser - will behave as if the discarded value was never read. - - In case a value outside a structured type is skipped, it is replaced - with `null`. This case happens if the top-level element is skipped. + /// the number of characters read + std::size_t chars_read = 0; - @param[in] depth the depth of the recursion during parsing + /// raw input token string (for error messages) + std::vector token_string {}; - @param[in] event an event of type parse_event_t indicating the context in - the callback function has been called + /// buffer for variable-length tokens (numbers, strings) + string_t token_buffer {}; - @param[in,out] parsed the current intermediate parse result; note that - writing to this value has no effect for parse_event_t::key events + /// a description of occurred lexer errors + const char* error_message = ""; - @return Whether the JSON value which called the function during parsing - should be kept (`true`) or not (`false`). In the latter case, it is either - skipped completely or replaced by an empty discarded object. + // number values + number_integer_t value_integer = 0; + number_unsigned_t value_unsigned = 0; + number_float_t value_float = 0; - @sa @ref parse(std::istream&, parser_callback_t) or - @ref parse(const CharT, const parser_callback_t) for examples + /// the decimal point + const char decimal_point_char = '.'; +}; +} +} - @since version 1.0.0 - */ - using parser_callback_t = std::function; +// #include - ////////////////// - // constructors // - ////////////////// +#include // assert +#include // isfinite +#include // uint8_t +#include // function +#include // string +#include // move - /// @name constructors and destructors - /// Constructors of class @ref basic_json, copy/move constructor, copy - /// assignment, static functions creating objects, and the destructor. - /// @{ +// #include - /*! - @brief create an empty value with a given type +// #include - Create an empty JSON value with a given type. The value will be default - initialized with an empty value which depends on the type: +// #include - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` +// #include - @param[in] value_type the type of the value to create - @complexity Constant. +#include +#include +#include - @liveexample{The following code shows the constructor for different @ref - value_t values,basic_json__value_t} +// #include - @since version 1.0.0 +// #include + + +namespace nlohmann +{ + +/*! +@brief SAX interface +*/ +template +struct json_sax +{ + /// type for (signed) integers + using number_integer_t = typename BasicJsonType::number_integer_t; + /// type for unsigned integers + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + /// type for floating-point numbers + using number_float_t = typename BasicJsonType::number_float_t; + /// type for strings + using string_t = typename BasicJsonType::string_t; + + /// constant to indicate that no size limit is given for array or object + static constexpr auto no_limit = std::size_t(-1); + + /*! + @brief a null value was read + @return whether parsing should proceed */ - basic_json(const value_t value_type) - : m_type(value_type), m_value(value_type) - { - assert_invariant(); - } + virtual bool null() = 0; /*! - @brief create a null object + @brief a boolean value was read + @param[in] val boolean value + @return whether parsing should proceed + */ + virtual bool boolean(bool val) = 0; - Create a `null` JSON value. It either takes a null pointer as parameter - (explicitly creating `null`) or no parameter (implicitly creating `null`). - The passed null pointer itself is not read -- it is only used to choose - the right constructor. + /*! + @brief an integer number was read + @param[in] val integer value + @return whether parsing should proceed + */ + virtual bool number_integer(number_integer_t val) = 0; - @complexity Constant. + /*! + @brief an unsigned integer number was read + @param[in] val unsigned integer value + @return whether parsing should proceed + */ + virtual bool number_unsigned(number_unsigned_t val) = 0; - @exceptionsafety No-throw guarantee: this constructor never throws - exceptions. + /*! + @brief an floating-point number was read + @param[in] val floating-point value + @param[in] s raw token value + @return whether parsing should proceed + */ + virtual bool number_float(number_float_t val, const string_t& s) = 0; - @liveexample{The following code shows the constructor with and without a - null pointer parameter.,basic_json__nullptr_t} + /*! + @brief a string was read + @param[in] val string value + @return whether parsing should proceed + */ + virtual bool string(string_t& val) = 0; - @since version 1.0.0 + /*! + @brief the beginning of an object was read + @param[in] elements number of object elements or no_limit if unknown + @return whether parsing should proceed + @note binary formats may report the number of elements */ - basic_json(std::nullptr_t = nullptr) noexcept - : basic_json(value_t::null) - { - assert_invariant(); - } + virtual bool start_object(std::size_t elements = no_limit) = 0; /*! - @brief create a JSON value + @brief an object key was read + @param[in] val object key + @return whether parsing should proceed + */ + virtual bool key(string_t& val) = 0; - This is a "catch all" constructor for all compatible JSON types; that is, - types for which a `to_json()` method exsits. The constructor forwards the - parameter @a val to that method (to `json_serializer::to_json` method - with `U = uncvref_t`, to be exact). + /*! + @brief the end of an object was read + @return whether parsing should proceed + */ + virtual bool end_object() = 0; - Template type @a CompatibleType includes, but is not limited to, the - following types: - - **arrays**: @ref array_t and all kinds of compatible containers such as - `std::vector`, `std::deque`, `std::list`, `std::forward_list`, - `std::array`, `std::set`, `std::unordered_set`, `std::multiset`, and - `unordered_multiset` with a `value_type` from which a @ref basic_json - value can be constructed. - - **objects**: @ref object_t and all kinds of compatible associative - containers such as `std::map`, `std::unordered_map`, `std::multimap`, - and `std::unordered_multimap` with a `key_type` compatible to - @ref string_t and a `value_type` from which a @ref basic_json value can - be constructed. - - **strings**: @ref string_t, string literals, and all compatible string - containers can be used. - - **numbers**: @ref number_integer_t, @ref number_unsigned_t, - @ref number_float_t, and all convertible number types such as `int`, - `size_t`, `int64_t`, `float` or `double` can be used. - - **boolean**: @ref boolean_t / `bool` can be used. + /*! + @brief the beginning of an array was read + @param[in] elements number of array elements or no_limit if unknown + @return whether parsing should proceed + @note binary formats may report the number of elements + */ + virtual bool start_array(std::size_t elements = no_limit) = 0; - See the examples below. + /*! + @brief the end of an array was read + @return whether parsing should proceed + */ + virtual bool end_array() = 0; - @tparam CompatibleType a type such that: - - @a CompatibleType is not derived from `std::istream`, - - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move - constructors), - - @a CompatibleType is not a @ref basic_json nested type (e.g., - @ref json_pointer, @ref iterator, etc ...) - - @ref @ref json_serializer has a - `to_json(basic_json_t&, CompatibleType&&)` method + /*! + @brief a parse error occurred + @param[in] position the position in the input where the error occurs + @param[in] last_token the last read token + @param[in] error_msg a detailed error message + @return whether parsing should proceed (must return false) + */ + virtual bool parse_error(std::size_t position, + const std::string& last_token, + const detail::exception& ex) = 0; - @tparam U = `uncvref_t` + virtual ~json_sax() = default; +}; - @param[in] val the value to be forwarded - @complexity Usually linear in the size of the passed @a val, also - depending on the implementation of the called `to_json()` - method. +namespace detail +{ +/*! +@brief SAX implementation to create a JSON value from SAX events - @throw what `json_serializer::to_json()` throws +This class implements the @ref json_sax interface and processes the SAX events +to create a JSON value which makes it basically a DOM parser. The structure or +hierarchy of the JSON value is managed by the stack `ref_stack` which contains +a pointer to the respective array or object for each recursion depth. - @liveexample{The following code shows the constructor with several - compatible types.,basic_json__CompatibleType} +After successful parsing, the value that is passed by reference to the +constructor contains the parsed value. - @since version 2.1.0 +@tparam BasicJsonType the JSON type +*/ +template +class json_sax_dom_parser : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + + /*! + @param[in, out] r reference to a JSON value that is manipulated while + parsing + @param[in] allow_exceptions_ whether parse errors yield exceptions */ - template, - detail::enable_if_t::value and - not std::is_same::value and - not detail::is_basic_json_nested_type< - basic_json_t, U>::value and - detail::has_to_json::value, - int> = 0> - basic_json(CompatibleType && val) noexcept(noexcept(JSONSerializer::to_json( - std::declval(), std::forward(val)))) + json_sax_dom_parser(BasicJsonType& r, const bool allow_exceptions_ = true) + : root(r), allow_exceptions(allow_exceptions_) + {} + + bool null() override { - JSONSerializer::to_json(*this, std::forward(val)); - assert_invariant(); + handle_value(nullptr); + return true; } - /*! - @brief create a container (array or object) from an initializer list - - Creates a JSON value of type array or object from the passed initializer - list @a init. In case @a type_deduction is `true` (default), the type of - the JSON value to be created is deducted from the initializer list @a init - according to the following rules: + bool boolean(bool val) override + { + handle_value(val); + return true; + } - 1. If the list is empty, an empty JSON object value `{}` is created. - 2. If the list consists of pairs whose first element is a string, a JSON - object value is created where the first elements of the pairs are - treated as keys and the second elements are as values. - 3. In all other cases, an array is created. + bool number_integer(number_integer_t val) override + { + handle_value(val); + return true; + } - The rules aim to create the best fit between a C++ initializer list and - JSON values. The rationale is as follows: - - 1. The empty initializer list is written as `{}` which is exactly an empty - JSON object. - 2. C++ has now way of describing mapped types other than to list a list of - pairs. As JSON requires that keys must be of type string, rule 2 is the - weakest constraint one can pose on initializer lists to interpret them - as an object. - 3. In all other cases, the initializer list could not be interpreted as - JSON object type, so interpreting it as JSON array type is safe. + bool number_unsigned(number_unsigned_t val) override + { + handle_value(val); + return true; + } - With the rules described above, the following JSON values cannot be - expressed by an initializer list: + bool number_float(number_float_t val, const string_t&) override + { + handle_value(val); + return true; + } - - the empty array (`[]`): use @ref array(std::initializer_list) - with an empty initializer list in this case - - arrays whose elements satisfy rule 2: use @ref - array(std::initializer_list) with the same initializer list - in this case + bool string(string_t& val) override + { + handle_value(val); + return true; + } - @note When used without parentheses around an empty initializer list, @ref - basic_json() is called instead of this function, yielding the JSON null - value. + bool start_object(std::size_t len) override + { + ref_stack.push_back(handle_value(BasicJsonType::value_t::object)); - @param[in] init initializer list with JSON values + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive object size: " + std::to_string(len))); + } - @param[in] type_deduction internal parameter; when set to `true`, the type - of the JSON value is deducted from the initializer list @a init; when set - to `false`, the type provided via @a manual_type is forced. This mode is - used by the functions @ref array(std::initializer_list) and - @ref object(std::initializer_list). + return true; + } - @param[in] manual_type internal parameter; when @a type_deduction is set - to `false`, the created JSON value will use the provided type (only @ref - value_t::array and @ref value_t::object are valid); when @a type_deduction - is set to `true`, this parameter has no effect + bool key(string_t& val) override + { + // add null at given key and store the reference for later + object_element = &(ref_stack.back()->m_value.object->operator[](val)); + return true; + } - @throw type_error.301 if @a type_deduction is `false`, @a manual_type is - `value_t::object`, but @a init contains an element which is not a pair - whose first element is a string. In this case, the constructor could not - create an object. If @a type_deduction would have be `true`, an array - would have been created. See @ref object(std::initializer_list) - for an example. + bool end_object() override + { + ref_stack.pop_back(); + return true; + } - @complexity Linear in the size of the initializer list @a init. + bool start_array(std::size_t len) override + { + ref_stack.push_back(handle_value(BasicJsonType::value_t::array)); - @liveexample{The example below shows how JSON values are created from - initializer lists.,basic_json__list_init_t} + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive array size: " + std::to_string(len))); + } - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list + return true; + } - @since version 1.0.0 - */ - basic_json(std::initializer_list init, - bool type_deduction = true, - value_t manual_type = value_t::array) + bool end_array() override { - // check if each element is an array with two elements whose first - // element is a string - bool is_an_object = std::all_of(init.begin(), init.end(), - [](const basic_json & element) - { - return element.is_array() and element.size() == 2 and element[0].is_string(); - }); + ref_stack.pop_back(); + return true; + } - // adjust type if type deduction is not wanted - if (not type_deduction) + bool parse_error(std::size_t, const std::string&, + const detail::exception& ex) override + { + errored = true; + if (allow_exceptions) { - // if array is wanted, do not create an object though possible - if (manual_type == value_t::array) - { - is_an_object = false; - } - - // if object is wanted but impossible, throw an exception - if (manual_type == value_t::object and not is_an_object) + // determine the proper exception type from the id + switch ((ex.id / 100) % 100) { - JSON_THROW(type_error::create(301, "cannot create object from initializer list")); + case 1: + JSON_THROW(*reinterpret_cast(&ex)); + case 2: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 3: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 4: + JSON_THROW(*reinterpret_cast(&ex)); + case 5: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + default: + assert(false); // LCOV_EXCL_LINE } } + return false; + } - if (is_an_object) - { - // the initializer list is a list of pairs -> create object - m_type = value_t::object; - m_value = value_t::object; + constexpr bool is_errored() const + { + return errored; + } - std::for_each(init.begin(), init.end(), [this](const basic_json & element) - { - m_value.object->emplace(*(element[0].m_value.string), element[1]); - }); + private: + /*! + @invariant If the ref stack is empty, then the passed value will be the new + root. + @invariant If the ref stack contains a value, then it is an array or an + object to which we can add elements + */ + template + BasicJsonType* handle_value(Value&& v) + { + if (ref_stack.empty()) + { + root = BasicJsonType(std::forward(v)); + return &root; } else { - // the initializer list describes an array -> create array - m_type = value_t::array; - m_value.array = create(init); + assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->emplace_back(std::forward(v)); + return &(ref_stack.back()->m_value.array->back()); + } + else + { + assert(object_element); + *object_element = BasicJsonType(std::forward(v)); + return object_element; + } } - - assert_invariant(); } - /*! - @brief explicitly create an array from an initializer list - - Creates a JSON array value from a given initializer list. That is, given a - list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the - initializer list is empty, the empty array `[]` is created. + /// the parsed JSON value + BasicJsonType& root; + /// stack to model hierarchy of values + std::vector ref_stack; + /// helper to hold the reference for the next object element + BasicJsonType* object_element = nullptr; + /// whether a syntax error occurred + bool errored = false; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; +}; - @note This function is only needed to express two edge cases that cannot - be realized with the initializer list constructor (@ref - basic_json(std::initializer_list, bool, value_t)). These cases - are: - 1. creating an array whose elements are all pairs whose first element is a - string -- in this case, the initializer list constructor would create an - object, taking the first elements as keys - 2. creating an empty array -- passing the empty initializer list to the - initializer list constructor yields an empty object +template +class json_sax_dom_callback_parser : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + using parser_callback_t = typename BasicJsonType::parser_callback_t; + using parse_event_t = typename BasicJsonType::parse_event_t; + + json_sax_dom_callback_parser(BasicJsonType& r, + const parser_callback_t cb, + const bool allow_exceptions_ = true) + : root(r), callback(cb), allow_exceptions(allow_exceptions_) + { + keep_stack.push_back(true); + } - @param[in] init initializer list with JSON values to create an array from - (optional) + bool null() override + { + handle_value(nullptr); + return true; + } - @return JSON array value + bool boolean(bool val) override + { + handle_value(val); + return true; + } - @complexity Linear in the size of @a init. + bool number_integer(number_integer_t val) override + { + handle_value(val); + return true; + } - @liveexample{The following code shows an example for the `array` - function.,array} + bool number_unsigned(number_unsigned_t val) override + { + handle_value(val); + return true; + } - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref object(std::initializer_list) -- create a JSON object - value from an initializer list + bool number_float(number_float_t val, const string_t&) override + { + handle_value(val); + return true; + } - @since version 1.0.0 - */ - static basic_json array(std::initializer_list init = - std::initializer_list()) + bool string(string_t& val) override { - return basic_json(init, false, value_t::array); + handle_value(val); + return true; } - /*! - @brief explicitly create an object from an initializer list + bool start_object(std::size_t len) override + { + // check callback for object start + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::object_start, discarded); + keep_stack.push_back(keep); - Creates a JSON object value from a given initializer list. The initializer - lists elements must be pairs, and their first elements must be strings. If - the initializer list is empty, the empty object `{}` is created. + auto val = handle_value(BasicJsonType::value_t::object, true); + ref_stack.push_back(val.second); - @note This function is only added for symmetry reasons. In contrast to the - related function @ref array(std::initializer_list), there are - no cases which can only be expressed by this function. That is, any - initializer list @a init can also be passed to the initializer list - constructor @ref basic_json(std::initializer_list, bool, value_t). + // check object limit + if (ref_stack.back()) + { + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive object size: " + std::to_string(len))); + } + } - @param[in] init initializer list to create an object from (optional) + return true; + } - @return JSON object value + bool key(string_t& val) override + { + BasicJsonType k = BasicJsonType(val); - @throw type_error.301 if @a init is not a list of pairs whose first - elements are strings. In this case, no object can be created. When such a - value is passed to @ref basic_json(std::initializer_list, bool, value_t), - an array would have been created from the passed initializer list @a init. - See example below. + // check callback for key + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::key, k); + key_keep_stack.push_back(keep); - @complexity Linear in the size of @a init. + // add discarded value at given key and store the reference for later + if (keep and ref_stack.back()) + { + object_element = &(ref_stack.back()->m_value.object->operator[](val) = discarded); + } - @liveexample{The following code shows an example for the `object` - function.,object} + return true; + } - @sa @ref basic_json(std::initializer_list, bool, value_t) -- - create a JSON value from an initializer list - @sa @ref array(std::initializer_list) -- create a JSON array - value from an initializer list + bool end_object() override + { + if (ref_stack.back()) + { + if (not callback(static_cast(ref_stack.size()) - 1, parse_event_t::object_end, *ref_stack.back())) + { + // discard object + *ref_stack.back() = discarded; + } + } - @since version 1.0.0 - */ - static basic_json object(std::initializer_list init = - std::initializer_list()) + assert(not ref_stack.empty()); + assert(not keep_stack.empty()); + ref_stack.pop_back(); + keep_stack.pop_back(); + + if (not ref_stack.empty() and ref_stack.back()) + { + // remove discarded value + if (ref_stack.back()->is_object()) + { + for (auto it = ref_stack.back()->begin(); it != ref_stack.back()->end(); ++it) + { + if (it->is_discarded()) + { + ref_stack.back()->erase(it); + break; + } + } + } + } + + return true; + } + + bool start_array(std::size_t len) override { - return basic_json(init, false, value_t::object); + const bool keep = callback(static_cast(ref_stack.size()), parse_event_t::array_start, discarded); + keep_stack.push_back(keep); + + auto val = handle_value(BasicJsonType::value_t::array, true); + ref_stack.push_back(val.second); + + // check array limit + if (ref_stack.back()) + { + if (JSON_UNLIKELY(len != json_sax::no_limit and len > ref_stack.back()->max_size())) + { + JSON_THROW(out_of_range::create(408, + "excessive array size: " + std::to_string(len))); + } + } + + return true; } - /*! - @brief construct an array with count copies of given value + bool end_array() override + { + bool keep = true; - Constructs a JSON array value by creating @a cnt copies of a passed value. - In case @a cnt is `0`, an empty array is created. As postcondition, - `std::distance(begin(),end()) == cnt` holds. + if (ref_stack.back()) + { + keep = callback(static_cast(ref_stack.size()) - 1, parse_event_t::array_end, *ref_stack.back()); + if (not keep) + { + // discard array + *ref_stack.back() = discarded; + } + } - @param[in] cnt the number of JSON copies of @a val to create - @param[in] val the JSON value to copy + assert(not ref_stack.empty()); + assert(not keep_stack.empty()); + ref_stack.pop_back(); + keep_stack.pop_back(); - @complexity Linear in @a cnt. + // remove discarded value + if (not keep and not ref_stack.empty()) + { + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->pop_back(); + } + } - @liveexample{The following code shows examples for the @ref - basic_json(size_type\, const basic_json&) - constructor.,basic_json__size_type_basic_json} + return true; + } - @since version 1.0.0 - */ - basic_json(size_type cnt, const basic_json& val) - : m_type(value_t::array) + bool parse_error(std::size_t, const std::string&, + const detail::exception& ex) override { - m_value.array = create(cnt, val); - assert_invariant(); + errored = true; + if (allow_exceptions) + { + // determine the proper exception type from the id + switch ((ex.id / 100) % 100) + { + case 1: + JSON_THROW(*reinterpret_cast(&ex)); + case 2: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 3: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + case 4: + JSON_THROW(*reinterpret_cast(&ex)); + case 5: + JSON_THROW(*reinterpret_cast(&ex)); // LCOV_EXCL_LINE + default: + assert(false); // LCOV_EXCL_LINE + } + } + return false; } - /*! - @brief construct a JSON container given an iterator range + constexpr bool is_errored() const + { + return errored; + } - Constructs the JSON value with the contents of the range `[first, last)`. - The semantics depends on the different types a JSON value can have: - - In case of primitive types (number, boolean, or string), @a first must - be `begin()` and @a last must be `end()`. In this case, the value is - copied. Otherwise, invalid_iterator.204 is thrown. - - In case of structured types (array, object), the constructor behaves as - similar versions for `std::vector`. - - In case of a null type, invalid_iterator.206 is thrown. + private: + /*! + @param[in] v value to add to the JSON value we build during parsing + @param[in] skip_callback whether we should skip calling the callback + function; this is required after start_array() and + start_object() SAX events, because otherwise we would call the + callback function with an empty array or object, respectively. + + @invariant If the ref stack is empty, then the passed value will be the new + root. + @invariant If the ref stack contains a value, then it is an array or an + object to which we can add elements + + @return pair of boolean (whether value should be kept) and pointer (to the + passed value in the ref_stack hierarchy; nullptr if not kept) + */ + template + std::pair handle_value(Value&& v, const bool skip_callback = false) + { + assert(not keep_stack.empty()); - @tparam InputIT an input iterator type (@ref iterator or @ref - const_iterator) + // do not handle this value if we know it would be added to a discarded + // container + if (not keep_stack.back()) + { + return {false, nullptr}; + } - @param[in] first begin of the range to copy from (included) - @param[in] last end of the range to copy from (excluded) + // create value + auto value = BasicJsonType(std::forward(v)); - @pre Iterators @a first and @a last must be initialized. **This - precondition is enforced with an assertion.** + // check callback + const bool keep = skip_callback or callback(static_cast(ref_stack.size()), parse_event_t::value, value); - @pre Range `[first, last)` is valid. Usually, this precondition cannot be - checked efficiently. Only certain edge cases are detected; see the - description of the exceptions below. + // do not handle this value if we just learnt it shall be discarded + if (not keep) + { + return {false, nullptr}; + } - @throw invalid_iterator.201 if iterators @a first and @a last are not - compatible (i.e., do not belong to the same JSON value). In this case, - the range `[first, last)` is undefined. - @throw invalid_iterator.204 if iterators @a first and @a last belong to a - primitive type (number, boolean, or string), but @a first does not point - to the first element any more. In this case, the range `[first, last)` is - undefined. See example code below. - @throw invalid_iterator.206 if iterators @a first and @a last belong to a - null value. In this case, the range `[first, last)` is undefined. - - @complexity Linear in distance between @a first and @a last. - - @liveexample{The example below shows several ways to create JSON values by - specifying a subrange with iterators.,basic_json__InputIt_InputIt} - - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type = 0> - basic_json(InputIT first, InputIT last) - { - assert(first.m_object != nullptr); - assert(last.m_object != nullptr); - - // make sure iterator fits the current value - if (first.m_object != last.m_object) + if (ref_stack.empty()) { - JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); + root = std::move(value); + return {true, &root}; } - - // copy type from first iterator - m_type = first.m_object->m_type; - - // check if iterator range is complete for primitive values - switch (m_type) + else { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: + assert(ref_stack.back()->is_array() or ref_stack.back()->is_object()); + if (ref_stack.back()->is_array()) + { + ref_stack.back()->m_value.array->push_back(std::move(value)); + return {true, &(ref_stack.back()->m_value.array->back())}; + } + else { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) + // check if we should store an element for the current key + assert(not key_keep_stack.empty()); + const bool store_element = key_keep_stack.back(); + key_keep_stack.pop_back(); + + if (not store_element) { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + return {false, nullptr}; } - break; - } - default: - { - break; + assert(object_element); + *object_element = std::move(value); + return {true, object_element}; } } + } - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = first.m_object->m_value.number_integer; - break; - } + /// the parsed JSON value + BasicJsonType& root; + /// stack to model hierarchy of values + std::vector ref_stack; + /// stack to manage which values to keep + std::vector keep_stack; + /// stack to manage which object keys to keep + std::vector key_keep_stack; + /// helper to hold the reference for the next object element + BasicJsonType* object_element = nullptr; + /// whether a syntax error occurred + bool errored = false; + /// callback function + const parser_callback_t callback = nullptr; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; + /// a discarded value for the callback + BasicJsonType discarded = BasicJsonType::value_t::discarded; +}; - case value_t::number_unsigned: - { - m_value.number_unsigned = first.m_object->m_value.number_unsigned; - break; - } +template +class json_sax_acceptor : public json_sax +{ + public: + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; - case value_t::number_float: - { - m_value.number_float = first.m_object->m_value.number_float; - break; - } + bool null() override + { + return true; + } - case value_t::boolean: - { - m_value.boolean = first.m_object->m_value.boolean; - break; - } + bool boolean(bool) override + { + return true; + } - case value_t::string: - { - m_value = *first.m_object->m_value.string; - break; - } + bool number_integer(number_integer_t) override + { + return true; + } - case value_t::object: - { - m_value.object = create(first.m_it.object_iterator, - last.m_it.object_iterator); - break; - } + bool number_unsigned(number_unsigned_t) override + { + return true; + } - case value_t::array: - { - m_value.array = create(first.m_it.array_iterator, - last.m_it.array_iterator); - break; - } + bool number_float(number_float_t, const string_t&) override + { + return true; + } - default: - { - JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + - first.m_object->type_name())); - } - } + bool string(string_t&) override + { + return true; + } - assert_invariant(); + bool start_object(std::size_t) override + { + return true; } + bool key(string_t&) override + { + return true; + } - /////////////////////////////////////// - // other constructors and destructor // - /////////////////////////////////////// + bool end_object() override + { + return true; + } - /*! - @brief copy constructor + bool start_array(std::size_t) override + { + return true; + } - Creates a copy of a given JSON value. + bool end_array() override + { + return true; + } - @param[in] other the JSON value to copy + bool parse_error(std::size_t, const std::string&, const detail::exception&) override + { + return false; + } +}; +} - @complexity Linear in the size of @a other. +} - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - As postcondition, it holds: `other == basic_json(other)`. +// #include - @liveexample{The following code shows an example for the copy - constructor.,basic_json__basic_json} +// #include - @since version 1.0.0 - */ - basic_json(const basic_json& other) - : m_type(other.m_type) + +namespace nlohmann +{ +namespace detail +{ +//////////// +// parser // +//////////// + +/*! +@brief syntax analysis + +This class implements a recursive decent parser. +*/ +template +class parser +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + using lexer_t = lexer; + using token_type = typename lexer_t::token_type; + + public: + enum class parse_event_t : uint8_t { - // check of passed value is valid - other.assert_invariant(); + /// the parser read `{` and started to process a JSON object + object_start, + /// the parser read `}` and finished processing a JSON object + object_end, + /// the parser read `[` and started to process a JSON array + array_start, + /// the parser read `]` and finished processing a JSON array + array_end, + /// the parser read a key of a value in an object + key, + /// the parser finished reading a JSON value + value + }; - switch (m_type) - { - case value_t::object: - { - m_value = *other.m_value.object; - break; - } + using json_sax_t = json_sax; - case value_t::array: - { - m_value = *other.m_value.array; - break; - } + using parser_callback_t = + std::function; - case value_t::string: - { - m_value = *other.m_value.string; - break; - } + /// a parser reading from an input adapter + explicit parser(detail::input_adapter_t&& adapter, + const parser_callback_t cb = nullptr, + const bool allow_exceptions_ = true) + : callback(cb), m_lexer(std::move(adapter)), allow_exceptions(allow_exceptions_) + { + // read first token + get_token(); + } - case value_t::boolean: + /*! + @brief public parser interface + + @param[in] strict whether to expect the last token to be EOF + @param[in,out] result parsed JSON value + + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails + */ + void parse(const bool strict, BasicJsonType& result) + { + if (callback) + { + json_sax_dom_callback_parser sdp(result, callback, allow_exceptions); + sax_parse_internal(&sdp); + result.assert_invariant(); + + // in strict mode, input must be completely read + if (strict and (get_token() != token_type::end_of_input)) { - m_value = other.m_value.boolean; - break; + sdp.parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); } - case value_t::number_integer: + // in case of an error, return discarded value + if (sdp.is_errored()) { - m_value = other.m_value.number_integer; - break; + result = value_t::discarded; + return; } - case value_t::number_unsigned: + // set top-level value to null if it was discarded by the callback + // function + if (result.is_discarded()) { - m_value = other.m_value.number_unsigned; - break; + result = nullptr; } + } + else + { + json_sax_dom_parser sdp(result, allow_exceptions); + sax_parse_internal(&sdp); + result.assert_invariant(); - case value_t::number_float: + // in strict mode, input must be completely read + if (strict and (get_token() != token_type::end_of_input)) { - m_value = other.m_value.number_float; - break; + sdp.parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); } - default: + // in case of an error, return discarded value + if (sdp.is_errored()) { - break; + result = value_t::discarded; + return; } } - - assert_invariant(); } /*! - @brief move constructor - - Move constructor. Constructs a JSON value with the contents of the given - value @a other using move semantics. It "steals" the resources from @a - other and leaves it as JSON null value. - - @param[in,out] other value to move to this object + @brief public accept interface - @post @a other is a JSON null value - - @complexity Constant. - - @liveexample{The code below shows the move constructor explicitly called - via std::move.,basic_json__moveconstructor} - - @since version 1.0.0 + @param[in] strict whether to expect the last token to be EOF + @return whether the input is a proper JSON text */ - basic_json(basic_json&& other) noexcept - : m_type(std::move(other.m_type)), - m_value(std::move(other.m_value)) + bool accept(const bool strict = true) { - // check that passed value is valid - other.assert_invariant(); + json_sax_acceptor sax_acceptor; + return sax_parse(&sax_acceptor, strict); + } - // invalidate payload - other.m_type = value_t::null; - other.m_value = {}; + bool sax_parse(json_sax_t* sax, const bool strict = true) + { + const bool result = sax_parse_internal(sax); - assert_invariant(); + // strict mode: next byte must be EOF + if (result and strict and (get_token() != token_type::end_of_input)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input))); + } + + return result; } - /*! - @brief copy assignment + private: + bool sax_parse_internal(json_sax_t* sax) + { + // stack to remember the hieararchy of structured values we are parsing + // true = array; false = object + std::vector states; + // value to avoid a goto (see comment where set to true) + bool skip_to_state_evaluation = false; - Copy assignment operator. Copies a JSON value via the "copy and swap" - strategy: It is expressed in terms of the copy constructor, destructor, - and the swap() member function. + while (true) + { + if (not skip_to_state_evaluation) + { + // invariant: get_token() was called before each iteration + switch (last_token) + { + case token_type::begin_object: + { + if (JSON_UNLIKELY(not sax->start_object())) + { + return false; + } - @param[in] other value to copy from + // closing } -> we are done + if (get_token() == token_type::end_object) + { + if (JSON_UNLIKELY(not sax->end_object())) + { + return false; + } + break; + } - @complexity Linear. + // parse key + if (JSON_UNLIKELY(last_token != token_type::value_string)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::value_string))); + } + else + { + if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) + { + return false; + } + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. + // parse separator (:) + if (JSON_UNLIKELY(get_token() != token_type::name_separator)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::name_separator))); + } - @liveexample{The code below shows and example for the copy assignment. It - creates a copy of value `a` which is then swapped with `b`. Finally\, the - copy of `a` (which is the null value after the swap) is - destroyed.,basic_json__copyassignment} + // remember we are now inside an object + states.push_back(false); - @since version 1.0.0 - */ - reference& operator=(basic_json other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - // check that passed value is valid - other.assert_invariant(); + // parse values + get_token(); + continue; + } - using std::swap; - swap(m_type, other.m_type); - swap(m_value, other.m_value); + case token_type::begin_array: + { + if (JSON_UNLIKELY(not sax->start_array())) + { + return false; + } - assert_invariant(); - return *this; - } + // closing ] -> we are done + if (get_token() == token_type::end_array) + { + if (JSON_UNLIKELY(not sax->end_array())) + { + return false; + } + break; + } - /*! - @brief destructor + // remember we are now inside an array + states.push_back(true); - Destroys the JSON value and frees all allocated memory. + // parse values (no need to call get_token) + continue; + } - @complexity Linear. + case token_type::value_float: + { + const auto res = m_lexer.get_number_float(); - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is linear. - - All stored elements are destroyed and all memory is freed. + if (JSON_UNLIKELY(not std::isfinite(res))) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); + } + else + { + if (JSON_UNLIKELY(not sax->number_float(res, m_lexer.get_string()))) + { + return false; + } + break; + } + } - @since version 1.0.0 - */ - ~basic_json() - { - assert_invariant(); + case token_type::literal_false: + { + if (JSON_UNLIKELY(not sax->boolean(false))) + { + return false; + } + break; + } - switch (m_type) - { - case value_t::object: - { - AllocatorType alloc; - alloc.destroy(m_value.object); - alloc.deallocate(m_value.object, 1); - break; - } + case token_type::literal_null: + { + if (JSON_UNLIKELY(not sax->null())) + { + return false; + } + break; + } - case value_t::array: - { - AllocatorType alloc; - alloc.destroy(m_value.array); - alloc.deallocate(m_value.array, 1); - break; - } + case token_type::literal_true: + { + if (JSON_UNLIKELY(not sax->boolean(true))) + { + return false; + } + break; + } - case value_t::string: - { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - break; - } + case token_type::value_integer: + { + if (JSON_UNLIKELY(not sax->number_integer(m_lexer.get_number_integer()))) + { + return false; + } + break; + } - default: - { - // all other types need no specific destructor - break; - } - } - } + case token_type::value_string: + { + if (JSON_UNLIKELY(not sax->string(m_lexer.get_string()))) + { + return false; + } + break; + } - /// @} + case token_type::value_unsigned: + { + if (JSON_UNLIKELY(not sax->number_unsigned(m_lexer.get_number_unsigned()))) + { + return false; + } + break; + } - public: - /////////////////////// - // object inspection // - /////////////////////// + case token_type::parse_error: + { + // using "uninitialized" to avoid "expected" message + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::uninitialized))); + } - /// @name object inspection - /// Functions to inspect the type of a JSON value. - /// @{ + default: // the last token was unexpected + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::literal_or_value))); + } + } + } + else + { + skip_to_state_evaluation = false; + } - /*! - @brief serialization + // we reached this line after we successfully parsed a value + if (states.empty()) + { + // empty stack: we reached the end of the hieararchy: done + return true; + } + else + { + if (states.back()) // array + { + // comma -> next value + if (get_token() == token_type::value_separator) + { + // parse a new value + get_token(); + continue; + } - Serialization function for JSON values. The function tries to mimic - Python's `json.dumps()` function, and currently supports its @a indent - parameter. + // closing ] + if (JSON_LIKELY(last_token == token_type::end_array)) + { + if (JSON_UNLIKELY(not sax->end_array())) + { + return false; + } - @param[in] indent If indent is nonnegative, then array elements and object - members will be pretty-printed with that indent level. An indent level of - `0` will only insert newlines. `-1` (the default) selects the most compact - representation. - @param[in] indent_char The character to use for indentation of @a indent is - greate than `0`. The default is ` ` (space). + // We are done with this array. Before we can parse a + // new value, we need to evaluate the new state first. + // By setting skip_to_state_evaluation to false, we + // are effectively jumping to the beginning of this if. + assert(not states.empty()); + states.pop_back(); + skip_to_state_evaluation = true; + continue; + } + else + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_array))); + } + } + else // object + { + // comma -> next value + if (get_token() == token_type::value_separator) + { + // parse key + if (JSON_UNLIKELY(get_token() != token_type::value_string)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::value_string))); + } + else + { + if (JSON_UNLIKELY(not sax->key(m_lexer.get_string()))) + { + return false; + } + } - @return string containing the serialization of the JSON value + // parse separator (:) + if (JSON_UNLIKELY(get_token() != token_type::name_separator)) + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::name_separator))); + } - @complexity Linear. + // parse values + get_token(); + continue; + } - @liveexample{The following example shows the effect of different @a indent - parameters to the result of the serialization.,dump} + // closing } + if (JSON_LIKELY(last_token == token_type::end_object)) + { + if (JSON_UNLIKELY(not sax->end_object())) + { + return false; + } - @see https://docs.python.org/2/library/json.html#json.dump + // We are done with this object. Before we can parse a + // new value, we need to evaluate the new state first. + // By setting skip_to_state_evaluation to false, we + // are effectively jumping to the beginning of this if. + assert(not states.empty()); + states.pop_back(); + skip_to_state_evaluation = true; + continue; + } + else + { + return sax->parse_error(m_lexer.get_position(), + m_lexer.get_token_string(), + parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_object))); + } + } + } + } + } - @since version 1.0.0; indentaction character added in version 3.0.0 - */ - string_t dump(const int indent = -1, const char indent_char = ' ') const + /// get next token from lexer + token_type get_token() { - string_t result; - serializer s(output_adapter::create(result), indent_char); + return (last_token = m_lexer.scan()); + } - if (indent >= 0) + std::string exception_message(const token_type expected) + { + std::string error_msg = "syntax error - "; + if (last_token == token_type::parse_error) { - s.dump(*this, true, static_cast(indent)); + error_msg += std::string(m_lexer.get_error_message()) + "; last read: '" + + m_lexer.get_token_string() + "'"; } else { - s.dump(*this, false, 0); + error_msg += "unexpected " + std::string(lexer_t::token_type_name(last_token)); } - return result; + if (expected != token_type::uninitialized) + { + error_msg += "; expected " + std::string(lexer_t::token_type_name(expected)); + } + + return error_msg; } - /*! - @brief return the type of the JSON value (explicit) + private: + /// callback function + const parser_callback_t callback = nullptr; + /// the type of the last read token + token_type last_token = token_type::uninitialized; + /// the lexer + lexer_t m_lexer; + /// whether to throw exceptions in case of errors + const bool allow_exceptions = true; +}; +} +} - Return the type of the JSON value as a value from the @ref value_t - enumeration. +// #include - @return the type of the JSON value - @complexity Constant. +#include // ptrdiff_t +#include // numeric_limits - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +namespace nlohmann +{ +namespace detail +{ +/* +@brief an iterator for primitive JSON types - @liveexample{The following code exemplifies `type()` for all JSON - types.,type} +This class models an iterator for primitive JSON types (boolean, number, +string). It's only purpose is to allow the iterator/const_iterator classes +to "iterate" over primitive values. Internally, the iterator is modeled by +a `difference_type` variable. Value begin_value (`0`) models the begin, +end_value (`1`) models past the end. +*/ +class primitive_iterator_t +{ + private: + using difference_type = std::ptrdiff_t; + static constexpr difference_type begin_value = 0; + static constexpr difference_type end_value = begin_value + 1; - @since version 1.0.0 - */ - constexpr value_t type() const noexcept + /// iterator as signed integer type + difference_type m_it = (std::numeric_limits::min)(); + + public: + constexpr difference_type get_value() const noexcept { - return m_type; + return m_it; } - /*! - @brief return whether type is primitive - - This function returns true iff the JSON type is primitive (string, number, - boolean, or null). + /// set iterator to a defined beginning + void set_begin() noexcept + { + m_it = begin_value; + } - @return `true` if type is primitive (string, number, boolean, or null), - `false` otherwise. - - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - - @liveexample{The following code exemplifies `is_primitive()` for all JSON - types.,is_primitive} - - @sa @ref is_structured() -- returns whether JSON value is structured - @sa @ref is_null() -- returns whether JSON value is `null` - @sa @ref is_string() -- returns whether JSON value is a string - @sa @ref is_boolean() -- returns whether JSON value is a boolean - @sa @ref is_number() -- returns whether JSON value is a number + /// set iterator to a defined past the end + void set_end() noexcept + { + m_it = end_value; + } - @since version 1.0.0 - */ - constexpr bool is_primitive() const noexcept + /// return whether the iterator can be dereferenced + constexpr bool is_begin() const noexcept { - return is_null() or is_string() or is_boolean() or is_number(); + return m_it == begin_value; } - /*! - @brief return whether type is structured + /// return whether the iterator is at end + constexpr bool is_end() const noexcept + { + return m_it == end_value; + } - This function returns true iff the JSON type is structured (array or - object). + friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it == rhs.m_it; + } - @return `true` if type is structured (array or object), `false` otherwise. + friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it < rhs.m_it; + } - @complexity Constant. + primitive_iterator_t operator+(difference_type n) noexcept + { + auto result = *this; + result += n; + return result; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept + { + return lhs.m_it - rhs.m_it; + } - @liveexample{The following code exemplifies `is_structured()` for all JSON - types.,is_structured} + primitive_iterator_t& operator++() noexcept + { + ++m_it; + return *this; + } - @sa @ref is_primitive() -- returns whether value is primitive - @sa @ref is_array() -- returns whether value is an array - @sa @ref is_object() -- returns whether value is an object + primitive_iterator_t const operator++(int) noexcept + { + auto result = *this; + ++m_it; + return result; + } - @since version 1.0.0 - */ - constexpr bool is_structured() const noexcept + primitive_iterator_t& operator--() noexcept { - return is_array() or is_object(); + --m_it; + return *this; } - /*! - @brief return whether value is null + primitive_iterator_t const operator--(int) noexcept + { + auto result = *this; + --m_it; + return result; + } - This function returns true iff the JSON value is null. + primitive_iterator_t& operator+=(difference_type n) noexcept + { + m_it += n; + return *this; + } - @return `true` if type is null, `false` otherwise. + primitive_iterator_t& operator-=(difference_type n) noexcept + { + m_it -= n; + return *this; + } +}; +} +} - @complexity Constant. +// #include - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - @liveexample{The following code exemplifies `is_null()` for all JSON - types.,is_null} +// #include - @since version 1.0.0 - */ - constexpr bool is_null() const noexcept - { - return m_type == value_t::null; - } - /*! - @brief return whether value is a boolean +namespace nlohmann +{ +namespace detail +{ +/*! +@brief an iterator value - This function returns true iff the JSON value is a boolean. +@note This structure could easily be a union, but MSVC currently does not allow +unions members with complex constructors, see https://github.com/nlohmann/json/pull/105. +*/ +template struct internal_iterator +{ + /// iterator for JSON objects + typename BasicJsonType::object_t::iterator object_iterator {}; + /// iterator for JSON arrays + typename BasicJsonType::array_t::iterator array_iterator {}; + /// generic iterator for all other types + primitive_iterator_t primitive_iterator {}; +}; +} +} - @return `true` if type is boolean, `false` otherwise. +// #include - @complexity Constant. - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. +#include // not +#include // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next +#include // conditional, is_const, remove_const - @liveexample{The following code exemplifies `is_boolean()` for all JSON - types.,is_boolean} +// #include - @since version 1.0.0 - */ - constexpr bool is_boolean() const noexcept - { - return m_type == value_t::boolean; - } +// #include - /*! - @brief return whether value is a number +// #include - This function returns true iff the JSON value is a number. This includes - both integer and floating-point values. +// #include - @return `true` if type is number (regardless whether integer, unsigned - integer or floating-type), `false` otherwise. +// #include - @complexity Constant. +// #include - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. - @liveexample{The following code exemplifies `is_number()` for all JSON - types.,is_number} +namespace nlohmann +{ +namespace detail +{ +// forward declare, to be able to friend it later on +template class iteration_proxy; - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number +/*! +@brief a template for a bidirectional iterator for the @ref basic_json class - @since version 1.0.0 - */ - constexpr bool is_number() const noexcept - { - return is_number_integer() or is_number_float(); - } +This class implements a both iterators (iterator and const_iterator) for the +@ref basic_json class. - /*! - @brief return whether value is an integer number +@note An iterator is called *initialized* when a pointer to a JSON value has + been set (e.g., by a constructor or a copy assignment). If the iterator is + default-constructed, it is *uninitialized* and most methods are undefined. + **The library uses assertions to detect calls on uninitialized iterators.** - This function returns true iff the JSON value is an integer or unsigned - integer number. This excludes floating-point values. +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). - @return `true` if type is an integer or unsigned integer number, `false` - otherwise. +@since version 1.0.0, simplified in version 2.0.9, change to bidirectional + iterators in version 3.0.0 (see https://github.com/nlohmann/json/issues/593) +*/ +template +class iter_impl +{ + /// allow basic_json to access private members + friend iter_impl::value, typename std::remove_const::type, const BasicJsonType>::type>; + friend BasicJsonType; + friend iteration_proxy; - @complexity Constant. + using object_t = typename BasicJsonType::object_t; + using array_t = typename BasicJsonType::array_t; + // make sure BasicJsonType is basic_json or const basic_json + static_assert(is_basic_json::type>::value, + "iter_impl only accepts (const) basic_json"); - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + public: - @liveexample{The following code exemplifies `is_number_integer()` for all - JSON types.,is_number_integer} + /// The std::iterator class template (used as a base class to provide typedefs) is deprecated in C++17. + /// The C++ Standard has never required user-defined iterators to derive from std::iterator. + /// A user-defined iterator should provide publicly accessible typedefs named + /// iterator_category, value_type, difference_type, pointer, and reference. + /// Note that value_type is required to be non-const, even for constant iterators. + using iterator_category = std::bidirectional_iterator_tag; - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number - @sa @ref is_number_float() -- check if value is a floating-point number + /// the type of the values when the iterator is dereferenced + using value_type = typename BasicJsonType::value_type; + /// a type to represent differences between iterators + using difference_type = typename BasicJsonType::difference_type; + /// defines a pointer to the type iterated over (value_type) + using pointer = typename std::conditional::value, + typename BasicJsonType::const_pointer, + typename BasicJsonType::pointer>::type; + /// defines a reference to the type iterated over (value_type) + using reference = + typename std::conditional::value, + typename BasicJsonType::const_reference, + typename BasicJsonType::reference>::type; + + /// default constructor + iter_impl() = default; - @since version 1.0.0 + /*! + @brief constructor for a given JSON instance + @param[in] object pointer to a JSON object for this iterator + @pre object != nullptr + @post The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_number_integer() const noexcept + explicit iter_impl(pointer object) noexcept : m_object(object) { - return m_type == value_t::number_integer or m_type == value_t::number_unsigned; - } + assert(m_object != nullptr); - /*! - @brief return whether value is an unsigned integer number - - This function returns true iff the JSON value is an unsigned integer - number. This excludes floating-point and (signed) integer values. - - @return `true` if type is an unsigned integer number, `false` otherwise. + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = typename object_t::iterator(); + break; + } - @complexity Constant. + case value_t::array: + { + m_it.array_iterator = typename array_t::iterator(); + break; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + default: + { + m_it.primitive_iterator = primitive_iterator_t(); + break; + } + } + } - @liveexample{The following code exemplifies `is_number_unsigned()` for all - JSON types.,is_number_unsigned} + /*! + @note The conventional copy constructor and copy assignment are implicitly + defined. Combined with the following converting constructor and + assignment, they support: (1) copy from iterator to iterator, (2) + copy from const iterator to const iterator, and (3) conversion from + iterator to const iterator. However conversion from const iterator + to iterator is not defined. + */ - @sa @ref is_number() -- check if value is a number - @sa @ref is_number_integer() -- check if value is an integer or unsigned - integer number - @sa @ref is_number_float() -- check if value is a floating-point number + /*! + @brief converting constructor + @param[in] other non-const iterator to copy from + @note It is not checked whether @a other is initialized. + */ + iter_impl(const iter_impl::type>& other) noexcept + : m_object(other.m_object), m_it(other.m_it) {} - @since version 2.0.0 + /*! + @brief converting assignment + @param[in,out] other non-const iterator to copy from + @return const/non-const iterator + @note It is not checked whether @a other is initialized. */ - constexpr bool is_number_unsigned() const noexcept + iter_impl& operator=(const iter_impl::type>& other) noexcept { - return m_type == value_t::number_unsigned; + m_object = other.m_object; + m_it = other.m_it; + return *this; } + private: /*! - @brief return whether value is a floating-point number - - This function returns true iff the JSON value is a floating-point number. - This excludes integer and unsigned integer values. - - @return `true` if type is a floating-point number, `false` otherwise. + @brief set the iterator to the first value + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + void set_begin() noexcept + { + assert(m_object != nullptr); - @complexity Constant. + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = m_object->m_value.object->begin(); + break; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::array: + { + m_it.array_iterator = m_object->m_value.array->begin(); + break; + } - @liveexample{The following code exemplifies `is_number_float()` for all - JSON types.,is_number_float} + case value_t::null: + { + // set to end so begin()==end() is true: null is empty + m_it.primitive_iterator.set_end(); + break; + } - @sa @ref is_number() -- check if value is number - @sa @ref is_number_integer() -- check if value is an integer number - @sa @ref is_number_unsigned() -- check if value is an unsigned integer - number + default: + { + m_it.primitive_iterator.set_begin(); + break; + } + } + } - @since version 1.0.0 + /*! + @brief set the iterator past the last value + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_number_float() const noexcept + void set_end() noexcept { - return m_type == value_t::number_float; + assert(m_object != nullptr); + + switch (m_object->m_type) + { + case value_t::object: + { + m_it.object_iterator = m_object->m_value.object->end(); + break; + } + + case value_t::array: + { + m_it.array_iterator = m_object->m_value.array->end(); + break; + } + + default: + { + m_it.primitive_iterator.set_end(); + break; + } + } } + public: /*! - @brief return whether value is an object + @brief return a reference to the value pointed to by the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference operator*() const + { + assert(m_object != nullptr); - This function returns true iff the JSON value is an object. + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return m_it.object_iterator->second; + } - @return `true` if type is object, `false` otherwise. + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return *m_it.array_iterator; + } - @complexity Constant. - - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); - @liveexample{The following code exemplifies `is_object()` for all JSON - types.,is_object} + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return *m_object; + } - @since version 1.0.0 - */ - constexpr bool is_object() const noexcept - { - return m_type == value_t::object; + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } } /*! - @brief return whether value is an array - - This function returns true iff the JSON value is an array. + @brief dereference the iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + pointer operator->() const + { + assert(m_object != nullptr); - @return `true` if type is array, `false` otherwise. + switch (m_object->m_type) + { + case value_t::object: + { + assert(m_it.object_iterator != m_object->m_value.object->end()); + return &(m_it.object_iterator->second); + } - @complexity Constant. + case value_t::array: + { + assert(m_it.array_iterator != m_object->m_value.array->end()); + return &*m_it.array_iterator; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.is_begin())) + { + return m_object; + } - @liveexample{The following code exemplifies `is_array()` for all JSON - types.,is_array} + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } - @since version 1.0.0 + /*! + @brief post-increment (it++) + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_array() const noexcept + iter_impl const operator++(int) { - return m_type == value_t::array; + auto result = *this; + ++(*this); + return result; } /*! - @brief return whether value is a string - - This function returns true iff the JSON value is a string. + @brief pre-increment (++it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator++() + { + assert(m_object != nullptr); - @return `true` if type is string, `false` otherwise. + switch (m_object->m_type) + { + case value_t::object: + { + std::advance(m_it.object_iterator, 1); + break; + } - @complexity Constant. + case value_t::array: + { + std::advance(m_it.array_iterator, 1); + break; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + default: + { + ++m_it.primitive_iterator; + break; + } + } - @liveexample{The following code exemplifies `is_string()` for all JSON - types.,is_string} + return *this; + } - @since version 1.0.0 + /*! + @brief post-decrement (it--) + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr bool is_string() const noexcept + iter_impl const operator--(int) { - return m_type == value_t::string; + auto result = *this; + --(*this); + return result; } /*! - @brief return whether value is discarded - - This function returns true iff the JSON value was discarded during parsing - with a callback function (see @ref parser_callback_t). - - @note This function will always be `false` for JSON values after parsing. - That is, discarded values can only occur during parsing, but will be - removed when inside a structured value or replaced by null in other cases. - - @return `true` if type is discarded, `false` otherwise. + @brief pre-decrement (--it) + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator--() + { + assert(m_object != nullptr); - @complexity Constant. + switch (m_object->m_type) + { + case value_t::object: + { + std::advance(m_it.object_iterator, -1); + break; + } - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::array: + { + std::advance(m_it.array_iterator, -1); + break; + } - @liveexample{The following code exemplifies `is_discarded()` for all JSON - types.,is_discarded} + default: + { + --m_it.primitive_iterator; + break; + } + } - @since version 1.0.0 - */ - constexpr bool is_discarded() const noexcept - { - return m_type == value_t::discarded; + return *this; } /*! - @brief return the type of the JSON value (implicit) - - Implicitly return the type of the JSON value as a value from the @ref - value_t enumeration. + @brief comparison: equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator==(const iter_impl& other) const + { + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) + { + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); + } - @return the type of the JSON value + assert(m_object != nullptr); - @complexity Constant. + switch (m_object->m_type) + { + case value_t::object: + return (m_it.object_iterator == other.m_it.object_iterator); - @exceptionsafety No-throw guarantee: this member function never throws - exceptions. + case value_t::array: + return (m_it.array_iterator == other.m_it.array_iterator); - @liveexample{The following code exemplifies the @ref value_t operator for - all JSON types.,operator__value_t} + default: + return (m_it.primitive_iterator == other.m_it.primitive_iterator); + } + } - @since version 1.0.0 + /*! + @brief comparison: not equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - constexpr operator value_t() const noexcept + bool operator!=(const iter_impl& other) const { - return m_type; + return not operator==(other); } - /// @} - - private: - ////////////////// - // value access // - ////////////////// - - /// get a boolean (explicit) - boolean_t get_impl(boolean_t* /*unused*/) const + /*! + @brief comparison: smaller + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<(const iter_impl& other) const { - if (is_boolean()) + // if objects are not the same, the comparison is undefined + if (JSON_UNLIKELY(m_object != other.m_object)) { - return m_value.boolean; + JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); } - JSON_THROW(type_error::create(302, "type must be boolean, but is " + type_name())); - } + assert(m_object != nullptr); - /// get a pointer to the value (object) - object_t* get_impl_ptr(object_t* /*unused*/) noexcept - { - return is_object() ? m_value.object : nullptr; - } + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); - /// get a pointer to the value (object) - constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept - { - return is_object() ? m_value.object : nullptr; - } + case value_t::array: + return (m_it.array_iterator < other.m_it.array_iterator); - /// get a pointer to the value (array) - array_t* get_impl_ptr(array_t* /*unused*/) noexcept - { - return is_array() ? m_value.array : nullptr; + default: + return (m_it.primitive_iterator < other.m_it.primitive_iterator); + } } - /// get a pointer to the value (array) - constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept + /*! + @brief comparison: less than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator<=(const iter_impl& other) const { - return is_array() ? m_value.array : nullptr; + return not other.operator < (*this); } - /// get a pointer to the value (string) - string_t* get_impl_ptr(string_t* /*unused*/) noexcept + /*! + @brief comparison: greater than + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>(const iter_impl& other) const { - return is_string() ? m_value.string : nullptr; + return not operator<=(other); } - /// get a pointer to the value (string) - constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept + /*! + @brief comparison: greater than or equal + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + bool operator>=(const iter_impl& other) const { - return is_string() ? m_value.string : nullptr; + return not operator<(other); } - /// get a pointer to the value (boolean) - boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept + /*! + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator+=(difference_type i) { - return is_boolean() ? &m_value.boolean : nullptr; - } + assert(m_object != nullptr); - /// get a pointer to the value (boolean) - constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept - { - return is_boolean() ? &m_value.boolean : nullptr; - } + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - /// get a pointer to the value (integer number) - number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept - { - return is_number_integer() ? &m_value.number_integer : nullptr; - } + case value_t::array: + { + std::advance(m_it.array_iterator, i); + break; + } - /// get a pointer to the value (integer number) - constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept - { - return is_number_integer() ? &m_value.number_integer : nullptr; + default: + { + m_it.primitive_iterator += i; + break; + } + } + + return *this; } - /// get a pointer to the value (unsigned number) - number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl& operator-=(difference_type i) { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + return operator+=(-i); } - /// get a pointer to the value (unsigned number) - constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept + /*! + @brief add to iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator+(difference_type i) const { - return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + auto result = *this; + result += i; + return result; } - /// get a pointer to the value (floating-point number) - number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept + /*! + @brief addition of distance and iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + friend iter_impl operator+(difference_type i, const iter_impl& it) { - return is_number_float() ? &m_value.number_float : nullptr; + auto result = it; + result += i; + return result; } - /// get a pointer to the value (floating-point number) - constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept + /*! + @brief subtract from iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + iter_impl operator-(difference_type i) const { - return is_number_float() ? &m_value.number_float : nullptr; + auto result = *this; + result -= i; + return result; } /*! - @brief helper function to implement get_ref() - - This funcion helps to implement get_ref() without code duplication for - const and non-const overloads - - @tparam ThisType will be deduced as `basic_json` or `const basic_json` - - @throw type_error.303 if ReferenceType does not match underlying value - type of the current JSON + @brief return difference + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - template - static ReferenceType get_ref_impl(ThisType& obj) + difference_type operator-(const iter_impl& other) const { - // helper type - using PointerType = typename std::add_pointer::type; - - // delegate the call to get_ptr<>() - auto ptr = obj.template get_ptr(); + assert(m_object != nullptr); - if (ptr != nullptr) + switch (m_object->m_type) { - return *ptr; - } + case value_t::object: + JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); + + case value_t::array: + return m_it.array_iterator - other.m_it.array_iterator; - JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + obj.type_name())); + default: + return m_it.primitive_iterator - other.m_it.primitive_iterator; + } } - public: - /// @name value access - /// Direct access to the stored value of a JSON value. - /// @{ - /*! - @brief get special-case overload + @brief access to successor + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference operator[](difference_type n) const + { + assert(m_object != nullptr); - This overloads avoids a lot of template boilerplate, it can be seen as the - identity method + switch (m_object->m_type) + { + case value_t::object: + JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); - @tparam BasicJsonType == @ref basic_json + case value_t::array: + return *std::next(m_it.array_iterator, n); - @return a copy of *this + case value_t::null: + JSON_THROW(invalid_iterator::create(214, "cannot get value")); - @complexity Constant. + default: + { + if (JSON_LIKELY(m_it.primitive_iterator.get_value() == -n)) + { + return *m_object; + } - @since version 2.1.0 + JSON_THROW(invalid_iterator::create(214, "cannot get value")); + } + } + } + + /*! + @brief return the key of an object iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. */ - template < - typename BasicJsonType, - detail::enable_if_t::type, - basic_json_t>::value, - int> = 0 > - basic_json get() const + const typename object_t::key_type& key() const { - return *this; + assert(m_object != nullptr); + + if (JSON_LIKELY(m_object->is_object())) + { + return m_it.object_iterator->first; + } + + JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); } /*! - @brief get a value (explicit) + @brief return the value of an iterator + @pre The iterator is initialized; i.e. `m_object != nullptr`. + */ + reference value() const + { + return operator*(); + } - Explicit type conversion between the JSON value and a compatible value - which is [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. + private: + /// associated JSON instance + pointer m_object = nullptr; + /// the actual iterator of the associated instance + internal_iterator::type> m_it; +}; +} +} - The function is equivalent to executing - @code {.cpp} - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; - @endcode +// #include - This overloads is chosen if: - - @a ValueType is not @ref basic_json, - - @ref json_serializer has a `from_json()` method of the form - `void from_json(const basic_json&, ValueType&)`, and - - @ref json_serializer does not have a `from_json()` method of - the form `ValueType from_json(const basic_json&)` +// #include - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type - @return copy of the JSON value, converted to @a ValueType +#include // ptrdiff_t +#include // reverse_iterator +#include // declval - @throw what @ref json_serializer `from_json()` method throws +namespace nlohmann +{ +namespace detail +{ +////////////////////// +// reverse_iterator // +////////////////////// - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,get__ValueType_const} +/*! +@brief a template for a reverse iterator class - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t < - not std::is_same::value and - detail::has_from_json::value and - not detail::has_non_default_from_json::value, - int > = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval(), std::declval()))) +@tparam Base the base iterator type to reverse. Valid types are @ref +iterator (to create @ref reverse_iterator) and @ref const_iterator (to +create @ref const_reverse_iterator). + +@requirement The class satisfies the following concept requirements: +- +[BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator): + The iterator that can be moved can be moved in both directions (i.e. + incremented and decremented). +- [OutputIterator](https://en.cppreference.com/w/cpp/named_req/OutputIterator): + It is possible to write to the pointed-to element (only if @a Base is + @ref iterator). + +@since version 1.0.0 +*/ +template +class json_reverse_iterator : public std::reverse_iterator +{ + public: + using difference_type = std::ptrdiff_t; + /// shortcut to the reverse iterator adapter + using base_iterator = std::reverse_iterator; + /// the reference type for the pointed-to element + using reference = typename Base::reference; + + /// create reverse iterator from iterator + explicit json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept + : base_iterator(it) {} + + /// create reverse iterator from base class + explicit json_reverse_iterator(const base_iterator& it) noexcept : base_iterator(it) {} + + /// post-increment (it++) + json_reverse_iterator const operator++(int) { - // we cannot static_assert on ValueTypeCV being non-const, because - // there is support for get(), which is why we - // still need the uncvref - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - static_assert(std::is_default_constructible::value, - "types must be DefaultConstructible when used with get()"); + return static_cast(base_iterator::operator++(1)); + } - ValueType ret; - JSONSerializer::from_json(*this, ret); - return ret; + /// pre-increment (++it) + json_reverse_iterator& operator++() + { + return static_cast(base_iterator::operator++()); } - /*! - @brief get a value (explicit); special case + /// post-decrement (it--) + json_reverse_iterator const operator--(int) + { + return static_cast(base_iterator::operator--(1)); + } - Explicit type conversion between the JSON value and a compatible value - which is **not** [CopyConstructible](http://en.cppreference.com/w/cpp/concept/CopyConstructible) - and **not** [DefaultConstructible](http://en.cppreference.com/w/cpp/concept/DefaultConstructible). - The value is converted by calling the @ref json_serializer - `from_json()` method. + /// pre-decrement (--it) + json_reverse_iterator& operator--() + { + return static_cast(base_iterator::operator--()); + } - The function is equivalent to executing - @code {.cpp} - return JSONSerializer::from_json(*this); - @endcode + /// add to iterator + json_reverse_iterator& operator+=(difference_type i) + { + return static_cast(base_iterator::operator+=(i)); + } - This overloads is chosen if: - - @a ValueType is not @ref basic_json and - - @ref json_serializer has a `from_json()` method of the form - `ValueType from_json(const basic_json&)` + /// add to iterator + json_reverse_iterator operator+(difference_type i) const + { + return static_cast(base_iterator::operator+(i)); + } - @note If @ref json_serializer has both overloads of - `from_json()`, this one is chosen. + /// subtract from iterator + json_reverse_iterator operator-(difference_type i) const + { + return static_cast(base_iterator::operator-(i)); + } - @tparam ValueTypeCV the provided value type - @tparam ValueType the returned value type + /// return difference + difference_type operator-(const json_reverse_iterator& other) const + { + return base_iterator(*this) - base_iterator(other); + } - @return copy of the JSON value, converted to @a ValueType + /// access to successor + reference operator[](difference_type n) const + { + return *(this->operator+(n)); + } - @throw what @ref json_serializer `from_json()` method throws + /// return the key of an object iterator + auto key() const -> decltype(std::declval().key()) + { + auto it = --this->base(); + return it.key(); + } - @since version 2.1.0 - */ - template < - typename ValueTypeCV, - typename ValueType = detail::uncvref_t, - detail::enable_if_t::value and - detail::has_non_default_from_json::value, int> = 0 > - ValueType get() const noexcept(noexcept( - JSONSerializer::from_json(std::declval()))) + /// return the value of an iterator + reference value() const { - static_assert(not std::is_reference::value, - "get() cannot be used with reference types, you might want to use get_ref()"); - return JSONSerializer::from_json(*this); + auto it = --this->base(); + return it.operator * (); } +}; +} +} - /*! - @brief get a pointer value (explicit) +// #include - Explicit pointer access to the internally stored JSON value. No copies are - made. - @warning The pointer becomes invalid if the underlying JSON object - changes. +#include // copy +#include // size_t +#include // streamsize +#include // back_inserter +#include // shared_ptr, make_shared +#include // basic_ostream +#include // basic_string +#include // vector - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. +namespace nlohmann +{ +namespace detail +{ +/// abstract output adapter interface +template struct output_adapter_protocol +{ + virtual void write_character(CharType c) = 0; + virtual void write_characters(const CharType* s, std::size_t length) = 0; + virtual ~output_adapter_protocol() = default; +}; - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise +/// a type to simplify interfaces +template +using output_adapter_t = std::shared_ptr>; - @complexity Constant. +/// output adapter for byte vectors +template +class output_vector_adapter : public output_adapter_protocol +{ + public: + explicit output_vector_adapter(std::vector& vec) : v(vec) {} - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get__PointerType} + void write_character(CharType c) override + { + v.push_back(c); + } - @sa @ref get_ptr() for explicit pointer-member access + void write_characters(const CharType* s, std::size_t length) override + { + std::copy(s, s + length, std::back_inserter(v)); + } - @since version 1.0.0 - */ - template::value, int>::type = 0> - PointerType get() noexcept + private: + std::vector& v; +}; + +/// output adapter for output streams +template +class output_stream_adapter : public output_adapter_protocol +{ + public: + explicit output_stream_adapter(std::basic_ostream& s) : stream(s) {} + + void write_character(CharType c) override { - // delegate the call to get_ptr - return get_ptr(); + stream.put(c); } - /*! - @brief get a pointer value (explicit) - @copydoc get() - */ - template::value, int>::type = 0> - constexpr const PointerType get() const noexcept + void write_characters(const CharType* s, std::size_t length) override { - // delegate the call to get_ptr - return get_ptr(); + stream.write(s, static_cast(length)); } - /*! - @brief get a pointer value (implicit) + private: + std::basic_ostream& stream; +}; - Implicit pointer access to the internally stored JSON value. No copies are - made. +/// output adapter for basic_string +template> +class output_string_adapter : public output_adapter_protocol +{ + public: + explicit output_string_adapter(StringType& s) : str(s) {} - @warning Writing data to the pointee of the result yields an undefined - state. + void write_character(CharType c) override + { + str.push_back(c); + } - @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref - object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, - @ref number_unsigned_t, or @ref number_float_t. Enforced by a static - assertion. + void write_characters(const CharType* s, std::size_t length) override + { + str.append(s, length); + } - @return pointer to the internally stored JSON value if the requested - pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + private: + StringType& str; +}; - @complexity Constant. +template> +class output_adapter +{ + public: + output_adapter(std::vector& vec) + : oa(std::make_shared>(vec)) {} - @liveexample{The example below shows how pointers to internal values of a - JSON value can be requested. Note that no type conversions are made and a - `nullptr` is returned if the value and the requested pointer type does not - match.,get_ptr} + output_adapter(std::basic_ostream& s) + : oa(std::make_shared>(s)) {} - @since version 1.0.0 - */ - template::value, int>::type = 0> - PointerType get_ptr() noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); + output_adapter(StringType& s) + : oa(std::make_shared>(s)) {} - // delegate the call to get_impl_ptr<>() - return get_impl_ptr(static_cast(nullptr)); + operator output_adapter_t() + { + return oa; } - /*! - @brief get a pointer value (implicit) - @copydoc get_ptr() - */ - template::value and - std::is_const::type>::value, int>::type = 0> - constexpr const PointerType get_ptr() const noexcept - { - // get the type of the PointerType (remove pointer and const) - using pointee_t = typename std::remove_const::type>::type>::type; - // make sure the type matches the allowed types - static_assert( - std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - or std::is_same::value - , "incompatible pointer type"); + private: + output_adapter_t oa = nullptr; +}; +} +} - // delegate the call to get_impl_ptr<>() const - return get_impl_ptr(static_cast(nullptr)); - } +// #include - /*! - @brief get a reference value (implicit) - Implicit reference access to the internally stored JSON value. No copies - are made. +#include // generate_n +#include // array +#include // assert +#include // ldexp +#include // size_t +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // snprintf +#include // memcpy +#include // back_inserter +#include // numeric_limits +#include // char_traits, string +#include // make_pair, move - @warning Writing data to the referee of the result yields an undefined - state. +// #include - @tparam ReferenceType reference type; must be a reference to @ref array_t, - @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or - @ref number_float_t. Enforced by static assertion. +// #include - @return reference to the internally stored JSON value if the requested - reference type @a ReferenceType fits to the JSON value; throws - type_error.303 otherwise +// #include - @throw type_error.303 in case passed type @a ReferenceType is incompatible - with the stored JSON value; see example below +// #include - @complexity Constant. +// #include - @liveexample{The example shows several calls to `get_ref()`.,get_ref} - @since version 1.1.0 +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary reader // +/////////////////// + +/*! +@brief deserialization of CBOR, MessagePack, and UBJSON values +*/ +template +class binary_reader +{ + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using number_float_t = typename BasicJsonType::number_float_t; + using string_t = typename BasicJsonType::string_t; + using json_sax_t = json_sax; + + public: + /*! + @brief create a binary reader + + @param[in] adapter input adapter to read from */ - template::value, int>::type = 0> - ReferenceType get_ref() + explicit binary_reader(input_adapter_t adapter) : ia(std::move(adapter)) { - // delegate call to get_ref_impl - return get_ref_impl(*this); + assert(ia); } /*! - @brief get a reference value (implicit) - @copydoc get_ref() + @param[in] format the binary format to parse + @param[in] sax_ a SAX event processor + @param[in] strict whether to expect the input to be consumed completed + + @return */ - template::value and - std::is_const::type>::value, int>::type = 0> - ReferenceType get_ref() const + bool sax_parse(const input_format_t format, + json_sax_t* sax_, + const bool strict = true) { - // delegate call to get_ref_impl - return get_ref_impl(*this); - } + sax = sax_; + bool result; - /*! - @brief get a value (implicit) + switch (format) + { + case input_format_t::cbor: + result = parse_cbor_internal(); + break; - Implicit type conversion between the JSON value and a compatible value. - The call is realized by calling @ref get() const. + case input_format_t::msgpack: + result = parse_msgpack_internal(); + break; - @tparam ValueType non-pointer type compatible to the JSON value, for - instance `int` for JSON integer numbers, `bool` for JSON booleans, or - `std::vector` types for JSON arrays. The character type of @ref string_t - as well as an initializer list of this type is excluded to avoid - ambiguities as these types implicitly convert to `std::string`. + case input_format_t::ubjson: + result = parse_ubjson_internal(); + break; - @return copy of the JSON value, converted to type @a ValueType + default: + assert(false); // LCOV_EXCL_LINE + } - @throw type_error.302 in case passed type @a ValueType is incompatible - to the JSON value type (e.g., the JSON value is of type boolean, but a - string is requested); see example below + // strict mode: next byte must be EOF + if (result and strict) + { + if (format == input_format_t::ubjson) + { + get_ignore_noop(); + } + else + { + get(); + } - @complexity Linear in the size of the JSON value. + if (JSON_UNLIKELY(current != std::char_traits::eof())) + { + return sax->parse_error(chars_read, get_token_string(), parse_error::create(110, chars_read, "expected end of input")); + } + } - @liveexample{The example below shows several conversions from JSON values - to other types. There a few things to note: (1) Floating-point numbers can - be converted to integers\, (2) A JSON array can be converted to a standard - `std::vector`\, (3) A JSON object can be converted to C++ - associative containers such as `std::unordered_map`.,operator__ValueType} + return result; + } - @since version 1.0.0 + /*! + @brief determine system byte order + + @return true if and only if system's byte order is little endian + + @note from http://stackoverflow.com/a/1001328/266378 */ - template < typename ValueType, typename std::enable_if < - not std::is_pointer::value and - not std::is_same::value -#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 - and not std::is_same>::value -#endif -#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_MSC_VER) && _MSC_VER >1900 && defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464 - and not std::is_same::value -#endif - , int >::type = 0 > - operator ValueType() const + static constexpr bool little_endianess(int num = 1) noexcept { - // delegate the call to get<>() const - return get(); + return (*reinterpret_cast(&num) == 1); } - /// @} + private: + /*! + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead + + @return whether a valid CBOR value was passed to the SAX parser + */ + bool parse_cbor_internal(const bool get_char = true) + { + switch (get_char ? get() : current) + { + // EOF + case std::char_traits::eof(): + return unexpect_eof(); + + // Integer 0x00..0x17 (0..23) + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + return sax->number_unsigned(static_cast(current)); + + case 0x18: // Unsigned integer (one-byte uint8_t follows) + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } + case 0x19: // Unsigned integer (two-byte uint16_t follows) + { + uint16_t number; + return get_number(number) and sax->number_unsigned(number); + } - //////////////////// - // element access // - //////////////////// + case 0x1A: // Unsigned integer (four-byte uint32_t follows) + { + uint32_t number; + return get_number(number) and sax->number_unsigned(number); + } - /// @name element access - /// Access to the JSON value. - /// @{ + case 0x1B: // Unsigned integer (eight-byte uint64_t follows) + { + uint64_t number; + return get_number(number) and sax->number_unsigned(number); + } - /*! - @brief access specified array element with bounds checking + // Negative integer -1-0x00..-1-0x17 (-1..-24) + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + return sax->number_integer(static_cast(0x20 - 1 - current)); + + case 0x38: // Negative integer (one-byte uint8_t follows) + { + uint8_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - Returns a reference to the element at specified location @a idx, with - bounds checking. + case 0x39: // Negative integer -1-n (two-byte uint16_t follows) + { + uint16_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - @param[in] idx index of the element to access + case 0x3A: // Negative integer -1-n (four-byte uint32_t follows) + { + uint32_t number; + return get_number(number) and sax->number_integer(static_cast(-1) - number); + } - @return reference to the element at index @a idx + case 0x3B: // Negative integer -1-n (eight-byte uint64_t follows) + { + uint64_t number; + return get_number(number) and sax->number_integer(static_cast(-1) + - static_cast(number)); + } - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) + case 0x7F: // UTF-8 string (indefinite length) + { + string_t s; + return get_cbor_string(s) and sax->string(s); + } - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + // array (0x00..0x17 data items follow) + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + return get_cbor_array(static_cast(current & 0x1F)); + + case 0x98: // array (one-byte uint8_t for n follows) + { + uint8_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - @complexity Constant. + case 0x99: // array (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - @since version 1.0.0 + case 0x9A: // array (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_cbor_array(static_cast(len)); + } - @liveexample{The example below shows how array elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__size_type} - */ - reference at(size_type idx) - { - // at only works for arrays - if (is_array()) - { - JSON_TRY + case 0x9B: // array (eight-byte uint64_t for n follow) { - return m_value.array->at(idx); + uint64_t len; + return get_number(len) and get_cbor_array(static_cast(len)); } - JSON_CATCH (std::out_of_range&) + + case 0x9F: // array (indefinite length) + return get_cbor_array(json_sax_t::no_limit); + + // map (0x00..0x17 pairs of data items follow) + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + return get_cbor_object(static_cast(current & 0x1F)); + + case 0xB8: // map (one-byte uint8_t for n follows) { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + uint8_t len; + return get_number(len) and get_cbor_object(static_cast(len)); } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } - } - /*! - @brief access specified array element with bounds checking + case 0xB9: // map (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - Returns a const reference to the element at specified location @a idx, - with bounds checking. + case 0xBA: // map (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - @param[in] idx index of the element to access + case 0xBB: // map (eight-byte uint64_t for n follow) + { + uint64_t len; + return get_number(len) and get_cbor_object(static_cast(len)); + } - @return const reference to the element at index @a idx + case 0xBF: // map (indefinite length) + return get_cbor_object(json_sax_t::no_limit); - @throw type_error.304 if the JSON value is not an array; in this case, - calling `at` with an index makes no sense. See example below. - @throw out_of_range.401 if the index @a idx is out of range of the array; - that is, `idx >= size()`. See example below. + case 0xF4: // false + return sax->boolean(false); - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + case 0xF5: // true + return sax->boolean(true); - @complexity Constant. + case 0xF6: // null + return sax->null(); - @since version 1.0.0 + case 0xF9: // Half-Precision Float (two-byte IEEE 754) + { + const int byte1 = get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + const int byte2 = get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - @liveexample{The example below shows how array elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__size_type_const} - */ - const_reference at(size_type idx) const - { - // at only works for arrays - if (is_array()) - { - JSON_TRY + // code from RFC 7049, Appendix D, Figure 3: + // As half-precision floating-point numbers were only added + // to IEEE 754 in 2008, today's programming platforms often + // still only have limited support for them. It is very + // easy to include at least decoding support for them even + // without such support. An example of a small decoder for + // half-precision floating-point numbers in the C language + // is shown in Fig. 3. + const int half = (byte1 << 8) + byte2; + const double val = [&half] + { + const int exp = (half >> 10) & 0x1F; + const int mant = half & 0x3FF; + assert(0 <= exp and exp <= 32); + assert(0 <= mant and mant <= 1024); + switch (exp) + { + case 0: + return std::ldexp(mant, -24); + case 31: + return (mant == 0) + ? std::numeric_limits::infinity() + : std::numeric_limits::quiet_NaN(); + default: + return std::ldexp(mant + 1024, exp - 25); + } + }(); + return sax->number_float((half & 0x8000) != 0 + ? static_cast(-val) + : static_cast(val), ""); + } + + case 0xFA: // Single-Precision Float (four-byte IEEE 754) { - return m_value.array->at(idx); + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); } - JSON_CATCH (std::out_of_range&) + + case 0xFB: // Double-Precision Float (eight-byte IEEE 754) { - // create better exception explanation - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + double number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } + + default: // anything else (0xFF is handled inside the other types) + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + last_token)); } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); } } /*! - @brief access specified object element with bounds checking + @return whether a valid MessagePack value was passed to the SAX parser + */ + bool parse_msgpack_internal() + { + switch (get()) + { + // EOF + case std::char_traits::eof(): + return unexpect_eof(); + + // positive fixint + case 0x00: + case 0x01: + case 0x02: + case 0x03: + case 0x04: + case 0x05: + case 0x06: + case 0x07: + case 0x08: + case 0x09: + case 0x0A: + case 0x0B: + case 0x0C: + case 0x0D: + case 0x0E: + case 0x0F: + case 0x10: + case 0x11: + case 0x12: + case 0x13: + case 0x14: + case 0x15: + case 0x16: + case 0x17: + case 0x18: + case 0x19: + case 0x1A: + case 0x1B: + case 0x1C: + case 0x1D: + case 0x1E: + case 0x1F: + case 0x20: + case 0x21: + case 0x22: + case 0x23: + case 0x24: + case 0x25: + case 0x26: + case 0x27: + case 0x28: + case 0x29: + case 0x2A: + case 0x2B: + case 0x2C: + case 0x2D: + case 0x2E: + case 0x2F: + case 0x30: + case 0x31: + case 0x32: + case 0x33: + case 0x34: + case 0x35: + case 0x36: + case 0x37: + case 0x38: + case 0x39: + case 0x3A: + case 0x3B: + case 0x3C: + case 0x3D: + case 0x3E: + case 0x3F: + case 0x40: + case 0x41: + case 0x42: + case 0x43: + case 0x44: + case 0x45: + case 0x46: + case 0x47: + case 0x48: + case 0x49: + case 0x4A: + case 0x4B: + case 0x4C: + case 0x4D: + case 0x4E: + case 0x4F: + case 0x50: + case 0x51: + case 0x52: + case 0x53: + case 0x54: + case 0x55: + case 0x56: + case 0x57: + case 0x58: + case 0x59: + case 0x5A: + case 0x5B: + case 0x5C: + case 0x5D: + case 0x5E: + case 0x5F: + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + case 0x78: + case 0x79: + case 0x7A: + case 0x7B: + case 0x7C: + case 0x7D: + case 0x7E: + case 0x7F: + return sax->number_unsigned(static_cast(current)); + + // fixmap + case 0x80: + case 0x81: + case 0x82: + case 0x83: + case 0x84: + case 0x85: + case 0x86: + case 0x87: + case 0x88: + case 0x89: + case 0x8A: + case 0x8B: + case 0x8C: + case 0x8D: + case 0x8E: + case 0x8F: + return get_msgpack_object(static_cast(current & 0x0F)); + + // fixarray + case 0x90: + case 0x91: + case 0x92: + case 0x93: + case 0x94: + case 0x95: + case 0x96: + case 0x97: + case 0x98: + case 0x99: + case 0x9A: + case 0x9B: + case 0x9C: + case 0x9D: + case 0x9E: + case 0x9F: + return get_msgpack_array(static_cast(current & 0x0F)); + + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + { + string_t s; + return get_msgpack_string(s) and sax->string(s); + } - Returns a reference to the element at with specified key @a key, with - bounds checking. + case 0xC0: // nil + return sax->null(); - @param[in] key key of the element to access + case 0xC2: // false + return sax->boolean(false); - @return reference to the element at key @a key + case 0xC3: // true + return sax->boolean(true); - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. - - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. - - @complexity Logarithmic in the size of the container. + case 0xCA: // float 32 + { + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value + case 0xCB: // float 64 + { + double number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - @since version 1.0.0 + case 0xCC: // uint 8 + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } - @liveexample{The example below shows how object elements can be read and - written using `at()`. It also demonstrates the different exceptions that - can be thrown.,at__object_t_key_type} - */ - reference at(const typename object_t::key_type& key) - { - // at only works for objects - if (is_object()) - { - JSON_TRY + case 0xCD: // uint 16 { - return m_value.object->at(key); + uint16_t number; + return get_number(number) and sax->number_unsigned(number); } - JSON_CATCH (std::out_of_range&) + + case 0xCE: // uint 32 { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + uint32_t number; + return get_number(number) and sax->number_unsigned(number); } - } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } - } - /*! - @brief access specified object element with bounds checking + case 0xCF: // uint 64 + { + uint64_t number; + return get_number(number) and sax->number_unsigned(number); + } - Returns a const reference to the element at with specified key @a key, - with bounds checking. + case 0xD0: // int 8 + { + int8_t number; + return get_number(number) and sax->number_integer(number); + } - @param[in] key key of the element to access + case 0xD1: // int 16 + { + int16_t number; + return get_number(number) and sax->number_integer(number); + } - @return const reference to the element at key @a key + case 0xD2: // int 32 + { + int32_t number; + return get_number(number) and sax->number_integer(number); + } - @throw type_error.304 if the JSON value is not an object; in this case, - calling `at` with a key makes no sense. See example below. - @throw out_of_range.403 if the key @a key is is not stored in the object; - that is, `find(key) == end()`. See example below. + case 0xD3: // int 64 + { + int64_t number; + return get_number(number) and sax->number_integer(number); + } - @exceptionsafety Strong guarantee: if an exception is thrown, there are no - changes in the JSON value. + case 0xD9: // str 8 + case 0xDA: // str 16 + case 0xDB: // str 32 + { + string_t s; + return get_msgpack_string(s) and sax->string(s); + } - @complexity Logarithmic in the size of the container. + case 0xDC: // array 16 + { + uint16_t len; + return get_number(len) and get_msgpack_array(static_cast(len)); + } - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @sa @ref value() for access by value with a default value + case 0xDD: // array 32 + { + uint32_t len; + return get_number(len) and get_msgpack_array(static_cast(len)); + } - @since version 1.0.0 + case 0xDE: // map 16 + { + uint16_t len; + return get_number(len) and get_msgpack_object(static_cast(len)); + } - @liveexample{The example below shows how object elements can be read using - `at()`. It also demonstrates the different exceptions that can be thrown., - at__object_t_key_type_const} - */ - const_reference at(const typename object_t::key_type& key) const - { - // at only works for objects - if (is_object()) - { - JSON_TRY + case 0xDF: // map 32 { - return m_value.object->at(key); + uint32_t len; + return get_number(len) and get_msgpack_object(static_cast(len)); } - JSON_CATCH (std::out_of_range&) + + // negative fixint + case 0xE0: + case 0xE1: + case 0xE2: + case 0xE3: + case 0xE4: + case 0xE5: + case 0xE6: + case 0xE7: + case 0xE8: + case 0xE9: + case 0xEA: + case 0xEB: + case 0xEC: + case 0xED: + case 0xEE: + case 0xEF: + case 0xF0: + case 0xF1: + case 0xF2: + case 0xF3: + case 0xF4: + case 0xF5: + case 0xF6: + case 0xF7: + case 0xF8: + case 0xF9: + case 0xFA: + case 0xFB: + case 0xFC: + case 0xFD: + case 0xFE: + case 0xFF: + return sax->number_integer(static_cast(current)); + + default: // anything else { - // create better exception explanation - JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading MessagePack; last byte: 0x" + last_token)); } } - else - { - JSON_THROW(type_error::create(304, "cannot use at() with " + type_name())); - } } /*! - @brief access specified array element - - Returns a reference to the element at specified location @a idx. - - @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), - then the array is silently filled up with `null` values to make `idx` a - valid reference to the last stored element. + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - @param[in] idx index of the element to access - - @return reference to the element at index @a idx + @return whether a valid UBJSON value was passed to the SAX parser + */ + bool parse_ubjson_internal(const bool get_char = true) + { + return get_ubjson_value(get_char ? get_ignore_noop() : current); + } - @throw type_error.305 if the JSON value is not an array or null; in that - cases, using the [] operator with an index makes no sense. + /*! + @brief get next character from the input - @complexity Constant if @a idx is in the range of the array. Otherwise - linear in `idx - size()`. + This function provides the interface to the used input adapter. It does + not throw in case the input reached EOF, but returns a -'ve valued + `std::char_traits::eof()` in that case. - @liveexample{The example below shows how array elements can be read and - written using `[]` operator. Note the addition of `null` - values.,operatorarray__size_type} + @return character read from the input + */ + int get() + { + ++chars_read; + return (current = ia->get_character()); + } - @since version 1.0.0 + /*! + @return character read from the input after ignoring all 'N' entries */ - reference operator[](size_type idx) + int get_ignore_noop() { - // implicitly convert null value to an empty array - if (is_null()) + do { - m_type = value_t::array; - m_value.array = create(); - assert_invariant(); + get(); } + while (current == 'N'); - // operator[] only works for arrays - if (is_array()) + return current; + } + + /* + @brief read a number from the input + + @tparam NumberType the type of the number + @param[out] result number of type @a NumberType + + @return whether conversion completed + + @note This function needs to respect the system's endianess, because + bytes in CBOR, MessagePack, and UBJSON are stored in network order + (big endian) and therefore need reordering on little endian systems. + */ + template + bool get_number(NumberType& result) + { + // step 1: read input into array with system's byte order + std::array vec; + for (std::size_t i = 0; i < sizeof(NumberType); ++i) { - // fill up array with null values if given idx is outside range - if (idx >= m_value.array->size()) + get(); + if (JSON_UNLIKELY(not unexpect_eof())) { - m_value.array->insert(m_value.array->end(), - idx - m_value.array->size() + 1, - basic_json()); + return false; } - return m_value.array->operator[](idx); + // reverse byte order prior to conversion if necessary + if (is_little_endian) + { + vec[sizeof(NumberType) - i - 1] = static_cast(current); + } + else + { + vec[i] = static_cast(current); // LCOV_EXCL_LINE + } } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + // step 2: convert array into number of type T and return + std::memcpy(&result, vec.data(), sizeof(NumberType)); + return true; } /*! - @brief access specified array element - - Returns a const reference to the element at specified location @a idx. + @brief create a string by reading characters from the input - @param[in] idx index of the element to access - - @return const reference to the element at index @a idx - - @throw type_error.305 if the JSON value is not an array; in that cases, - using the [] operator with an index makes no sense. - - @complexity Constant. + @tparam NumberType the type of the number + @param[in] len number of characters to read + @param[out] string created by reading @a len bytes - @liveexample{The example below shows how array elements can be read using - the `[]` operator.,operatorarray__size_type_const} + @return whether string creation completed - @since version 1.0.0 + @note We can not reserve @a len bytes for the result, because @a len + may be too large. Usually, @ref unexpect_eof() detects the end of + the input before we run out of string memory. */ - const_reference operator[](size_type idx) const + template + bool get_string(const NumberType len, string_t& result) { - // const operator[] only works for arrays - if (is_array()) + bool success = true; + std::generate_n(std::back_inserter(result), len, [this, &success]() { - return m_value.array->operator[](idx); - } - - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + success = false; + } + return static_cast(current); + }); + return success; } /*! - @brief access specified object element + @brief reads a CBOR string - Returns a reference to the element at with specified key @a key. + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. + Additionally, CBOR's strings with indefinite lengths are supported. - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + @param[out] result created string - @param[in] key key of the element to access + @return whether string creation completed + */ + bool get_cbor_string(string_t& result) + { + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + + switch (current) + { + // UTF-8 string (0x00..0x17 bytes follow) + case 0x60: + case 0x61: + case 0x62: + case 0x63: + case 0x64: + case 0x65: + case 0x66: + case 0x67: + case 0x68: + case 0x69: + case 0x6A: + case 0x6B: + case 0x6C: + case 0x6D: + case 0x6E: + case 0x6F: + case 0x70: + case 0x71: + case 0x72: + case 0x73: + case 0x74: + case 0x75: + case 0x76: + case 0x77: + { + return get_string(current & 0x1F, result); + } - @return reference to the element at key @a key + case 0x78: // UTF-8 string (one-byte uint8_t for n follows) + { + uint8_t len; + return get_number(len) and get_string(len, result); + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case 0x79: // UTF-8 string (two-byte uint16_t for n follow) + { + uint16_t len; + return get_number(len) and get_string(len, result); + } - @complexity Logarithmic in the size of the container. + case 0x7A: // UTF-8 string (four-byte uint32_t for n follow) + { + uint32_t len; + return get_number(len) and get_string(len, result); + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + case 0x7B: // UTF-8 string (eight-byte uint64_t for n follow) + { + uint64_t len; + return get_number(len) and get_string(len, result); + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + case 0x7F: // UTF-8 string (indefinite length) + { + while (get() != 0xFF) + { + string_t chunk; + if (not get_cbor_string(chunk)) + { + return false; + } + result.append(chunk); + } + return true; + } - @since version 1.0.0 + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + last_token)); + } + } + } + + /*! + @param[in] len the length of the array or json_sax_t::no_limit for an + array of indefinite size + @return whether array creation completed */ - reference operator[](const typename object_t::key_type& key) + bool get_cbor_array(const std::size_t len) { - // implicitly convert null value to an empty object - if (is_null()) + if (JSON_UNLIKELY(not sax->start_array(len))) { - m_type = value_t::object; - m_value.object = create(); - assert_invariant(); + return false; } - // operator[] only works for objects - if (is_object()) + if (len != json_sax_t::no_limit) + for (std::size_t i = 0; i < len; ++i) + { + if (JSON_UNLIKELY(not parse_cbor_internal())) + { + return false; + } + } + else { - return m_value.object->operator[](key); + while (get() != 0xFF) + { + if (JSON_UNLIKELY(not parse_cbor_internal(false))) + { + return false; + } + } } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return sax->end_array(); } /*! - @brief read-only access specified object element - - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. - - @warning If the element with key @a key does not exist, the behavior is - undefined. - - @param[in] key key of the element to access - - @return const reference to the element at key @a key - - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** - - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value - - @since version 1.0.0 + @param[in] len the length of the object or json_sax_t::no_limit for an + object of indefinite size + @return whether object creation completed */ - const_reference operator[](const typename object_t::key_type& key) const + bool get_cbor_object(const std::size_t len) { - // const operator[] only works for objects - if (is_object()) + if (not JSON_UNLIKELY(sax->start_object(len))) { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; + return false; } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + string_t key; + if (len != json_sax_t::no_limit) + { + for (std::size_t i = 0; i < len; ++i) + { + get(); + if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key))) + { + return false; + } + + if (JSON_UNLIKELY(not parse_cbor_internal())) + { + return false; + } + key.clear(); + } + } + else + { + while (get() != 0xFF) + { + if (JSON_UNLIKELY(not get_cbor_string(key) or not sax->key(key))) + { + return false; + } + + if (JSON_UNLIKELY(not parse_cbor_internal())) + { + return false; + } + key.clear(); + } + } + + return sax->end_object(); } /*! - @brief access specified object element + @brief reads a MessagePack string - Returns a reference to the element at with specified key @a key. + This function first reads starting bytes to determine the expected + string length and then copies this number of bytes into a string. - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + @param[out] result created string - @param[in] key key of the element to access + @return whether string creation completed + */ + bool get_msgpack_string(string_t& result) + { + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + + switch (current) + { + // fixstr + case 0xA0: + case 0xA1: + case 0xA2: + case 0xA3: + case 0xA4: + case 0xA5: + case 0xA6: + case 0xA7: + case 0xA8: + case 0xA9: + case 0xAA: + case 0xAB: + case 0xAC: + case 0xAD: + case 0xAE: + case 0xAF: + case 0xB0: + case 0xB1: + case 0xB2: + case 0xB3: + case 0xB4: + case 0xB5: + case 0xB6: + case 0xB7: + case 0xB8: + case 0xB9: + case 0xBA: + case 0xBB: + case 0xBC: + case 0xBD: + case 0xBE: + case 0xBF: + { + return get_string(current & 0x1F, result); + } - @return reference to the element at key @a key + case 0xD9: // str 8 + { + uint8_t len; + return get_number(len) and get_string(len, result); + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + case 0xDA: // str 16 + { + uint16_t len; + return get_number(len) and get_string(len, result); + } - @complexity Logarithmic in the size of the container. + case 0xDB: // str 32 + { + uint32_t len; + return get_number(len) and get_string(len, result); + } - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a MessagePack string; last byte: 0x" + last_token)); + } + } + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + /*! + @param[in] len the length of the array + @return whether array creation completed + */ + bool get_msgpack_array(const std::size_t len) + { + if (JSON_UNLIKELY(not sax->start_array(len))) + { + return false; + } - @since version 1.0.0 + for (std::size_t i = 0; i < len; ++i) + { + if (JSON_UNLIKELY(not parse_msgpack_internal())) + { + return false; + } + } + + return sax->end_array(); + } + + /*! + @param[in] len the length of the object + @return whether object creation completed */ - template - reference operator[](T * (&key)[n]) + bool get_msgpack_object(const std::size_t len) { - return operator[](static_cast(key)); + if (JSON_UNLIKELY(not sax->start_object(len))) + { + return false; + } + + string_t key; + for (std::size_t i = 0; i < len; ++i) + { + get(); + if (JSON_UNLIKELY(not get_msgpack_string(key) or not sax->key(key))) + { + return false; + } + + if (JSON_UNLIKELY(not parse_msgpack_internal())) + { + return false; + } + key.clear(); + } + + return sax->end_object(); } /*! - @brief read-only access specified object element + @brief reads a UBJSON string - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + This function is either called after reading the 'S' byte explicitly + indicating a string, or in case of an object key where the 'S' byte can be + left out. - @warning If the element with key @a key does not exist, the behavior is - undefined. + @param[out] result created string + @param[in] get_char whether a new character should be retrieved from the + input (true, default) or whether the last read + character should be considered instead - @note This function is required for compatibility reasons with Clang. + @return whether string creation completed + */ + bool get_ubjson_string(string_t& result, const bool get_char = true) + { + if (get_char) + { + get(); // TODO: may we ignore N here? + } - @param[in] key key of the element to access + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - @return const reference to the element at key @a key + switch (current) + { + case 'U': + { + uint8_t len; + return get_number(len) and get_string(len, result); + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + case 'i': + { + int8_t len; + return get_number(len) and get_string(len, result); + } - @complexity Logarithmic in the size of the container. + case 'I': + { + int16_t len; + return get_number(len) and get_string(len, result); + } - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + case 'l': + { + int32_t len; + return get_number(len) and get_string(len, result); + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + case 'L': + { + int64_t len; + return get_number(len) and get_string(len, result); + } - @since version 1.0.0 - */ - template - const_reference operator[](T * (&key)[n]) const - { - return operator[](static_cast(key)); + default: + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "expected a UBJSON string; last byte: 0x" + last_token)); + } } /*! - @brief access specified object element + @param[out] result determined size + @return whether size determination completed + */ + bool get_ubjson_size_value(std::size_t& result) + { + switch (get_ignore_noop()) + { + case 'U': + { + uint8_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - Returns a reference to the element at with specified key @a key. + case 'i': + { + int8_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @note If @a key is not found in the object, then it is silently added to - the object and filled with a `null` value to make `key` a valid reference. - In case the value was `null` before, it is converted to an object. + case 'I': + { + int16_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @param[in] key key of the element to access + case 'l': + { + int32_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @return reference to the element at key @a key + case 'L': + { + int64_t number; + if (JSON_UNLIKELY(not get_number(number))) + { + return false; + } + result = static_cast(number); + return true; + } - @throw type_error.305 if the JSON value is not an object or null; in that - cases, using the [] operator with a key makes no sense. + default: + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "byte after '#' must denote a number type; last byte: 0x" + last_token)); + } + } + } - @complexity Logarithmic in the size of the container. + /*! + @brief determine the type and size for a container - @liveexample{The example below shows how object elements can be read and - written using the `[]` operator.,operatorarray__key_type} + In the optimized UBJSON format, a type and a size can be provided to allow + for a more compact representation. - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + @param[out] result pair of the size and the type - @since version 1.1.0 + @return whether pair creation completed */ - template - reference operator[](T* key) + bool get_ubjson_size_type(std::pair& result) { - // implicitly convert null to object - if (is_null()) + result.first = string_t::npos; // size + result.second = 0; // type + + get_ignore_noop(); + + if (current == '$') { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); - } + result.second = get(); // must not ignore 'N', because 'N' maybe the type + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } - // at only works for objects - if (is_object()) + get_ignore_noop(); + if (JSON_UNLIKELY(current != '#')) + { + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "expected '#' after UBJSON type information; last byte: 0x" + last_token)); + } + + return get_ubjson_size_value(result.first); + } + else if (current == '#') { - return m_value.object->operator[](key); + return get_ubjson_size_value(result.first); } - - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); + return true; } /*! - @brief read-only access specified object element + @param prefix the previously read or set type prefix + @return whether value creation completed + */ + bool get_ubjson_value(const int prefix) + { + switch (prefix) + { + case std::char_traits::eof(): // EOF + return unexpect_eof(); - Returns a const reference to the element at with specified key @a key. No - bounds checking is performed. + case 'T': // true + return sax->boolean(true); + case 'F': // false + return sax->boolean(false); - @warning If the element with key @a key does not exist, the behavior is - undefined. + case 'Z': // null + return sax->null(); - @param[in] key key of the element to access + case 'U': + { + uint8_t number; + return get_number(number) and sax->number_unsigned(number); + } - @return const reference to the element at key @a key + case 'i': + { + int8_t number; + return get_number(number) and sax->number_integer(number); + } - @pre The element with key @a key must exist. **This precondition is - enforced with an assertion.** + case 'I': + { + int16_t number; + return get_number(number) and sax->number_integer(number); + } - @throw type_error.305 if the JSON value is not an object; in that cases, - using the [] operator with a key makes no sense. + case 'l': + { + int32_t number; + return get_number(number) and sax->number_integer(number); + } - @complexity Logarithmic in the size of the container. + case 'L': + { + int64_t number; + return get_number(number) and sax->number_integer(number); + } - @liveexample{The example below shows how object elements can be read using - the `[]` operator.,operatorarray__key_type_const} + case 'd': + { + float number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref value() for access by value with a default value + case 'D': + { + double number; + return get_number(number) and sax->number_float(static_cast(number), ""); + } - @since version 1.1.0 - */ - template - const_reference operator[](T* key) const - { - // at only works for objects - if (is_object()) - { - assert(m_value.object->find(key) != m_value.object->end()); - return m_value.object->find(key)->second; - } + case 'C': // char + { + get(); + if (JSON_UNLIKELY(not unexpect_eof())) + { + return false; + } + if (JSON_UNLIKELY(current > 127)) + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read, "byte after 'C' must be in range 0x00..0x7F; last byte: 0x" + last_token)); + } + string_t s(1, static_cast(current)); + return sax->string(s); + } - JSON_THROW(type_error::create(305, "cannot use operator[] with " + type_name())); - } + case 'S': // string + { + string_t s; + return get_ubjson_string(s) and sax->string(s); + } - /*! - @brief access specified object element with default value + case '[': // array + return get_ubjson_array(); - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. + case '{': // object + return get_ubjson_object(); - The function is basically equivalent to executing - @code {.cpp} - try { - return at(key); - } catch(out_of_range) { - return default_value; + default: // anything else + { + auto last_token = get_token_string(); + return sax->parse_error(chars_read, last_token, parse_error::create(112, chars_read, "error reading UBJSON; last byte: 0x" + last_token)); + } + } } - @endcode - - @note Unlike @ref at(const typename object_t::key_type&), this function - does not throw if the given key @a key was not found. - - @note Unlike @ref operator[](const typename object_t::key_type& key), this - function does not implicitly add an element to the position defined by @a - key. This function is furthermore also applicable to const objects. - - @param[in] key key of the element to access - @param[in] default_value the value to return if @a key is not found - - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. - - @return copy of the element at key @a key or @a default_value if @a key - is not found - - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value} - - @sa @ref at(const typename object_t::key_type&) for access by reference - with range checking - @sa @ref operator[](const typename object_t::key_type&) for unchecked - access by reference - @since version 1.0.0 + /*! + @return whether array creation completed */ - template::value, int>::type = 0> - ValueType value(const typename object_t::key_type& key, ValueType default_value) const + bool get_ubjson_array() { - // at only works for objects - if (is_object()) + std::pair size_and_type; + if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type))) { - // if key is found, return value and given default value otherwise - const auto it = find(key); - if (it != end()) + return false; + } + + if (size_and_type.first != string_t::npos) + { + if (JSON_UNLIKELY(not sax->start_array(size_and_type.first))) { - return *it; + return false; } - return default_value; + if (size_and_type.second != 0) + { + if (size_and_type.second != 'N') + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second))) + { + return false; + } + } + } + } + else + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + } + } } else { - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); + if (JSON_UNLIKELY(not sax->start_array())) + { + return false; + } + + while (current != ']') + { + if (JSON_UNLIKELY(not parse_ubjson_internal(false))) + { + return false; + } + get_ignore_noop(); + } } + + return sax->end_array(); } /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const + @return whether object creation completed */ - string_t value(const typename object_t::key_type& key, const char* default_value) const + bool get_ubjson_object() { - return value(key, string_t(default_value)); - } - - /*! - @brief access specified object element via JSON Pointer with default value - - Returns either a copy of an object's element at the specified key @a key - or a given default value if no element with key @a key exists. - - The function is basically equivalent to executing - @code {.cpp} - try { - return at(ptr); - } catch(out_of_range) { - return default_value; - } - @endcode - - @note Unlike @ref at(const json_pointer&), this function does not throw - if the given key @a key was not found. - - @param[in] ptr a JSON pointer to the element to access - @param[in] default_value the value to return if @a ptr found no value - - @tparam ValueType type compatible to JSON values, for instance `int` for - JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for - JSON arrays. Note the type of the expected value at @a key and the default - value @a default_value must be compatible. - - @return copy of the element at key @a key or @a default_value if @a key - is not found - - @throw type_error.306 if the JSON value is not an objec; in that cases, - using `value()` with a key makes no sense. - - @complexity Logarithmic in the size of the container. - - @liveexample{The example below shows how object elements can be queried - with a default value.,basic_json__value_ptr} + std::pair size_and_type; + if (JSON_UNLIKELY(not get_ubjson_size_type(size_and_type))) + { + return false; + } - @sa @ref operator[](const json_pointer&) for unchecked access by reference + string_t key; + if (size_and_type.first != string_t::npos) + { + if (JSON_UNLIKELY(not sax->start_object(size_and_type.first))) + { + return false; + } - @since version 2.0.2 - */ - template::value, int>::type = 0> - ValueType value(const json_pointer& ptr, ValueType default_value) const - { - // at only works for objects - if (is_object()) + if (size_and_type.second != 0) + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not get_ubjson_value(size_and_type.second))) + { + return false; + } + key.clear(); + } + } + else + { + for (std::size_t i = 0; i < size_and_type.first; ++i) + { + if (JSON_UNLIKELY(not get_ubjson_string(key) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + key.clear(); + } + } + } + else { - // if pointer resolves a value, return it or use default value - JSON_TRY + if (JSON_UNLIKELY(not sax->start_object())) { - return ptr.get_checked(this); + return false; } - JSON_CATCH (out_of_range&) + + while (current != '}') { - return default_value; + if (JSON_UNLIKELY(not get_ubjson_string(key, false) or not sax->key(key))) + { + return false; + } + if (JSON_UNLIKELY(not parse_ubjson_internal())) + { + return false; + } + get_ignore_noop(); + key.clear(); } } - JSON_THROW(type_error::create(306, "cannot use value() with " + type_name())); + return sax->end_object(); } /*! - @brief overload for a default value of type const char* - @copydoc basic_json::value(const json_pointer&, ValueType) const + @return whether the last read character is not EOF */ - string_t value(const json_pointer& ptr, const char* default_value) const + bool unexpect_eof() const { - return value(ptr, string_t(default_value)); + if (JSON_UNLIKELY(current == std::char_traits::eof())) + { + return sax->parse_error(chars_read, "", parse_error::create(110, chars_read, "unexpected end of input")); + } + return true; } /*! - @brief access the first element - - Returns a reference to the first element in the container. For a JSON - container `c`, the expression `c.front()` is equivalent to `*c.begin()`. - - @return In case of a structured type (array or object), a reference to the - first element is returned. In case of number, string, or boolean values, a - reference to the value is returned. - - @complexity Constant. - - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. + @return a string representation of the last read byte + */ + std::string get_token_string() const + { + char cr[3]; + snprintf(cr, 3, "%.2hhX", static_cast(current)); + return std::string{cr}; + } - @throw invalid_iterator.214 when called on `null` value + private: + /// input adapter + input_adapter_t ia = nullptr; - @liveexample{The following code shows an example for `front()`.,front} + /// the current character + int current = std::char_traits::eof(); - @sa @ref back() -- access the last element + /// the number of characters read + std::size_t chars_read = 0; - @since version 1.0.0 - */ - reference front() - { - return *begin(); - } + /// whether we can assume little endianess + const bool is_little_endian = little_endianess(); - /*! - @copydoc basic_json::front() - */ - const_reference front() const - { - return *cbegin(); - } + /// the SAX parser + json_sax_t* sax = nullptr; +}; +} +} - /*! - @brief access the last element +// #include - Returns a reference to the last element in the container. For a JSON - container `c`, the expression `c.back()` is equivalent to - @code {.cpp} - auto tmp = c.end(); - --tmp; - return *tmp; - @endcode - @return In case of a structured type (array or object), a reference to the - last element is returned. In case of number, string, or boolean values, a - reference to the value is returned. +#include // reverse +#include // array +#include // uint8_t, uint16_t, uint32_t, uint64_t +#include // memcpy +#include // numeric_limits - @complexity Constant. +// #include - @pre The JSON value must not be `null` (would throw `std::out_of_range`) - or an empty array or object (undefined behavior, **guarded by - assertions**). - @post The JSON value remains unchanged. +// #include - @throw invalid_iterator.214 when called on a `null` value. See example - below. - @liveexample{The following code shows an example for `back()`.,back} +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// binary writer // +/////////////////// - @sa @ref front() -- access the first element +/*! +@brief serialization to CBOR and MessagePack values +*/ +template +class binary_writer +{ + public: + /*! + @brief create a binary writer - @since version 1.0.0 + @param[in] adapter output adapter to write to */ - reference back() + explicit binary_writer(output_adapter_t adapter) : oa(adapter) { - auto tmp = end(); - --tmp; - return *tmp; + assert(oa); } /*! - @copydoc basic_json::back() + @brief[in] j JSON value to serialize */ - const_reference back() const + void write_cbor(const BasicJsonType& j) { - auto tmp = cend(); - --tmp; - return *tmp; - } - - /*! - @brief remove element given an iterator - - Removes the element specified by iterator @a pos. The iterator @a pos must - be valid and dereferenceable. Thus the `end()` iterator (which is valid, - but is not dereferenceable) cannot be used as a value for @a pos. - - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. - - @param[in] pos iterator to the element to remove - @return Iterator following the last removed element. If the iterator @a - pos refers to the last element, the `end()` iterator is returned. - - @tparam IteratorType an @ref iterator or @ref const_iterator - - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. - - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.202 if called on an iterator which does not belong - to the current JSON value; example: `"iterator does not fit current - value"` - @throw invalid_iterator.205 if called on a primitive type with invalid - iterator (i.e., any iterator which is not `begin()`); example: `"iterator - out of range"` - - @complexity The complexity depends on the type: - - objects: amortized constant - - arrays: linear in distance between @a pos and the end of the container - - strings: linear in the length of the string - - other types: constant - - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType} - - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index - - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType pos) - { - // make sure iterator fits the current value - if (this != pos.m_object) + switch (j.type()) { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } - - IteratorType result = end(); + case value_t::null: + { + oa->write_character(static_cast(0xF6)); + break; + } - switch (m_type) - { case value_t::boolean: - case value_t::number_float: + { + oa->write_character(j.m_value.boolean + ? static_cast(0xF5) + : static_cast(0xF4)); + break; + } + case value_t::number_integer: - case value_t::number_unsigned: - case value_t::string: { - if (not pos.m_it.primitive_iterator.is_begin()) + if (j.m_value.number_integer >= 0) { - JSON_THROW(invalid_iterator::create(205, "iterator out of range")); + // CBOR does not differentiate between positive signed + // integers and unsigned integers. Therefore, we used the + // code from the value_t::number_unsigned case here. + if (j.m_value.number_integer <= 0x17) + { + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_integer)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_integer)); + } } - - if (is_string()) + else { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; + // The conversions below encode the sign in the first + // byte, and the value is converted to a positive number. + const auto positive_number = -1 - j.m_value.number_integer; + if (j.m_value.number_integer >= -24) + { + write_number(static_cast(0x20 + positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x38)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x39)); + write_number(static_cast(positive_number)); + } + else if (positive_number <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x3A)); + write_number(static_cast(positive_number)); + } + else + { + oa->write_character(static_cast(0x3B)); + write_number(static_cast(positive_number)); + } } - - m_type = value_t::null; - assert_invariant(); break; } - case value_t::object: + case value_t::number_unsigned: { - result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); + if (j.m_value.number_unsigned <= 0x17) + { + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x18)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x19)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x1A)); + write_number(static_cast(j.m_value.number_unsigned)); + } + else + { + oa->write_character(static_cast(0x1B)); + write_number(static_cast(j.m_value.number_unsigned)); + } break; } - case value_t::array: + case value_t::number_float: { - result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); + oa->write_character(get_cbor_float_prefix(j.m_value.number_float)); + write_number(j.m_value.number_float); break; } - default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } - - return result; - } - - /*! - @brief remove elements given an iterator range - - Removes the element specified by the range `[first; last)`. The iterator - @a first does not need to be dereferenceable if `first == last`: erasing - an empty range is a no-op. - - If called on a primitive type other than `null`, the resulting JSON value - will be `null`. - - @param[in] first iterator to the beginning of the range to remove - @param[in] last iterator past the end of the range to remove - @return Iterator following the last removed element. If the iterator @a - second refers to the last element, the `end()` iterator is returned. - - @tparam IteratorType an @ref iterator or @ref const_iterator - - @post Invalidates iterators and references at or after the point of the - erase, including the `end()` iterator. - - @throw type_error.307 if called on a `null` value; example: `"cannot use - erase() with null"` - @throw invalid_iterator.203 if called on iterators which does not belong - to the current JSON value; example: `"iterators do not fit current value"` - @throw invalid_iterator.204 if called on a primitive type with invalid - iterators (i.e., if `first != begin()` and `last != end()`); example: - `"iterators out of range"` - - @complexity The complexity depends on the type: - - objects: `log(size()) + std::distance(first, last)` - - arrays: linear in the distance between @a first and @a last, plus linear - in the distance between @a last and end of the container - - strings: linear in the length of the string - - other types: constant - - @liveexample{The example shows the result of `erase()` for different JSON - types.,erase__IteratorType_IteratorType} - - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key - @sa @ref erase(const size_type) -- removes the element from an array at - the given index - - @since version 1.0.0 - */ - template::value or - std::is_same::value, int>::type - = 0> - IteratorType erase(IteratorType first, IteratorType last) - { - // make sure iterator fits the current value - if (this != first.m_object or this != last.m_object) - { - JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); - } - - IteratorType result = end(); - - switch (m_type) - { - case value_t::boolean: - case value_t::number_float: - case value_t::number_integer: - case value_t::number_unsigned: case value_t::string: { - if (not first.m_it.primitive_iterator.is_begin() or not last.m_it.primitive_iterator.is_end()) + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 0x17) { - JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + write_number(static_cast(0x60 + N)); } - - if (is_string()) + else if (N <= (std::numeric_limits::max)()) { - AllocatorType alloc; - alloc.destroy(m_value.string); - alloc.deallocate(m_value.string, 1); - m_value.string = nullptr; + oa->write_character(static_cast(0x78)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x79)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x7B)); + write_number(static_cast(N)); } + // LCOV_EXCL_STOP - m_type = value_t::null; - assert_invariant(); + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); break; } - case value_t::object: + case value_t::array: { - result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, - last.m_it.object_iterator); + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 0x17) + { + write_number(static_cast(0x80 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x98)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x99)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9A)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0x9B)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_cbor(el); + } break; } - case value_t::array: + case value_t::object: { - result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, - last.m_it.array_iterator); + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 0x17) + { + write_number(static_cast(0xA0 + N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB8)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xB9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBA)); + write_number(static_cast(N)); + } + // LCOV_EXCL_START + else if (N <= (std::numeric_limits::max)()) + { + oa->write_character(static_cast(0xBB)); + write_number(static_cast(N)); + } + // LCOV_EXCL_STOP + + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_cbor(el.first); + write_cbor(el.second); + } break; } default: - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } + break; } - - return result; } /*! - @brief remove element from a JSON object given a key + @brief[in] j JSON value to serialize + */ + void write_msgpack(const BasicJsonType& j) + { + switch (j.type()) + { + case value_t::null: // nil + { + oa->write_character(static_cast(0xC0)); + break; + } - Removes elements from a JSON object with the key value @a key. + case value_t::boolean: // true and false + { + oa->write_character(j.m_value.boolean + ? static_cast(0xC3) + : static_cast(0xC2)); + break; + } - @param[in] key value of the elements to remove + case value_t::number_integer: + { + if (j.m_value.number_integer >= 0) + { + // MessagePack does not differentiate between positive + // signed integers and unsigned integers. Therefore, we used + // the code from the value_t::number_unsigned case here. + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } + } + else + { + if (j.m_value.number_integer >= -32) + { + // negative fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 8 + oa->write_character(static_cast(0xD0)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 16 + oa->write_character(static_cast(0xD1)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 32 + oa->write_character(static_cast(0xD2)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_integer >= (std::numeric_limits::min)() and + j.m_value.number_integer <= (std::numeric_limits::max)()) + { + // int 64 + oa->write_character(static_cast(0xD3)); + write_number(static_cast(j.m_value.number_integer)); + } + } + break; + } - @return Number of elements removed. If @a ObjectType is the default - `std::map` type, the return value will always be `0` (@a key was not - found) or `1` (@a key was found). + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned < 128) + { + // positive fixnum + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 8 + oa->write_character(static_cast(0xCC)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 16 + oa->write_character(static_cast(0xCD)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 32 + oa->write_character(static_cast(0xCE)); + write_number(static_cast(j.m_value.number_integer)); + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + // uint 64 + oa->write_character(static_cast(0xCF)); + write_number(static_cast(j.m_value.number_integer)); + } + break; + } - @post References and iterators to the erased elements are invalidated. - Other references and iterators are not affected. + case value_t::number_float: + { + oa->write_character(get_msgpack_float_prefix(j.m_value.number_float)); + write_number(j.m_value.number_float); + break; + } - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` + case value_t::string: + { + // step 1: write control byte and the string length + const auto N = j.m_value.string->size(); + if (N <= 31) + { + // fixstr + write_number(static_cast(0xA0 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 8 + oa->write_character(static_cast(0xD9)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 16 + oa->write_character(static_cast(0xDA)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // str 32 + oa->write_character(static_cast(0xDB)); + write_number(static_cast(N)); + } - @complexity `log(size()) + count(key)` + // step 2: write the string + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); + break; + } - @liveexample{The example shows the effect of `erase()`.,erase__key_type} + case value_t::array: + { + // step 1: write control byte and the array size + const auto N = j.m_value.array->size(); + if (N <= 15) + { + // fixarray + write_number(static_cast(0x90 | N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 16 + oa->write_character(static_cast(0xDC)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // array 32 + oa->write_character(static_cast(0xDD)); + write_number(static_cast(N)); + } - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const size_type) -- removes the element from an array at - the given index + // step 2: write each element + for (const auto& el : *j.m_value.array) + { + write_msgpack(el); + } + break; + } - @since version 1.0.0 + case value_t::object: + { + // step 1: write control byte and the object size + const auto N = j.m_value.object->size(); + if (N <= 15) + { + // fixmap + write_number(static_cast(0x80 | (N & 0xF))); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 16 + oa->write_character(static_cast(0xDE)); + write_number(static_cast(N)); + } + else if (N <= (std::numeric_limits::max)()) + { + // map 32 + oa->write_character(static_cast(0xDF)); + write_number(static_cast(N)); + } + + // step 2: write each element + for (const auto& el : *j.m_value.object) + { + write_msgpack(el.first); + write_msgpack(el.second); + } + break; + } + + default: + break; + } + } + + /*! + @param[in] j JSON value to serialize + @param[in] use_count whether to use '#' prefixes (optimized format) + @param[in] use_type whether to use '$' prefixes (optimized format) + @param[in] add_prefix whether prefixes need to be used for this value */ - size_type erase(const typename object_t::key_type& key) + void write_ubjson(const BasicJsonType& j, const bool use_count, + const bool use_type, const bool add_prefix = true) { - // this erase only works for objects - if (is_object()) + switch (j.type()) { - return m_value.object->erase(key); - } + case value_t::null: + { + if (add_prefix) + { + oa->write_character(static_cast('Z')); + } + break; + } - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } + case value_t::boolean: + { + if (add_prefix) + oa->write_character(j.m_value.boolean + ? static_cast('T') + : static_cast('F')); + break; + } - /*! - @brief remove element from a JSON array given an index + case value_t::number_integer: + { + write_number_with_ubjson_prefix(j.m_value.number_integer, add_prefix); + break; + } - Removes element from a JSON array at the index @a idx. + case value_t::number_unsigned: + { + write_number_with_ubjson_prefix(j.m_value.number_unsigned, add_prefix); + break; + } - @param[in] idx index of the element to remove + case value_t::number_float: + { + write_number_with_ubjson_prefix(j.m_value.number_float, add_prefix); + break; + } - @throw type_error.307 when called on a type other than JSON object; - example: `"cannot use erase() with null"` - @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 - is out of range"` + case value_t::string: + { + if (add_prefix) + { + oa->write_character(static_cast('S')); + } + write_number_with_ubjson_prefix(j.m_value.string->size(), true); + oa->write_characters( + reinterpret_cast(j.m_value.string->c_str()), + j.m_value.string->size()); + break; + } - @complexity Linear in distance between @a idx and the end of the container. + case value_t::array: + { + if (add_prefix) + { + oa->write_character(static_cast('[')); + } - @liveexample{The example shows the effect of `erase()`.,erase__size_type} + bool prefix_required = true; + if (use_type and not j.m_value.array->empty()) + { + assert(use_count); + const CharType first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin() + 1, j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - @sa @ref erase(IteratorType) -- removes the element at a given position - @sa @ref erase(IteratorType, IteratorType) -- removes the elements in - the given range - @sa @ref erase(const typename object_t::key_type&) -- removes the element - from an object at the given key + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(first_prefix); + } + } - @since version 1.0.0 - */ - void erase(const size_type idx) - { - // this erase only works for arrays - if (is_array()) - { - if (idx >= size()) - { - JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); - } + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.array->size(), true); + } - m_value.array->erase(m_value.array->begin() + static_cast(idx)); - } - else - { - JSON_THROW(type_error::create(307, "cannot use erase() with " + type_name())); - } - } + for (const auto& el : *j.m_value.array) + { + write_ubjson(el, use_count, use_type, prefix_required); + } - /// @} + if (not use_count) + { + oa->write_character(static_cast(']')); + } + break; + } - //////////// - // lookup // - //////////// + case value_t::object: + { + if (add_prefix) + { + oa->write_character(static_cast('{')); + } - /// @name lookup - /// @{ + bool prefix_required = true; + if (use_type and not j.m_value.object->empty()) + { + assert(use_count); + const CharType first_prefix = ubjson_prefix(j.front()); + const bool same_prefix = std::all_of(j.begin(), j.end(), + [this, first_prefix](const BasicJsonType & v) + { + return ubjson_prefix(v) == first_prefix; + }); - /*! - @brief find an element in a JSON object + if (same_prefix) + { + prefix_required = false; + oa->write_character(static_cast('$')); + oa->write_character(first_prefix); + } + } - Finds an element in a JSON object with key equivalent to @a key. If the - element is not found or the JSON value is not an object, end() is - returned. + if (use_count) + { + oa->write_character(static_cast('#')); + write_number_with_ubjson_prefix(j.m_value.object->size(), true); + } - @note This method always returns @ref end() when executed on a JSON type - that is not an object. + for (const auto& el : *j.m_value.object) + { + write_number_with_ubjson_prefix(el.first.size(), true); + oa->write_characters( + reinterpret_cast(el.first.c_str()), + el.first.size()); + write_ubjson(el.second, use_count, use_type, prefix_required); + } - @param[in] key key value of the element to search for + if (not use_count) + { + oa->write_character(static_cast('}')); + } - @return Iterator to an element with key equivalent to @a key. If no such - element is found or the JSON value is not an object, past-the-end (see - @ref end()) iterator is returned. + break; + } - @complexity Logarithmic in the size of the JSON object. + default: + break; + } + } - @liveexample{The example shows how `find()` is used.,find__key_type} + private: + /* + @brief write a number to output input - @since version 1.0.0 + @param[in] n number of type @a NumberType + @tparam NumberType the type of the number + + @note This function needs to respect the system's endianess, because bytes + in CBOR, MessagePack, and UBJSON are stored in network order (big + endian) and therefore need reordering on little endian systems. */ - iterator find(typename object_t::key_type key) + template + void write_number(const NumberType n) { - auto result = end(); + // step 1: write number to array of length NumberType + std::array vec; + std::memcpy(vec.data(), &n, sizeof(NumberType)); - if (is_object()) + // step 2: write array to output (with possible reordering) + if (is_little_endian) { - result.m_it.object_iterator = m_value.object->find(key); + // reverse byte order prior to conversion if necessary + std::reverse(vec.begin(), vec.end()); } - return result; + oa->write_characters(vec.data(), sizeof(NumberType)); } - /*! - @brief find an element in a JSON object - @copydoc find(typename object_t::key_type) - */ - const_iterator find(typename object_t::key_type key) const + // UBJSON: write number (floating point) + template::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) { - auto result = cend(); + if (add_prefix) + { + oa->write_character(get_ubjson_float_prefix(n)); + } + write_number(n); + } - if (is_object()) + // UBJSON: write number (unsigned integer) + template::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) + { + if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if (n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) { - result.m_it.object_iterator = m_value.object->find(key); + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if (n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); } + } - return result; + // UBJSON: write number (signed integer) + template::value and + not std::is_floating_point::value, int>::type = 0> + void write_number_with_ubjson_prefix(const NumberType n, + const bool add_prefix) + { + if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('i')); // int8 + } + write_number(static_cast(n)); + } + else if (static_cast((std::numeric_limits::min)()) <= n and n <= static_cast((std::numeric_limits::max)())) + { + if (add_prefix) + { + oa->write_character(static_cast('U')); // uint8 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('I')); // int16 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('l')); // int32 + } + write_number(static_cast(n)); + } + else if ((std::numeric_limits::min)() <= n and n <= (std::numeric_limits::max)()) + { + if (add_prefix) + { + oa->write_character(static_cast('L')); // int64 + } + write_number(static_cast(n)); + } + // LCOV_EXCL_START + else + { + JSON_THROW(out_of_range::create(407, "number overflow serializing " + std::to_string(n))); + } + // LCOV_EXCL_STOP } /*! - @brief returns the number of occurrences of a key in a JSON object - - Returns the number of elements with key @a key. If ObjectType is the - default `std::map` type, the return value will always be `0` (@a key was - not found) or `1` (@a key was found). - - @note This method always returns `0` when executed on a JSON type that is - not an object. - - @param[in] key key value of the element to count - - @return Number of elements with key @a key. If the JSON value is not an - object, the return value will be `0`. - - @complexity Logarithmic in the size of the JSON object. - - @liveexample{The example shows how `count()` is used.,count} + @brief determine the type prefix of container values - @since version 1.0.0 + @note This function does not need to be 100% accurate when it comes to + integer limits. In case a number exceeds the limits of int64_t, + this will be detected by a later call to function + write_number_with_ubjson_prefix. Therefore, we return 'L' for any + value that does not fit the previous limits. */ - size_type count(typename object_t::key_type key) const + CharType ubjson_prefix(const BasicJsonType& j) const noexcept { - // return 0 for all nonobject types - return is_object() ? m_value.object->count(key) : 0; - } + switch (j.type()) + { + case value_t::null: + return 'Z'; - /// @} + case value_t::boolean: + return j.m_value.boolean ? 'T' : 'F'; + case value_t::number_integer: + { + if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if ((std::numeric_limits::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - /////////////// - // iterators // - /////////////// + case value_t::number_unsigned: + { + if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'i'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'U'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'I'; + } + else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) + { + return 'l'; + } + else // no check and assume int64_t (see note above) + { + return 'L'; + } + } - /// @name iterators - /// @{ + case value_t::number_float: + return get_ubjson_float_prefix(j.m_value.number_float); - /*! - @brief returns an iterator to the first element + case value_t::string: + return 'S'; - Returns an iterator to the first element. + case value_t::array: + return '['; - @image html range-begin-end.svg "Illustration from cppreference.com" + case value_t::object: + return '{'; - @return iterator to the first element + default: // discarded values + return 'N'; + } + } - @complexity Constant. + static constexpr CharType get_cbor_float_prefix(float) + { + return static_cast(0xFA); // Single-Precision Float + } - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. + static constexpr CharType get_cbor_float_prefix(double) + { + return static_cast(0xFB); // Double-Precision Float + } - @liveexample{The following code shows an example for `begin()`.,begin} + static constexpr CharType get_msgpack_float_prefix(float) + { + return static_cast(0xCA); // float 32 + } - @sa @ref cbegin() -- returns a const iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end + static constexpr CharType get_msgpack_float_prefix(double) + { + return static_cast(0xCB); // float 64 + } - @since version 1.0.0 - */ - iterator begin() noexcept + static constexpr CharType get_ubjson_float_prefix(float) { - iterator result(this); - result.set_begin(); - return result; + return 'd'; // float 32 } - /*! - @copydoc basic_json::cbegin() - */ - const_iterator begin() const noexcept + static constexpr CharType get_ubjson_float_prefix(double) { - return cbegin(); + return 'D'; // float 64 } - /*! - @brief returns a const iterator to the first element + private: + /// whether we can assume little endianess + const bool is_little_endian = binary_reader::little_endianess(); - Returns a const iterator to the first element. + /// the output + output_adapter_t oa = nullptr; +}; +} +} - @image html range-begin-end.svg "Illustration from cppreference.com" +// #include - @return const iterator to the first element - @complexity Constant. +#include // reverse, remove, fill, find, none_of +#include // array +#include // assert +#include // and, or +#include // localeconv, lconv +#include // labs, isfinite, isnan, signbit +#include // size_t, ptrdiff_t +#include // uint8_t +#include // snprintf +#include // numeric_limits +#include // string +#include // is_same - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).begin()`. +// #include - @liveexample{The following code shows an example for `cbegin()`.,cbegin} +// #include - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref end() -- returns an iterator to the end - @sa @ref cend() -- returns a const iterator to the end - @since version 1.0.0 - */ - const_iterator cbegin() const noexcept - { - const_iterator result(this); - result.set_begin(); - return result; - } +#include // assert +#include // or, and, not +#include // signbit, isfinite +#include // intN_t, uintN_t +#include // memcpy, memmove - /*! - @brief returns an iterator to one past the last element +namespace nlohmann +{ +namespace detail +{ - Returns an iterator to one past the last element. +/*! +@brief implements the Grisu2 algorithm for binary to decimal floating-point +conversion. - @image html range-begin-end.svg "Illustration from cppreference.com" +This implementation is a slightly modified version of the reference +implementation which may be obtained from +http://florian.loitsch.com/publications (bench.tar.gz). - @return iterator one past the last element +The code is distributed under the MIT license, Copyright (c) 2009 Florian Loitsch. - @complexity Constant. +For a detailed description of the algorithm see: - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. +[1] Loitsch, "Printing Floating-Point Numbers Quickly and Accurately with + Integers", Proceedings of the ACM SIGPLAN 2010 Conference on Programming + Language Design and Implementation, PLDI 2010 +[2] Burger, Dybvig, "Printing Floating-Point Numbers Quickly and Accurately", + Proceedings of the ACM SIGPLAN 1996 Conference on Programming Language + Design and Implementation, PLDI 1996 +*/ +namespace dtoa_impl +{ - @liveexample{The following code shows an example for `end()`.,end} +template +Target reinterpret_bits(const Source source) +{ + static_assert(sizeof(Target) == sizeof(Source), "size mismatch"); - @sa @ref cend() -- returns a const iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + Target target; + std::memcpy(&target, &source, sizeof(Source)); + return target; +} - @since version 1.0.0 +struct diyfp // f * 2^e +{ + static constexpr int kPrecision = 64; // = q + + uint64_t f; + int e; + + constexpr diyfp() noexcept : f(0), e(0) {} + constexpr diyfp(uint64_t f_, int e_) noexcept : f(f_), e(e_) {} + + /*! + @brief returns x - y + @pre x.e == y.e and x.f >= y.f */ - iterator end() noexcept + static diyfp sub(const diyfp& x, const diyfp& y) noexcept { - iterator result(this); - result.set_end(); - return result; + assert(x.e == y.e); + assert(x.f >= y.f); + + return diyfp(x.f - y.f, x.e); } /*! - @copydoc basic_json::cend() + @brief returns x * y + @note The result is rounded. (Only the upper q bits are returned.) */ - const_iterator end() const noexcept + static diyfp mul(const diyfp& x, const diyfp& y) noexcept { - return cend(); + static_assert(kPrecision == 64, "internal error"); + + // Computes: + // f = round((x.f * y.f) / 2^q) + // e = x.e + y.e + q + + // Emulate the 64-bit * 64-bit multiplication: + // + // p = u * v + // = (u_lo + 2^32 u_hi) (v_lo + 2^32 v_hi) + // = (u_lo v_lo ) + 2^32 ((u_lo v_hi ) + (u_hi v_lo )) + 2^64 (u_hi v_hi ) + // = (p0 ) + 2^32 ((p1 ) + (p2 )) + 2^64 (p3 ) + // = (p0_lo + 2^32 p0_hi) + 2^32 ((p1_lo + 2^32 p1_hi) + (p2_lo + 2^32 p2_hi)) + 2^64 (p3 ) + // = (p0_lo ) + 2^32 (p0_hi + p1_lo + p2_lo ) + 2^64 (p1_hi + p2_hi + p3) + // = (p0_lo ) + 2^32 (Q ) + 2^64 (H ) + // = (p0_lo ) + 2^32 (Q_lo + 2^32 Q_hi ) + 2^64 (H ) + // + // (Since Q might be larger than 2^32 - 1) + // + // = (p0_lo + 2^32 Q_lo) + 2^64 (Q_hi + H) + // + // (Q_hi + H does not overflow a 64-bit int) + // + // = p_lo + 2^64 p_hi + + const uint64_t u_lo = x.f & 0xFFFFFFFF; + const uint64_t u_hi = x.f >> 32; + const uint64_t v_lo = y.f & 0xFFFFFFFF; + const uint64_t v_hi = y.f >> 32; + + const uint64_t p0 = u_lo * v_lo; + const uint64_t p1 = u_lo * v_hi; + const uint64_t p2 = u_hi * v_lo; + const uint64_t p3 = u_hi * v_hi; + + const uint64_t p0_hi = p0 >> 32; + const uint64_t p1_lo = p1 & 0xFFFFFFFF; + const uint64_t p1_hi = p1 >> 32; + const uint64_t p2_lo = p2 & 0xFFFFFFFF; + const uint64_t p2_hi = p2 >> 32; + + uint64_t Q = p0_hi + p1_lo + p2_lo; + + // The full product might now be computed as + // + // p_hi = p3 + p2_hi + p1_hi + (Q >> 32) + // p_lo = p0_lo + (Q << 32) + // + // But in this particular case here, the full p_lo is not required. + // Effectively we only need to add the highest bit in p_lo to p_hi (and + // Q_hi + 1 does not overflow). + + Q += uint64_t{1} << (64 - 32 - 1); // round, ties up + + const uint64_t h = p3 + p2_hi + p1_hi + (Q >> 32); + + return diyfp(h, x.e + y.e + 64); } /*! - @brief returns a const iterator to one past the last element - - Returns a const iterator to one past the last element. - - @image html range-begin-end.svg "Illustration from cppreference.com" - - @return const iterator one past the last element - - @complexity Constant. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).end()`. + @brief normalize x such that the significand is >= 2^(q-1) + @pre x.f != 0 + */ + static diyfp normalize(diyfp x) noexcept + { + assert(x.f != 0); - @liveexample{The following code shows an example for `cend()`.,cend} + while ((x.f >> 63) == 0) + { + x.f <<= 1; + x.e--; + } - @sa @ref end() -- returns an iterator to the end - @sa @ref begin() -- returns an iterator to the beginning - @sa @ref cbegin() -- returns a const iterator to the beginning + return x; + } - @since version 1.0.0 + /*! + @brief normalize x such that the result has the exponent E + @pre e >= x.e and the upper e - x.e bits of x.f must be zero. */ - const_iterator cend() const noexcept + static diyfp normalize_to(const diyfp& x, const int target_exponent) noexcept { - const_iterator result(this); - result.set_end(); - return result; - } + const int delta = x.e - target_exponent; - /*! - @brief returns an iterator to the reverse-beginning + assert(delta >= 0); + assert(((x.f << delta) >> delta) == x.f); - Returns an iterator to the reverse-beginning; that is, the last element. + return diyfp(x.f << delta, target_exponent); + } +}; - @image html range-rbegin-rend.svg "Illustration from cppreference.com" +struct boundaries +{ + diyfp w; + diyfp minus; + diyfp plus; +}; - @complexity Constant. +/*! +Compute the (normalized) diyfp representing the input number 'value' and its +boundaries. - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(end())`. +@pre value must be finite and positive +*/ +template +boundaries compute_boundaries(FloatType value) +{ + assert(std::isfinite(value)); + assert(value > 0); + + // Convert the IEEE representation into a diyfp. + // + // If v is denormal: + // value = 0.F * 2^(1 - bias) = ( F) * 2^(1 - bias - (p-1)) + // If v is normalized: + // value = 1.F * 2^(E - bias) = (2^(p-1) + F) * 2^(E - bias - (p-1)) + + static_assert(std::numeric_limits::is_iec559, + "internal error: dtoa_short requires an IEEE-754 floating-point implementation"); + + constexpr int kPrecision = std::numeric_limits::digits; // = p (includes the hidden bit) + constexpr int kBias = std::numeric_limits::max_exponent - 1 + (kPrecision - 1); + constexpr int kMinExp = 1 - kBias; + constexpr uint64_t kHiddenBit = uint64_t{1} << (kPrecision - 1); // = 2^(p-1) + + using bits_type = typename std::conditional< kPrecision == 24, uint32_t, uint64_t >::type; + + const uint64_t bits = reinterpret_bits(value); + const uint64_t E = bits >> (kPrecision - 1); + const uint64_t F = bits & (kHiddenBit - 1); + + const bool is_denormal = (E == 0); + const diyfp v = is_denormal + ? diyfp(F, kMinExp) + : diyfp(F + kHiddenBit, static_cast(E) - kBias); + + // Compute the boundaries m- and m+ of the floating-point value + // v = f * 2^e. + // + // Determine v- and v+, the floating-point predecessor and successor if v, + // respectively. + // + // v- = v - 2^e if f != 2^(p-1) or e == e_min (A) + // = v - 2^(e-1) if f == 2^(p-1) and e > e_min (B) + // + // v+ = v + 2^e + // + // Let m- = (v- + v) / 2 and m+ = (v + v+) / 2. All real numbers _strictly_ + // between m- and m+ round to v, regardless of how the input rounding + // algorithm breaks ties. + // + // ---+-------------+-------------+-------------+-------------+--- (A) + // v- m- v m+ v+ + // + // -----------------+------+------+-------------+-------------+--- (B) + // v- m- v m+ v+ + + const bool lower_boundary_is_closer = (F == 0 and E > 1); + const diyfp m_plus = diyfp(2 * v.f + 1, v.e - 1); + const diyfp m_minus = lower_boundary_is_closer + ? diyfp(4 * v.f - 1, v.e - 2) // (B) + : diyfp(2 * v.f - 1, v.e - 1); // (A) + + // Determine the normalized w+ = m+. + const diyfp w_plus = diyfp::normalize(m_plus); + + // Determine w- = m- such that e_(w-) = e_(w+). + const diyfp w_minus = diyfp::normalize_to(m_minus, w_plus.e); + + return {diyfp::normalize(v), w_minus, w_plus}; +} - @liveexample{The following code shows an example for `rbegin()`.,rbegin} +// Given normalized diyfp w, Grisu needs to find a (normalized) cached +// power-of-ten c, such that the exponent of the product c * w = f * 2^e lies +// within a certain range [alpha, gamma] (Definition 3.2 from [1]) +// +// alpha <= e = e_c + e_w + q <= gamma +// +// or +// +// f_c * f_w * 2^alpha <= f_c 2^(e_c) * f_w 2^(e_w) * 2^q +// <= f_c * f_w * 2^gamma +// +// Since c and w are normalized, i.e. 2^(q-1) <= f < 2^q, this implies +// +// 2^(q-1) * 2^(q-1) * 2^alpha <= c * w * 2^q < 2^q * 2^q * 2^gamma +// +// or +// +// 2^(q - 2 + alpha) <= c * w < 2^(q + gamma) +// +// The choice of (alpha,gamma) determines the size of the table and the form of +// the digit generation procedure. Using (alpha,gamma)=(-60,-32) works out well +// in practice: +// +// The idea is to cut the number c * w = f * 2^e into two parts, which can be +// processed independently: An integral part p1, and a fractional part p2: +// +// f * 2^e = ( (f div 2^-e) * 2^-e + (f mod 2^-e) ) * 2^e +// = (f div 2^-e) + (f mod 2^-e) * 2^e +// = p1 + p2 * 2^e +// +// The conversion of p1 into decimal form requires a series of divisions and +// modulos by (a power of) 10. These operations are faster for 32-bit than for +// 64-bit integers, so p1 should ideally fit into a 32-bit integer. This can be +// achieved by choosing +// +// -e >= 32 or e <= -32 := gamma +// +// In order to convert the fractional part +// +// p2 * 2^e = p2 / 2^-e = d[-1] / 10^1 + d[-2] / 10^2 + ... +// +// into decimal form, the fraction is repeatedly multiplied by 10 and the digits +// d[-i] are extracted in order: +// +// (10 * p2) div 2^-e = d[-1] +// (10 * p2) mod 2^-e = d[-2] / 10^1 + ... +// +// The multiplication by 10 must not overflow. It is sufficient to choose +// +// 10 * p2 < 16 * p2 = 2^4 * p2 <= 2^64. +// +// Since p2 = f mod 2^-e < 2^-e, +// +// -e <= 60 or e >= -60 := alpha + +constexpr int kAlpha = -60; +constexpr int kGamma = -32; + +struct cached_power // c = f * 2^e ~= 10^k +{ + uint64_t f; + int e; + int k; +}; - @sa @ref crbegin() -- returns a const reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end +/*! +For a normalized diyfp w = f * 2^e, this function returns a (normalized) cached +power-of-ten c = f_c * 2^e_c, such that the exponent of the product w * c +satisfies (Definition 3.2 from [1]) - @since version 1.0.0 - */ - reverse_iterator rbegin() noexcept + alpha <= e_c + e + q <= gamma. +*/ +inline cached_power get_cached_power_for_binary_exponent(int e) +{ + // Now + // + // alpha <= e_c + e + q <= gamma (1) + // ==> f_c * 2^alpha <= c * 2^e * 2^q + // + // and since the c's are normalized, 2^(q-1) <= f_c, + // + // ==> 2^(q - 1 + alpha) <= c * 2^(e + q) + // ==> 2^(alpha - e - 1) <= c + // + // If c were an exakt power of ten, i.e. c = 10^k, one may determine k as + // + // k = ceil( log_10( 2^(alpha - e - 1) ) ) + // = ceil( (alpha - e - 1) * log_10(2) ) + // + // From the paper: + // "In theory the result of the procedure could be wrong since c is rounded, + // and the computation itself is approximated [...]. In practice, however, + // this simple function is sufficient." + // + // For IEEE double precision floating-point numbers converted into + // normalized diyfp's w = f * 2^e, with q = 64, + // + // e >= -1022 (min IEEE exponent) + // -52 (p - 1) + // -52 (p - 1, possibly normalize denormal IEEE numbers) + // -11 (normalize the diyfp) + // = -1137 + // + // and + // + // e <= +1023 (max IEEE exponent) + // -52 (p - 1) + // -11 (normalize the diyfp) + // = 960 + // + // This binary exponent range [-1137,960] results in a decimal exponent + // range [-307,324]. One does not need to store a cached power for each + // k in this range. For each such k it suffices to find a cached power + // such that the exponent of the product lies in [alpha,gamma]. + // This implies that the difference of the decimal exponents of adjacent + // table entries must be less than or equal to + // + // floor( (gamma - alpha) * log_10(2) ) = 8. + // + // (A smaller distance gamma-alpha would require a larger table.) + + // NB: + // Actually this function returns c, such that -60 <= e_c + e + 64 <= -34. + + constexpr int kCachedPowersSize = 79; + constexpr int kCachedPowersMinDecExp = -300; + constexpr int kCachedPowersDecStep = 8; + + static constexpr cached_power kCachedPowers[] = { - return reverse_iterator(end()); + { 0xAB70FE17C79AC6CA, -1060, -300 }, + { 0xFF77B1FCBEBCDC4F, -1034, -292 }, + { 0xBE5691EF416BD60C, -1007, -284 }, + { 0x8DD01FAD907FFC3C, -980, -276 }, + { 0xD3515C2831559A83, -954, -268 }, + { 0x9D71AC8FADA6C9B5, -927, -260 }, + { 0xEA9C227723EE8BCB, -901, -252 }, + { 0xAECC49914078536D, -874, -244 }, + { 0x823C12795DB6CE57, -847, -236 }, + { 0xC21094364DFB5637, -821, -228 }, + { 0x9096EA6F3848984F, -794, -220 }, + { 0xD77485CB25823AC7, -768, -212 }, + { 0xA086CFCD97BF97F4, -741, -204 }, + { 0xEF340A98172AACE5, -715, -196 }, + { 0xB23867FB2A35B28E, -688, -188 }, + { 0x84C8D4DFD2C63F3B, -661, -180 }, + { 0xC5DD44271AD3CDBA, -635, -172 }, + { 0x936B9FCEBB25C996, -608, -164 }, + { 0xDBAC6C247D62A584, -582, -156 }, + { 0xA3AB66580D5FDAF6, -555, -148 }, + { 0xF3E2F893DEC3F126, -529, -140 }, + { 0xB5B5ADA8AAFF80B8, -502, -132 }, + { 0x87625F056C7C4A8B, -475, -124 }, + { 0xC9BCFF6034C13053, -449, -116 }, + { 0x964E858C91BA2655, -422, -108 }, + { 0xDFF9772470297EBD, -396, -100 }, + { 0xA6DFBD9FB8E5B88F, -369, -92 }, + { 0xF8A95FCF88747D94, -343, -84 }, + { 0xB94470938FA89BCF, -316, -76 }, + { 0x8A08F0F8BF0F156B, -289, -68 }, + { 0xCDB02555653131B6, -263, -60 }, + { 0x993FE2C6D07B7FAC, -236, -52 }, + { 0xE45C10C42A2B3B06, -210, -44 }, + { 0xAA242499697392D3, -183, -36 }, + { 0xFD87B5F28300CA0E, -157, -28 }, + { 0xBCE5086492111AEB, -130, -20 }, + { 0x8CBCCC096F5088CC, -103, -12 }, + { 0xD1B71758E219652C, -77, -4 }, + { 0x9C40000000000000, -50, 4 }, + { 0xE8D4A51000000000, -24, 12 }, + { 0xAD78EBC5AC620000, 3, 20 }, + { 0x813F3978F8940984, 30, 28 }, + { 0xC097CE7BC90715B3, 56, 36 }, + { 0x8F7E32CE7BEA5C70, 83, 44 }, + { 0xD5D238A4ABE98068, 109, 52 }, + { 0x9F4F2726179A2245, 136, 60 }, + { 0xED63A231D4C4FB27, 162, 68 }, + { 0xB0DE65388CC8ADA8, 189, 76 }, + { 0x83C7088E1AAB65DB, 216, 84 }, + { 0xC45D1DF942711D9A, 242, 92 }, + { 0x924D692CA61BE758, 269, 100 }, + { 0xDA01EE641A708DEA, 295, 108 }, + { 0xA26DA3999AEF774A, 322, 116 }, + { 0xF209787BB47D6B85, 348, 124 }, + { 0xB454E4A179DD1877, 375, 132 }, + { 0x865B86925B9BC5C2, 402, 140 }, + { 0xC83553C5C8965D3D, 428, 148 }, + { 0x952AB45CFA97A0B3, 455, 156 }, + { 0xDE469FBD99A05FE3, 481, 164 }, + { 0xA59BC234DB398C25, 508, 172 }, + { 0xF6C69A72A3989F5C, 534, 180 }, + { 0xB7DCBF5354E9BECE, 561, 188 }, + { 0x88FCF317F22241E2, 588, 196 }, + { 0xCC20CE9BD35C78A5, 614, 204 }, + { 0x98165AF37B2153DF, 641, 212 }, + { 0xE2A0B5DC971F303A, 667, 220 }, + { 0xA8D9D1535CE3B396, 694, 228 }, + { 0xFB9B7CD9A4A7443C, 720, 236 }, + { 0xBB764C4CA7A44410, 747, 244 }, + { 0x8BAB8EEFB6409C1A, 774, 252 }, + { 0xD01FEF10A657842C, 800, 260 }, + { 0x9B10A4E5E9913129, 827, 268 }, + { 0xE7109BFBA19C0C9D, 853, 276 }, + { 0xAC2820D9623BF429, 880, 284 }, + { 0x80444B5E7AA7CF85, 907, 292 }, + { 0xBF21E44003ACDD2D, 933, 300 }, + { 0x8E679C2F5E44FF8F, 960, 308 }, + { 0xD433179D9C8CB841, 986, 316 }, + { 0x9E19DB92B4E31BA9, 1013, 324 }, + }; + + // This computation gives exactly the same results for k as + // k = ceil((kAlpha - e - 1) * 0.30102999566398114) + // for |e| <= 1500, but doesn't require floating-point operations. + // NB: log_10(2) ~= 78913 / 2^18 + assert(e >= -1500); + assert(e <= 1500); + const int f = kAlpha - e - 1; + const int k = (f * 78913) / (1 << 18) + (f > 0); + + const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep; + assert(index >= 0); + assert(index < kCachedPowersSize); + static_cast(kCachedPowersSize); // Fix warning. + + const cached_power cached = kCachedPowers[index]; + assert(kAlpha <= cached.e + e + 64); + assert(kGamma >= cached.e + e + 64); + + return cached; +} + +/*! +For n != 0, returns k, such that pow10 := 10^(k-1) <= n < 10^k. +For n == 0, returns 1 and sets pow10 := 1. +*/ +inline int find_largest_pow10(const uint32_t n, uint32_t& pow10) +{ + // LCOV_EXCL_START + if (n >= 1000000000) + { + pow10 = 1000000000; + return 10; + } + // LCOV_EXCL_STOP + else if (n >= 100000000) + { + pow10 = 100000000; + return 9; + } + else if (n >= 10000000) + { + pow10 = 10000000; + return 8; + } + else if (n >= 1000000) + { + pow10 = 1000000; + return 7; } + else if (n >= 100000) + { + pow10 = 100000; + return 6; + } + else if (n >= 10000) + { + pow10 = 10000; + return 5; + } + else if (n >= 1000) + { + pow10 = 1000; + return 4; + } + else if (n >= 100) + { + pow10 = 100; + return 3; + } + else if (n >= 10) + { + pow10 = 10; + return 2; + } + else + { + pow10 = 1; + return 1; + } +} - /*! - @copydoc basic_json::crbegin() - */ - const_reverse_iterator rbegin() const noexcept +inline void grisu2_round(char* buf, int len, uint64_t dist, uint64_t delta, + uint64_t rest, uint64_t ten_k) +{ + assert(len >= 1); + assert(dist <= delta); + assert(rest <= delta); + assert(ten_k > 0); + + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // ten_k + // <------> + // <---- rest ----> + // --------------[------------------+----+--------------]-------------- + // w V + // = buf * 10^k + // + // ten_k represents a unit-in-the-last-place in the decimal representation + // stored in buf. + // Decrement buf by ten_k while this takes buf closer to w. + + // The tests are written in this order to avoid overflow in unsigned + // integer arithmetic. + + while (rest < dist + and delta - rest >= ten_k + and (rest + ten_k < dist or dist - rest > rest + ten_k - dist)) { - return crbegin(); + assert(buf[len - 1] != '0'); + buf[len - 1]--; + rest += ten_k; } +} - /*! - @brief returns an iterator to the reverse-end +/*! +Generates V = buffer * 10^decimal_exponent, such that M- <= V <= M+. +M- and M+ must be normalized and share the same exponent -60 <= e <= -32. +*/ +inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent, + diyfp M_minus, diyfp w, diyfp M_plus) +{ + static_assert(kAlpha >= -60, "internal error"); + static_assert(kGamma <= -32, "internal error"); + + // Generates the digits (and the exponent) of a decimal floating-point + // number V = buffer * 10^decimal_exponent in the range [M-, M+]. The diyfp's + // w, M- and M+ share the same exponent e, which satisfies alpha <= e <= gamma. + // + // <--------------------------- delta ----> + // <---- dist ---------> + // --------------[------------------+-------------------]-------------- + // M- w M+ + // + // Grisu2 generates the digits of M+ from left to right and stops as soon as + // V is in [M-,M+]. + + assert(M_plus.e >= kAlpha); + assert(M_plus.e <= kGamma); + + uint64_t delta = diyfp::sub(M_plus, M_minus).f; // (significand of (M+ - M-), implicit exponent is e) + uint64_t dist = diyfp::sub(M_plus, w ).f; // (significand of (M+ - w ), implicit exponent is e) + + // Split M+ = f * 2^e into two parts p1 and p2 (note: e < 0): + // + // M+ = f * 2^e + // = ((f div 2^-e) * 2^-e + (f mod 2^-e)) * 2^e + // = ((p1 ) * 2^-e + (p2 )) * 2^e + // = p1 + p2 * 2^e + + const diyfp one(uint64_t{1} << -M_plus.e, M_plus.e); + + uint32_t p1 = static_cast(M_plus.f >> -one.e); // p1 = f div 2^-e (Since -e >= 32, p1 fits into a 32-bit int.) + uint64_t p2 = M_plus.f & (one.f - 1); // p2 = f mod 2^-e + + // 1) + // + // Generate the digits of the integral part p1 = d[n-1]...d[1]d[0] + + assert(p1 > 0); + + uint32_t pow10; + const int k = find_largest_pow10(p1, pow10); + + // 10^(k-1) <= p1 < 10^k, pow10 = 10^(k-1) + // + // p1 = (p1 div 10^(k-1)) * 10^(k-1) + (p1 mod 10^(k-1)) + // = (d[k-1] ) * 10^(k-1) + (p1 mod 10^(k-1)) + // + // M+ = p1 + p2 * 2^e + // = d[k-1] * 10^(k-1) + (p1 mod 10^(k-1)) + p2 * 2^e + // = d[k-1] * 10^(k-1) + ((p1 mod 10^(k-1)) * 2^-e + p2) * 2^e + // = d[k-1] * 10^(k-1) + ( rest) * 2^e + // + // Now generate the digits d[n] of p1 from left to right (n = k-1,...,0) + // + // p1 = d[k-1]...d[n] * 10^n + d[n-1]...d[0] + // + // but stop as soon as + // + // rest * 2^e = (d[n-1]...d[0] * 2^-e + p2) * 2^e <= delta * 2^e + + int n = k; + while (n > 0) + { + // Invariants: + // M+ = buffer * 10^n + (p1 + p2 * 2^e) (buffer = 0 for n = k) + // pow10 = 10^(n-1) <= p1 < 10^n + // + const uint32_t d = p1 / pow10; // d = p1 div 10^(n-1) + const uint32_t r = p1 % pow10; // r = p1 mod 10^(n-1) + // + // M+ = buffer * 10^n + (d * 10^(n-1) + r) + p2 * 2^e + // = (buffer * 10 + d) * 10^(n-1) + (r + p2 * 2^e) + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(n-1) + (r + p2 * 2^e) + // + p1 = r; + n--; + // + // M+ = buffer * 10^n + (p1 + p2 * 2^e) + // pow10 = 10^n + // + + // Now check if enough digits have been generated. + // Compute + // + // p1 + p2 * 2^e = (p1 * 2^-e + p2) * 2^e = rest * 2^e + // + // Note: + // Since rest and delta share the same exponent e, it suffices to + // compare the significands. + const uint64_t rest = (uint64_t{p1} << -one.e) + p2; + if (rest <= delta) + { + // V = buffer * 10^n, with M- <= V <= M+. + + decimal_exponent += n; + + // We may now just stop. But instead look if the buffer could be + // decremented to bring V closer to w. + // + // pow10 = 10^n is now 1 ulp in the decimal representation V. + // The rounding procedure works with diyfp's with an implicit + // exponent of e. + // + // 10^n = (10^n * 2^-e) * 2^e = ulp * 2^e + // + const uint64_t ten_n = uint64_t{pow10} << -one.e; + grisu2_round(buffer, length, dist, delta, rest, ten_n); + + return; + } + + pow10 /= 10; + // + // pow10 = 10^(n-1) <= p1 < 10^n + // Invariants restored. + } - Returns an iterator to the reverse-end; that is, one before the first - element. + // 2) + // + // The digits of the integral part have been generated: + // + // M+ = d[k-1]...d[1]d[0] + p2 * 2^e + // = buffer + p2 * 2^e + // + // Now generate the digits of the fractional part p2 * 2^e. + // + // Note: + // No decimal point is generated: the exponent is adjusted instead. + // + // p2 actually represents the fraction + // + // p2 * 2^e + // = p2 / 2^-e + // = d[-1] / 10^1 + d[-2] / 10^2 + ... + // + // Now generate the digits d[-m] of p1 from left to right (m = 1,2,...) + // + // p2 * 2^e = d[-1]d[-2]...d[-m] * 10^-m + // + 10^-m * (d[-m-1] / 10^1 + d[-m-2] / 10^2 + ...) + // + // using + // + // 10^m * p2 = ((10^m * p2) div 2^-e) * 2^-e + ((10^m * p2) mod 2^-e) + // = ( d) * 2^-e + ( r) + // + // or + // 10^m * p2 * 2^e = d + r * 2^e + // + // i.e. + // + // M+ = buffer + p2 * 2^e + // = buffer + 10^-m * (d + r * 2^e) + // = (buffer * 10^m + d) * 10^-m + 10^-m * r * 2^e + // + // and stop as soon as 10^-m * r * 2^e <= delta * 2^e + + assert(p2 > delta); + + int m = 0; + for (;;) + { + // Invariant: + // M+ = buffer * 10^-m + 10^-m * (d[-m-1] / 10 + d[-m-2] / 10^2 + ...) * 2^e + // = buffer * 10^-m + 10^-m * (p2 ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (10 * p2) ) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * ((10*p2 div 2^-e) * 2^-e + (10*p2 mod 2^-e)) * 2^e + // + assert(p2 <= UINT64_MAX / 10); + p2 *= 10; + const uint64_t d = p2 >> -one.e; // d = (10 * p2) div 2^-e + const uint64_t r = p2 & (one.f - 1); // r = (10 * p2) mod 2^-e + // + // M+ = buffer * 10^-m + 10^-m * (1/10 * (d * 2^-e + r) * 2^e + // = buffer * 10^-m + 10^-m * (1/10 * (d + r * 2^e)) + // = (buffer * 10 + d) * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + assert(d <= 9); + buffer[length++] = static_cast('0' + d); // buffer := buffer * 10 + d + // + // M+ = buffer * 10^(-m-1) + 10^(-m-1) * r * 2^e + // + p2 = r; + m++; + // + // M+ = buffer * 10^-m + 10^-m * p2 * 2^e + // Invariant restored. + + // Check if enough digits have been generated. + // + // 10^-m * p2 * 2^e <= delta * 2^e + // p2 * 2^e <= 10^m * delta * 2^e + // p2 <= 10^m * delta + delta *= 10; + dist *= 10; + if (p2 <= delta) + { + break; + } + } - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + // V = buffer * 10^-m, with M- <= V <= M+. + + decimal_exponent -= m; + + // 1 ulp in the decimal representation is now 10^-m. + // Since delta and dist are now scaled by 10^m, we need to do the + // same with ulp in order to keep the units in sync. + // + // 10^m * 10^-m = 1 = 2^-e * 2^e = ten_m * 2^e + // + const uint64_t ten_m = one.f; + grisu2_round(buffer, length, dist, delta, p2, ten_m); + + // By construction this algorithm generates the shortest possible decimal + // number (Loitsch, Theorem 6.2) which rounds back to w. + // For an input number of precision p, at least + // + // N = 1 + ceil(p * log_10(2)) + // + // decimal digits are sufficient to identify all binary floating-point + // numbers (Matula, "In-and-Out conversions"). + // This implies that the algorithm does not produce more than N decimal + // digits. + // + // N = 17 for p = 53 (IEEE double precision) + // N = 9 for p = 24 (IEEE single precision) +} - @complexity Constant. +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +inline void grisu2(char* buf, int& len, int& decimal_exponent, + diyfp m_minus, diyfp v, diyfp m_plus) +{ + assert(m_plus.e == m_minus.e); + assert(m_plus.e == v.e); + + // --------(-----------------------+-----------------------)-------- (A) + // m- v m+ + // + // --------------------(-----------+-----------------------)-------- (B) + // m- v m+ + // + // First scale v (and m- and m+) such that the exponent is in the range + // [alpha, gamma]. + + const cached_power cached = get_cached_power_for_binary_exponent(m_plus.e); + + const diyfp c_minus_k(cached.f, cached.e); // = c ~= 10^-k + + // The exponent of the products is = v.e + c_minus_k.e + q and is in the range [alpha,gamma] + const diyfp w = diyfp::mul(v, c_minus_k); + const diyfp w_minus = diyfp::mul(m_minus, c_minus_k); + const diyfp w_plus = diyfp::mul(m_plus, c_minus_k); + + // ----(---+---)---------------(---+---)---------------(---+---)---- + // w- w w+ + // = c*m- = c*v = c*m+ + // + // diyfp::mul rounds its result and c_minus_k is approximated too. w, w- and + // w+ are now off by a small amount. + // In fact: + // + // w - v * 10^k < 1 ulp + // + // To account for this inaccuracy, add resp. subtract 1 ulp. + // + // --------+---[---------------(---+---)---------------]---+-------- + // w- M- w M+ w+ + // + // Now any number in [M-, M+] (bounds included) will round to w when input, + // regardless of how the input rounding algorithm breaks ties. + // + // And digit_gen generates the shortest possible such number in [M-, M+]. + // Note that this does not mean that Grisu2 always generates the shortest + // possible number in the interval (m-, m+). + const diyfp M_minus(w_minus.f + 1, w_minus.e); + const diyfp M_plus (w_plus.f - 1, w_plus.e ); + + decimal_exponent = -cached.k; // = -(-k) = k + + grisu2_digit_gen(buf, len, decimal_exponent, M_minus, w, M_plus); +} - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `reverse_iterator(begin())`. +/*! +v = buf * 10^decimal_exponent +len is the length of the buffer (number of decimal digits) +The buffer must be large enough, i.e. >= max_digits10. +*/ +template +void grisu2(char* buf, int& len, int& decimal_exponent, FloatType value) +{ + static_assert(diyfp::kPrecision >= std::numeric_limits::digits + 3, + "internal error: not enough precision"); + + assert(std::isfinite(value)); + assert(value > 0); + + // If the neighbors (and boundaries) of 'value' are always computed for double-precision + // numbers, all float's can be recovered using strtod (and strtof). However, the resulting + // decimal representations are not exactly "short". + // + // The documentation for 'std::to_chars' (https://en.cppreference.com/w/cpp/utility/to_chars) + // says "value is converted to a string as if by std::sprintf in the default ("C") locale" + // and since sprintf promotes float's to double's, I think this is exactly what 'std::to_chars' + // does. + // On the other hand, the documentation for 'std::to_chars' requires that "parsing the + // representation using the corresponding std::from_chars function recovers value exactly". That + // indicates that single precision floating-point numbers should be recovered using + // 'std::strtof'. + // + // NB: If the neighbors are computed for single-precision numbers, there is a single float + // (7.0385307e-26f) which can't be recovered using strtod. The resulting double precision + // value is off by 1 ulp. +#if 0 + const boundaries w = compute_boundaries(static_cast(value)); +#else + const boundaries w = compute_boundaries(value); +#endif - @liveexample{The following code shows an example for `rend()`.,rend} + grisu2(buf, len, decimal_exponent, w.minus, w.w, w.plus); +} - @sa @ref crend() -- returns a const reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning +/*! +@brief appends a decimal representation of e to buf +@return a pointer to the element following the exponent. +@pre -1000 < e < 1000 +*/ +inline char* append_exponent(char* buf, int e) +{ + assert(e > -1000); + assert(e < 1000); - @since version 1.0.0 - */ - reverse_iterator rend() noexcept + if (e < 0) { - return reverse_iterator(begin()); + e = -e; + *buf++ = '-'; } - - /*! - @copydoc basic_json::crend() - */ - const_reverse_iterator rend() const noexcept + else { - return crend(); + *buf++ = '+'; } - /*! - @brief returns a const reverse iterator to the last element + uint32_t k = static_cast(e); + if (k < 10) + { + // Always print at least two digits in the exponent. + // This is for compatibility with printf("%g"). + *buf++ = '0'; + *buf++ = static_cast('0' + k); + } + else if (k < 100) + { + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); + } + else + { + *buf++ = static_cast('0' + k / 100); + k %= 100; + *buf++ = static_cast('0' + k / 10); + k %= 10; + *buf++ = static_cast('0' + k); + } - Returns a const iterator to the reverse-beginning; that is, the last - element. + return buf; +} - @image html range-rbegin-rend.svg "Illustration from cppreference.com" +/*! +@brief prettify v = buf * 10^decimal_exponent - @complexity Constant. +If v is in the range [10^min_exp, 10^max_exp) it will be printed in fixed-point +notation. Otherwise it will be printed in exponential notation. - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rbegin()`. +@pre min_exp < 0 +@pre max_exp > 0 +*/ +inline char* format_buffer(char* buf, int len, int decimal_exponent, + int min_exp, int max_exp) +{ + assert(min_exp < 0); + assert(max_exp > 0); - @liveexample{The following code shows an example for `crbegin()`.,crbegin} + const int k = len; + const int n = len + decimal_exponent; - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref crend() -- returns a const reverse iterator to the end + // v = buf * 10^(n-k) + // k is the length of the buffer (number of decimal digits) + // n is the position of the decimal point relative to the start of the buffer. - @since version 1.0.0 - */ - const_reverse_iterator crbegin() const noexcept + if (k <= n and n <= max_exp) { - return const_reverse_iterator(cend()); + // digits[000] + // len <= max_exp + 2 + + std::memset(buf + k, '0', static_cast(n - k)); + // Make it look like a floating-point number (#362, #378) + buf[n + 0] = '.'; + buf[n + 1] = '0'; + return buf + (n + 2); } - /*! - @brief returns a const reverse iterator to one before the first - - Returns a const reverse iterator to the reverse-end; that is, one before - the first element. - - @image html range-rbegin-rend.svg "Illustration from cppreference.com" + if (0 < n and n <= max_exp) + { + // dig.its + // len <= max_digits10 + 1 - @complexity Constant. + assert(k > n); - @requirement This function helps `basic_json` satisfying the - [ReversibleContainer](http://en.cppreference.com/w/cpp/concept/ReversibleContainer) - requirements: - - The complexity is constant. - - Has the semantics of `const_cast(*this).rend()`. + std::memmove(buf + (n + 1), buf + n, static_cast(k - n)); + buf[n] = '.'; + return buf + (k + 1); + } - @liveexample{The following code shows an example for `crend()`.,crend} + if (min_exp < n and n <= 0) + { + // 0.[000]digits + // len <= 2 + (-min_exp - 1) + max_digits10 + + std::memmove(buf + (2 + -n), buf, static_cast(k)); + buf[0] = '0'; + buf[1] = '.'; + std::memset(buf + 2, '0', static_cast(-n)); + return buf + (2 + (-n) + k); + } - @sa @ref rend() -- returns a reverse iterator to the end - @sa @ref rbegin() -- returns a reverse iterator to the beginning - @sa @ref crbegin() -- returns a const reverse iterator to the beginning + if (k == 1) + { + // dE+123 + // len <= 1 + 5 - @since version 1.0.0 - */ - const_reverse_iterator crend() const noexcept + buf += 1; + } + else { - return const_reverse_iterator(cbegin()); + // d.igitsE+123 + // len <= max_digits10 + 1 + 5 + + std::memmove(buf + 2, buf + 1, static_cast(k - 1)); + buf[1] = '.'; + buf += 1 + k; } - private: - // forward declaration - template class iteration_proxy; + *buf++ = 'e'; + return append_exponent(buf, n - 1); +} - public: - /*! - @brief wrapper to access iterator member functions in range-based for +} // namespace dtoa_impl - This function allows to access @ref iterator::key() and @ref - iterator::value() during range-based for loops. In these loops, a - reference to the JSON values is returned, so there is no access to the - underlying iterator. +/*! +@brief generates a decimal representation of the floating-point number value in [first, last). - @liveexample{The following code shows how the wrapper is used,iterator_wrapper} +The format of the resulting decimal representation is similar to printf's %g +format. Returns an iterator pointing past-the-end of the decimal representation. - @note The name of this function is not yet final and may change in the - future. - */ - static iteration_proxy iterator_wrapper(reference cont) +@note The input number must be finite, i.e. NaN's and Inf's are not supported. +@note The buffer must be large enough. +@note The result is NOT null-terminated. +*/ +template +char* to_chars(char* first, char* last, FloatType value) +{ + static_cast(last); // maybe unused - fix warning + assert(std::isfinite(value)); + + // Use signbit(value) instead of (value < 0) since signbit works for -0. + if (std::signbit(value)) { - return iteration_proxy(cont); + value = -value; + *first++ = '-'; } - /*! - @copydoc iterator_wrapper(reference) - */ - static iteration_proxy iterator_wrapper(const_reference cont) + if (value == 0) // +-0 { - return iteration_proxy(cont); + *first++ = '0'; + // Make it look like a floating-point number (#362, #378) + *first++ = '.'; + *first++ = '0'; + return first; } - /// @} + assert(last - first >= std::numeric_limits::max_digits10); + // Compute v = buffer * 10^decimal_exponent. + // The decimal digits are stored in the buffer, which needs to be interpreted + // as an unsigned decimal integer. + // len is the length of the buffer, i.e. the number of decimal digits. + int len = 0; + int decimal_exponent = 0; + dtoa_impl::grisu2(first, len, decimal_exponent, value); - ////////////// - // capacity // - ////////////// + assert(len <= std::numeric_limits::max_digits10); - /// @name capacity - /// @{ + // Format the buffer like printf("%.*g", prec, value) + constexpr int kMinExp = -4; + // Use digits10 here to increase compatibility with version 2. + constexpr int kMaxExp = std::numeric_limits::digits10; - /*! - @brief checks whether the container is empty + assert(last - first >= kMaxExp + 2); + assert(last - first >= 2 + (-kMinExp - 1) + std::numeric_limits::max_digits10); + assert(last - first >= std::numeric_limits::max_digits10 + 6); - Checks if a JSON value has no elements. + return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp); +} - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `true` - boolean | `false` - string | `false` - number | `false` - object | result of function `object_t::empty()` - array | result of function `array_t::empty()` +} // namespace detail +} // namespace nlohmann - @note This function does not return whether a string stored as JSON value - is empty - it returns whether the JSON container itself is empty which is - false in the case of a string. +// #include - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `empty()` functions have constant - complexity. +// #include - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `begin() == end()`. +// #include - @liveexample{The following code uses `empty()` to check if a JSON - object contains any elements.,empty} +// #include - @sa @ref size() -- returns the number of elements - @since version 1.0.0 - */ - bool empty() const noexcept - { - switch (m_type) - { - case value_t::null: - { - // null values are empty - return true; - } +namespace nlohmann +{ +namespace detail +{ +/////////////////// +// serialization // +/////////////////// - case value_t::array: - { - // delegate call to array_t::empty() - return m_value.array->empty(); - } +template +class serializer +{ + using string_t = typename BasicJsonType::string_t; + using number_float_t = typename BasicJsonType::number_float_t; + using number_integer_t = typename BasicJsonType::number_integer_t; + using number_unsigned_t = typename BasicJsonType::number_unsigned_t; + static constexpr uint8_t UTF8_ACCEPT = 0; + static constexpr uint8_t UTF8_REJECT = 1; - case value_t::object: - { - // delegate call to object_t::empty() - return m_value.object->empty(); - } + public: + /*! + @param[in] s output stream to serialize to + @param[in] ichar indentation character to use + */ + serializer(output_adapter_t s, const char ichar) + : o(std::move(s)), loc(std::localeconv()), + thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep)), + decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point)), + indent_char(ichar), indent_string(512, indent_char) + {} - default: - { - // all other types are nonempty - return false; - } - } - } + // delete because of pointer members + serializer(const serializer&) = delete; + serializer& operator=(const serializer&) = delete; /*! - @brief returns the number of elements + @brief internal implementation of the serialization function - Returns the number of elements in a JSON value. + This function is called by the public member function dump and organizes + the serialization internally. The indentation level is propagated as + additional parameter. In case of arrays and objects, the function is + called recursively. - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` - boolean | `1` - string | `1` - number | `1` - object | result of function object_t::size() - array | result of function array_t::size() - - @note This function does not return the length of a string stored as JSON - value - it returns the number of elements in the JSON value which is 1 in - the case of a string. - - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their size() functions have constant - complexity. - - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of `std::distance(begin(), end())`. - - @liveexample{The following code calls `size()` on the different value - types.,size} - - @sa @ref empty() -- checks whether the container is empty - @sa @ref max_size() -- returns the maximal number of elements + - strings and object keys are escaped using `escape_string()` + - integer numbers are converted implicitly via `operator<<` + - floating-point numbers are converted to a string using `"%g"` format - @since version 1.0.0 + @param[in] val value to serialize + @param[in] pretty_print whether the output shall be pretty-printed + @param[in] indent_step the indent level + @param[in] current_indent the current indent level (only used internally) */ - size_type size() const noexcept + void dump(const BasicJsonType& val, const bool pretty_print, + const bool ensure_ascii, + const unsigned int indent_step, + const unsigned int current_indent = 0) { - switch (m_type) + switch (val.m_type) { - case value_t::null: - { - // null values are empty - return 0; - } - - case value_t::array: - { - // delegate call to array_t::size() - return m_value.array->size(); - } - case value_t::object: { - // delegate call to object_t::size() - return m_value.object->size(); - } - - default: - { - // all other types have size 1 - return 1; - } - } - } + if (val.m_value.object->empty()) + { + o->write_characters("{}", 2); + return; + } - /*! - @brief returns the maximum possible number of elements + if (pretty_print) + { + o->write_characters("{\n", 2); - Returns the maximum number of elements a JSON value is able to hold due to - system or library implementation limitations, i.e. `std::distance(begin(), - end())` for the JSON value. + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } - @return The return value depends on the different types and is - defined as follows: - Value type | return value - ----------- | ------------- - null | `0` (same as `size()`) - boolean | `1` (same as `size()`) - string | `1` (same as `size()`) - number | `1` (same as `size()`) - object | result of function `object_t::max_size()` - array | result of function `array_t::max_size()` + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } - @complexity Constant, as long as @ref array_t and @ref object_t satisfy - the Container concept; that is, their `max_size()` functions have constant - complexity. + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_characters(indent_string.c_str(), new_indent); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\": ", 3); + dump(i->second, true, ensure_ascii, indent_step, new_indent); - @requirement This function helps `basic_json` satisfying the - [Container](http://en.cppreference.com/w/cpp/concept/Container) - requirements: - - The complexity is constant. - - Has the semantics of returning `b.size()` where `b` is the largest - possible JSON value. + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character('}'); + } + else + { + o->write_character('{'); - @liveexample{The following code calls `max_size()` on the different value - types. Note the output is implementation specific.,max_size} + // first n-1 elements + auto i = val.m_value.object->cbegin(); + for (std::size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) + { + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - @sa @ref size() -- returns the number of elements + // last element + assert(i != val.m_value.object->cend()); + assert(std::next(i) == val.m_value.object->cend()); + o->write_character('\"'); + dump_escaped(i->first, ensure_ascii); + o->write_characters("\":", 2); + dump(i->second, false, ensure_ascii, indent_step, current_indent); - @since version 1.0.0 - */ - size_type max_size() const noexcept - { - switch (m_type) - { - case value_t::array: - { - // delegate call to array_t::max_size() - return m_value.array->max_size(); - } + o->write_character('}'); + } - case value_t::object: - { - // delegate call to object_t::max_size() - return m_value.object->max_size(); + return; } - default: + case value_t::array: { - // all other types have max_size() == size() - return size(); - } - } - } - - /// @} + if (val.m_value.array->empty()) + { + o->write_characters("[]", 2); + return; + } + if (pretty_print) + { + o->write_characters("[\n", 2); - /////////////// - // modifiers // - /////////////// + // variable to hold indentation for recursive calls + const auto new_indent = current_indent + indent_step; + if (JSON_UNLIKELY(indent_string.size() < new_indent)) + { + indent_string.resize(indent_string.size() * 2, ' '); + } - /// @name modifiers - /// @{ + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + o->write_characters(indent_string.c_str(), new_indent); + dump(*i, true, ensure_ascii, indent_step, new_indent); + o->write_characters(",\n", 2); + } - /*! - @brief clears the contents + // last element + assert(not val.m_value.array->empty()); + o->write_characters(indent_string.c_str(), new_indent); + dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent); - Clears the content of a JSON value and resets it to the default value as - if @ref basic_json(value_t) would have been called: + o->write_character('\n'); + o->write_characters(indent_string.c_str(), current_indent); + o->write_character(']'); + } + else + { + o->write_character('['); - Value type | initial value - ----------- | ------------- - null | `null` - boolean | `false` - string | `""` - number | `0` - object | `{}` - array | `[]` + // first n-1 elements + for (auto i = val.m_value.array->cbegin(); + i != val.m_value.array->cend() - 1; ++i) + { + dump(*i, false, ensure_ascii, indent_step, current_indent); + o->write_character(','); + } - @complexity Linear in the size of the JSON value. + // last element + assert(not val.m_value.array->empty()); + dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent); - @liveexample{The example below shows the effect of `clear()` to different - JSON types.,clear} + o->write_character(']'); + } - @since version 1.0.0 - */ - void clear() noexcept - { - switch (m_type) - { - case value_t::number_integer: - { - m_value.number_integer = 0; - break; + return; } - case value_t::number_unsigned: + case value_t::string: { - m_value.number_unsigned = 0; - break; + o->write_character('\"'); + dump_escaped(*val.m_value.string, ensure_ascii); + o->write_character('\"'); + return; } - case value_t::number_float: + case value_t::boolean: { - m_value.number_float = 0.0; - break; + if (val.m_value.boolean) + { + o->write_characters("true", 4); + } + else + { + o->write_characters("false", 5); + } + return; } - case value_t::boolean: + case value_t::number_integer: { - m_value.boolean = false; - break; + dump_integer(val.m_value.number_integer); + return; } - case value_t::string: + case value_t::number_unsigned: { - m_value.string->clear(); - break; + dump_integer(val.m_value.number_unsigned); + return; } - case value_t::array: + case value_t::number_float: { - m_value.array->clear(); - break; + dump_float(val.m_value.number_float); + return; } - case value_t::object: + case value_t::discarded: { - m_value.object->clear(); - break; + o->write_characters("", 11); + return; } - default: + case value_t::null: { - break; + o->write_characters("null", 4); + return; } } } + private: /*! - @brief add an object to an array - - Appends the given element @a val to the end of the JSON value. If the - function is called on a JSON null value, an empty array is created before - appending @a val. - - @param[in] val the value to add to the JSON array - - @throw type_error.308 when called on a type other than JSON array or - null; example: `"cannot use push_back() with number"` + @brief dump escaped string - @complexity Amortized constant. + Escape a string by replacing certain special characters by a sequence of an + escape character (backslash) and another character and other control + characters by a sequence of "\u" followed by a four-digit hex + representation. The escaped string is written to output stream @a o. - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON array. Note how the `null` value was silently - converted to a JSON array.,push_back} + @param[in] s the string to escape + @param[in] ensure_ascii whether to escape non-ASCII characters with + \uXXXX sequences - @since version 1.0.0 + @complexity Linear in the length of string @a s. */ - void push_back(basic_json&& val) + void dump_escaped(const string_t& s, const bool ensure_ascii) { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } + uint32_t codepoint; + uint8_t state = UTF8_ACCEPT; + std::size_t bytes = 0; // number of bytes written to string_buffer - // transform null object into an array - if (is_null()) + for (std::size_t i = 0; i < s.size(); ++i) { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } + const auto byte = static_cast(s[i]); - // add element to array (move semantics) - m_value.array->push_back(std::move(val)); - // invalidate object - val.m_type = value_t::null; - } + switch (decode(state, codepoint, byte)) + { + case UTF8_ACCEPT: // decode found a new code point + { + switch (codepoint) + { + case 0x08: // backspace + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'b'; + break; + } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(basic_json&& val) - { - push_back(std::move(val)); - return *this; - } + case 0x09: // horizontal tab + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 't'; + break; + } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - void push_back(const basic_json& val) - { - // push_back only works for null objects or arrays - if (not(is_null() or is_array())) - { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); - } - - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } + case 0x0A: // newline + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'n'; + break; + } - // add element to array - m_value.array->push_back(val); - } + case 0x0C: // formfeed + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'f'; + break; + } - /*! - @brief add an object to an array - @copydoc push_back(basic_json&&) - */ - reference operator+=(const basic_json& val) - { - push_back(val); - return *this; - } + case 0x0D: // carriage return + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = 'r'; + break; + } - /*! - @brief add an object to an object + case 0x22: // quotation mark + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\"'; + break; + } - Inserts the given element @a val to the JSON object. If the function is - called on a JSON null value, an empty object is created before inserting - @a val. + case 0x5C: // reverse solidus + { + string_buffer[bytes++] = '\\'; + string_buffer[bytes++] = '\\'; + break; + } - @param[in] val the value to add to the JSON object + default: + { + // escape control characters (0x00..0x1F) or, if + // ensure_ascii parameter is used, non-ASCII characters + if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F))) + { + if (codepoint <= 0xFFFF) + { + std::snprintf(string_buffer.data() + bytes, 7, "\\u%04x", + static_cast(codepoint)); + bytes += 6; + } + else + { + std::snprintf(string_buffer.data() + bytes, 13, "\\u%04x\\u%04x", + static_cast(0xD7C0 + (codepoint >> 10)), + static_cast(0xDC00 + (codepoint & 0x3FF))); + bytes += 12; + } + } + else + { + // copy byte to buffer (all previous bytes + // been copied have in default case above) + string_buffer[bytes++] = s[i]; + } + break; + } + } - @throw type_error.308 when called on a type other than JSON object or - null; example: `"cannot use push_back() with number"` + // write buffer and reset index; there must be 13 bytes + // left, as this is the maximal number of bytes to be + // written ("\uxxxx\uxxxx\0") for one code point + if (string_buffer.size() - bytes < 13) + { + o->write_characters(string_buffer.data(), bytes); + bytes = 0; + } + break; + } - @complexity Logarithmic in the size of the container, O(log(`size()`)). + case UTF8_REJECT: // decode found invalid UTF-8 byte + { + std::string sn(3, '\0'); + snprintf(&sn[0], sn.size(), "%.2X", byte); + JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + std::to_string(i) + ": 0x" + sn)); + } - @liveexample{The example shows how `push_back()` and `+=` can be used to - add elements to a JSON object. Note how the `null` value was silently - converted to a JSON object.,push_back__object_t__value} + default: // decode found yet incomplete multi-byte code point + { + if (not ensure_ascii) + { + // code point will not be escaped - copy byte to buffer + string_buffer[bytes++] = s[i]; + } + break; + } + } + } - @since version 1.0.0 - */ - void push_back(const typename object_t::value_type& val) - { - // push_back only works for null objects or objects - if (not(is_null() or is_object())) + if (JSON_LIKELY(state == UTF8_ACCEPT)) { - JSON_THROW(type_error::create(308, "cannot use push_back() with " + type_name())); + // write buffer + if (bytes > 0) + { + o->write_characters(string_buffer.data(), bytes); + } } - - // transform null object into an object - if (is_null()) + else { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); + // we finish reading, but do not accept: string was incomplete + std::string sn(3, '\0'); + snprintf(&sn[0], sn.size(), "%.2X", static_cast(s.back())); + JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + sn)); } - - // add element to array - m_value.object->insert(val); - } - - /*! - @brief add an object to an object - @copydoc push_back(const typename object_t::value_type&) - */ - reference operator+=(const typename object_t::value_type& val) - { - push_back(val); - return *this; } /*! - @brief add an object to an object - - This function allows to use `push_back` with an initializer list. In case - - 1. the current value is an object, - 2. the initializer list @a init contains only two elements, and - 3. the first element of @a init is a string, - - @a init is converted into an object element and added using - @ref push_back(const typename object_t::value_type&). Otherwise, @a init - is converted to a JSON value and added using @ref push_back(basic_json&&). - - @param[in] init an initializer list - - @complexity Linear in the size of the initializer list @a init. + @brief dump an integer - @note This function is required to resolve an ambiguous overload error, - because pairs like `{"key", "value"}` can be both interpreted as - `object_t::value_type` or `std::initializer_list`, see - https://github.com/nlohmann/json/issues/235 for more information. + Dump a given integer to output stream @a o. Works internally with + @a number_buffer. - @liveexample{The example shows how initializer lists are treated as - objects when possible.,push_back__initializer_list} + @param[in] x integer number (signed or unsigned) to dump + @tparam NumberType either @a number_integer_t or @a number_unsigned_t */ - void push_back(std::initializer_list init) + template::value or + std::is_same::value, + int> = 0> + void dump_integer(NumberType x) { - if (is_object() and init.size() == 2 and init.begin()->is_string()) - { - const string_t key = *init.begin(); - push_back(typename object_t::value_type(key, *(init.begin() + 1))); - } - else + // special case for "0" + if (x == 0) { - push_back(basic_json(init)); + o->write_character('0'); + return; } - } - /*! - @brief add an object to an object - @copydoc push_back(std::initializer_list) - */ - reference operator+=(std::initializer_list init) - { - push_back(init); - return *this; - } + const bool is_negative = (x <= 0) and (x != 0); // see issue #755 + std::size_t i = 0; - /*! - @brief add an object to an array + while (x != 0) + { + // spare 1 byte for '\0' + assert(i < number_buffer.size() - 1); - Creates a JSON value from the passed parameters @a args to the end of the - JSON value. If the function is called on a JSON null value, an empty array - is created before appending the value created from @a args. + const auto digit = std::labs(static_cast(x % 10)); + number_buffer[i++] = static_cast('0' + digit); + x /= 10; + } - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object + if (is_negative) + { + // make sure there is capacity for the '-' + assert(i < number_buffer.size() - 2); + number_buffer[i++] = '-'; + } - @throw type_error.311 when called on a type other than JSON array or - null; example: `"cannot use emplace_back() with number"` + std::reverse(number_buffer.begin(), number_buffer.begin() + i); + o->write_characters(number_buffer.data(), i); + } - @complexity Amortized constant. + /*! + @brief dump a floating-point number - @liveexample{The example shows how `push_back()` can be used to add - elements to a JSON array. Note how the `null` value was silently converted - to a JSON array.,emplace_back} + Dump a given floating-point number to output stream @a o. Works internally + with @a number_buffer. - @since version 2.0.8 + @param[in] x floating-point number to dump */ - template - void emplace_back(Args&& ... args) + void dump_float(number_float_t x) { - // emplace_back only works for null objects or arrays - if (not(is_null() or is_array())) + // NaN / inf + if (not std::isfinite(x)) { - JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + type_name())); + o->write_characters("null", 4); + return; } - // transform null object into an array - if (is_null()) - { - m_type = value_t::array; - m_value = value_t::array; - assert_invariant(); - } + // If number_float_t is an IEEE-754 single or double precision number, + // use the Grisu2 algorithm to produce short numbers which are + // guaranteed to round-trip, using strtof and strtod, resp. + // + // NB: The test below works if == . + static constexpr bool is_ieee_single_or_double + = (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 24 and std::numeric_limits::max_exponent == 128) or + (std::numeric_limits::is_iec559 and std::numeric_limits::digits == 53 and std::numeric_limits::max_exponent == 1024); - // add element to array (perfect forwarding) - m_value.array->emplace_back(std::forward(args)...); + dump_float(x, std::integral_constant()); } - /*! - @brief add an object to an object if key does not exist - - Inserts a new element into a JSON object constructed in-place with the - given @a args if there is no element with the key in the container. If the - function is called on a JSON null value, an empty object is created before - appending the value created from @a args. - - @param[in] args arguments to forward to a constructor of @ref basic_json - @tparam Args compatible types to create a @ref basic_json object + void dump_float(number_float_t x, std::true_type /*is_ieee_single_or_double*/) + { + char* begin = number_buffer.data(); + char* end = ::nlohmann::detail::to_chars(begin, begin + number_buffer.size(), x); - @return a pair consisting of an iterator to the inserted element, or the - already-existing element if no insertion happened, and a bool - denoting whether the insertion took place. + o->write_characters(begin, static_cast(end - begin)); + } - @throw type_error.311 when called on a type other than JSON object or - null; example: `"cannot use emplace() with number"` + void dump_float(number_float_t x, std::false_type /*is_ieee_single_or_double*/) + { + // get number of digits for a float -> text -> float round-trip + static constexpr auto d = std::numeric_limits::max_digits10; - @complexity Logarithmic in the size of the container, O(log(`size()`)). + // the actual conversion + std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), "%.*g", d, x); - @liveexample{The example shows how `emplace()` can be used to add elements - to a JSON object. Note how the `null` value was silently converted to a - JSON object. Further note how no value is added if there was already one - value stored with the same key.,emplace} + // negative value indicates an error + assert(len > 0); + // check if buffer was large enough + assert(static_cast(len) < number_buffer.size()); - @since version 2.0.8 - */ - template - std::pair emplace(Args&& ... args) - { - // emplace only works for null objects or arrays - if (not(is_null() or is_object())) + // erase thousands separator + if (thousands_sep != '\0') { - JSON_THROW(type_error::create(311, "cannot use emplace() with " + type_name())); + const auto end = std::remove(number_buffer.begin(), + number_buffer.begin() + len, thousands_sep); + std::fill(end, number_buffer.end(), '\0'); + assert((end - number_buffer.begin()) <= len); + len = (end - number_buffer.begin()); } - // transform null object into an object - if (is_null()) + // convert decimal point to '.' + if (decimal_point != '\0' and decimal_point != '.') { - m_type = value_t::object; - m_value = value_t::object; - assert_invariant(); + const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point); + if (dec_pos != number_buffer.end()) + { + *dec_pos = '.'; + } } - // add element to array (perfect forwarding) - auto res = m_value.object->emplace(std::forward(args)...); - // create result iterator and set iterator to the result of emplace - auto it = begin(); - it.m_it.object_iterator = res.first; + o->write_characters(number_buffer.data(), static_cast(len)); - // return pair of iterator and boolean - return {it, res.second}; + // determine if need to append ".0" + const bool value_is_int_like = + std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1, + [](char c) + { + return (c == '.' or c == 'e'); + }); + + if (value_is_int_like) + { + o->write_characters(".0", 2); + } } /*! - @brief inserts element - - Inserts element @a val before iterator @a pos. - - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] val element to insert - @return iterator pointing to the inserted @a val. + @brief check whether a string is UTF-8 encoded - @throw type_error.309 if called on JSON values other than arrays; - example: `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + The function checks each byte of a string whether it is UTF-8 encoded. The + result of the check is stored in the @a state parameter. The function must + be called initially with state 0 (accept). State 1 means the string must + be rejected, because the current byte is not allowed. If the string is + completely processed, but the state is non-zero, the string ended + prematurely; that is, the last byte indicated more bytes should have + followed. - @complexity Constant plus linear in the distance between @a pos and end of - the container. + @param[in,out] state the state of the decoding + @param[in,out] codep codepoint (valid only if resulting state is UTF8_ACCEPT) + @param[in] byte next byte to decode + @return new state - @liveexample{The example shows how `insert()` is used.,insert} + @note The function has been edited: a std::array is used. - @since version 1.0.0 + @copyright Copyright (c) 2008-2009 Bjoern Hoehrmann + @sa http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ */ - iterator insert(const_iterator pos, const basic_json& val) + static uint8_t decode(uint8_t& state, uint32_t& codep, const uint8_t byte) noexcept { - // insert only works for arrays - if (is_array()) + static const std::array utf8d = { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 00..1F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 20..3F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 40..5F + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 60..7F + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, // 80..9F + 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, // A0..BF + 8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, // C0..DF + 0xA, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x3, 0x4, 0x3, 0x3, // E0..EF + 0xB, 0x6, 0x6, 0x6, 0x5, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, 0x8, // F0..FF + 0x0, 0x1, 0x2, 0x3, 0x5, 0x8, 0x7, 0x1, 0x1, 0x1, 0x4, 0x6, 0x1, 0x1, 0x1, 0x1, // s0..s0 + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, // s1..s2 + 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, // s3..s4 + 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, // s5..s6 + 1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 // s7..s8 } + }; - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); - return result; - } + const uint8_t type = utf8d[byte]; - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } + codep = (state != UTF8_ACCEPT) + ? (byte & 0x3fu) | (codep << 6) + : static_cast(0xff >> type) & (byte); - /*! - @brief inserts element - @copydoc insert(const_iterator, const basic_json&) - */ - iterator insert(const_iterator pos, basic_json&& val) - { - return insert(pos, val); + state = utf8d[256u + state * 16u + type]; + return state; } - /*! - @brief inserts elements + private: + /// the output of the serializer + output_adapter_t o = nullptr; + + /// a (hopefully) large enough character buffer + std::array number_buffer{{}}; + + /// the locale + const std::lconv* loc = nullptr; + /// the locale's thousand separator character + const char thousands_sep = '\0'; + /// the locale's decimal point character + const char decimal_point = '\0'; + + /// string buffer + std::array string_buffer{{}}; + + /// the indentation character + const char indent_char; + /// the indentation string + string_t indent_string; +}; +} +} - Inserts @a cnt copies of @a val before iterator @a pos. +// #include - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] cnt number of copies of @a val to insert - @param[in] val element to insert - @return iterator pointing to the first element inserted, or @a pos if - `cnt==0` - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` +#include +#include - @complexity Linear in @a cnt plus linear in the distance between @a pos - and end of the container. +namespace nlohmann +{ +namespace detail +{ +template +class json_ref +{ + public: + using value_type = BasicJsonType; - @liveexample{The example shows how `insert()` is used.,insert__count} + json_ref(value_type&& value) + : owned_value(std::move(value)), value_ref(&owned_value), is_rvalue(true) + {} - @since version 1.0.0 - */ - iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + json_ref(const value_type& value) + : value_ref(const_cast(&value)), is_rvalue(false) + {} + + json_ref(std::initializer_list init) + : owned_value(init), value_ref(&owned_value), is_rvalue(true) + {} + + template + json_ref(Args&& ... args) + : owned_value(std::forward(args)...), value_ref(&owned_value), is_rvalue(true) + {} + + // class should be movable only + json_ref(json_ref&&) = default; + json_ref(const json_ref&) = delete; + json_ref& operator=(const json_ref&) = delete; + + value_type moved_or_copied() const { - // insert only works for arrays - if (is_array()) + if (is_rvalue) { - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } - - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); - return result; + return std::move(*value_ref); } + return *value_ref; + } - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); + value_type const& operator*() const + { + return *static_cast(value_ref); } - /*! - @brief inserts elements + value_type const* operator->() const + { + return static_cast(value_ref); + } - Inserts elements from range `[first, last)` before iterator @a pos. + private: + mutable value_type owned_value = nullptr; + value_type* value_ref = nullptr; + const bool is_rvalue; +}; +} +} - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert +// #include - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` - @throw invalid_iterator.211 if @a first or @a last are iterators into - container for which insert is called; example: `"passed iterators may not - belong to container"` - @return iterator pointing to the first element inserted, or @a pos if - `first==last` +#include // assert +#include // accumulate +#include // string +#include // vector - @complexity Linear in `std::distance(first, last)` plus linear in the - distance between @a pos and end of the container. +// #include - @liveexample{The example shows how `insert()` is used.,insert__range} +// #include - @since version 1.0.0 - */ - iterator insert(const_iterator pos, const_iterator first, const_iterator last) - { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } +// #include - // check if iterator pos fits to this JSON value - if (pos.m_object != this) - { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); - } +namespace nlohmann +{ +template +class json_pointer +{ + // allow basic_json to access private members + NLOHMANN_BASIC_JSON_TPL_DECLARATION + friend class basic_json; - if (first.m_object == this or last.m_object == this) - { - JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); - } + public: + /*! + @brief create JSON pointer - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert( - pos.m_it.array_iterator, - first.m_it.array_iterator, - last.m_it.array_iterator); - return result; - } + Create a JSON pointer according to the syntax described in + [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - /*! - @brief inserts elements + @param[in] s string representing the JSON pointer; if omitted, the empty + string is assumed which references the whole JSON value - Inserts elements from initializer list @a ilist before iterator @a pos. + @throw parse_error.107 if the given JSON pointer @a s is nonempty and does + not begin with a slash (`/`); see example below - @param[in] pos iterator before which the content will be inserted; may be - the end() iterator - @param[in] ilist initializer list to insert the values from + @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s is + not followed by `0` (representing `~`) or `1` (representing `/`); see + example below - @throw type_error.309 if called on JSON values other than arrays; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if @a pos is not an iterator of *this; - example: `"iterator does not fit current value"` + @liveexample{The example shows the construction several valid JSON pointers + as well as the exceptional behavior.,json_pointer} - @return iterator pointing to the first element inserted, or @a pos if - `ilist` is empty + @since version 2.0.0 + */ + explicit json_pointer(const std::string& s = "") + : reference_tokens(split(s)) + {} - @complexity Linear in `ilist.size()` plus linear in the distance between - @a pos and end of the container. + /*! + @brief return a string representation of the JSON pointer - @liveexample{The example shows how `insert()` is used.,insert__ilist} + @invariant For each JSON pointer `ptr`, it holds: + @code {.cpp} + ptr == json_pointer(ptr.to_string()); + @endcode - @since version 1.0.0 + @return a string representation of the JSON pointer + + @liveexample{The example shows the result of `to_string`., + json_pointer__to_string} + + @since version 2.0.0 */ - iterator insert(const_iterator pos, std::initializer_list ilist) + std::string to_string() const noexcept { - // insert only works for arrays - if (not is_array()) - { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); - } - - // check if iterator pos fits to this JSON value - if (pos.m_object != this) + return std::accumulate(reference_tokens.begin(), reference_tokens.end(), + std::string{}, + [](const std::string & a, const std::string & b) { - JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); - } + return a + "/" + escape(b); + }); + } - // insert to array and return iterator - iterator result(this); - result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist); - return result; + /// @copydoc to_string() + operator std::string() const + { + return to_string(); } /*! - @brief inserts elements - - Inserts elements from range `[first, last)`. + @param[in] s reference token to be converted into an array index - @param[in] first begin of the range of elements to insert - @param[in] last end of the range of elements to insert + @return integer representation of @a s - @throw type_error.309 if called on JSON values other than objects; example: - `"cannot use insert() with string"` - @throw invalid_iterator.202 if iterator @a first or @a last does does not - point to an object; example: `"iterators first and last must point to - objects"` - @throw invalid_iterator.210 if @a first and @a last do not belong to the - same JSON value; example: `"iterators do not fit"` + @throw out_of_range.404 if string @a s could not be converted to an integer + */ + static int array_index(const std::string& s) + { + std::size_t processed_chars = 0; + const int res = std::stoi(s, &processed_chars); - @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number - of elements to insert. + // check if the string was completely read + if (JSON_UNLIKELY(processed_chars != s.size())) + { + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'")); + } - @liveexample{The example shows how `insert()` is used.,insert__range_object} + return res; + } - @since version 3.0.0 + private: + /*! + @brief remove and return last reference pointer + @throw out_of_range.405 if JSON pointer has no parent */ - void insert(const_iterator first, const_iterator last) + std::string pop_back() { - // insert only works for objects - if (not is_object()) + if (JSON_UNLIKELY(is_root())) { - JSON_THROW(type_error::create(309, "cannot use insert() with " + type_name())); + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); } - // check if range iterators belong to the same JSON object - if (first.m_object != last.m_object) - { - JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); - } + auto last = reference_tokens.back(); + reference_tokens.pop_back(); + return last; + } - // passed iterators must belong to objects - if (not first.m_object->is_object() or not first.m_object->is_object()) + /// return whether pointer points to the root document + bool is_root() const + { + return reference_tokens.empty(); + } + + json_pointer top() const + { + if (JSON_UNLIKELY(is_root())) { - JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); + JSON_THROW(detail::out_of_range::create(405, "JSON pointer has no parent")); } - m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); + json_pointer result = *this; + result.reference_tokens = {reference_tokens[0]}; + return result; } /*! - @brief exchanges the values + @brief create and return a reference to the pointed to value - Exchanges the contents of the JSON value with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @complexity Linear in the number of reference tokens. - @param[in,out] other JSON value to exchange the contents with + @throw parse_error.109 if array index is not a number + @throw type_error.313 if value cannot be unflattened + */ + BasicJsonType& get_and_create(BasicJsonType& j) const + { + using size_type = typename BasicJsonType::size_type; + auto result = &j; - @complexity Constant. + // in case no reference tokens exist, return a reference to the JSON value + // j which will be overwritten by a primitive value + for (const auto& reference_token : reference_tokens) + { + switch (result->m_type) + { + case detail::value_t::null: + { + if (reference_token == "0") + { + // start a new array if reference token is 0 + result = &result->operator[](0); + } + else + { + // start a new object otherwise + result = &result->operator[](reference_token); + } + break; + } - @liveexample{The example below shows how JSON values can be swapped with - `swap()`.,swap__reference} + case detail::value_t::object: + { + // create an entry in the object + result = &result->operator[](reference_token); + break; + } - @since version 1.0.0 - */ - void swap(reference other) noexcept ( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - std::swap(m_type, other.m_type); - std::swap(m_value, other.m_value); - assert_invariant(); + case detail::value_t::array: + { + // create an entry in the array + JSON_TRY + { + result = &result->operator[](static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } + + /* + The following code is only reached if there exists a reference + token _and_ the current value is primitive. In this case, we have + an error situation, because primitive values may only occur as + single value; that is, with an empty list of reference tokens. + */ + default: + JSON_THROW(detail::type_error::create(313, "invalid value to unflatten")); + } + } + + return *result; } /*! - @brief exchanges the values - - Exchanges the contents of a JSON array with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @brief return a reference to the pointed to value - @param[in,out] other array to exchange the contents with + @note This version does not throw if a value is not present, but tries to + create nested values instead. For instance, calling this function + with pointer `"/this/that"` on a null value is equivalent to calling + `operator[]("this").operator[]("that")` on that value, effectively + changing the null value to an object. - @throw type_error.310 when JSON value is not an array; example: `"cannot - use swap() with string"` + @param[in] ptr a JSON value - @complexity Constant. + @return reference to the JSON value pointed to by the JSON pointer - @liveexample{The example below shows how arrays can be swapped with - `swap()`.,swap__array_t} + @complexity Linear in the length of the JSON pointer. - @since version 1.0.0 + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.404 if the JSON pointer can not be resolved */ - void swap(array_t& other) + BasicJsonType& get_unchecked(BasicJsonType* ptr) const { - // swap only works for arrays - if (is_array()) - { - std::swap(*(m_value.array), other); - } - else + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); - } - } + // convert null values to arrays or objects before continuing + if (ptr->m_type == detail::value_t::null) + { + // check if reference token is a number + const bool nums = + std::all_of(reference_token.begin(), reference_token.end(), + [](const char x) + { + return (x >= '0' and x <= '9'); + }); - /*! - @brief exchanges the values + // change value to array for numbers or "-" or to object otherwise + *ptr = (nums or reference_token == "-") + ? detail::value_t::array + : detail::value_t::object; + } - Exchanges the contents of a JSON object with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + switch (ptr->m_type) + { + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - @param[in,out] other object to exchange the contents with + case detail::value_t::array: + { + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - @throw type_error.310 when JSON value is not an object; example: - `"cannot use swap() with string"` + if (reference_token == "-") + { + // explicitly treat "-" as index beyond the end + ptr = &ptr->operator[](ptr->m_value.array->size()); + } + else + { + // convert array index to number; unchecked access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + } + break; + } - @complexity Constant. + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } - @liveexample{The example below shows how objects can be swapped with - `swap()`.,swap__object_t} + return *ptr; + } - @since version 1.0.0 + /*! + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved */ - void swap(object_t& other) + BasicJsonType& get_checked(BasicJsonType* ptr) const { - // swap only works for objects - if (is_object()) - { - std::swap(*(m_value.object), other); - } - else + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); + switch (ptr->m_type) + { + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } + + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } + + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } + + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } + + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } } + + return *ptr; } /*! - @brief exchanges the values + @brief return a const reference to the pointed to value - Exchanges the contents of a JSON string with those of @a other. Does not - invoke any move, copy, or swap operations on individual elements. All - iterators and references remain valid. The past-the-end iterator is - invalidated. + @param[in] ptr a JSON value - @param[in,out] other string to exchange the contents with + @return const reference to the JSON value pointed to by the JSON + pointer - @throw type_error.310 when JSON value is not a string; example: `"cannot - use swap() with boolean"` + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved + */ + const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const + { + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) + { + switch (ptr->m_type) + { + case detail::value_t::object: + { + // use unchecked object access + ptr = &ptr->operator[](reference_token); + break; + } - @complexity Constant. + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" cannot be used for const access + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } - @liveexample{The example below shows how strings can be swapped with - `swap()`.,swap__string_t} + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } - @since version 1.0.0 + // use unchecked array access + JSON_TRY + { + ptr = &ptr->operator[]( + static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } + + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } + } + + return *ptr; + } + + /*! + @throw parse_error.106 if an array index begins with '0' + @throw parse_error.109 if an array index was not a number + @throw out_of_range.402 if the array index '-' is used + @throw out_of_range.404 if the JSON pointer can not be resolved */ - void swap(string_t& other) + const BasicJsonType& get_checked(const BasicJsonType* ptr) const { - // swap only works for strings - if (is_string()) + using size_type = typename BasicJsonType::size_type; + for (const auto& reference_token : reference_tokens) { - std::swap(*(m_value.string), other); + switch (ptr->m_type) + { + case detail::value_t::object: + { + // note: at performs range check + ptr = &ptr->at(reference_token); + break; + } + + case detail::value_t::array: + { + if (JSON_UNLIKELY(reference_token == "-")) + { + // "-" always fails the range check + JSON_THROW(detail::out_of_range::create(402, + "array index '-' (" + std::to_string(ptr->m_value.array->size()) + + ") is out of range")); + } + + // error condition (cf. RFC 6901, Sect. 4) + if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0')) + { + JSON_THROW(detail::parse_error::create(106, 0, + "array index '" + reference_token + + "' must not begin with '0'")); + } + + // note: at performs range check + JSON_TRY + { + ptr = &ptr->at(static_cast(array_index(reference_token))); + } + JSON_CATCH(std::invalid_argument&) + { + JSON_THROW(detail::parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); + } + break; + } + + default: + JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); + } } - else + + return *ptr; + } + + /*! + @brief split the string input to reference tokens + + @note This function is only called by the json_pointer constructor. + All exceptions below are documented there. + + @throw parse_error.107 if the pointer is not empty or begins with '/' + @throw parse_error.108 if character '~' is not followed by '0' or '1' + */ + static std::vector split(const std::string& reference_string) + { + std::vector result; + + // special case: empty reference string -> no reference tokens + if (reference_string.empty()) { - JSON_THROW(type_error::create(310, "cannot use swap() with " + type_name())); + return result; } - } - /// @} + // check if nonempty reference string begins with slash + if (JSON_UNLIKELY(reference_string[0] != '/')) + { + JSON_THROW(detail::parse_error::create(107, 1, + "JSON pointer must be empty or begin with '/' - was: '" + + reference_string + "'")); + } + + // extract the reference tokens: + // - slash: position of the last read slash (or end of string) + // - start: position after the previous slash + for ( + // search for the first slash after the first character + std::size_t slash = reference_string.find_first_of('/', 1), + // set the beginning of the first reference token + start = 1; + // we can stop if start == string::npos+1 = 0 + start != 0; + // set the beginning of the next reference token + // (will eventually be 0 if slash == std::string::npos) + start = slash + 1, + // find next slash + slash = reference_string.find_first_of('/', start)) + { + // use the text between the beginning of the reference token + // (start) and the last slash (slash). + auto reference_token = reference_string.substr(start, slash - start); + + // check reference tokens are properly escaped + for (std::size_t pos = reference_token.find_first_of('~'); + pos != std::string::npos; + pos = reference_token.find_first_of('~', pos + 1)) + { + assert(reference_token[pos] == '~'); - public: - ////////////////////////////////////////// - // lexicographical comparison operators // - ////////////////////////////////////////// + // ~ must be followed by 0 or 1 + if (JSON_UNLIKELY(pos == reference_token.size() - 1 or + (reference_token[pos + 1] != '0' and + reference_token[pos + 1] != '1'))) + { + JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); + } + } - /// @name lexicographical comparison operators - /// @{ + // finally, store the reference token + unescape(reference_token); + result.push_back(reference_token); + } + + return result; + } /*! - @brief comparison: equal + @brief replace all occurrences of a substring by another string - Compares two JSON values for equality according to the following rules: - - Two JSON values are equal if (1) they are from the same type and (2) - their stored values are the same according to their respective - `operator==`. - - Integer and floating-point numbers are automatically converted before - comparison. Floating-point numbers are compared indirectly: two - floating-point numbers `f1` and `f2` are considered equal if neither - `f1 > f2` nor `f2 > f1` holds. Note than two NaN values are always - treated as unequal. - - Two JSON null values are equal. + @param[in,out] s the string to manipulate; changed so that all + occurrences of @a f are replaced with @a t + @param[in] f the substring to replace with @a t + @param[in] t the string to replace @a f - @note NaN values never compare equal to themselves or to other NaN values. + @pre The search string @a f must not be empty. **This precondition is + enforced with an assertion.** - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are equal + @since version 2.0.0 + */ + static void replace_substring(std::string& s, const std::string& f, + const std::string& t) + { + assert(not f.empty()); + for (auto pos = s.find(f); // find first occurrence of f + pos != std::string::npos; // make sure f was found + s.replace(pos, f.size(), t), // replace with t, and + pos = s.find(f, pos + t.size())) // find next occurrence of f + {} + } - @complexity Linear. + /// escape "~"" to "~0" and "/" to "~1" + static std::string escape(std::string s) + { + replace_substring(s, "~", "~0"); + replace_substring(s, "/", "~1"); + return s; + } - @liveexample{The example demonstrates comparing several JSON - types.,operator__equal} + /// unescape "~1" to tilde and "~0" to slash (order is important!) + static void unescape(std::string& s) + { + replace_substring(s, "~1", "/"); + replace_substring(s, "~0", "~"); + } - @since version 1.0.0 + /*! + @param[in] reference_string the reference string to the current value + @param[in] value the value to consider + @param[in,out] result the result object to insert values to + + @note Empty objects or arrays are flattened to `null`. */ - friend bool operator==(const_reference lhs, const_reference rhs) noexcept + static void flatten(const std::string& reference_string, + const BasicJsonType& value, + BasicJsonType& result) { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); - - if (lhs_type == rhs_type) + switch (value.m_type) { - switch (lhs_type) + case detail::value_t::array: { - case value_t::array: - { - return *lhs.m_value.array == *rhs.m_value.array; - } - case value_t::object: - { - return *lhs.m_value.object == *rhs.m_value.object; - } - case value_t::null: - { - return true; - } - case value_t::string: - { - return *lhs.m_value.string == *rhs.m_value.string; - } - case value_t::boolean: + if (value.m_value.array->empty()) { - return lhs.m_value.boolean == rhs.m_value.boolean; + // flatten empty array as null + result[reference_string] = nullptr; } - case value_t::number_integer: - { - return lhs.m_value.number_integer == rhs.m_value.number_integer; - } - case value_t::number_unsigned: + else { - return lhs.m_value.number_unsigned == rhs.m_value.number_unsigned; + // iterate array and use index as reference string + for (std::size_t i = 0; i < value.m_value.array->size(); ++i) + { + flatten(reference_string + "/" + std::to_string(i), + value.m_value.array->operator[](i), result); + } } - case value_t::number_float: + break; + } + + case detail::value_t::object: + { + if (value.m_value.object->empty()) { - return lhs.m_value.number_float == rhs.m_value.number_float; + // flatten empty object as null + result[reference_string] = nullptr; } - default: + else { - return false; + // iterate object and use keys as reference string + for (const auto& element : *value.m_value.object) + { + flatten(reference_string + "/" + escape(element.first), element.second, result); + } } + break; + } + + default: + { + // add primitive value with its reference string + result[reference_string] = value; + break; } } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) + } + + /*! + @param[in] value flattened JSON + + @return unflattened JSON + + @throw parse_error.109 if array index is not a number + @throw type_error.314 if value is not an object + @throw type_error.315 if object values are not primitive + @throw type_error.313 if value cannot be unflattened + */ + static BasicJsonType + unflatten(const BasicJsonType& value) + { + if (JSON_UNLIKELY(not value.is_object())) { - return static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float; + JSON_THROW(detail::type_error::create(314, "only objects can be unflattened")); } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) + + BasicJsonType result; + + // iterate the JSON object values + for (const auto& element : *value.m_value.object) { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer; - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned); + if (JSON_UNLIKELY(not element.second.is_primitive())) + { + JSON_THROW(detail::type_error::create(315, "values in object must be primitive")); + } + + // assign value to reference pointed to by JSON pointer; Note that if + // the JSON pointer is "" (i.e., points to the whole value), function + // get_and_create returns a reference to result itself. An assignment + // will then create a primitive value. + json_pointer(element.first).get_and_create(result) = element.second; } - return false; + return result; } - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept + friend bool operator==(json_pointer const& lhs, + json_pointer const& rhs) noexcept { - return (lhs == basic_json(rhs)); + return (lhs.reference_tokens == rhs.reference_tokens); } - /*! - @brief comparison: equal - @copydoc operator==(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept + friend bool operator!=(json_pointer const& lhs, + json_pointer const& rhs) noexcept { - return (basic_json(lhs) == rhs); + return not (lhs == rhs); } - /*! - @brief comparison: not equal + /// the reference tokens + std::vector reference_tokens; +}; +} - Compares two JSON values for inequality by calculating `not (lhs == rhs)`. +// #include - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether the values @a lhs and @a rhs are not equal - @complexity Linear. +#include - @liveexample{The example demonstrates comparing several JSON - types.,operator__notequal} +// #include - @since version 1.0.0 - */ - friend bool operator!=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs == rhs); - } +// #include + +namespace nlohmann +{ +template +struct adl_serializer +{ /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) + @brief convert a JSON value to any value type + + This function is usually called by the `get()` function of the + @ref basic_json class (either explicit or via conversion operators). + + @param[in] j JSON value to read from + @param[in,out] val value to write to */ - template::value, int>::type = 0> - friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept + template + static void from_json(BasicJsonType&& j, ValueType& val) noexcept( + noexcept(::nlohmann::from_json(std::forward(j), val))) { - return (lhs != basic_json(rhs)); + ::nlohmann::from_json(std::forward(j), val); } /*! - @brief comparison: not equal - @copydoc operator!=(const_reference, const_reference) + @brief convert any value type to a JSON value + + This function is usually called by the constructors of the @ref basic_json + class. + + @param[in,out] j JSON value to write to + @param[in] val value to read from */ - template::value, int>::type = 0> - friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept + template + static void to_json(BasicJsonType& j, ValueType&& val) noexcept( + noexcept(::nlohmann::to_json(j, std::forward(val)))) { - return (basic_json(lhs) != rhs); + ::nlohmann::to_json(j, std::forward(val)); } +}; +} - /*! - @brief comparison: less than - Compares whether one JSON value @a lhs is less than another JSON value @a - rhs according to the following rules: - - If @a lhs and @a rhs have the same type, the values are compared using - the default `<` operator. - - Integer and floating-point numbers are automatically converted before - comparison - - In case @a lhs and @a rhs have different types, the values are ignored - and the order of the types is considered, see - @ref operator<(const value_t, const value_t). +/*! +@brief namespace for Niels Lohmann +@see https://github.com/nlohmann +@since version 1.0.0 +*/ +namespace nlohmann +{ - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than @a rhs +/*! +@brief a class to store JSON values - @complexity Linear. +@tparam ObjectType type for JSON objects (`std::map` by default; will be used +in @ref object_t) +@tparam ArrayType type for JSON arrays (`std::vector` by default; will be used +in @ref array_t) +@tparam StringType type for JSON strings and object keys (`std::string` by +default; will be used in @ref string_t) +@tparam BooleanType type for JSON booleans (`bool` by default; will be used +in @ref boolean_t) +@tparam NumberIntegerType type for JSON integer numbers (`int64_t` by +default; will be used in @ref number_integer_t) +@tparam NumberUnsignedType type for JSON unsigned integer numbers (@c +`uint64_t` by default; will be used in @ref number_unsigned_t) +@tparam NumberFloatType type for JSON floating-point numbers (`double` by +default; will be used in @ref number_float_t) +@tparam AllocatorType type of the allocator to use (`std::allocator` by +default) +@tparam JSONSerializer the serializer to resolve internal calls to `to_json()` +and `from_json()` (@ref adl_serializer by default) - @liveexample{The example demonstrates comparing several JSON - types.,operator__less} +@requirement The class satisfies the following concept requirements: +- Basic + - [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible): + JSON values can be default constructed. The result will be a JSON null + value. + - [MoveConstructible](https://en.cppreference.com/w/cpp/named_req/MoveConstructible): + A JSON value can be constructed from an rvalue argument. + - [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible): + A JSON value can be copy-constructed from an lvalue expression. + - [MoveAssignable](https://en.cppreference.com/w/cpp/named_req/MoveAssignable): + A JSON value van be assigned from an rvalue argument. + - [CopyAssignable](https://en.cppreference.com/w/cpp/named_req/CopyAssignable): + A JSON value can be copy-assigned from an lvalue expression. + - [Destructible](https://en.cppreference.com/w/cpp/named_req/Destructible): + JSON values can be destructed. +- Layout + - [StandardLayoutType](https://en.cppreference.com/w/cpp/named_req/StandardLayoutType): + JSON values have + [standard layout](https://en.cppreference.com/w/cpp/language/data_members#Standard_layout): + All non-static data members are private and standard layout types, the + class has no virtual functions or (virtual) base classes. +- Library-wide + - [EqualityComparable](https://en.cppreference.com/w/cpp/named_req/EqualityComparable): + JSON values can be compared with `==`, see @ref + operator==(const_reference,const_reference). + - [LessThanComparable](https://en.cppreference.com/w/cpp/named_req/LessThanComparable): + JSON values can be compared with `<`, see @ref + operator<(const_reference,const_reference). + - [Swappable](https://en.cppreference.com/w/cpp/named_req/Swappable): + Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of + other compatible types, using unqualified function call @ref swap(). + - [NullablePointer](https://en.cppreference.com/w/cpp/named_req/NullablePointer): + JSON values can be compared against `std::nullptr_t` objects which are used + to model the `null` value. +- Container + - [Container](https://en.cppreference.com/w/cpp/named_req/Container): + JSON values can be used like STL containers and provide iterator access. + - [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer); + JSON values can be used like STL containers and provide reverse iterator + access. - @since version 1.0.0 - */ - friend bool operator<(const_reference lhs, const_reference rhs) noexcept - { - const auto lhs_type = lhs.type(); - const auto rhs_type = rhs.type(); +@invariant The member variables @a m_value and @a m_type have the following +relationship: +- If `m_type == value_t::object`, then `m_value.object != nullptr`. +- If `m_type == value_t::array`, then `m_value.array != nullptr`. +- If `m_type == value_t::string`, then `m_value.string != nullptr`. +The invariants are checked by member function assert_invariant(). - if (lhs_type == rhs_type) - { - switch (lhs_type) - { - case value_t::array: - { - //return *lhs.m_value.array < *rhs.m_value.array; - //return *lhs.m_value.array.operator<(rhs); - return (*lhs.m_value.array) < *rhs.m_value.array; - // return nlohmann::detail::operator<(lhs, rhs); - } - case value_t::object: - { - return *lhs.m_value.object < *rhs.m_value.object; - } - case value_t::null: - { - return false; - } - case value_t::string: - { - return *lhs.m_value.string < *rhs.m_value.string; - } - case value_t::boolean: - { - return lhs.m_value.boolean < rhs.m_value.boolean; - } - case value_t::number_integer: - { - return lhs.m_value.number_integer < rhs.m_value.number_integer; - } - case value_t::number_unsigned: - { - return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - } - case value_t::number_float: - { - return lhs.m_value.number_float < rhs.m_value.number_float; - } - default: - { - return false; - } - } - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; - } - else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) - { - return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); - } - else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) - { - return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; - } +@internal +@note ObjectType trick from http://stackoverflow.com/a/9860911 +@endinternal - // We only reach this line if we cannot compare values. In that case, - // we compare types. Note we have to call the operator explicitly, - // because MSVC has problems otherwise. - return operator<(lhs_type, rhs_type); - } +@see [RFC 7159: The JavaScript Object Notation (JSON) Data Interchange +Format](http://rfc7159.net/rfc7159) - /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs < basic_json(rhs)); - } +@since version 1.0.0 - /*! - @brief comparison: less than - @copydoc operator<(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) < rhs); - } +@nosubgrouping +*/ +NLOHMANN_BASIC_JSON_TPL_DECLARATION +class basic_json +{ + private: + template friend struct detail::external_constructor; + friend ::nlohmann::json_pointer; + friend ::nlohmann::detail::parser; + friend ::nlohmann::detail::serializer; + template + friend class ::nlohmann::detail::iter_impl; + template + friend class ::nlohmann::detail::binary_writer; + template + friend class ::nlohmann::detail::binary_reader; + template + friend class ::nlohmann::detail::json_sax_dom_parser; + template + friend class ::nlohmann::detail::json_sax_dom_callback_parser; - /*! - @brief comparison: less than or equal + /// workaround type for MSVC + using basic_json_t = NLOHMANN_BASIC_JSON_TPL; - Compares whether one JSON value @a lhs is less than or equal to another - JSON value by calculating `not (rhs < lhs)`. + // convenience aliases for types residing in namespace detail; + using lexer = ::nlohmann::detail::lexer; + using parser = ::nlohmann::detail::parser; - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is less than or equal to @a rhs + using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t; + template + using internal_iterator = ::nlohmann::detail::internal_iterator; + template + using iter_impl = ::nlohmann::detail::iter_impl; + template + using iteration_proxy = ::nlohmann::detail::iteration_proxy; + template using json_reverse_iterator = ::nlohmann::detail::json_reverse_iterator; - @complexity Linear. + template + using output_adapter_t = ::nlohmann::detail::output_adapter_t; - @liveexample{The example demonstrates comparing several JSON - types.,operator__greater} + using binary_reader = ::nlohmann::detail::binary_reader; + template using binary_writer = ::nlohmann::detail::binary_writer; - @since version 1.0.0 - */ - friend bool operator<=(const_reference lhs, const_reference rhs) noexcept - { - return not (rhs < lhs); - } + using serializer = ::nlohmann::detail::serializer; - /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs <= basic_json(rhs)); - } + public: + using value_t = detail::value_t; + /// @copydoc nlohmann::json_pointer + using json_pointer = ::nlohmann::json_pointer; + template + using json_serializer = JSONSerializer; + /// helper type for initializer lists of basic_json values + using initializer_list_t = std::initializer_list>; - /*! - @brief comparison: less than or equal - @copydoc operator<=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) <= rhs); - } + using input_format_t = detail::input_format_t; - /*! - @brief comparison: greater than + //////////////// + // exceptions // + //////////////// - Compares whether one JSON value @a lhs is greater than another - JSON value by calculating `not (lhs <= rhs)`. + /// @name exceptions + /// Classes to implement user-defined exceptions. + /// @{ - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than to @a rhs + /// @copydoc detail::exception + using exception = detail::exception; + /// @copydoc detail::parse_error + using parse_error = detail::parse_error; + /// @copydoc detail::invalid_iterator + using invalid_iterator = detail::invalid_iterator; + /// @copydoc detail::type_error + using type_error = detail::type_error; + /// @copydoc detail::out_of_range + using out_of_range = detail::out_of_range; + /// @copydoc detail::other_error + using other_error = detail::other_error; - @complexity Linear. + /// @} - @liveexample{The example demonstrates comparing several JSON - types.,operator__lessequal} - @since version 1.0.0 - */ - friend bool operator>(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs <= rhs); - } + ///////////////////// + // container types // + ///////////////////// - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs > basic_json(rhs)); - } + /// @name container types + /// The canonic container types to use @ref basic_json like any other STL + /// container. + /// @{ - /*! - @brief comparison: greater than - @copydoc operator>(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept - { - return (basic_json(lhs) > rhs); - } + /// the type of elements in a basic_json container + using value_type = basic_json; - /*! - @brief comparison: greater than or equal + /// the type of an element reference + using reference = value_type&; + /// the type of an element const reference + using const_reference = const value_type&; - Compares whether one JSON value @a lhs is greater than or equal to another - JSON value by calculating `not (lhs < rhs)`. + /// a type to represent differences between iterators + using difference_type = std::ptrdiff_t; + /// a type to represent container sizes + using size_type = std::size_t; - @param[in] lhs first JSON value to consider - @param[in] rhs second JSON value to consider - @return whether @a lhs is greater than or equal to @a rhs + /// the allocator type + using allocator_type = AllocatorType; - @complexity Linear. + /// the type of an element pointer + using pointer = typename std::allocator_traits::pointer; + /// the type of an element const pointer + using const_pointer = typename std::allocator_traits::const_pointer; - @liveexample{The example demonstrates comparing several JSON - types.,operator__greaterequal} + /// an iterator for a basic_json container + using iterator = iter_impl; + /// a const iterator for a basic_json container + using const_iterator = iter_impl; + /// a reverse iterator for a basic_json container + using reverse_iterator = json_reverse_iterator; + /// a const reverse iterator for a basic_json container + using const_reverse_iterator = json_reverse_iterator; - @since version 1.0.0 - */ - friend bool operator>=(const_reference lhs, const_reference rhs) noexcept - { - return not (lhs < rhs); - } + /// @} - /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) - */ - template::value, int>::type = 0> - friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept - { - return (lhs >= basic_json(rhs)); - } /*! - @brief comparison: greater than or equal - @copydoc operator>=(const_reference, const_reference) + @brief returns the allocator associated with the container */ - template::value, int>::type = 0> - friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept + static allocator_type get_allocator() { - return (basic_json(lhs) >= rhs); + return allocator_type(); } - /// @} - - private: - ///////////////////// - // output adapters // - ///////////////////// + /*! + @brief returns version information on the library - /// abstract output adapter interface - template - class output_adapter - { - public: - virtual void write_character(CharType c) = 0; - virtual void write_characters(const CharType* s, size_t length) = 0; - virtual ~output_adapter() {} + This function returns a JSON object with information about the library, + including the version number and information on the platform and compiler. - static std::shared_ptr> create(std::vector& vec) - { - return std::shared_ptr(new output_vector_adapter(vec)); - } + @return JSON object holding version information + key | description + ----------- | --------------- + `compiler` | Information on the used compiler. It is an object with the following keys: `c++` (the used C++ standard), `family` (the compiler family; possible values are `clang`, `icc`, `gcc`, `ilecpp`, `msvc`, `pgcpp`, `sunpro`, and `unknown`), and `version` (the compiler version). + `copyright` | The copyright line for the library as string. + `name` | The name of the library as string. + `platform` | The used platform as string. Possible values are `win32`, `linux`, `apple`, `unix`, and `unknown`. + `url` | The URL of the project as string. + `version` | The version of the library. It is an object with the following keys: `major`, `minor`, and `patch` as defined by [Semantic Versioning](http://semver.org), and `string` (the version string). - static std::shared_ptr> create(std::ostream& s) - { - return std::shared_ptr(new output_stream_adapter(s)); - } + @liveexample{The following code shows an example output of the `meta()` + function.,meta} - static std::shared_ptr> create(std::string& s) - { - return std::shared_ptr(new output_string_adapter(s)); - } - }; + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - /// a type to simplify interfaces - template - using output_adapter_t = std::shared_ptr>; + @complexity Constant. - /// output adapter for byte vectors - template - class output_vector_adapter : public output_adapter + @since 2.1.0 + */ + static basic_json meta() { - public: - output_vector_adapter(std::vector& vec) - : v(vec) - {} - - void write_character(CharType c) override - { - v.push_back(c); - } - - void write_characters(const CharType* s, size_t length) override - { - std::copy(s, s + length, std::back_inserter(v)); - } - - private: - std::vector& v; - }; + basic_json result; - /// putput adatpter for output streams - template - class output_stream_adapter : public output_adapter - { - public: - output_stream_adapter(std::basic_ostream& s) - : stream(s) - {} + result["copyright"] = "(C) 2013-2017 Niels Lohmann"; + result["name"] = "JSON for Modern C++"; + result["url"] = "https://github.com/nlohmann/json"; + result["version"]["string"] = + std::to_string(NLOHMANN_JSON_VERSION_MAJOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_MINOR) + "." + + std::to_string(NLOHMANN_JSON_VERSION_PATCH); + result["version"]["major"] = NLOHMANN_JSON_VERSION_MAJOR; + result["version"]["minor"] = NLOHMANN_JSON_VERSION_MINOR; + result["version"]["patch"] = NLOHMANN_JSON_VERSION_PATCH; - void write_character(CharType c) override - { - stream.put(c); - } +#ifdef _WIN32 + result["platform"] = "win32"; +#elif defined __linux__ + result["platform"] = "linux"; +#elif defined __APPLE__ + result["platform"] = "apple"; +#elif defined __unix__ + result["platform"] = "unix"; +#else + result["platform"] = "unknown"; +#endif - void write_characters(const CharType* s, size_t length) override - { - stream.write(s, static_cast(length)); - } +#if defined(__ICC) || defined(__INTEL_COMPILER) + result["compiler"] = {{"family", "icc"}, {"version", __INTEL_COMPILER}}; +#elif defined(__clang__) + result["compiler"] = {{"family", "clang"}, {"version", __clang_version__}}; +#elif defined(__GNUC__) || defined(__GNUG__) + result["compiler"] = {{"family", "gcc"}, {"version", std::to_string(__GNUC__) + "." + std::to_string(__GNUC_MINOR__) + "." + std::to_string(__GNUC_PATCHLEVEL__)}}; +#elif defined(__HP_cc) || defined(__HP_aCC) + result["compiler"] = "hp" +#elif defined(__IBMCPP__) + result["compiler"] = {{"family", "ilecpp"}, {"version", __IBMCPP__}}; +#elif defined(_MSC_VER) + result["compiler"] = {{"family", "msvc"}, {"version", _MSC_VER}}; +#elif defined(__PGI) + result["compiler"] = {{"family", "pgcpp"}, {"version", __PGI}}; +#elif defined(__SUNPRO_CC) + result["compiler"] = {{"family", "sunpro"}, {"version", __SUNPRO_CC}}; +#else + result["compiler"] = {{"family", "unknown"}, {"version", "unknown"}}; +#endif - private: - std::basic_ostream& stream; - }; +#ifdef __cplusplus + result["compiler"]["c++"] = std::to_string(__cplusplus); +#else + result["compiler"]["c++"] = "unknown"; +#endif + return result; + } - /// output adapter for basic_string - template - class output_string_adapter : public output_adapter - { - public: - output_string_adapter(std::string& s) - : str(s) - {} - void write_character(CharType c) override - { - str.push_back(c); - } + /////////////////////////// + // JSON value data types // + /////////////////////////// - void write_characters(const CharType* s, size_t length) override - { - str.append(s, length); - } + /// @name JSON value data types + /// The data types to store a JSON value. These types are derived from + /// the template arguments passed to class @ref basic_json. + /// @{ - private: - std::basic_string& str; - }; +#if defined(JSON_HAS_CPP_14) + // Use transparent comparator if possible, combined with perfect forwarding + // on find() and count() calls prevents unnecessary string construction. + using object_comparator_t = std::less<>; +#else + using object_comparator_t = std::less; +#endif + /*! + @brief a type for an object - /////////////////// - // serialization // - /////////////////// + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON objects as follows: + > An object is an unordered collection of zero or more name/value pairs, + > where a name is a string and a value is a string, number, boolean, null, + > object, or array. - /// @name serialization - /// @{ + To store objects in C++, a type is defined by the template parameters + described below. - private: - /*! - @brief wrapper around the serialization functions - */ - class serializer - { - private: - serializer(const serializer&) = delete; - serializer& operator=(const serializer&) = delete; + @tparam ObjectType the container to store objects (e.g., `std::map` or + `std::unordered_map`) + @tparam StringType the type of the keys or names (e.g., `std::string`). + The comparison function `std::less` is used to order elements + inside the container. + @tparam AllocatorType the allocator to use for objects (e.g., + `std::allocator`) - public: - /*! - @param[in] s output stream to serialize to - @param[in] ichar indentation character to use - */ - serializer(output_adapter_t s, const char ichar) - : o(s), loc(std::localeconv()), - thousands_sep(!loc->thousands_sep ? '\0' : loc->thousands_sep[0]), - decimal_point(!loc->decimal_point ? '\0' : loc->decimal_point[0]), - indent_char(ichar), indent_string(512, indent_char) - {} + #### Default type - /*! - @brief internal implementation of the serialization function + With the default values for @a ObjectType (`std::map`), @a StringType + (`std::string`), and @a AllocatorType (`std::allocator`), the default + value for @a object_t is: - This function is called by the public member function dump and - organizes the serialization internally. The indentation level is - propagated as additional parameter. In case of arrays and objects, the - function is called recursively. + @code {.cpp} + std::map< + std::string, // key_type + basic_json, // value_type + std::less, // key_compare + std::allocator> // allocator_type + > + @endcode - - strings and object keys are escaped using `escape_string()` - - integer numbers are converted implicitly via `operator<<` - - floating-point numbers are converted to a string using `"%g"` format + #### Behavior - @param[in] val value to serialize - @param[in] pretty_print whether the output shall be pretty-printed - @param[in] indent_step the indent level - @param[in] current_indent the current indent level (only used internally) - */ - void dump(const basic_json& val, - const bool pretty_print, - const unsigned int indent_step, - const unsigned int current_indent = 0) - { - switch (val.m_type) - { - case value_t::object: - { - if (val.m_value.object->empty()) - { - o->write_characters("{}", 2); - return; - } + The choice of @a object_t influences the behavior of the JSON class. With + the default type, objects have the following behavior: - if (pretty_print) - { - o->write_characters("{\n", 2); + - When all names are unique, objects will be interoperable in the sense + that all software implementations receiving that object will agree on + the name-value mappings. + - When the names within an object are not unique, it is unspecified which + one of the values for a given key will be chosen. For instance, + `{"key": 2, "key": 1}` could be equal to either `{"key": 1}` or + `{"key": 2}`. + - Internally, name/value pairs are stored in lexicographical order of the + names. Objects will also be serialized (see @ref dump) in this order. + For instance, `{"b": 1, "a": 2}` and `{"a": 2, "b": 1}` will be stored + and serialized as `{"a": 2, "b": 1}`. + - When comparing objects, the order of the name/value pairs is irrelevant. + This makes objects interoperable in the sense that they will not be + affected by these differences. For instance, `{"b": 1, "a": 2}` and + `{"a": 2, "b": 1}` will be treated as equal. - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } + #### Limits - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - // last element - assert(i != val.m_value.object->cend()); - o->write_characters(indent_string.c_str(), new_indent); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\": ", 3); - dump(i->second, true, indent_step, new_indent); + In this class, the object's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON object. - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character('}'); - } - else - { - o->write_character('{'); + #### Storage - // first n-1 elements - auto i = val.m_value.object->cbegin(); - for (size_t cnt = 0; cnt < val.m_value.object->size() - 1; ++cnt, ++i) - { - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); - o->write_character(','); - } + Objects are stored as pointers in a @ref basic_json type. That is, for any + access to object values, a pointer of type `object_t*` must be + dereferenced. - // last element - assert(i != val.m_value.object->cend()); - o->write_character('\"'); - dump_escaped(i->first); - o->write_characters("\":", 2); - dump(i->second, false, indent_step, current_indent); + @sa @ref array_t -- type for an array value - o->write_character('}'); - } + @since version 1.0.0 - return; - } + @note The order name/value pairs are added to the object is *not* + preserved by the library. Therefore, iterating an object may return + name/value pairs in a different order than they were originally stored. In + fact, keys will be traversed in alphabetical order as `std::map` with + `std::less` is used by default. Please note this behavior conforms to [RFC + 7159](http://rfc7159.net/rfc7159), because any order implements the + specified "unordered" nature of JSON objects. + */ + using object_t = ObjectType>>; - case value_t::array: - { - if (val.m_value.array->empty()) - { - o->write_characters("[]", 2); - return; - } + /*! + @brief a type for an array - if (pretty_print) - { - o->write_characters("[\n", 2); + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON arrays as follows: + > An array is an ordered sequence of zero or more values. - // variable to hold indentation for recursive calls - const auto new_indent = current_indent + indent_step; - if (indent_string.size() < new_indent) - { - indent_string.resize(new_indent, ' '); - } + To store objects in C++, a type is defined by the template parameters + explained below. - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - o->write_characters(indent_string.c_str(), new_indent); - dump(*i, true, indent_step, new_indent); - o->write_characters(",\n", 2); - } + @tparam ArrayType container type to store arrays (e.g., `std::vector` or + `std::list`) + @tparam AllocatorType allocator to use for arrays (e.g., `std::allocator`) - // last element - assert(not val.m_value.array->empty()); - o->write_characters(indent_string.c_str(), new_indent); - dump(val.m_value.array->back(), true, indent_step, new_indent); + #### Default type - o->write_character('\n'); - o->write_characters(indent_string.c_str(), current_indent); - o->write_character(']'); - } - else - { - o->write_character('['); + With the default values for @a ArrayType (`std::vector`) and @a + AllocatorType (`std::allocator`), the default value for @a array_t is: - // first n-1 elements - for (auto i = val.m_value.array->cbegin(); i != val.m_value.array->cend() - 1; ++i) - { - dump(*i, false, indent_step, current_indent); - o->write_character(','); - } + @code {.cpp} + std::vector< + basic_json, // value_type + std::allocator // allocator_type + > + @endcode - // last element - assert(not val.m_value.array->empty()); - dump(val.m_value.array->back(), false, indent_step, current_indent); + #### Limits - o->write_character(']'); - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the maximum depth of nesting. - return; - } + In this class, the array's limit of nesting is not explicitly constrained. + However, a maximum depth of nesting may be introduced by the compiler or + runtime environment. A theoretical limit can be queried by calling the + @ref max_size function of a JSON array. - case value_t::string: - { - o->write_character('\"'); - dump_escaped(*val.m_value.string); - o->write_character('\"'); - return; - } + #### Storage - case value_t::boolean: - { - if (val.m_value.boolean) - { - o->write_characters("true", 4); - } - else - { - o->write_characters("false", 5); - } - return; - } + Arrays are stored as pointers in a @ref basic_json type. That is, for any + access to array values, a pointer of type `array_t*` must be dereferenced. - case value_t::number_integer: - { - dump_integer(val.m_value.number_integer); - return; - } + @sa @ref object_t -- type for an object value - case value_t::number_unsigned: - { - dump_integer(val.m_value.number_unsigned); - return; - } + @since version 1.0.0 + */ + using array_t = ArrayType>; - case value_t::number_float: - { - dump_float(val.m_value.number_float); - return; - } + /*! + @brief a type for a string - case value_t::discarded: - { - o->write_characters("", 11); - return; - } + [RFC 7159](http://rfc7159.net/rfc7159) describes JSON strings as follows: + > A string is a sequence of zero or more Unicode characters. - case value_t::null: - { - o->write_characters("null", 4); - return; - } - } - } + To store objects in C++, a type is defined by the template parameter + described below. Unicode values are split by the JSON class into + byte-sized characters during deserialization. - private: - /*! - @brief calculates the extra space to escape a JSON string + @tparam StringType the container to store strings (e.g., `std::string`). + Note this container is used for keys/names in objects, see @ref object_t. - @param[in] s the string to escape - @return the number of characters required to escape string @a s + #### Default type - @complexity Linear in the length of string @a s. - */ - static std::size_t extra_space(const string_t& s) noexcept - { - return std::accumulate(s.begin(), s.end(), size_t{}, - [](size_t res, typename string_t::value_type c) - { - switch (c) - { - case '"': - case '\\': - case '\b': - case '\f': - case '\n': - case '\r': - case '\t': - { - // from c (1 byte) to \x (2 bytes) - return res + 1; - } + With the default values for @a StringType (`std::string`), the default + value for @a string_t is: - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // from c (1 byte) to \uxxxx (6 bytes) - return res + 5; - } + @code {.cpp} + std::string + @endcode - default: - { - return res; - } - } - }); - } + #### Encoding - /*! - @brief dump escaped string + Strings are stored in UTF-8 encoding. Therefore, functions like + `std::string::size()` or `std::string::length()` return the number of + bytes in the string rather than the number of characters or glyphs. - Escape a string by replacing certain special characters by a sequence - of an escape character (backslash) and another character and other - control characters by a sequence of "\u" followed by a four-digit hex - representation. The escaped string is written to output stream @a o. + #### String comparison - @param[in] s the string to escape + [RFC 7159](http://rfc7159.net/rfc7159) states: + > Software implementations are typically required to test names of object + > members for equality. Implementations that transform the textual + > representation into sequences of Unicode code units and then perform the + > comparison numerically, code unit by code unit, are interoperable in the + > sense that implementations will agree in all cases on equality or + > inequality of two strings. For example, implementations that compare + > strings with escaped characters unconverted may incorrectly find that + > `"a\\b"` and `"a\u005Cb"` are not equal. - @complexity Linear in the length of string @a s. - */ - void dump_escaped(const string_t& s) const - { - const auto space = extra_space(s); - if (space == 0) - { - o->write_characters(s.c_str(), s.size()); - return; - } + This implementation is interoperable as it does compare strings code unit + by code unit. - // create a result string of necessary size - string_t result(s.size() + space, '\\'); - std::size_t pos = 0; + #### Storage - for (const auto& c : s) - { - switch (c) - { - // quotation mark (0x22) - case '"': - { - result[pos + 1] = '"'; - pos += 2; - break; - } + String values are stored as pointers in a @ref basic_json type. That is, + for any access to string values, a pointer of type `string_t*` must be + dereferenced. - // reverse solidus (0x5c) - case '\\': - { - // nothing to change - pos += 2; - break; - } + @since version 1.0.0 + */ + using string_t = StringType; - // backspace (0x08) - case '\b': - { - result[pos + 1] = 'b'; - pos += 2; - break; - } + /*! + @brief a type for a boolean - // formfeed (0x0c) - case '\f': - { - result[pos + 1] = 'f'; - pos += 2; - break; - } + [RFC 7159](http://rfc7159.net/rfc7159) implicitly describes a boolean as a + type which differentiates the two literals `true` and `false`. - // newline (0x0a) - case '\n': - { - result[pos + 1] = 'n'; - pos += 2; - break; - } + To store objects in C++, a type is defined by the template parameter @a + BooleanType which chooses the type to use. - // carriage return (0x0d) - case '\r': - { - result[pos + 1] = 'r'; - pos += 2; - break; - } + #### Default type - // horizontal tab (0x09) - case '\t': - { - result[pos + 1] = 't'; - pos += 2; - break; - } + With the default values for @a BooleanType (`bool`), the default value for + @a boolean_t is: - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x0b: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - // convert a number 0..15 to its hex representation - // (0..f) - static const char hexify[16] = - { - '0', '1', '2', '3', '4', '5', '6', '7', - '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' - }; - - // print character c as \uxxxx - for (const char m : - { 'u', '0', '0', hexify[c >> 4], hexify[c & 0x0f] - }) - { - result[++pos] = m; - } + @code {.cpp} + bool + @endcode - ++pos; - break; - } + #### Storage - default: - { - // all other characters are added as-is - result[pos++] = c; - break; - } - } - } + Boolean values are stored directly inside a @ref basic_json type. - assert(pos == s.size() + space); - o->write_characters(result.c_str(), result.size()); - } + @since version 1.0.0 + */ + using boolean_t = BooleanType; - /*! - @brief dump an integer + /*! + @brief a type for a number (integer) - Dump a given integer to output stream @a o. Works internally with - @a number_buffer. + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - @param[in] x integer number (signed or unsigned) to dump - @tparam NumberType either @a number_integer_t or @a number_unsigned_t - */ - template::value or - std::is_same::value, int> = 0> - void dump_integer(NumberType x) - { - // special case for "0" - if (x == 0) - { - o->write_character('0'); - return; - } + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - const bool is_negative = x < 0; - size_t i = 0; + To store integer numbers in C++, a type is defined by the template + parameter @a NumberIntegerType which chooses the type to use. - // spare 1 byte for '\0' - while (x != 0 and i < number_buffer.size() - 1) - { - const auto digit = std::labs(static_cast(x % 10)); - number_buffer[i++] = static_cast('0' + digit); - x /= 10; - } + #### Default type - // make sure the number has been processed completely - assert(x == 0); + With the default values for @a NumberIntegerType (`int64_t`), the default + value for @a number_integer_t is: - if (is_negative) - { - // make sure there is capacity for the '-' - assert(i < number_buffer.size() - 2); - number_buffer[i++] = '-'; - } + @code {.cpp} + int64_t + @endcode - std::reverse(number_buffer.begin(), number_buffer.begin() + i); - o->write_characters(number_buffer.data(), i); - } + #### Default behavior - /*! - @brief dump a floating-point number + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - Dump a given floating-point number to output stream @a o. Works - internally with @a number_buffer. + #### Limits - @param[in] x floating-point number to dump - */ - void dump_float(number_float_t x) - { - // NaN / inf - if (not std::isfinite(x) or std::isnan(x)) - { - o->write_characters("null", 4); - return; - } + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - // special case for 0.0 and -0.0 - if (x == 0) - { - if (std::signbit(x)) - { - o->write_characters("-0.0", 4); - } - else - { - o->write_characters("0.0", 3); - } - return; - } + When the default type is used, the maximal integer number that can be + stored is `9223372036854775807` (INT64_MAX) and the minimal integer number + that can be stored is `-9223372036854775808` (INT64_MIN). Integer numbers + that are out of range will yield over/underflow when used in a + constructor. During deserialization, too large or small integer numbers + will be automatically be stored as @ref number_unsigned_t or @ref + number_float_t. - // get number of digits for a text -> float -> text round-trip - static constexpr auto d = std::numeric_limits::digits10; + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - // the actual conversion - std::ptrdiff_t len = snprintf(number_buffer.data(), number_buffer.size(), - "%.*g", d, x); + As this range is a subrange of the exactly supported range [INT64_MIN, + INT64_MAX], this class's integer type is interoperable. - // negative value indicates an error - assert(len > 0); - // check if buffer was large enough - assert(static_cast(len) < number_buffer.size()); + #### Storage - // erase thousands separator - if (thousands_sep != '\0') - { - const auto end = std::remove(number_buffer.begin(), - number_buffer.begin() + len, - thousands_sep); - std::fill(end, number_buffer.end(), '\0'); - assert((end - number_buffer.begin()) <= len); - len = (end - number_buffer.begin()); - } + Integer number values are stored directly inside a @ref basic_json type. - // convert decimal point to '.' - if (decimal_point != '\0' and decimal_point != '.') - { - for (auto& c : number_buffer) - { - if (c == decimal_point) - { - c = '.'; - break; - } - } - } + @sa @ref number_float_t -- type for number values (floating-point) - o->write_characters(number_buffer.data(), static_cast(len)); + @sa @ref number_unsigned_t -- type for number values (unsigned integer) - // determine if need to append ".0" - const bool value_is_int_like = std::none_of(number_buffer.begin(), - number_buffer.begin() + len + 1, - [](char c) - { - return c == '.' or c == 'e'; - }); + @since version 1.0.0 + */ + using number_integer_t = NumberIntegerType; - if (value_is_int_like) - { - o->write_characters(".0", 2); - } - } + /*! + @brief a type for a number (unsigned) - private: - /// the output of the serializer - output_adapter_t o = nullptr; + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - /// a (hopefully) large enough character buffer - std::array number_buffer{{}}; + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - /// the locale - const std::lconv* loc = nullptr; - /// the locale's thousand separator character - const char thousands_sep = '\0'; - /// the locale's decimal point character - const char decimal_point = '\0'; + To store unsigned integer numbers in C++, a type is defined by the + template parameter @a NumberUnsignedType which chooses the type to use. - /// the indentation character - const char indent_char; + #### Default type - /// the indentation string - string_t indent_string; - }; + With the default values for @a NumberUnsignedType (`uint64_t`), the + default value for @a number_unsigned_t is: - public: - /*! - @brief serialize to stream + @code {.cpp} + uint64_t + @endcode - Serialize the given JSON value @a j to the output stream @a o. The JSON - value will be serialized using the @ref dump member function. + #### Default behavior - - The indentation of the output can be controlled with the member variable - `width` of the output stream @a o. For instance, using the manipulator - `std::setw(4)` on @a o sets the indentation level to `4` and the - serialization result is the same as calling `dump(4)`. + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in integer literals lead to an interpretation as octal + number. Internally, the value will be stored as decimal number. For + instance, the C++ integer literal `010` will be serialized to `8`. + During deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - - The indentation characrer can be controlled with the member variable - `fill` of the output stream @a o. For instance, the manipulator - `std::setfill('\\t')` sets indentation to use a tab character rather than - the default space character. + #### Limits - @param[in,out] o stream to serialize to - @param[in] j JSON value to serialize + [RFC 7159](http://rfc7159.net/rfc7159) specifies: + > An implementation may set limits on the range and precision of numbers. - @return the stream @a o + When the default type is used, the maximal integer number that can be + stored is `18446744073709551615` (UINT64_MAX) and the minimal integer + number that can be stored is `0`. Integer numbers that are out of range + will yield over/underflow when used in a constructor. During + deserialization, too large or small integer numbers will be automatically + be stored as @ref number_integer_t or @ref number_float_t. - @complexity Linear. + [RFC 7159](http://rfc7159.net/rfc7159) further states: + > Note that when such software is used, numbers that are integers and are + > in the range \f$[-2^{53}+1, 2^{53}-1]\f$ are interoperable in the sense + > that implementations will agree exactly on their numeric values. - @liveexample{The example below shows the serialization with different - parameters to `width` to adjust the indentation level.,operator_serialize} + As this range is a subrange (when considered in conjunction with the + number_integer_t type) of the exactly supported range [0, UINT64_MAX], + this class's integer type is interoperable. - @since version 1.0.0; indentaction character added in version 3.0.0 - */ - friend std::ostream& operator<<(std::ostream& o, const basic_json& j) - { - // read width member and use it as indentation parameter if nonzero - const bool pretty_print = (o.width() > 0); - const auto indentation = (pretty_print ? o.width() : 0); + #### Storage - // reset width to 0 for subsequent calls to this stream - o.width(0); + Integer number values are stored directly inside a @ref basic_json type. - // do the actual serialization - serializer s(output_adapter::create(o), o.fill()); - s.dump(j, pretty_print, static_cast(indentation)); - return o; - } + @sa @ref number_float_t -- type for number values (floating-point) + @sa @ref number_integer_t -- type for number values (integer) - /*! - @brief serialize to stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::ostream& operator<<(std::ostream&, const basic_json&) - instead; that is, replace calls like `j >> o;` with `o << j;`. + @since version 2.0.0 */ - JSON_DEPRECATED - friend std::ostream& operator>>(const basic_json& j, std::ostream& o) - { - return o << j; - } - - /// @} - - - ///////////////////// - // deserialization // - ///////////////////// - - /// @name deserialization - /// @{ + using number_unsigned_t = NumberUnsignedType; /*! - @brief deserialize from an array - - This function reads from an array of 1-byte values. - - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + @brief a type for a number (floating-point) - @param[in] array array to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + [RFC 7159](http://rfc7159.net/rfc7159) describes numbers as follows: + > The representation of numbers is similar to that used in most + > programming languages. A number is represented in base 10 using decimal + > digits. It contains an integer component that may be prefixed with an + > optional minus sign, which may be followed by a fraction part and/or an + > exponent part. Leading zeros are not allowed. (...) Numeric values that + > cannot be represented in the grammar below (such as Infinity and NaN) + > are not permitted. - @return result of the deserialization + This description includes both integer and floating-point numbers. + However, C++ allows more precise storage if it is known whether the number + is a signed integer, an unsigned integer or a floating-point number. + Therefore, three different types, @ref number_integer_t, @ref + number_unsigned_t and @ref number_float_t are used. - @throw parse_error.101 if a parse error occurs; example: `""unexpected end - of input; expected string literal""` - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + To store floating-point numbers in C++, a type is defined by the template + parameter @a NumberFloatType which chooses the type to use. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + #### Default type - @note A UTF-8 byte order mark is silently ignored. + With the default values for @a NumberFloatType (`double`), the default + value for @a number_float_t is: - @liveexample{The example below demonstrates the `parse()` function reading - from an array.,parse__array__parser_callback_t} + @code {.cpp} + double + @endcode - @since version 2.0.3 - */ - template - static basic_json parse(T (&array)[N], - const parser_callback_t cb = nullptr) - { - // delegate the call to the iterator-range parse overload - return parse(std::begin(array), std::end(array), cb); - } + #### Default behavior - /*! - @brief deserialize from string literal + - The restrictions about leading zeros is not enforced in C++. Instead, + leading zeros in floating-point literals will be ignored. Internally, + the value will be stored as decimal number. For instance, the C++ + floating-point literal `01.2` will be serialized to `1.2`. During + deserialization, leading zeros yield an error. + - Not-a-number (NaN) values will be serialized to `null`. - @tparam CharT character/literal type with size of 1 byte - @param[in] s string literal to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + #### Limits - @return result of the deserialization + [RFC 7159](http://rfc7159.net/rfc7159) states: + > This specification allows implementations to set limits on the range and + > precision of numbers accepted. Since software that implements IEEE + > 754-2008 binary64 (double precision) numbers is generally available and + > widely used, good interoperability can be achieved by implementations + > that expect no more precision or range than these provide, in the sense + > that implementations will approximate JSON numbers within the expected + > precision. - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + This implementation does exactly follow this approach, as it uses double + precision floating-point numbers. Note values smaller than + `-1.79769313486232e+308` and values greater than `1.79769313486232e+308` + will be stored as NaN internally and be serialized to `null`. - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + #### Storage - @note A UTF-8 byte order mark is silently ignored. - @note String containers like `std::string` or @ref string_t can be parsed - with @ref parse(const ContiguousContainer&, const parser_callback_t) + Floating-point number values are stored directly inside a @ref basic_json + type. - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__string__parser_callback_t} + @sa @ref number_integer_t -- type for number values (integer) - @sa @ref parse(std::istream&, const parser_callback_t) for a version that - reads from an input stream + @sa @ref number_unsigned_t -- type for number values (unsigned integer) - @since version 1.0.0 (originally for @ref string_t) + @since version 1.0.0 */ - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static basic_json parse(const CharT s, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(s), cb).parse(true); - } + using number_float_t = NumberFloatType; - /*! - @brief deserialize from stream + /// @} - @param[in,out] i stream to read a serialized JSON value from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + private: - @return result of the deserialization + /// helper for exception-safe object creation + template + static T* create(Args&& ... args) + { + AllocatorType alloc; + using AllocatorTraits = std::allocator_traits>; - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + auto deleter = [&](T * object) + { + AllocatorTraits::deallocate(alloc, object, 1); + }; + std::unique_ptr object(AllocatorTraits::allocate(alloc, 1), deleter); + AllocatorTraits::construct(alloc, object.get(), std::forward(args)...); + assert(object != nullptr); + return object.release(); + } - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + //////////////////////// + // JSON value storage // + //////////////////////// - @note A UTF-8 byte order mark is silently ignored. + /*! + @brief a JSON value - @liveexample{The example below demonstrates the `parse()` function with - and without callback function.,parse__istream__parser_callback_t} + The actual storage for a JSON value of the @ref basic_json class. This + union combines the different storage types for the JSON value types + defined in @ref value_t. + + JSON type | value_t type | used type + --------- | --------------- | ------------------------ + object | object | pointer to @ref object_t + array | array | pointer to @ref array_t + string | string | pointer to @ref string_t + boolean | boolean | @ref boolean_t + number | number_integer | @ref number_integer_t + number | number_unsigned | @ref number_unsigned_t + number | number_float | @ref number_float_t + null | null | *no value is stored* - @sa @ref parse(const CharT, const parser_callback_t) for a version - that reads from a string + @note Variable-length types (objects, arrays, and strings) are stored as + pointers. The size of the union should not exceed 64 bits if the default + value types are used. @since version 1.0.0 */ - static basic_json parse(std::istream& i, - const parser_callback_t cb = nullptr) + union json_value { - return parser(input_adapter::create(i), cb).parse(true); - } + /// object (stored with pointer to save storage) + object_t* object; + /// array (stored with pointer to save storage) + array_t* array; + /// string (stored with pointer to save storage) + string_t* string; + /// boolean + boolean_t boolean; + /// number (integer) + number_integer_t number_integer; + /// number (unsigned integer) + number_unsigned_t number_unsigned; + /// number (floating-point) + number_float_t number_float; - /*! - @copydoc parse(std::istream&, const parser_callback_t) - */ - static basic_json parse(std::istream&& i, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(i), cb).parse(true); - } + /// default constructor (for null values) + json_value() = default; + /// constructor for booleans + json_value(boolean_t v) noexcept : boolean(v) {} + /// constructor for numbers (integer) + json_value(number_integer_t v) noexcept : number_integer(v) {} + /// constructor for numbers (unsigned) + json_value(number_unsigned_t v) noexcept : number_unsigned(v) {} + /// constructor for numbers (floating-point) + json_value(number_float_t v) noexcept : number_float(v) {} + /// constructor for empty values of a given type + json_value(value_t t) + { + switch (t) + { + case value_t::object: + { + object = create(); + break; + } - /*! - @brief deserialize from an iterator range with contiguous storage + case value_t::array: + { + array = create(); + break; + } - This function reads from an iterator range of a container with contiguous - storage of 1-byte values. Compatible container types include - `std::vector`, `std::string`, `std::array`, `std::valarray`, and - `std::initializer_list`. Furthermore, C-style arrays can be used with - `std::begin()`/`std::end()`. User-defined containers can be used as long - as they implement random-access iterators and a contiguous storage. + case value_t::string: + { + string = create(""); + break; + } - @pre The iterator range is contiguous. Violating this precondition yields - undefined behavior. **This precondition is enforced with an assertion.** - @pre Each element in the range has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + case value_t::boolean: + { + boolean = boolean_t(false); + break; + } - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with noncompliant iterators and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + case value_t::number_integer: + { + number_integer = number_integer_t(0); + break; + } - @tparam IteratorType iterator of container with contiguous storage - @param[in] first begin of the range to parse (included) - @param[in] last end of the range to parse (excluded) - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + case value_t::number_unsigned: + { + number_unsigned = number_unsigned_t(0); + break; + } - @return result of the deserialization + case value_t::number_float: + { + number_float = number_float_t(0.0); + break; + } - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. - - @note A UTF-8 byte order mark is silently ignored. + case value_t::null: + { + object = nullptr; // silence warning, see #821 + break; + } - @liveexample{The example below demonstrates the `parse()` function reading - from an iterator range.,parse__iteratortype__parser_callback_t} + default: + { + object = nullptr; // silence warning, see #821 + if (JSON_UNLIKELY(t == value_t::null)) + { + JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.1.2")); // LCOV_EXCL_LINE + } + break; + } + } + } - @since version 2.0.3 - */ - template::iterator_category>::value, int>::type = 0> - static basic_json parse(IteratorType first, IteratorType last, - const parser_callback_t cb = nullptr) - { - return parser(input_adapter::create(first, last), cb).parse(true); - } + /// constructor for strings + json_value(const string_t& value) + { + string = create(value); + } - /*! - @brief deserialize from a container with contiguous storage + /// constructor for rvalue strings + json_value(string_t&& value) + { + string = create(std::move(value)); + } - This function reads from a container with contiguous storage of 1-byte - values. Compatible container types include `std::vector`, `std::string`, - `std::array`, and `std::initializer_list`. User-defined containers can be - used as long as they implement random-access iterators and a contiguous - storage. + /// constructor for objects + json_value(const object_t& value) + { + object = create(value); + } - @pre The container storage is contiguous. Violating this precondition - yields undefined behavior. **This precondition is enforced with an - assertion.** - @pre Each element of the container has a size of 1 byte. Violating this - precondition yields undefined behavior. **This precondition is enforced - with a static assertion.** + /// constructor for rvalue objects + json_value(object_t&& value) + { + object = create(std::move(value)); + } - @warning There is no way to enforce all preconditions at compile-time. If - the function is called with a noncompliant container and with - assertions switched off, the behavior is undefined and will most - likely yield segmentation violation. + /// constructor for arrays + json_value(const array_t& value) + { + array = create(value); + } - @tparam ContiguousContainer container type with contiguous storage - @param[in] c container to read from - @param[in] cb a parser callback function of type @ref parser_callback_t - which is used to control the deserialization by filtering unwanted values - (optional) + /// constructor for rvalue arrays + json_value(array_t&& value) + { + array = create(std::move(value)); + } - @return result of the deserialization + void destroy(value_t t) noexcept + { + switch (t) + { + case value_t::object: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, object); + std::allocator_traits::deallocate(alloc, object, 1); + break; + } - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails + case value_t::array: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, array); + std::allocator_traits::deallocate(alloc, array, 1); + break; + } - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. The complexity can be higher if the parser callback function - @a cb has a super-linear complexity. + case value_t::string: + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, string); + std::allocator_traits::deallocate(alloc, string, 1); + break; + } - @note A UTF-8 byte order mark is silently ignored. + default: + { + break; + } + } + } + }; - @liveexample{The example below demonstrates the `parse()` function reading - from a contiguous container.,parse__contiguouscontainer__parser_callback_t} + /*! + @brief checks the class invariants - @since version 2.0.3 + This function asserts the class invariants. It needs to be called at the + end of every constructor to make sure that created objects respect the + invariant. Furthermore, it has to be called each time the type of a JSON + value is changed, because the invariant expresses a relationship between + @a m_type and @a m_value. */ - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static basic_json parse(const ContiguousContainer& c, - const parser_callback_t cb = nullptr) + void assert_invariant() const noexcept { - // delegate the call to the iterator-range parse overload - return parse(std::begin(c), std::end(c), cb); + assert(m_type != value_t::object or m_value.object != nullptr); + assert(m_type != value_t::array or m_value.array != nullptr); + assert(m_type != value_t::string or m_value.string != nullptr); } + public: + ////////////////////////// + // JSON parser callback // + ////////////////////////// + /*! - @brief deserialize from stream - @deprecated This stream operator is deprecated and will be removed in a - future version of the library. Please use - @ref std::istream& operator>>(std::istream&, basic_json&) - instead; that is, replace calls like `j << i;` with `i >> j;`. + @brief parser event types + + The parser callback distinguishes the following events: + - `object_start`: the parser read `{` and started to process a JSON object + - `key`: the parser read a key of a value in an object + - `object_end`: the parser read `}` and finished processing a JSON object + - `array_start`: the parser read `[` and started to process a JSON array + - `array_end`: the parser read `]` and finished processing a JSON array + - `value`: the parser finished reading a JSON value + + @image html callback_events.png "Example when certain parse events are triggered" + + @sa @ref parser_callback_t for more information and examples */ - JSON_DEPRECATED - friend std::istream& operator<<(basic_json& j, std::istream& i) - { - j = parser(input_adapter::create(i)).parse(false); - return i; - } + using parse_event_t = typename parser::parse_event_t; /*! - @brief deserialize from stream + @brief per-element parser callback type - Deserializes an input stream to a JSON value. + With a parser callback function, the result of parsing a JSON text can be + influenced. When passed to @ref parse, it is called on certain events + (passed as @ref parse_event_t via parameter @a event) with a set recursion + depth @a depth and context JSON value @a parsed. The return value of the + callback function is a boolean indicating whether the element that emitted + the callback shall be kept or not. - @param[in,out] i input stream to read a serialized JSON value from - @param[in,out] j JSON value to write the deserialized input to + We distinguish six scenarios (determined by the event type) in which the + callback function can be called. The following table describes the values + of the parameters @a depth, @a event, and @a parsed. - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - @throw parse_error.111 if input stream is in a bad state + parameter @a event | description | parameter @a depth | parameter @a parsed + ------------------ | ----------- | ------------------ | ------------------- + parse_event_t::object_start | the parser read `{` and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded + parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key + parse_event_t::object_end | the parser read `}` and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object + parse_event_t::array_start | the parser read `[` and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded + parse_event_t::array_end | the parser read `]` and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array + parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value - @complexity Linear in the length of the input. The parser is a predictive - LL(1) parser. + @image html callback_events.png "Example when certain parse events are triggered" - @note A UTF-8 byte order mark is silently ignored. + Discarding a value (i.e., returning `false`) has different effects + depending on the context in which function was called: - @liveexample{The example below shows how a JSON value is constructed by - reading a serialization from a stream.,operator_deserialize} + - Discarded values in structured types are skipped. That is, the parser + will behave as if the discarded value was never read. + - In case a value outside a structured type is skipped, it is replaced + with `null`. This case happens if the top-level element is skipped. - @sa parse(std::istream&, const parser_callback_t) for a variant with a - parser callback function to filter values while parsing + @param[in] depth the depth of the recursion during parsing + + @param[in] event an event of type parse_event_t indicating the context in + the callback function has been called + + @param[in,out] parsed the current intermediate parse result; note that + writing to this value has no effect for parse_event_t::key events + + @return Whether the JSON value which called the function during parsing + should be kept (`true`) or not (`false`). In the latter case, it is either + skipped completely or replaced by an empty discarded object. + + @sa @ref parse for examples @since version 1.0.0 */ - friend std::istream& operator>>(std::istream& i, basic_json& j) - { - j = parser(input_adapter::create(i)).parse(false); - return i; - } + using parser_callback_t = typename parser::parser_callback_t; - /// @} + using json_sax_t = typename parser::json_sax_t; - /////////////////////////// - // convenience functions // - /////////////////////////// + ////////////////// + // constructors // + ////////////////// + + /// @name constructors and destructors + /// Constructors of class @ref basic_json, copy/move constructor, copy + /// assignment, static functions creating objects, and the destructor. + /// @{ /*! - @brief return the type as string + @brief create an empty value with a given type - Returns the type name as string to be used in error messages - usually to - indicate that a function was called on a wrong JSON type. + Create an empty JSON value with a given type. The value will be default + initialized with an empty value which depends on the type: + + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` - @return basically a string representation of a the @a m_type member + @param[in] v the type of the value to create @complexity Constant. - @liveexample{The following code exemplifies `type_name()` for all JSON - types.,type_name} + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + + @liveexample{The following code shows the constructor for different @ref + value_t values,basic_json__value_t} - @since version 1.0.0, public since 2.1.0 + @sa @ref clear() -- restores the postcondition of this constructor + + @since version 1.0.0 */ - std::string type_name() const + basic_json(const value_t v) + : m_type(v), m_value(v) { - { - switch (m_type) - { - case value_t::null: - return "null"; - case value_t::object: - return "object"; - case value_t::array: - return "array"; - case value_t::string: - return "string"; - case value_t::boolean: - return "boolean"; - case value_t::discarded: - return "discarded"; - default: - return "number"; - } - } + assert_invariant(); } + /*! + @brief create a null object - private: - ////////////////////// - // member variables // - ////////////////////// - - /// the type of the current element - value_t m_type = value_t::null; + Create a `null` JSON value. It either takes a null pointer as parameter + (explicitly creating `null`) or no parameter (implicitly creating `null`). + The passed null pointer itself is not read -- it is only used to choose + the right constructor. - /// the value of the current element - json_value m_value = {}; + @complexity Constant. + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - private: - /////////////// - // iterators // - /////////////// + @liveexample{The following code shows the constructor with and without a + null pointer parameter.,basic_json__nullptr_t} - /*! - @brief an iterator for primitive JSON types - - This class models an iterator for primitive JSON types (boolean, number, - string). It's only purpose is to allow the iterator/const_iterator classes - to "iterate" over primitive values. Internally, the iterator is modeled by - a `difference_type` variable. Value begin_value (`0`) models the begin, - end_value (`1`) models past the end. + @since version 1.0.0 */ - class primitive_iterator_t + basic_json(std::nullptr_t = nullptr) noexcept + : basic_json(value_t::null) { - public: - - difference_type get_value() const noexcept - { - return m_it; - } - /// set iterator to a defined beginning - void set_begin() noexcept - { - m_it = begin_value; - } - - /// set iterator to a defined past the end - void set_end() noexcept - { - m_it = end_value; - } - - /// return whether the iterator can be dereferenced - constexpr bool is_begin() const noexcept - { - return (m_it == begin_value); - } - - /// return whether the iterator is at end - constexpr bool is_end() const noexcept - { - return (m_it == end_value); - } + assert_invariant(); + } - friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it == rhs.m_it; - } + /*! + @brief create a JSON value - friend constexpr bool operator!=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return !(lhs == rhs); - } + This is a "catch all" constructor for all compatible JSON types; that is, + types for which a `to_json()` method exists. The constructor forwards the + parameter @a val to that method (to `json_serializer::to_json` method + with `U = uncvref_t`, to be exact). - friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it < rhs.m_it; - } + Template type @a CompatibleType includes, but is not limited to, the + following types: + - **arrays**: @ref array_t and all kinds of compatible containers such as + `std::vector`, `std::deque`, `std::list`, `std::forward_list`, + `std::array`, `std::valarray`, `std::set`, `std::unordered_set`, + `std::multiset`, and `std::unordered_multiset` with a `value_type` from + which a @ref basic_json value can be constructed. + - **objects**: @ref object_t and all kinds of compatible associative + containers such as `std::map`, `std::unordered_map`, `std::multimap`, + and `std::unordered_multimap` with a `key_type` compatible to + @ref string_t and a `value_type` from which a @ref basic_json value can + be constructed. + - **strings**: @ref string_t, string literals, and all compatible string + containers can be used. + - **numbers**: @ref number_integer_t, @ref number_unsigned_t, + @ref number_float_t, and all convertible number types such as `int`, + `size_t`, `int64_t`, `float` or `double` can be used. + - **boolean**: @ref boolean_t / `bool` can be used. - friend constexpr bool operator<=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it <= rhs.m_it; - } + See the examples below. - friend constexpr bool operator>(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it > rhs.m_it; - } + @tparam CompatibleType a type such that: + - @a CompatibleType is not derived from `std::istream`, + - @a CompatibleType is not @ref basic_json (to avoid hijacking copy/move + constructors), + - @a CompatibleType is not a different @ref basic_json type (i.e. with different template arguments) + - @a CompatibleType is not a @ref basic_json nested type (e.g., + @ref json_pointer, @ref iterator, etc ...) + - @ref @ref json_serializer has a + `to_json(basic_json_t&, CompatibleType&&)` method - friend constexpr bool operator>=(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it >= rhs.m_it; - } + @tparam U = `uncvref_t` - primitive_iterator_t operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } + @param[in] val the value to be forwarded to the respective constructor - friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept - { - return lhs.m_it - rhs.m_it; - } + @complexity Usually linear in the size of the passed @a val, also + depending on the implementation of the called `to_json()` + method. - friend std::ostream& operator<<(std::ostream& os, primitive_iterator_t it) - { - return os << it.m_it; - } + @exceptionsafety Depends on the called constructor. For types directly + supported by the library (i.e., all types for which no `to_json()` function + was provided), strong guarantee holds: if an exception is thrown, there are + no changes to any JSON value. - primitive_iterator_t& operator++() - { - ++m_it; - return *this; - } + @liveexample{The following code shows the constructor with several + compatible types.,basic_json__CompatibleType} - primitive_iterator_t operator++(int) - { - auto result = *this; - m_it++; - return result; - } + @since version 2.1.0 + */ + template , + detail::enable_if_t< + detail::is_compatible_type::value, int> = 0> + basic_json(CompatibleType && val) noexcept(noexcept( + JSONSerializer::to_json(std::declval(), + std::forward(val)))) + { + JSONSerializer::to_json(*this, std::forward(val)); + assert_invariant(); + } - primitive_iterator_t& operator--() - { - --m_it; - return *this; - } + /*! + @brief create a JSON value from an existing one - primitive_iterator_t operator--(int) - { - auto result = *this; - m_it--; - return result; - } + This is a constructor for existing @ref basic_json types. + It does not hijack copy/move constructors, since the parameter has different + template arguments than the current ones. - primitive_iterator_t& operator+=(difference_type n) - { - m_it += n; - return *this; - } + The constructor tries to convert the internal @ref m_value of the parameter. - primitive_iterator_t& operator-=(difference_type n) - { - m_it -= n; - return *this; - } + @tparam BasicJsonType a type such that: + - @a BasicJsonType is a @ref basic_json type. + - @a BasicJsonType has different template arguments than @ref basic_json_t. - private: - static constexpr difference_type begin_value = 0; - static constexpr difference_type end_value = begin_value + 1; + @param[in] val the @ref basic_json value to be converted. - /// iterator as signed integer type - difference_type m_it = std::numeric_limits::denorm_min(); - }; + @complexity Usually linear in the size of the passed @a val, also + depending on the implementation of the called `to_json()` + method. - /*! - @brief an iterator value + @exceptionsafety Depends on the called constructor. For types directly + supported by the library (i.e., all types for which no `to_json()` function + was provided), strong guarantee holds: if an exception is thrown, there are + no changes to any JSON value. - @note This structure could easily be a union, but MSVC currently does not - allow unions members with complex constructors, see - https://github.com/nlohmann/json/pull/105. + @since version 3.1.2 */ - struct internal_iterator + template ::value and not std::is_same::value, int> = 0> + basic_json(const BasicJsonType& val) { - /// iterator for JSON objects - typename object_t::iterator object_iterator; - /// iterator for JSON arrays - typename array_t::iterator array_iterator; - /// generic iterator for all other types - primitive_iterator_t primitive_iterator; - - /// create an uninitialized internal_iterator - internal_iterator() noexcept - : object_iterator(), array_iterator(), primitive_iterator() - {} - }; + using other_boolean_t = typename BasicJsonType::boolean_t; + using other_number_float_t = typename BasicJsonType::number_float_t; + using other_number_integer_t = typename BasicJsonType::number_integer_t; + using other_number_unsigned_t = typename BasicJsonType::number_unsigned_t; + using other_string_t = typename BasicJsonType::string_t; + using other_object_t = typename BasicJsonType::object_t; + using other_array_t = typename BasicJsonType::array_t; - /// proxy class for the iterator_wrapper functions - template - class iteration_proxy - { - private: - /// helper class for iteration - class iteration_proxy_internal + switch (val.type()) { - private: - /// the iterator - IteratorType anchor; - /// an index for arrays (used to create key names) - size_t array_index = 0; - - public: - explicit iteration_proxy_internal(IteratorType it) noexcept - : anchor(it) - {} - - /// dereference operator (needed for range-based for) - iteration_proxy_internal& operator*() - { - return *this; - } + case value_t::boolean: + JSONSerializer::to_json(*this, val.template get()); + break; + case value_t::number_float: + JSONSerializer::to_json(*this, val.template get()); + break; + case value_t::number_integer: + JSONSerializer::to_json(*this, val.template get()); + break; + case value_t::number_unsigned: + JSONSerializer::to_json(*this, val.template get()); + break; + case value_t::string: + JSONSerializer::to_json(*this, val.template get_ref()); + break; + case value_t::object: + JSONSerializer::to_json(*this, val.template get_ref()); + break; + case value_t::array: + JSONSerializer::to_json(*this, val.template get_ref()); + break; + case value_t::null: + *this = nullptr; + break; + case value_t::discarded: + m_type = value_t::discarded; + break; + } + assert_invariant(); + } - /// increment operator (needed for range-based for) - iteration_proxy_internal& operator++() - { - ++anchor; - ++array_index; + /*! + @brief create a container (array or object) from an initializer list - return *this; - } + Creates a JSON value of type array or object from the passed initializer + list @a init. In case @a type_deduction is `true` (default), the type of + the JSON value to be created is deducted from the initializer list @a init + according to the following rules: - /// inequality operator (needed for range-based for) - bool operator!= (const iteration_proxy_internal& o) const - { - return anchor != o.anchor; - } + 1. If the list is empty, an empty JSON object value `{}` is created. + 2. If the list consists of pairs whose first element is a string, a JSON + object value is created where the first elements of the pairs are + treated as keys and the second elements are as values. + 3. In all other cases, an array is created. - /// return key of the iterator - typename basic_json::string_t key() const - { - assert(anchor.m_object != nullptr); + The rules aim to create the best fit between a C++ initializer list and + JSON values. The rationale is as follows: - switch (anchor.m_object->type()) - { - // use integer array index as key - case value_t::array: - { - return std::to_string(array_index); - } + 1. The empty initializer list is written as `{}` which is exactly an empty + JSON object. + 2. C++ has no way of describing mapped types other than to list a list of + pairs. As JSON requires that keys must be of type string, rule 2 is the + weakest constraint one can pose on initializer lists to interpret them + as an object. + 3. In all other cases, the initializer list could not be interpreted as + JSON object type, so interpreting it as JSON array type is safe. - // use key from the object - case value_t::object: - { - return anchor.key(); - } + With the rules described above, the following JSON values cannot be + expressed by an initializer list: - // use an empty key for all primitive types - default: - { - return ""; - } - } - } + - the empty array (`[]`): use @ref array(initializer_list_t) + with an empty initializer list in this case + - arrays whose elements satisfy rule 2: use @ref + array(initializer_list_t) with the same initializer list + in this case - /// return value of the iterator - typename IteratorType::reference value() const - { - return anchor.value(); - } - }; + @note When used without parentheses around an empty initializer list, @ref + basic_json() is called instead of this function, yielding the JSON null + value. - /// the container to iterate - typename IteratorType::reference container; + @param[in] init initializer list with JSON values - public: - /// construct iteration proxy from a container - explicit iteration_proxy(typename IteratorType::reference cont) - : container(cont) - {} + @param[in] type_deduction internal parameter; when set to `true`, the type + of the JSON value is deducted from the initializer list @a init; when set + to `false`, the type provided via @a manual_type is forced. This mode is + used by the functions @ref array(initializer_list_t) and + @ref object(initializer_list_t). - /// return iterator begin (needed for range-based for) - iteration_proxy_internal begin() noexcept - { - return iteration_proxy_internal(container.begin()); - } + @param[in] manual_type internal parameter; when @a type_deduction is set + to `false`, the created JSON value will use the provided type (only @ref + value_t::array and @ref value_t::object are valid); when @a type_deduction + is set to `true`, this parameter has no effect - /// return iterator end (needed for range-based for) - iteration_proxy_internal end() noexcept - { - return iteration_proxy_internal(container.end()); - } - }; + @throw type_error.301 if @a type_deduction is `false`, @a manual_type is + `value_t::object`, but @a init contains an element which is not a pair + whose first element is a string. In this case, the constructor could not + create an object. If @a type_deduction would have be `true`, an array + would have been created. See @ref object(initializer_list_t) + for an example. - public: - /*! - @brief a template for a random access iterator for the @ref basic_json class + @complexity Linear in the size of the initializer list @a init. - This class implements a both iterators (iterator and const_iterator) for the - @ref basic_json class. + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - @note An iterator is called *initialized* when a pointer to a JSON value - has been set (e.g., by a constructor or a copy assignment). If the - iterator is default-constructed, it is *uninitialized* and most - methods are undefined. **The library uses assertions to detect calls - on uninitialized iterators.** + @liveexample{The example below shows how JSON values are created from + initializer lists.,basic_json__list_init_t} - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list - @since version 1.0.0, simplified in version 2.0.9 + @since version 1.0.0 */ - template - class iter_impl : public std::iterator + basic_json(initializer_list_t init, + bool type_deduction = true, + value_t manual_type = value_t::array) { - /// allow basic_json to access private members - friend class basic_json; - - // make sure U is basic_json or const basic_json - static_assert(std::is_same::value - or std::is_same::value, - "iter_impl only accepts (const) basic_json"); - - public: - /// the type of the values when the iterator is dereferenced - using value_type = typename basic_json::value_type; - /// a type to represent differences between iterators - using difference_type = typename basic_json::difference_type; - /// defines a pointer to the type iterated over (value_type) - using pointer = typename std::conditional::value, - typename basic_json::const_pointer, - typename basic_json::pointer>::type; - /// defines a reference to the type iterated over (value_type) - using reference = typename std::conditional::value, - typename basic_json::const_reference, - typename basic_json::reference>::type; - /// the category of the iterator - using iterator_category = std::bidirectional_iterator_tag; - - /// default constructor - iter_impl() = default; - - /*! - @brief constructor for a given JSON instance - @param[in] object pointer to a JSON object for this iterator - @pre object != nullptr - @post The iterator is initialized; i.e. `m_object != nullptr`. - */ - explicit iter_impl(pointer object) noexcept - : m_object(object) - { - assert(m_object != nullptr); - - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = typename object_t::iterator(); - break; - } + // check if each element is an array with two elements whose first + // element is a string + bool is_an_object = std::all_of(init.begin(), init.end(), + [](const detail::json_ref& element_ref) + { + return (element_ref->is_array() and element_ref->size() == 2 and (*element_ref)[0].is_string()); + }); - case basic_json::value_t::array: - { - m_it.array_iterator = typename array_t::iterator(); - break; - } + // adjust type if type deduction is not wanted + if (not type_deduction) + { + // if array is wanted, do not create an object though possible + if (manual_type == value_t::array) + { + is_an_object = false; + } - default: - { - m_it.primitive_iterator = primitive_iterator_t(); - break; - } + // if object is wanted but impossible, throw an exception + if (JSON_UNLIKELY(manual_type == value_t::object and not is_an_object)) + { + JSON_THROW(type_error::create(301, "cannot create object from initializer list")); } } - /* - Use operator `const_iterator` instead of `const_iterator(const iterator& - other) noexcept` to avoid two class definitions for @ref iterator and - @ref const_iterator. - - This function is only called if this class is an @ref iterator. If this - class is a @ref const_iterator this function is not called. - */ - operator const_iterator() const + if (is_an_object) { - const_iterator ret; + // the initializer list is a list of pairs -> create object + m_type = value_t::object; + m_value = value_t::object; - if (m_object) + std::for_each(init.begin(), init.end(), [this](const detail::json_ref& element_ref) { - ret.m_object = m_object; - ret.m_it = m_it; - } - - return ret; + auto element = element_ref.moved_or_copied(); + m_value.object->emplace( + std::move(*((*element.m_value.array)[0].m_value.string)), + std::move((*element.m_value.array)[1])); + }); + } + else + { + // the initializer list describes an array -> create array + m_type = value_t::array; + m_value.array = create(init.begin(), init.end()); } - /*! - @brief copy constructor - @param[in] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl(const iter_impl& other) noexcept - : m_object(other.m_object), m_it(other.m_it) - {} + assert_invariant(); + } - /*! - @brief copy assignment - @param[in,out] other iterator to copy from - @note It is not checked whether @a other is initialized. - */ - iter_impl& operator=(iter_impl other) noexcept( - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value and - std::is_nothrow_move_constructible::value and - std::is_nothrow_move_assignable::value - ) - { - std::swap(m_object, other.m_object); - std::swap(m_it, other.m_it); - return *this; - } + /*! + @brief explicitly create an array from an initializer list - private: - /*! - @brief set the iterator to the first value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_begin() noexcept - { - assert(m_object != nullptr); + Creates a JSON array value from a given initializer list. That is, given a + list of values `a, b, c`, creates the JSON value `[a, b, c]`. If the + initializer list is empty, the empty array `[]` is created. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->begin(); - break; - } + @note This function is only needed to express two edge cases that cannot + be realized with the initializer list constructor (@ref + basic_json(initializer_list_t, bool, value_t)). These cases + are: + 1. creating an array whose elements are all pairs whose first element is a + string -- in this case, the initializer list constructor would create an + object, taking the first elements as keys + 2. creating an empty array -- passing the empty initializer list to the + initializer list constructor yields an empty object - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->begin(); - break; - } + @param[in] init initializer list with JSON values to create an array from + (optional) - case basic_json::value_t::null: - { - // set to end so begin()==end() is true: null is empty - m_it.primitive_iterator.set_end(); - break; - } + @return JSON array value - default: - { - m_it.primitive_iterator.set_begin(); - break; - } - } - } + @complexity Linear in the size of @a init. - /*! - @brief set the iterator past the last value - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - void set_end() noexcept - { - assert(m_object != nullptr); + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - m_it.object_iterator = m_object->m_value.object->end(); - break; - } + @liveexample{The following code shows an example for the `array` + function.,array} - case basic_json::value_t::array: - { - m_it.array_iterator = m_object->m_value.array->end(); - break; - } + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref object(initializer_list_t) -- create a JSON object + value from an initializer list - default: - { - m_it.primitive_iterator.set_end(); - break; - } - } - } + @since version 1.0.0 + */ + static basic_json array(initializer_list_t init = {}) + { + return basic_json(init, false, value_t::array); + } - public: - /*! - @brief return a reference to the value pointed to by the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator*() const - { - assert(m_object != nullptr); + /*! + @brief explicitly create an object from an initializer list - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return m_it.object_iterator->second; - } + Creates a JSON object value from a given initializer list. The initializer + lists elements must be pairs, and their first elements must be strings. If + the initializer list is empty, the empty object `{}` is created. - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return *m_it.array_iterator; - } + @note This function is only added for symmetry reasons. In contrast to the + related function @ref array(initializer_list_t), there are + no cases which can only be expressed by this function. That is, any + initializer list @a init can also be passed to the initializer list + constructor @ref basic_json(initializer_list_t, bool, value_t). - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + @param[in] init initializer list to create an object from (optional) - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return *m_object; - } + @return JSON object value - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @throw type_error.301 if @a init is not a list of pairs whose first + elements are strings. In this case, no object can be created. When such a + value is passed to @ref basic_json(initializer_list_t, bool, value_t), + an array would have been created from the passed initializer list @a init. + See example below. - /*! - @brief dereference the iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - pointer operator->() const - { - assert(m_object != nullptr); + @complexity Linear in the size of @a init. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - assert(m_it.object_iterator != m_object->m_value.object->end()); - return &(m_it.object_iterator->second); - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - case basic_json::value_t::array: - { - assert(m_it.array_iterator != m_object->m_value.array->end()); - return &*m_it.array_iterator; - } + @liveexample{The following code shows an example for the `object` + function.,object} - default: - { - if (m_it.primitive_iterator.is_begin()) - { - return m_object; - } + @sa @ref basic_json(initializer_list_t, bool, value_t) -- + create a JSON value from an initializer list + @sa @ref array(initializer_list_t) -- create a JSON array + value from an initializer list - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - } - } + @since version 1.0.0 + */ + static basic_json object(initializer_list_t init = {}) + { + return basic_json(init, false, value_t::object); + } - /*! - @brief post-increment (it++) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator++(int) - { - auto result = *this; - ++(*this); - return result; - } + /*! + @brief construct an array with count copies of given value - /*! - @brief pre-increment (++it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator++() - { - assert(m_object != nullptr); + Constructs a JSON array value by creating @a cnt copies of a passed value. + In case @a cnt is `0`, an empty array is created. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, 1); - break; - } + @param[in] cnt the number of JSON copies of @a val to create + @param[in] val the JSON value to copy - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, 1); - break; - } + @post `std::distance(begin(),end()) == cnt` holds. - default: - { - ++m_it.primitive_iterator; - break; - } - } + @complexity Linear in @a cnt. - return *this; - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - /*! - @brief post-decrement (it--) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator--(int) - { - auto result = *this; - --(*this); - return result; - } + @liveexample{The following code shows examples for the @ref + basic_json(size_type\, const basic_json&) + constructor.,basic_json__size_type_basic_json} - /*! - @brief pre-decrement (--it) - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator--() - { - assert(m_object != nullptr); + @since version 1.0.0 + */ + basic_json(size_type cnt, const basic_json& val) + : m_type(value_t::array) + { + m_value.array = create(cnt, val); + assert_invariant(); + } - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - std::advance(m_it.object_iterator, -1); - break; - } + /*! + @brief construct a JSON container given an iterator range - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, -1); - break; - } + Constructs the JSON value with the contents of the range `[first, last)`. + The semantics depends on the different types a JSON value can have: + - In case of a null type, invalid_iterator.206 is thrown. + - In case of other primitive types (number, boolean, or string), @a first + must be `begin()` and @a last must be `end()`. In this case, the value is + copied. Otherwise, invalid_iterator.204 is thrown. + - In case of structured types (array, object), the constructor behaves as + similar versions for `std::vector` or `std::map`; that is, a JSON array + or object is constructed from the values in the range. - default: - { - --m_it.primitive_iterator; - break; - } - } + @tparam InputIT an input iterator type (@ref iterator or @ref + const_iterator) - return *this; - } + @param[in] first begin of the range to copy from (included) + @param[in] last end of the range to copy from (excluded) - /*! - @brief comparison: equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator==(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + @pre Iterators @a first and @a last must be initialized. **This + precondition is enforced with an assertion (see warning).** If + assertions are switched off, a violation of this precondition yields + undefined behavior. - assert(m_object != nullptr); + @pre Range `[first, last)` is valid. Usually, this precondition cannot be + checked efficiently. Only certain edge cases are detected; see the + description of the exceptions below. A violation of this precondition + yields undefined behavior. - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - return (m_it.object_iterator == other.m_it.object_iterator); - } + @warning A precondition is enforced with a runtime assertion that will + result in calling `std::abort` if this precondition is not met. + Assertions can be disabled by defining `NDEBUG` at compile time. + See https://en.cppreference.com/w/cpp/error/assert for more + information. - case basic_json::value_t::array: - { - return (m_it.array_iterator == other.m_it.array_iterator); - } + @throw invalid_iterator.201 if iterators @a first and @a last are not + compatible (i.e., do not belong to the same JSON value). In this case, + the range `[first, last)` is undefined. + @throw invalid_iterator.204 if iterators @a first and @a last belong to a + primitive type (number, boolean, or string), but @a first does not point + to the first element any more. In this case, the range `[first, last)` is + undefined. See example code below. + @throw invalid_iterator.206 if iterators @a first and @a last belong to a + null value. In this case, the range `[first, last)` is undefined. - default: - { - return (m_it.primitive_iterator == other.m_it.primitive_iterator); - } - } - } + @complexity Linear in distance between @a first and @a last. - /*! - @brief comparison: not equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator!=(const iter_impl& other) const - { - return not operator==(other); - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. - /*! - @brief comparison: smaller - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<(const iter_impl& other) const - { - // if objects are not the same, the comparison is undefined - if (m_object != other.m_object) - { - JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers")); - } + @liveexample{The example below shows several ways to create JSON values by + specifying a subrange with iterators.,basic_json__InputIt_InputIt} - assert(m_object != nullptr); + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type = 0> + basic_json(InputIT first, InputIT last) + { + assert(first.m_object != nullptr); + assert(last.m_object != nullptr); - switch (m_object->m_type) - { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(213, "cannot compare order of object iterators")); - } + // make sure iterator fits the current value + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(201, "iterators are not compatible")); + } - case basic_json::value_t::array: - { - return (m_it.array_iterator < other.m_it.array_iterator); - } + // copy type from first iterator + m_type = first.m_object->m_type; - default: + // check if iterator range is complete for primitive values + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_UNLIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) { - return (m_it.primitive_iterator < other.m_it.primitive_iterator); + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); } + break; } - } - /*! - @brief comparison: less than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator<=(const iter_impl& other) const - { - return not other.operator < (*this); + default: + break; } - /*! - @brief comparison: greater than - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>(const iter_impl& other) const + switch (m_type) { - return not operator<=(other); - } - - /*! - @brief comparison: greater than or equal - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - bool operator>=(const iter_impl& other) const - { - return not operator<(other); - } - - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator+=(difference_type i) - { - assert(m_object != nullptr); - - switch (m_object->m_type) + case value_t::number_integer: { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } - - case basic_json::value_t::array: - { - std::advance(m_it.array_iterator, i); - break; - } - - default: - { - m_it.primitive_iterator += i; - break; - } + m_value.number_integer = first.m_object->m_value.number_integer; + break; } - return *this; - } - - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl& operator-=(difference_type i) - { - return operator+=(-i); - } - - /*! - @brief add to iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator+(difference_type i) - { - auto result = *this; - result += i; - return result; - } - - /*! - @brief subtract from iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - iter_impl operator-(difference_type i) - { - auto result = *this; - result -= i; - return result; - } - - /*! - @brief return difference - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - difference_type operator-(const iter_impl& other) const - { - assert(m_object != nullptr); - - switch (m_object->m_type) + case value_t::number_unsigned: { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators")); - } - - case basic_json::value_t::array: - { - return m_it.array_iterator - other.m_it.array_iterator; - } - - default: - { - return m_it.primitive_iterator - other.m_it.primitive_iterator; - } + m_value.number_unsigned = first.m_object->m_value.number_unsigned; + break; } - } - /*! - @brief access to successor - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference operator[](difference_type n) const - { - assert(m_object != nullptr); - - switch (m_object->m_type) + case value_t::number_float: { - case basic_json::value_t::object: - { - JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators")); - } - - case basic_json::value_t::array: - { - return *std::next(m_it.array_iterator, n); - } - - case basic_json::value_t::null: - { - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } - - default: - { - if (m_it.primitive_iterator.get_value() == -n) - { - return *m_object; - } - - JSON_THROW(invalid_iterator::create(214, "cannot get value")); - } + m_value.number_float = first.m_object->m_value.number_float; + break; } - } - - /*! - @brief return the key of an object iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - typename object_t::key_type key() const - { - assert(m_object != nullptr); - if (m_object->is_object()) + case value_t::boolean: { - return m_it.object_iterator->first; + m_value.boolean = first.m_object->m_value.boolean; + break; } - JSON_THROW(invalid_iterator::create(207, "cannot use key() for non-object iterators")); - } - - /*! - @brief return the value of an iterator - @pre The iterator is initialized; i.e. `m_object != nullptr`. - */ - reference value() const - { - return operator*(); - } - - private: - /// associated JSON instance - pointer m_object = nullptr; - /// the actual iterator of the associated instance - internal_iterator m_it = internal_iterator(); - }; - - /*! - @brief a template for a reverse iterator class - - @tparam Base the base iterator type to reverse. Valid types are @ref - iterator (to create @ref reverse_iterator) and @ref const_iterator (to - create @ref const_reverse_iterator). - - @requirement The class satisfies the following concept requirements: - - [RandomAccessIterator](http://en.cppreference.com/w/cpp/concept/RandomAccessIterator): - The iterator that can be moved to point (forward and backward) to any - element in constant time. - - [OutputIterator](http://en.cppreference.com/w/cpp/concept/OutputIterator): - It is possible to write to the pointed-to element (only if @a Base is - @ref iterator). + case value_t::string: + { + m_value = *first.m_object->m_value.string; + break; + } - @since version 1.0.0 - */ - template - class json_reverse_iterator : public std::reverse_iterator - { - public: - /// shortcut to the reverse iterator adaptor - using base_iterator = std::reverse_iterator; - /// the reference type for the pointed-to element - using reference = typename Base::reference; - - /// create reverse iterator from iterator - json_reverse_iterator(const typename base_iterator::iterator_type& it) noexcept - : base_iterator(it) - {} + case value_t::object: + { + m_value.object = create(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } - /// create reverse iterator from base class - json_reverse_iterator(const base_iterator& it) noexcept - : base_iterator(it) - {} + case value_t::array: + { + m_value.array = create(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } - /// post-increment (it++) - json_reverse_iterator operator++(int) - { - return base_iterator::operator++(1); + default: + JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " + + std::string(first.m_object->type_name()))); } - /// pre-increment (++it) - json_reverse_iterator& operator++() - { - base_iterator::operator++(); - return *this; - } + assert_invariant(); + } - /// post-decrement (it--) - json_reverse_iterator operator--(int) - { - return base_iterator::operator--(1); - } - /// pre-decrement (--it) - json_reverse_iterator& operator--() - { - base_iterator::operator--(); - return *this; - } + /////////////////////////////////////// + // other constructors and destructor // + /////////////////////////////////////// - /// add to iterator - json_reverse_iterator& operator+=(difference_type i) - { - base_iterator::operator+=(i); - return *this; - } + /// @private + basic_json(const detail::json_ref& ref) + : basic_json(ref.moved_or_copied()) + {} - /// add to iterator - json_reverse_iterator operator+(difference_type i) const - { - auto result = *this; - result += i; - return result; - } + /*! + @brief copy constructor - /// subtract from iterator - json_reverse_iterator operator-(difference_type i) const - { - auto result = *this; - result -= i; - return result; - } + Creates a copy of a given JSON value. - /// return difference - difference_type operator-(const json_reverse_iterator& other) const - { - return this->base() - other.base(); - } + @param[in] other the JSON value to copy - /// access to successor - reference operator[](difference_type n) const - { - return *(this->operator+(n)); - } + @post `*this == other` - /// return the key of an object iterator - typename object_t::key_type key() const - { - auto it = --this->base(); - return it.key(); - } + @complexity Linear in the size of @a other. - /// return the value of an iterator - reference value() const - { - auto it = --this->base(); - return it.operator * (); - } - }; + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes to any JSON value. + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is linear. + - As postcondition, it holds: `other == basic_json(other)`. - private: - //////////////////// - // input adapters // - //////////////////// + @liveexample{The following code shows an example for the copy + constructor.,basic_json__basic_json} - /// abstract input adapter interface - class input_adapter + @since version 1.0.0 + */ + basic_json(const basic_json& other) + : m_type(other.m_type) { - public: - virtual int get_character() = 0; - virtual std::string read(size_t offset, size_t length) = 0; - virtual ~input_adapter() {} - - // native support - - /// input adapter for input stream - static std::shared_ptr create(std::istream& i, const size_t buffer_size = 16384) - { - return std::shared_ptr(new cached_input_stream_adapter(i, buffer_size)); - } - - /// input adapter for input stream - static std::shared_ptr create(std::istream&& i, const size_t buffer_size = 16384) - { - return std::shared_ptr(new cached_input_stream_adapter(i, buffer_size)); - } - - /// input adapter for buffer - static std::shared_ptr create(const char* b, size_t l) - { - return std::shared_ptr(new input_buffer_adapter(b, l)); - } - - // derived support - - /// input adapter for string literal - template::value and - std::is_integral::type>::value and - sizeof(typename std::remove_pointer::type) == 1, int>::type = 0> - static std::shared_ptr create(CharT b) - { - return create(reinterpret_cast(b), - std::strlen(reinterpret_cast(b))); - } + // check of passed value is valid + other.assert_invariant(); - /// input adapter for iterator range with contiguous storage - template::iterator_category, std::random_access_iterator_tag>::value - , int>::type - = 0> - static std::shared_ptr create(IteratorType first, IteratorType last) + switch (m_type) { - // assertion to check that the iterator range is indeed contiguous, - // see http://stackoverflow.com/a/35008842/266378 for more discussion - assert(std::accumulate(first, last, std::pair(true, 0), - [&first](std::pair res, decltype(*first) val) + case value_t::object: { - res.first &= (val == *(std::next(std::addressof(*first), res.second++))); - return res; - }).first); - - // assertion to check that each element is 1 byte long - static_assert(sizeof(typename std::iterator_traits::value_type) == 1, - "each element in the iterator range must have the size of 1 byte"); - - return create(reinterpret_cast(&(*first)), - static_cast(std::distance(first, last))); - } - - /// input adapter for array - template - static std::shared_ptr create(T (&array)[N]) - { - // delegate the call to the iterator-range overload - return create(std::begin(array), std::end(array)); - } - - /// input adapter for contiguous container - template::value and - std::is_base_of< - std::random_access_iterator_tag, - typename std::iterator_traits()))>::iterator_category>::value - , int>::type = 0> - static std::shared_ptr create(const ContiguousContainer& c) - { - // delegate the call to the iterator-range overload - return create(std::begin(c), std::end(c)); - } - }; - - /// a type to simplify interfaces - using input_adapter_t = std::shared_ptr; + m_value = *other.m_value.object; + break; + } - /// input adapter for cached stream input - class cached_input_stream_adapter : public input_adapter - { - public: - cached_input_stream_adapter(std::istream& i, const size_t buffer_size) - : is(i), start_position(is.tellg()), buffer(buffer_size, '\0') - { - // immediately abort if stream is erroneous - if (JSON_UNLIKELY(i.fail())) + case value_t::array: { - JSON_THROW(parse_error::create(111, 0, "bad input stream")); + m_value = *other.m_value.array; + break; } - // initial fill - is.read(buffer.data(), static_cast(buffer.size())); - // store number of bytes in the buffer - fill_size = static_cast(is.gcount()); - - // skip byte order mark - if (fill_size >= 3 and buffer[0] == '\xEF' and buffer[1] == '\xBB' and buffer[2] == '\xBF') + case value_t::string: { - buffer_pos += 3; - processed_chars += 3; + m_value = *other.m_value.string; + break; } - } - ~cached_input_stream_adapter() override - { - // clear stream flags - is.clear(); - // We initially read a lot of characters into the buffer, and we - // may not have processed all of them. Therefore, we need to - // "rewind" the stream after the last processed char. - is.seekg(start_position + static_cast(processed_chars)); - // clear stream flags - is.clear(); - } + case value_t::boolean: + { + m_value = other.m_value.boolean; + break; + } - int get_character() override - { - // check if refilling is necessary and possible - if (buffer_pos == fill_size and not eof) + case value_t::number_integer: { - // refill - is.read(buffer.data(), static_cast(buffer.size())); - // store number of bytes in the buffer - fill_size = static_cast(is.gcount()); + m_value = other.m_value.number_integer; + break; + } - // the buffer is ready - buffer_pos = 0; + case value_t::number_unsigned: + { + m_value = other.m_value.number_unsigned; + break; + } - // remember that filling did not yield new input - if (fill_size == 0) - { - eof = true; - return std::char_traits::eof(); - } + case value_t::number_float: + { + m_value = other.m_value.number_float; + break; } - ++processed_chars; - return buffer[buffer_pos++] & 0xFF;; + default: + break; } - std::string read(size_t offset, size_t length) override - { - // create buffer - std::string result(length, '\0'); - - // save stream position - auto current_pos = is.tellg(); - // save stream flags - auto flags = is.rdstate(); + assert_invariant(); + } - // clear stream flags - is.clear(); - // set stream position - is.seekg(static_cast(offset)); - // read bytes - is.read(&result[0], static_cast(length)); + /*! + @brief move constructor - // reset stream position - is.seekg(current_pos); - // reset stream flags - is.setstate(flags); + Move constructor. Constructs a JSON value with the contents of the given + value @a other using move semantics. It "steals" the resources from @a + other and leaves it as JSON null value. - return result; - } + @param[in,out] other value to move to this object - private: - /// the associated input stream - std::istream& is; + @post `*this` has the same value as @a other before the call. + @post @a other is a JSON null value. - /// chars returned via get_character() - size_t processed_chars = 0; - /// chars processed in the current buffer - size_t buffer_pos = 0; + @complexity Constant. - /// whether stream reached eof - bool eof = false; - /// how many chars have been copied to the buffer by last (re)fill - size_t fill_size = 0; + @exceptionsafety No-throw guarantee: this constructor never throws + exceptions. - /// position of the stream when we started - const std::streampos start_position; + @requirement This function helps `basic_json` satisfying the + [MoveConstructible](https://en.cppreference.com/w/cpp/named_req/MoveConstructible) + requirements. - /// internal buffer - std::vector buffer; - }; + @liveexample{The code below shows the move constructor explicitly called + via std::move.,basic_json__moveconstructor} - /// input adapter for buffer input - class input_buffer_adapter : public input_adapter + @since version 1.0.0 + */ + basic_json(basic_json&& other) noexcept + : m_type(std::move(other.m_type)), + m_value(std::move(other.m_value)) { - public: - input_buffer_adapter(const char* b, size_t l) - : input_adapter(), cursor(b), limit(b + l), start(b) - { - // skip byte order mark - if (l >= 3 and b[0] == '\xEF' and b[1] == '\xBB' and b[2] == '\xBF') - { - cursor += 3; - } - } + // check that passed value is valid + other.assert_invariant(); - // delete because of pointer members - input_buffer_adapter(const input_buffer_adapter&) = delete; - input_buffer_adapter& operator=(input_buffer_adapter&) = delete; + // invalidate payload + other.m_type = value_t::null; + other.m_value = {}; - int get_character() override - { - if (JSON_LIKELY(cursor < limit)) - { - return *(cursor++) & 0xFF; - } - else - { - return std::char_traits::eof(); - } - } + assert_invariant(); + } - std::string read(size_t offset, size_t length) override - { - // avoid reading too many characters - const size_t max_length = static_cast(limit - start); - return std::string(start + offset, std::min(length, max_length - offset)); - } + /*! + @brief copy assignment - private: - /// pointer to the current character - const char* cursor; - /// pointer past the last character - const char* limit; - /// pointer to the first character - const char* start; - }; + Copy assignment operator. Copies a JSON value via the "copy and swap" + strategy: It is expressed in terms of the copy constructor, destructor, + and the `swap()` member function. - ////////////////////////////////////////// - // binary serialization/deserialization // - ////////////////////////////////////////// + @param[in] other value to copy from - /// @name binary serialization/deserialization support - /// @{ + @complexity Linear. - private: - /*! - @brief deserialization of CBOR and MessagePack values + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is linear. + + @liveexample{The code below shows and example for the copy assignment. It + creates a copy of value `a` which is then swapped with `b`. Finally\, the + copy of `a` (which is the null value after the swap) is + destroyed.,basic_json__copyassignment} + + @since version 1.0.0 */ - class binary_reader + reference& operator=(basic_json other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) { - public: - /*! - @brief create a binary reader + // check that passed value is valid + other.assert_invariant(); - @param[in] adapter input adapter to read from - */ - explicit binary_reader(input_adapter_t adapter) - : ia(adapter), is_little_endian(little_endianess()) - { - assert(ia); - } + using std::swap; + swap(m_type, other.m_type); + swap(m_value, other.m_value); - /*! - @brief create a JSON value from CBOR input + assert_invariant(); + return *this; + } - @param[in] get_char whether a new character should be retrieved from - the input (true, default) or whether the last - read character should be considered instead + /*! + @brief destructor - @return JSON value created from CBOR input + Destroys the JSON value and frees all allocated memory. - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_cbor(const bool get_char = true) - { - switch (get_char ? get() : current) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + @complexity Linear. - // Integer 0x00..0x17 (0..23) - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - { - return static_cast(current); - } + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is linear. + - All stored elements are destroyed and all memory is freed. - case 0x18: // Unsigned integer (one-byte uint8_t follows) - { - return get_number(); - } + @since version 1.0.0 + */ + ~basic_json() noexcept + { + assert_invariant(); + m_value.destroy(m_type); + } - case 0x19: // Unsigned integer (two-byte uint16_t follows) - { - return get_number(); - } + /// @} - case 0x1a: // Unsigned integer (four-byte uint32_t follows) - { - return get_number(); - } + public: + /////////////////////// + // object inspection // + /////////////////////// - case 0x1b: // Unsigned integer (eight-byte uint64_t follows) - { - return get_number(); - } + /// @name object inspection + /// Functions to inspect the type of a JSON value. + /// @{ - // Negative integer -1-0x00..-1-0x17 (-1..-24) - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - { - return static_cast(0x20 - 1 - current); - } + /*! + @brief serialization - case 0x38: // Negative integer (one-byte uint8_t follows) - { - // must be uint8_t ! - return static_cast(-1) - get_number(); - } + Serialization function for JSON values. The function tries to mimic + Python's `json.dumps()` function, and currently supports its @a indent + and @a ensure_ascii parameters. - case 0x39: // Negative integer -1-n (two-byte uint16_t follows) - { - return static_cast(-1) - get_number(); - } + @param[in] indent If indent is nonnegative, then array elements and object + members will be pretty-printed with that indent level. An indent level of + `0` will only insert newlines. `-1` (the default) selects the most compact + representation. + @param[in] indent_char The character to use for indentation if @a indent is + greater than `0`. The default is ` ` (space). + @param[in] ensure_ascii If @a ensure_ascii is true, all non-ASCII characters + in the output are escaped with `\uXXXX` sequences, and the result consists + of ASCII characters only. - case 0x3a: // Negative integer -1-n (four-byte uint32_t follows) - { - return static_cast(-1) - get_number(); - } + @return string containing the serialization of the JSON value - case 0x3b: // Negative integer -1-n (eight-byte uint64_t follows) - { - return static_cast(-1) - static_cast(get_number()); - } + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - case 0x7f: // UTF-8 string (indefinite length) - { - return get_cbor_string(); - } - - // array (0x00..0x17 data items follow) - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @complexity Linear. - case 0x98: // array (one-byte uint8_t for n follows) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. - case 0x99: // array (two-byte uint16_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @liveexample{The following example shows the effect of different @a indent\, + @a indent_char\, and @a ensure_ascii parameters to the result of the + serialization.,dump} - case 0x9a: // array (four-byte uint32_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @see https://docs.python.org/2/library/json.html#json.dump - case 0x9b: // array (eight-byte uint64_t for n follow) - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_cbor()); - } - return result; - } + @since version 1.0.0; indentation character @a indent_char, option + @a ensure_ascii and exceptions added in version 3.0.0 + */ + string_t dump(const int indent = -1, const char indent_char = ' ', + const bool ensure_ascii = false) const + { + string_t result; + serializer s(detail::output_adapter(result), indent_char); - case 0x9f: // array (indefinite length) - { - basic_json result = value_t::array; - while (get() != 0xff) - { - result.push_back(parse_cbor(false)); - } - return result; - } - - // map (0x00..0x17 pairs of data items follow) - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x1f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + if (indent >= 0) + { + s.dump(*this, true, ensure_ascii, static_cast(indent)); + } + else + { + s.dump(*this, false, ensure_ascii, 0); + } - case 0xb8: // map (one-byte uint8_t for n follows) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + return result; + } - case 0xb9: // map (two-byte uint16_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + /*! + @brief return the type of the JSON value (explicit) - case 0xba: // map (four-byte uint32_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + Return the type of the JSON value as a value from the @ref value_t + enumeration. - case 0xbb: // map (eight-byte uint64_t for n follow) - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @return the type of the JSON value + Value type | return value + ------------------------- | ------------------------- + null | value_t::null + boolean | value_t::boolean + string | value_t::string + number (integer) | value_t::number_integer + number (unsigned integer) | value_t::number_unsigned + number (floating-point) | value_t::number_float + object | value_t::object + array | value_t::array + discarded | value_t::discarded - case 0xbf: // map (indefinite length) - { - basic_json result = value_t::object; - while (get() != 0xff) - { - auto key = get_cbor_string(); - result[key] = parse_cbor(); - } - return result; - } + @complexity Constant. - case 0xf4: // false - { - return false; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case 0xf5: // true - { - return true; - } + @liveexample{The following code exemplifies `type()` for all JSON + types.,type} - case 0xf6: // null - { - return value_t::null; - } + @sa @ref operator value_t() -- return the type of the JSON value (implicit) + @sa @ref type_name() -- return the type as string - case 0xf9: // Half-Precision Float (two-byte IEEE 754) - { - const int byte1 = get(); - check_eof(); - const int byte2 = get(); - check_eof(); + @since version 1.0.0 + */ + constexpr value_t type() const noexcept + { + return m_type; + } - // code from RFC 7049, Appendix D, Figure 3: - // As half-precision floating-point numbers were only added - // to IEEE 754 in 2008, today's programming platforms often - // still only have limited support for them. It is very - // easy to include at least decoding support for them even - // without such support. An example of a small decoder for - // half-precision floating-point numbers in the C language - // is shown in Fig. 3. - const int half = (byte1 << 8) + byte2; - const int exp = (half >> 10) & 0x1f; - const int mant = half & 0x3ff; - double val; - if (exp == 0) - { - val = std::ldexp(mant, -24); - } - else if (exp != 31) - { - val = std::ldexp(mant + 1024, exp - 25); - } - else - { - val = mant == 0 - ? std::numeric_limits::infinity() - : std::numeric_limits::quiet_NaN(); - } - return (half & 0x8000) != 0 ? -val : val; - } + /*! + @brief return whether type is primitive - case 0xfa: // Single-Precision Float (four-byte IEEE 754) - { - return get_number(); - } + This function returns true if and only if the JSON type is primitive + (string, number, boolean, or null). - case 0xfb: // Double-Precision Float (eight-byte IEEE 754) - { - return get_number(); - } + @return `true` if type is primitive (string, number, boolean, or null), + `false` otherwise. - default: // anything else (0xFF is handled inside the other types) - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + ss.str())); - } - } - } + @complexity Constant. - /*! - @brief create a JSON value from MessagePack input + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - @return JSON value created from MessagePack input + @liveexample{The following code exemplifies `is_primitive()` for all JSON + types.,is_primitive} - @throw parse_error.110 if input ended unexpectedly - @throw parse_error.112 if unsupported byte was read - */ - basic_json parse_msgpack() - { - switch (get()) - { - // EOF - case std::char_traits::eof(): - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } + @sa @ref is_structured() -- returns whether JSON value is structured + @sa @ref is_null() -- returns whether JSON value is `null` + @sa @ref is_string() -- returns whether JSON value is a string + @sa @ref is_boolean() -- returns whether JSON value is a boolean + @sa @ref is_number() -- returns whether JSON value is a number - // positive fixint - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - case 0x20: - case 0x21: - case 0x22: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5c: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - return static_cast(current); - } - - // fixmap - case 0x80: - case 0x81: - case 0x82: - case 0x83: - case 0x84: - case 0x85: - case 0x86: - case 0x87: - case 0x88: - case 0x89: - case 0x8a: - case 0x8b: - case 0x8c: - case 0x8d: - case 0x8e: - case 0x8f: - { - basic_json result = value_t::object; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } - - // fixarray - case 0x90: - case 0x91: - case 0x92: - case 0x93: - case 0x94: - case 0x95: - case 0x96: - case 0x97: - case 0x98: - case 0x99: - case 0x9a: - case 0x9b: - case 0x9c: - case 0x9d: - case 0x9e: - case 0x9f: - { - basic_json result = value_t::array; - const auto len = static_cast(current & 0x0f); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } - - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - return get_msgpack_string(); - } - - case 0xc0: // nil - { - return value_t::null; - } - - case 0xc2: // false - { - return false; - } + @since version 1.0.0 + */ + constexpr bool is_primitive() const noexcept + { + return is_null() or is_string() or is_boolean() or is_number(); + } - case 0xc3: // true - { - return true; - } + /*! + @brief return whether type is structured - case 0xca: // float 32 - { - return get_number(); - } + This function returns true if and only if the JSON type is structured + (array or object). - case 0xcb: // float 64 - { - return get_number(); - } + @return `true` if type is structured (array or object), `false` otherwise. - case 0xcc: // uint 8 - { - return get_number(); - } + @complexity Constant. - case 0xcd: // uint 16 - { - return get_number(); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case 0xce: // uint 32 - { - return get_number(); - } + @liveexample{The following code exemplifies `is_structured()` for all JSON + types.,is_structured} - case 0xcf: // uint 64 - { - return get_number(); - } + @sa @ref is_primitive() -- returns whether value is primitive + @sa @ref is_array() -- returns whether value is an array + @sa @ref is_object() -- returns whether value is an object - case 0xd0: // int 8 - { - return get_number(); - } + @since version 1.0.0 + */ + constexpr bool is_structured() const noexcept + { + return is_array() or is_object(); + } - case 0xd1: // int 16 - { - return get_number(); - } + /*! + @brief return whether value is null - case 0xd2: // int 32 - { - return get_number(); - } + This function returns true if and only if the JSON value is null. - case 0xd3: // int 64 - { - return get_number(); - } + @return `true` if type is null, `false` otherwise. - case 0xd9: // str 8 - case 0xda: // str 16 - case 0xdb: // str 32 - { - return get_msgpack_string(); - } + @complexity Constant. - case 0xdc: // array 16 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case 0xdd: // array 32 - { - basic_json result = value_t::array; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - result.push_back(parse_msgpack()); - } - return result; - } + @liveexample{The following code exemplifies `is_null()` for all JSON + types.,is_null} - case 0xde: // map 16 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } + @since version 1.0.0 + */ + constexpr bool is_null() const noexcept + { + return (m_type == value_t::null); + } - case 0xdf: // map 32 - { - basic_json result = value_t::object; - const auto len = static_cast(get_number()); - for (size_t i = 0; i < len; ++i) - { - get(); - auto key = get_msgpack_string(); - result[key] = parse_msgpack(); - } - return result; - } + /*! + @brief return whether value is a boolean - // positive fixint - case 0xe0: - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xed: - case 0xee: - case 0xef: - case 0xf0: - case 0xf1: - case 0xf2: - case 0xf3: - case 0xf4: - case 0xf5: - case 0xf6: - case 0xf7: - case 0xf8: - case 0xf9: - case 0xfa: - case 0xfb: - case 0xfc: - case 0xfd: - case 0xfe: - case 0xff: - { - return static_cast(current); - } + This function returns true if and only if the JSON value is a boolean. - default: // anything else - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(112, chars_read, "error reading MessagePack; last byte: 0x" + ss.str())); - } - } - } + @return `true` if type is boolean, `false` otherwise. - /*! - @brief determine system byte order + @complexity Constant. - @return true iff system's byte order is little endian + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - @note from http://stackoverflow.com/a/1001328/266378 - */ - static bool little_endianess() noexcept - { - int num = 1; - return (*reinterpret_cast(&num) == 1); - } + @liveexample{The following code exemplifies `is_boolean()` for all JSON + types.,is_boolean} - private: - /*! - @brief get next character from the input + @since version 1.0.0 + */ + constexpr bool is_boolean() const noexcept + { + return (m_type == value_t::boolean); + } - This function provides the interface to the used input adapter. It does - not throw in case the input reached EOF, but returns - `std::char_traits::eof()` in that case. + /*! + @brief return whether value is a number - @return character read from the input - */ - int get() - { - ++chars_read; - return (current = ia->get_character()); - } + This function returns true if and only if the JSON value is a number. This + includes both integer (signed and unsigned) and floating-point values. - /* - @brief read a number from the input + @return `true` if type is number (regardless whether integer, unsigned + integer or floating-type), `false` otherwise. - @tparam T the type of the number + @complexity Constant. - @return number of type @a T + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. + @liveexample{The following code exemplifies `is_number()` for all JSON + types.,is_number} - @throw parse_error.110 if input has less than `sizeof(T)` bytes - */ - template - T get_number() - { - // step 1: read input into array with system's byte order - std::array vec; - for (size_t i = 0; i < sizeof(T); ++i) - { - get(); - check_eof(); + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - vec[sizeof(T) - i - 1] = static_cast(current); - } - else - { - vec[i] = static_cast(current); - } - } + @since version 1.0.0 + */ + constexpr bool is_number() const noexcept + { + return is_number_integer() or is_number_float(); + } - // step 2: convert array into number of type T and return - T result; - std::memcpy(&result, vec.data(), sizeof(T)); - return result; - } + /*! + @brief return whether value is an integer number - /*! - @brief create a string by reading characters from the input + This function returns true if and only if the JSON value is a signed or + unsigned integer number. This excludes floating-point values. - @param[in] len number of bytes to read + @return `true` if type is an integer or unsigned integer number, `false` + otherwise. - @return string created by reading @a len bytes + @complexity Constant. - @throw parse_error.110 if input has less than @a len bytes - */ - std::string get_string(const size_t len) - { - std::string result; - for (size_t i = 0; i < len; ++i) - { - get(); - check_eof(); - result.append(1, static_cast(current)); - } - return result; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /*! - @brief reads a CBOR string + @liveexample{The following code exemplifies `is_number_integer()` for all + JSON types.,is_number_integer} - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. - Additionally, CBOR's strings with indefinite lengths are supported. + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number + @sa @ref is_number_float() -- check if value is a floating-point number - @return string + @since version 1.0.0 + */ + constexpr bool is_number_integer() const noexcept + { + return (m_type == value_t::number_integer or m_type == value_t::number_unsigned); + } - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_cbor_string() - { - check_eof(); + /*! + @brief return whether value is an unsigned integer number - switch (current) - { - // UTF-8 string (0x00..0x17 bytes follow) - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + This function returns true if and only if the JSON value is an unsigned + integer number. This excludes floating-point and signed integer values. - case 0x78: // UTF-8 string (one-byte uint8_t for n follows) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @return `true` if type is an unsigned integer number, `false` otherwise. - case 0x79: // UTF-8 string (two-byte uint16_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @complexity Constant. - case 0x7a: // UTF-8 string (four-byte uint32_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case 0x7b: // UTF-8 string (eight-byte uint64_t for n follow) - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @liveexample{The following code exemplifies `is_number_unsigned()` for all + JSON types.,is_number_unsigned} - case 0x7f: // UTF-8 string (indefinite length) - { - std::string result; - while (get() != 0xff) - { - check_eof(); - result.append(1, static_cast(current)); - } - return result; - } + @sa @ref is_number() -- check if value is a number + @sa @ref is_number_integer() -- check if value is an integer or unsigned + integer number + @sa @ref is_number_float() -- check if value is a floating-point number - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + ss.str())); - } - } - } + @since version 2.0.0 + */ + constexpr bool is_number_unsigned() const noexcept + { + return (m_type == value_t::number_unsigned); + } - /*! - @brief reads a MessagePack string + /*! + @brief return whether value is a floating-point number - This function first reads starting bytes to determine the expected - string length and then copies this number of bytes into a string. + This function returns true if and only if the JSON value is a + floating-point number. This excludes signed and unsigned integer values. - @return string + @return `true` if type is a floating-point number, `false` otherwise. - @throw parse_error.110 if input ended - @throw parse_error.113 if an unexpexted byte is read - */ - std::string get_msgpack_string() - { - check_eof(); + @complexity Constant. - switch (current) - { - // fixstr - case 0xa0: - case 0xa1: - case 0xa2: - case 0xa3: - case 0xa4: - case 0xa5: - case 0xa6: - case 0xa7: - case 0xa8: - case 0xa9: - case 0xaa: - case 0xab: - case 0xac: - case 0xad: - case 0xae: - case 0xaf: - case 0xb0: - case 0xb1: - case 0xb2: - case 0xb3: - case 0xb4: - case 0xb5: - case 0xb6: - case 0xb7: - case 0xb8: - case 0xb9: - case 0xba: - case 0xbb: - case 0xbc: - case 0xbd: - case 0xbe: - case 0xbf: - { - const auto len = static_cast(current & 0x1f); - return get_string(len); - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case 0xd9: // str 8 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @liveexample{The following code exemplifies `is_number_float()` for all + JSON types.,is_number_float} - case 0xda: // str 16 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @sa @ref is_number() -- check if value is number + @sa @ref is_number_integer() -- check if value is an integer number + @sa @ref is_number_unsigned() -- check if value is an unsigned integer + number - case 0xdb: // str 32 - { - const auto len = static_cast(get_number()); - return get_string(len); - } + @since version 1.0.0 + */ + constexpr bool is_number_float() const noexcept + { + return (m_type == value_t::number_float); + } - default: - { - std::stringstream ss; - ss << std::setw(2) << std::setfill('0') << std::hex << current; - JSON_THROW(parse_error::create(113, chars_read, "expected a MessagePack string; last byte: 0x" + ss.str())); - } - } - } + /*! + @brief return whether value is an object - /*! - @brief check if input ended - @throw parse_error.110 if input ended - */ - void check_eof() const - { - if (JSON_UNLIKELY(current == std::char_traits::eof())) - { - JSON_THROW(parse_error::create(110, chars_read, "unexpected end of input")); - } - } + This function returns true if and only if the JSON value is an object. - private: - /// input adapter - input_adapter_t ia = nullptr; + @return `true` if type is object, `false` otherwise. - /// the current character - int current = std::char_traits::eof(); + @complexity Constant. - /// the number of characters read - size_t chars_read = 0; + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - /// whether we can assume little endianess - const bool is_little_endian = true; - }; + @liveexample{The following code exemplifies `is_object()` for all JSON + types.,is_object} - /*! - @brief serialization to CBOR and MessagePack values + @since version 1.0.0 */ - class binary_writer + constexpr bool is_object() const noexcept { - public: - /*! - @brief create a binary writer + return (m_type == value_t::object); + } - @param[in] adapter output adapter to write to - */ - explicit binary_writer(output_adapter_t adapter) - : is_little_endian(binary_reader::little_endianess()), oa(adapter) - { - assert(oa); - } + /*! + @brief return whether value is an array - /*! - @brief[in] j JSON value to serialize - */ - void write_cbor(const basic_json& j) - { - switch (j.type()) - { - case value_t::null: - { - oa->write_character(0xf6); - break; - } + This function returns true if and only if the JSON value is an array. - case value_t::boolean: - { - oa->write_character(j.m_value.boolean ? 0xf5 : 0xf4); - break; - } + @return `true` if type is array, `false` otherwise. - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // CBOR does not differentiate between positive signed - // integers and unsigned integers. Therefore, we used the - // code from the value_t::number_unsigned case here. - if (j.m_value.number_integer <= 0x17) - { - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_integer)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - // The conversions below encode the sign in the first - // byte, and the value is converted to a positive number. - const auto positive_number = -1 - j.m_value.number_integer; - if (j.m_value.number_integer >= -24) - { - write_number(static_cast(0x20 + positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x38); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x39); - write_number(static_cast(positive_number)); - } - else if (positive_number <= (std::numeric_limits::max)()) - { - oa->write_character(0x3a); - write_number(static_cast(positive_number)); - } - else - { - oa->write_character(0x3b); - write_number(static_cast(positive_number)); - } - } - break; - } + @complexity Constant. - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned <= 0x17) - { - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x18); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x19); - write_number(static_cast(j.m_value.number_unsigned)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - oa->write_character(0x1a); - write_number(static_cast(j.m_value.number_unsigned)); - } - else - { - oa->write_character(0x1b); - write_number(static_cast(j.m_value.number_unsigned)); - } - break; - } + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. - case value_t::number_float: - { - // Double-Precision Float - oa->write_character(0xfb); - write_number(j.m_value.number_float); - break; - } + @liveexample{The following code exemplifies `is_array()` for all JSON + types.,is_array} - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 0x17) - { - write_number(static_cast(0x60 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x78); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x79); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x7a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x7b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + @since version 1.0.0 + */ + constexpr bool is_array() const noexcept + { + return (m_type == value_t::array); + } - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + /*! + @brief return whether value is a string - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 0x17) - { - write_number(static_cast(0x80 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0x98); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0x99); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0x9a); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0x9b); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + This function returns true if and only if the JSON value is a string. - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_cbor(el); - } - break; - } + @return `true` if type is string, `false` otherwise. - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 0x17) - { - write_number(static_cast(0xa0 + N)); - } - else if (N <= 0xff) - { - oa->write_character(0xb8); - write_number(static_cast(N)); - } - else if (N <= 0xffff) - { - oa->write_character(0xb9); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - oa->write_character(0xba); - write_number(static_cast(N)); - } - // LCOV_EXCL_START - else if (N <= 0xffffffffffffffff) - { - oa->write_character(0xbb); - write_number(static_cast(N)); - } - // LCOV_EXCL_STOP + @complexity Constant. - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_cbor(el.first); - write_cbor(el.second); - } - break; + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_string()` for all JSON + types.,is_string} + + @since version 1.0.0 + */ + constexpr bool is_string() const noexcept + { + return (m_type == value_t::string); + } + + /*! + @brief return whether value is discarded + + This function returns true if and only if the JSON value was discarded + during parsing with a callback function (see @ref parser_callback_t). + + @note This function will always be `false` for JSON values after parsing. + That is, discarded values can only occur during parsing, but will be + removed when inside a structured value or replaced by null in other cases. + + @return `true` if type is discarded, `false` otherwise. + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies `is_discarded()` for all JSON + types.,is_discarded} + + @since version 1.0.0 + */ + constexpr bool is_discarded() const noexcept + { + return (m_type == value_t::discarded); + } + + /*! + @brief return the type of the JSON value (implicit) + + Implicitly return the type of the JSON value as a value from the @ref + value_t enumeration. + + @return the type of the JSON value + + @complexity Constant. + + @exceptionsafety No-throw guarantee: this member function never throws + exceptions. + + @liveexample{The following code exemplifies the @ref value_t operator for + all JSON types.,operator__value_t} + + @sa @ref type() -- return the type of the JSON value (explicit) + @sa @ref type_name() -- return the type as string + + @since version 1.0.0 + */ + constexpr operator value_t() const noexcept + { + return m_type; + } + + /// @} + + private: + ////////////////// + // value access // + ////////////////// + + /// get a boolean (explicit) + boolean_t get_impl(boolean_t* /*unused*/) const + { + if (JSON_LIKELY(is_boolean())) + { + return m_value.boolean; + } + + JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(type_name()))); + } + + /// get a pointer to the value (object) + object_t* get_impl_ptr(object_t* /*unused*/) noexcept + { + return is_object() ? m_value.object : nullptr; + } + + /// get a pointer to the value (object) + constexpr const object_t* get_impl_ptr(const object_t* /*unused*/) const noexcept + { + return is_object() ? m_value.object : nullptr; + } + + /// get a pointer to the value (array) + array_t* get_impl_ptr(array_t* /*unused*/) noexcept + { + return is_array() ? m_value.array : nullptr; + } + + /// get a pointer to the value (array) + constexpr const array_t* get_impl_ptr(const array_t* /*unused*/) const noexcept + { + return is_array() ? m_value.array : nullptr; + } + + /// get a pointer to the value (string) + string_t* get_impl_ptr(string_t* /*unused*/) noexcept + { + return is_string() ? m_value.string : nullptr; + } + + /// get a pointer to the value (string) + constexpr const string_t* get_impl_ptr(const string_t* /*unused*/) const noexcept + { + return is_string() ? m_value.string : nullptr; + } + + /// get a pointer to the value (boolean) + boolean_t* get_impl_ptr(boolean_t* /*unused*/) noexcept + { + return is_boolean() ? &m_value.boolean : nullptr; + } + + /// get a pointer to the value (boolean) + constexpr const boolean_t* get_impl_ptr(const boolean_t* /*unused*/) const noexcept + { + return is_boolean() ? &m_value.boolean : nullptr; + } + + /// get a pointer to the value (integer number) + number_integer_t* get_impl_ptr(number_integer_t* /*unused*/) noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } + + /// get a pointer to the value (integer number) + constexpr const number_integer_t* get_impl_ptr(const number_integer_t* /*unused*/) const noexcept + { + return is_number_integer() ? &m_value.number_integer : nullptr; + } + + /// get a pointer to the value (unsigned number) + number_unsigned_t* get_impl_ptr(number_unsigned_t* /*unused*/) noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } + + /// get a pointer to the value (unsigned number) + constexpr const number_unsigned_t* get_impl_ptr(const number_unsigned_t* /*unused*/) const noexcept + { + return is_number_unsigned() ? &m_value.number_unsigned : nullptr; + } + + /// get a pointer to the value (floating-point number) + number_float_t* get_impl_ptr(number_float_t* /*unused*/) noexcept + { + return is_number_float() ? &m_value.number_float : nullptr; + } + + /// get a pointer to the value (floating-point number) + constexpr const number_float_t* get_impl_ptr(const number_float_t* /*unused*/) const noexcept + { + return is_number_float() ? &m_value.number_float : nullptr; + } + + /*! + @brief helper function to implement get_ref() + + This function helps to implement get_ref() without code duplication for + const and non-const overloads + + @tparam ThisType will be deduced as `basic_json` or `const basic_json` + + @throw type_error.303 if ReferenceType does not match underlying value + type of the current JSON + */ + template + static ReferenceType get_ref_impl(ThisType& obj) + { + // delegate the call to get_ptr<>() + auto ptr = obj.template get_ptr::type>(); + + if (JSON_LIKELY(ptr != nullptr)) + { + return *ptr; + } + + JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + std::string(obj.type_name()))); + } + + public: + /// @name value access + /// Direct access to the stored value of a JSON value. + /// @{ + + /*! + @brief get special-case overload + + This overloads avoids a lot of template boilerplate, it can be seen as the + identity method + + @tparam BasicJsonType == @ref basic_json + + @return a copy of *this + + @complexity Constant. + + @since version 2.1.0 + */ + template::type, basic_json_t>::value, + int> = 0> + basic_json get() const + { + return *this; + } + + /*! + @brief get special-case overload + + This overloads converts the current @ref basic_json in a different + @ref basic_json type + + @tparam BasicJsonType == @ref basic_json + + @return a copy of *this, converted into @tparam BasicJsonType + + @complexity Depending on the implementation of the called `from_json()` + method. + + @since version 3.1.2 + */ + template::value and + detail::is_basic_json::value, int> = 0> + BasicJsonType get() const + { + return *this; + } + + /*! + @brief get a value (explicit) + + Explicit type conversion between the JSON value and a compatible value + which is [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible) + and [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. + + The function is equivalent to executing + @code {.cpp} + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + @endcode + + This overloads is chosen if: + - @a ValueType is not @ref basic_json, + - @ref json_serializer has a `from_json()` method of the form + `void from_json(const basic_json&, ValueType&)`, and + - @ref json_serializer does not have a `from_json()` method of + the form `ValueType from_json(const basic_json&)` + + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type + + @return copy of the JSON value, converted to @a ValueType + + @throw what @ref json_serializer `from_json()` method throws + + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,get__ValueType_const} + + @since version 2.1.0 + */ + template, + detail::enable_if_t < + not detail::is_basic_json::value and + detail::has_from_json::value and + not detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval(), std::declval()))) + { + // we cannot static_assert on ValueTypeCV being non-const, because + // there is support for get(), which is why we + // still need the uncvref + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + static_assert(std::is_default_constructible::value, + "types must be DefaultConstructible when used with get()"); + + ValueType ret; + JSONSerializer::from_json(*this, ret); + return ret; + } + + /*! + @brief get a value (explicit); special case + + Explicit type conversion between the JSON value and a compatible value + which is **not** [CopyConstructible](https://en.cppreference.com/w/cpp/named_req/CopyConstructible) + and **not** [DefaultConstructible](https://en.cppreference.com/w/cpp/named_req/DefaultConstructible). + The value is converted by calling the @ref json_serializer + `from_json()` method. + + The function is equivalent to executing + @code {.cpp} + return JSONSerializer::from_json(*this); + @endcode + + This overloads is chosen if: + - @a ValueType is not @ref basic_json and + - @ref json_serializer has a `from_json()` method of the form + `ValueType from_json(const basic_json&)` + + @note If @ref json_serializer has both overloads of + `from_json()`, this one is chosen. + + @tparam ValueTypeCV the provided value type + @tparam ValueType the returned value type + + @return copy of the JSON value, converted to @a ValueType + + @throw what @ref json_serializer `from_json()` method throws + + @since version 2.1.0 + */ + template, + detail::enable_if_t::value and + detail::has_non_default_from_json::value, + int> = 0> + ValueType get() const noexcept(noexcept( + JSONSerializer::from_json(std::declval()))) + { + static_assert(not std::is_reference::value, + "get() cannot be used with reference types, you might want to use get_ref()"); + return JSONSerializer::from_json(*this); + } + + /*! + @brief get a pointer value (explicit) + + Explicit pointer access to the internally stored JSON value. No copies are + made. + + @warning The pointer becomes invalid if the underlying JSON object + changes. + + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. + + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + + @complexity Constant. + + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get__PointerType} + + @sa @ref get_ptr() for explicit pointer-member access + + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get() noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } + + /*! + @brief get a pointer value (explicit) + @copydoc get() + */ + template::value, int>::type = 0> + constexpr const PointerType get() const noexcept + { + // delegate the call to get_ptr + return get_ptr(); + } + + /*! + @brief get a pointer value (implicit) + + Implicit pointer access to the internally stored JSON value. No copies are + made. + + @warning Writing data to the pointee of the result yields an undefined + state. + + @tparam PointerType pointer type; must be a pointer to @ref array_t, @ref + object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, + @ref number_unsigned_t, or @ref number_float_t. Enforced by a static + assertion. + + @return pointer to the internally stored JSON value if the requested + pointer type @a PointerType fits to the JSON value; `nullptr` otherwise + + @complexity Constant. + + @liveexample{The example below shows how pointers to internal values of a + JSON value can be requested. Note that no type conversions are made and a + `nullptr` is returned if the value and the requested pointer type does not + match.,get_ptr} + + @since version 1.0.0 + */ + template::value, int>::type = 0> + PointerType get_ptr() noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); + + // delegate the call to get_impl_ptr<>() + return get_impl_ptr(static_cast(nullptr)); + } + + /*! + @brief get a pointer value (implicit) + @copydoc get_ptr() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + constexpr const PointerType get_ptr() const noexcept + { + // get the type of the PointerType (remove pointer and const) + using pointee_t = typename std::remove_const::type>::type>::type; + // make sure the type matches the allowed types + static_assert( + std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + or std::is_same::value + , "incompatible pointer type"); + + // delegate the call to get_impl_ptr<>() const + return get_impl_ptr(static_cast(nullptr)); + } + + /*! + @brief get a reference value (implicit) + + Implicit reference access to the internally stored JSON value. No copies + are made. + + @warning Writing data to the referee of the result yields an undefined + state. + + @tparam ReferenceType reference type; must be a reference to @ref array_t, + @ref object_t, @ref string_t, @ref boolean_t, @ref number_integer_t, or + @ref number_float_t. Enforced by static assertion. + + @return reference to the internally stored JSON value if the requested + reference type @a ReferenceType fits to the JSON value; throws + type_error.303 otherwise + + @throw type_error.303 in case passed type @a ReferenceType is incompatible + with the stored JSON value; see example below + + @complexity Constant. + + @liveexample{The example shows several calls to `get_ref()`.,get_ref} + + @since version 1.1.0 + */ + template::value, int>::type = 0> + ReferenceType get_ref() + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } + + /*! + @brief get a reference value (implicit) + @copydoc get_ref() + */ + template::value and + std::is_const::type>::value, int>::type = 0> + ReferenceType get_ref() const + { + // delegate call to get_ref_impl + return get_ref_impl(*this); + } + + /*! + @brief get a value (implicit) + + Implicit type conversion between the JSON value and a compatible value. + The call is realized by calling @ref get() const. + + @tparam ValueType non-pointer type compatible to the JSON value, for + instance `int` for JSON integer numbers, `bool` for JSON booleans, or + `std::vector` types for JSON arrays. The character type of @ref string_t + as well as an initializer list of this type is excluded to avoid + ambiguities as these types implicitly convert to `std::string`. + + @return copy of the JSON value, converted to type @a ValueType + + @throw type_error.302 in case passed type @a ValueType is incompatible + to the JSON value type (e.g., the JSON value is of type boolean, but a + string is requested); see example below + + @complexity Linear in the size of the JSON value. + + @liveexample{The example below shows several conversions from JSON values + to other types. There a few things to note: (1) Floating-point numbers can + be converted to integers\, (2) A JSON array can be converted to a standard + `std::vector`\, (3) A JSON object can be converted to C++ + associative containers such as `std::unordered_map`.,operator__ValueType} + + @since version 1.0.0 + */ + template < typename ValueType, typename std::enable_if < + not std::is_pointer::value and + not std::is_same>::value and + not std::is_same::value and + not detail::is_basic_json::value +#ifndef _MSC_VER // fix for issue #167 operator<< ambiguity under VS2015 + and not std::is_same>::value +#if defined(JSON_HAS_CPP_17) && _MSC_VER <= 1914 + and not std::is_same::value +#endif +#endif + , int >::type = 0 > + operator ValueType() const + { + // delegate the call to get<>() const + return get(); + } + + /// @} + + + //////////////////// + // element access // + //////////////////// + + /// @name element access + /// Access to the JSON value. + /// @{ + + /*! + @brief access specified array element with bounds checking + + Returns a reference to the element at specified location @a idx, with + bounds checking. + + @param[in] idx index of the element to access + + @return reference to the element at index @a idx + + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 1.0.0 + + @liveexample{The example below shows how array elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__size_type} + */ + reference at(size_type idx) + { + // at only works for arrays + if (JSON_LIKELY(is_array())) + { + JSON_TRY + { + return m_value.array->at(idx); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } + + /*! + @brief access specified array element with bounds checking + + Returns a const reference to the element at specified location @a idx, + with bounds checking. + + @param[in] idx index of the element to access + + @return const reference to the element at index @a idx + + @throw type_error.304 if the JSON value is not an array; in this case, + calling `at` with an index makes no sense. See example below. + @throw out_of_range.401 if the index @a idx is out of range of the array; + that is, `idx >= size()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 1.0.0 + + @liveexample{The example below shows how array elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__size_type_const} + */ + const_reference at(size_type idx) const + { + // at only works for arrays + if (JSON_LIKELY(is_array())) + { + JSON_TRY + { + return m_value.array->at(idx); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } + + /*! + @brief access specified object element with bounds checking + + Returns a reference to the element at with specified key @a key, with + bounds checking. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Logarithmic in the size of the container. + + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + + @liveexample{The example below shows how object elements can be read and + written using `at()`. It also demonstrates the different exceptions that + can be thrown.,at__object_t_key_type} + */ + reference at(const typename object_t::key_type& key) + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + JSON_TRY + { + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } + + /*! + @brief access specified object element with bounds checking + + Returns a const reference to the element at with specified key @a key, + with bounds checking. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @throw type_error.304 if the JSON value is not an object; in this case, + calling `at` with a key makes no sense. See example below. + @throw out_of_range.403 if the key @a key is is not stored in the object; + that is, `find(key) == end()`. See example below. + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Logarithmic in the size of the container. + + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + + @liveexample{The example below shows how object elements can be read using + `at()`. It also demonstrates the different exceptions that can be thrown., + at__object_t_key_type_const} + */ + const_reference at(const typename object_t::key_type& key) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + JSON_TRY + { + return m_value.object->at(key); + } + JSON_CATCH (std::out_of_range&) + { + // create better exception explanation + JSON_THROW(out_of_range::create(403, "key '" + key + "' not found")); + } + } + else + { + JSON_THROW(type_error::create(304, "cannot use at() with " + std::string(type_name()))); + } + } + + /*! + @brief access specified array element + + Returns a reference to the element at specified location @a idx. + + @note If @a idx is beyond the range of the array (i.e., `idx >= size()`), + then the array is silently filled up with `null` values to make `idx` a + valid reference to the last stored element. + + @param[in] idx index of the element to access + + @return reference to the element at index @a idx + + @throw type_error.305 if the JSON value is not an array or null; in that + cases, using the [] operator with an index makes no sense. + + @complexity Constant if @a idx is in the range of the array. Otherwise + linear in `idx - size()`. + + @liveexample{The example below shows how array elements can be read and + written using `[]` operator. Note the addition of `null` + values.,operatorarray__size_type} + + @since version 1.0.0 + */ + reference operator[](size_type idx) + { + // implicitly convert null value to an empty array + if (is_null()) + { + m_type = value_t::array; + m_value.array = create(); + assert_invariant(); + } + + // operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + // fill up array with null values if given idx is outside range + if (idx >= m_value.array->size()) + { + m_value.array->insert(m_value.array->end(), + idx - m_value.array->size() + 1, + basic_json()); + } + + return m_value.array->operator[](idx); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified array element + + Returns a const reference to the element at specified location @a idx. + + @param[in] idx index of the element to access + + @return const reference to the element at index @a idx + + @throw type_error.305 if the JSON value is not an array; in that case, + using the [] operator with an index makes no sense. + + @complexity Constant. + + @liveexample{The example below shows how array elements can be read using + the `[]` operator.,operatorarray__size_type_const} + + @since version 1.0.0 + */ + const_reference operator[](size_type idx) const + { + // const operator[] only works for arrays + if (JSON_LIKELY(is_array())) + { + return m_value.array->operator[](idx); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element + + Returns a reference to the element at with specified key @a key. + + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + */ + reference operator[](const typename object_t::key_type& key) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } + + // operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief read-only access specified object element + + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. + + @warning If the element with key @a key does not exist, the behavior is + undefined. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** + + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.0.0 + */ + const_reference operator[](const typename object_t::key_type& key) const + { + // const operator[] only works for objects + if (JSON_LIKELY(is_object())) + { + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element + + Returns a reference to the element at with specified key @a key. + + @note If @a key is not found in the object, then it is silently added to + the object and filled with a `null` value to make `key` a valid reference. + In case the value was `null` before, it is converted to an object. + + @param[in] key key of the element to access + + @return reference to the element at key @a key + + @throw type_error.305 if the JSON value is not an object or null; in that + cases, using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read and + written using the `[]` operator.,operatorarray__key_type} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 + */ + template + reference operator[](T* key) + { + // implicitly convert null to object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } + + // at only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->operator[](key); + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief read-only access specified object element + + Returns a const reference to the element at with specified key @a key. No + bounds checking is performed. + + @warning If the element with key @a key does not exist, the behavior is + undefined. + + @param[in] key key of the element to access + + @return const reference to the element at key @a key + + @pre The element with key @a key must exist. **This precondition is + enforced with an assertion.** + + @throw type_error.305 if the JSON value is not an object; in that case, + using the [] operator with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be read using + the `[]` operator.,operatorarray__key_type_const} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref value() for access by value with a default value + + @since version 1.1.0 + */ + template + const_reference operator[](T* key) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + assert(m_value.object->find(key) != m_value.object->end()); + return m_value.object->find(key)->second; + } + + JSON_THROW(type_error::create(305, "cannot use operator[] with " + std::string(type_name()))); + } + + /*! + @brief access specified object element with default value + + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. + + The function is basically equivalent to executing + @code {.cpp} + try { + return at(key); + } catch(out_of_range) { + return default_value; + } + @endcode + + @note Unlike @ref at(const typename object_t::key_type&), this function + does not throw if the given key @a key was not found. + + @note Unlike @ref operator[](const typename object_t::key_type& key), this + function does not implicitly add an element to the position defined by @a + key. This function is furthermore also applicable to const objects. + + @param[in] key key of the element to access + @param[in] default_value the value to return if @a key is not found + + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. + + @return copy of the element at key @a key or @a default_value if @a key + is not found + + @throw type_error.306 if the JSON value is not an object; in that case, + using `value()` with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value} + + @sa @ref at(const typename object_t::key_type&) for access by reference + with range checking + @sa @ref operator[](const typename object_t::key_type&) for unchecked + access by reference + + @since version 1.0.0 + */ + template::value, int>::type = 0> + ValueType value(const typename object_t::key_type& key, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + // if key is found, return value and given default value otherwise + const auto it = find(key); + if (it != end()) + { + return *it; + } + + return default_value; + } + + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } + + /*! + @brief overload for a default value of type const char* + @copydoc basic_json::value(const typename object_t::key_type&, ValueType) const + */ + string_t value(const typename object_t::key_type& key, const char* default_value) const + { + return value(key, string_t(default_value)); + } + + /*! + @brief access specified object element via JSON Pointer with default value + + Returns either a copy of an object's element at the specified key @a key + or a given default value if no element with key @a key exists. + + The function is basically equivalent to executing + @code {.cpp} + try { + return at(ptr); + } catch(out_of_range) { + return default_value; + } + @endcode + + @note Unlike @ref at(const json_pointer&), this function does not throw + if the given key @a key was not found. + + @param[in] ptr a JSON pointer to the element to access + @param[in] default_value the value to return if @a ptr found no value + + @tparam ValueType type compatible to JSON values, for instance `int` for + JSON integer numbers, `bool` for JSON booleans, or `std::vector` types for + JSON arrays. Note the type of the expected value at @a key and the default + value @a default_value must be compatible. + + @return copy of the element at key @a key or @a default_value if @a key + is not found + + @throw type_error.306 if the JSON value is not an object; in that case, + using `value()` with a key makes no sense. + + @complexity Logarithmic in the size of the container. + + @liveexample{The example below shows how object elements can be queried + with a default value.,basic_json__value_ptr} + + @sa @ref operator[](const json_pointer&) for unchecked access by reference + + @since version 2.0.2 + */ + template::value, int>::type = 0> + ValueType value(const json_pointer& ptr, const ValueType& default_value) const + { + // at only works for objects + if (JSON_LIKELY(is_object())) + { + // if pointer resolves a value, return it or use default value + JSON_TRY + { + return ptr.get_checked(this); + } + JSON_CATCH (out_of_range&) + { + return default_value; + } + } + + JSON_THROW(type_error::create(306, "cannot use value() with " + std::string(type_name()))); + } + + /*! + @brief overload for a default value of type const char* + @copydoc basic_json::value(const json_pointer&, ValueType) const + */ + string_t value(const json_pointer& ptr, const char* default_value) const + { + return value(ptr, string_t(default_value)); + } + + /*! + @brief access the first element + + Returns a reference to the first element in the container. For a JSON + container `c`, the expression `c.front()` is equivalent to `*c.begin()`. + + @return In case of a structured type (array or object), a reference to the + first element is returned. In case of number, string, or boolean values, a + reference to the value is returned. + + @complexity Constant. + + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. + + @throw invalid_iterator.214 when called on `null` value + + @liveexample{The following code shows an example for `front()`.,front} + + @sa @ref back() -- access the last element + + @since version 1.0.0 + */ + reference front() + { + return *begin(); + } + + /*! + @copydoc basic_json::front() + */ + const_reference front() const + { + return *cbegin(); + } + + /*! + @brief access the last element + + Returns a reference to the last element in the container. For a JSON + container `c`, the expression `c.back()` is equivalent to + @code {.cpp} + auto tmp = c.end(); + --tmp; + return *tmp; + @endcode + + @return In case of a structured type (array or object), a reference to the + last element is returned. In case of number, string, or boolean values, a + reference to the value is returned. + + @complexity Constant. + + @pre The JSON value must not be `null` (would throw `std::out_of_range`) + or an empty array or object (undefined behavior, **guarded by + assertions**). + @post The JSON value remains unchanged. + + @throw invalid_iterator.214 when called on a `null` value. See example + below. + + @liveexample{The following code shows an example for `back()`.,back} + + @sa @ref front() -- access the first element + + @since version 1.0.0 + */ + reference back() + { + auto tmp = end(); + --tmp; + return *tmp; + } + + /*! + @copydoc basic_json::back() + */ + const_reference back() const + { + auto tmp = cend(); + --tmp; + return *tmp; + } + + /*! + @brief remove element given an iterator + + Removes the element specified by iterator @a pos. The iterator @a pos must + be valid and dereferenceable. Thus the `end()` iterator (which is valid, + but is not dereferenceable) cannot be used as a value for @a pos. + + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. + + @param[in] pos iterator to the element to remove + @return Iterator following the last removed element. If the iterator @a + pos refers to the last element, the `end()` iterator is returned. + + @tparam IteratorType an @ref iterator or @ref const_iterator + + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. + + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.202 if called on an iterator which does not belong + to the current JSON value; example: `"iterator does not fit current + value"` + @throw invalid_iterator.205 if called on a primitive type with invalid + iterator (i.e., any iterator which is not `begin()`); example: `"iterator + out of range"` + + @complexity The complexity depends on the type: + - objects: amortized constant + - arrays: linear in distance between @a pos and the end of the container + - strings: linear in the length of the string + - other types: constant + + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType} + + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType pos) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != pos.m_object)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } + + IteratorType result = end(); + + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_UNLIKELY(not pos.m_it.primitive_iterator.is_begin())) + { + JSON_THROW(invalid_iterator::create(205, "iterator out of range")); + } + + if (is_string()) + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; + } + + m_type = value_t::null; + assert_invariant(); + break; + } + + case value_t::object: + { + result.m_it.object_iterator = m_value.object->erase(pos.m_it.object_iterator); + break; + } + + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(pos.m_it.array_iterator); + break; + } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + return result; + } + + /*! + @brief remove elements given an iterator range + + Removes the element specified by the range `[first; last)`. The iterator + @a first does not need to be dereferenceable if `first == last`: erasing + an empty range is a no-op. + + If called on a primitive type other than `null`, the resulting JSON value + will be `null`. + + @param[in] first iterator to the beginning of the range to remove + @param[in] last iterator past the end of the range to remove + @return Iterator following the last removed element. If the iterator @a + second refers to the last element, the `end()` iterator is returned. + + @tparam IteratorType an @ref iterator or @ref const_iterator + + @post Invalidates iterators and references at or after the point of the + erase, including the `end()` iterator. + + @throw type_error.307 if called on a `null` value; example: `"cannot use + erase() with null"` + @throw invalid_iterator.203 if called on iterators which does not belong + to the current JSON value; example: `"iterators do not fit current value"` + @throw invalid_iterator.204 if called on a primitive type with invalid + iterators (i.e., if `first != begin()` and `last != end()`); example: + `"iterators out of range"` + + @complexity The complexity depends on the type: + - objects: `log(size()) + std::distance(first, last)` + - arrays: linear in the distance between @a first and @a last, plus linear + in the distance between @a last and end of the container + - strings: linear in the length of the string + - other types: constant + + @liveexample{The example shows the result of `erase()` for different JSON + types.,erase__IteratorType_IteratorType} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + template::value or + std::is_same::value, int>::type + = 0> + IteratorType erase(IteratorType first, IteratorType last) + { + // make sure iterator fits the current value + if (JSON_UNLIKELY(this != first.m_object or this != last.m_object)) + { + JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value")); + } + + IteratorType result = end(); + + switch (m_type) + { + case value_t::boolean: + case value_t::number_float: + case value_t::number_integer: + case value_t::number_unsigned: + case value_t::string: + { + if (JSON_LIKELY(not first.m_it.primitive_iterator.is_begin() + or not last.m_it.primitive_iterator.is_end())) + { + JSON_THROW(invalid_iterator::create(204, "iterators out of range")); + } + + if (is_string()) + { + AllocatorType alloc; + std::allocator_traits::destroy(alloc, m_value.string); + std::allocator_traits::deallocate(alloc, m_value.string, 1); + m_value.string = nullptr; } - default: - { - break; - } - } - } + m_type = value_t::null; + assert_invariant(); + break; + } + + case value_t::object: + { + result.m_it.object_iterator = m_value.object->erase(first.m_it.object_iterator, + last.m_it.object_iterator); + break; + } + + case value_t::array: + { + result.m_it.array_iterator = m_value.array->erase(first.m_it.array_iterator, + last.m_it.array_iterator); + break; + } + + default: + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + return result; + } + + /*! + @brief remove element from a JSON object given a key + + Removes elements from a JSON object with the key value @a key. + + @param[in] key value of the elements to remove + + @return Number of elements removed. If @a ObjectType is the default + `std::map` type, the return value will always be `0` (@a key was not + found) or `1` (@a key was found). + + @post References and iterators to the erased elements are invalidated. + Other references and iterators are not affected. + + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` + + @complexity `log(size()) + count(key)` + + @liveexample{The example shows the effect of `erase()`.,erase__key_type} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const size_type) -- removes the element from an array at + the given index + + @since version 1.0.0 + */ + size_type erase(const typename object_t::key_type& key) + { + // this erase only works for objects + if (JSON_LIKELY(is_object())) + { + return m_value.object->erase(key); + } + + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + + /*! + @brief remove element from a JSON array given an index + + Removes element from a JSON array at the index @a idx. + + @param[in] idx index of the element to remove + + @throw type_error.307 when called on a type other than JSON object; + example: `"cannot use erase() with null"` + @throw out_of_range.401 when `idx >= size()`; example: `"array index 17 + is out of range"` + + @complexity Linear in distance between @a idx and the end of the container. + + @liveexample{The example shows the effect of `erase()`.,erase__size_type} + + @sa @ref erase(IteratorType) -- removes the element at a given position + @sa @ref erase(IteratorType, IteratorType) -- removes the elements in + the given range + @sa @ref erase(const typename object_t::key_type&) -- removes the element + from an object at the given key + + @since version 1.0.0 + */ + void erase(const size_type idx) + { + // this erase only works for arrays + if (JSON_LIKELY(is_array())) + { + if (JSON_UNLIKELY(idx >= size())) + { + JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); + } + + m_value.array->erase(m_value.array->begin() + static_cast(idx)); + } + else + { + JSON_THROW(type_error::create(307, "cannot use erase() with " + std::string(type_name()))); + } + } + + /// @} + + + //////////// + // lookup // + //////////// + + /// @name lookup + /// @{ + + /*! + @brief find an element in a JSON object + + Finds an element in a JSON object with key equivalent to @a key. If the + element is not found or the JSON value is not an object, end() is + returned. + + @note This method always returns @ref end() when executed on a JSON type + that is not an object. + + @param[in] key key value of the element to search for. + + @return Iterator to an element with key equivalent to @a key. If no such + element is found or the JSON value is not an object, past-the-end (see + @ref end()) iterator is returned. + + @complexity Logarithmic in the size of the JSON object. + + @liveexample{The example shows how `find()` is used.,find__key_type} + + @since version 1.0.0 + */ + template + iterator find(KeyT&& key) + { + auto result = end(); + + if (is_object()) + { + result.m_it.object_iterator = m_value.object->find(std::forward(key)); + } + + return result; + } + + /*! + @brief find an element in a JSON object + @copydoc find(KeyT&&) + */ + template + const_iterator find(KeyT&& key) const + { + auto result = cend(); + + if (is_object()) + { + result.m_it.object_iterator = m_value.object->find(std::forward(key)); + } + + return result; + } + + /*! + @brief returns the number of occurrences of a key in a JSON object + + Returns the number of elements with key @a key. If ObjectType is the + default `std::map` type, the return value will always be `0` (@a key was + not found) or `1` (@a key was found). + + @note This method always returns `0` when executed on a JSON type that is + not an object. + + @param[in] key key value of the element to count + + @return Number of elements with key @a key. If the JSON value is not an + object, the return value will be `0`. + + @complexity Logarithmic in the size of the JSON object. + + @liveexample{The example shows how `count()` is used.,count} + + @since version 1.0.0 + */ + template + size_type count(KeyT&& key) const + { + // return 0 for all nonobject types + return is_object() ? m_value.object->count(std::forward(key)) : 0; + } + + /// @} + + + /////////////// + // iterators // + /////////////// + + /// @name iterators + /// @{ + + /*! + @brief returns an iterator to the first element + + Returns an iterator to the first element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return iterator to the first element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + + @liveexample{The following code shows an example for `begin()`.,begin} + + @sa @ref cbegin() -- returns a const iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end + + @since version 1.0.0 + */ + iterator begin() noexcept + { + iterator result(this); + result.set_begin(); + return result; + } + + /*! + @copydoc basic_json::cbegin() + */ + const_iterator begin() const noexcept + { + return cbegin(); + } + + /*! + @brief returns a const iterator to the first element + + Returns a const iterator to the first element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return const iterator to the first element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).begin()`. + + @liveexample{The following code shows an example for `cbegin()`.,cbegin} + + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref end() -- returns an iterator to the end + @sa @ref cend() -- returns a const iterator to the end + + @since version 1.0.0 + */ + const_iterator cbegin() const noexcept + { + const_iterator result(this); + result.set_begin(); + return result; + } + + /*! + @brief returns an iterator to one past the last element + + Returns an iterator to one past the last element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return iterator one past the last element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + + @liveexample{The following code shows an example for `end()`.,end} + + @sa @ref cend() -- returns a const iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning + + @since version 1.0.0 + */ + iterator end() noexcept + { + iterator result(this); + result.set_end(); + return result; + } + + /*! + @copydoc basic_json::cend() + */ + const_iterator end() const noexcept + { + return cend(); + } + + /*! + @brief returns a const iterator to one past the last element + + Returns a const iterator to one past the last element. + + @image html range-begin-end.svg "Illustration from cppreference.com" + + @return const iterator one past the last element + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).end()`. + + @liveexample{The following code shows an example for `cend()`.,cend} + + @sa @ref end() -- returns an iterator to the end + @sa @ref begin() -- returns an iterator to the beginning + @sa @ref cbegin() -- returns a const iterator to the beginning + + @since version 1.0.0 + */ + const_iterator cend() const noexcept + { + const_iterator result(this); + result.set_end(); + return result; + } + + /*! + @brief returns an iterator to the reverse-beginning + + Returns an iterator to the reverse-beginning; that is, the last element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(end())`. + + @liveexample{The following code shows an example for `rbegin()`.,rbegin} + + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end + + @since version 1.0.0 + */ + reverse_iterator rbegin() noexcept + { + return reverse_iterator(end()); + } + + /*! + @copydoc basic_json::crbegin() + */ + const_reverse_iterator rbegin() const noexcept + { + return crbegin(); + } + + /*! + @brief returns an iterator to the reverse-end + + Returns an iterator to the reverse-end; that is, one before the first + element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `reverse_iterator(begin())`. + + @liveexample{The following code shows an example for `rend()`.,rend} + + @sa @ref crend() -- returns a const reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + reverse_iterator rend() noexcept + { + return reverse_iterator(begin()); + } + + /*! + @copydoc basic_json::crend() + */ + const_reverse_iterator rend() const noexcept + { + return crend(); + } + + /*! + @brief returns a const reverse iterator to the last element + + Returns a const iterator to the reverse-beginning; that is, the last + element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rbegin()`. + + @liveexample{The following code shows an example for `crbegin()`.,crbegin} + + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref crend() -- returns a const reverse iterator to the end + + @since version 1.0.0 + */ + const_reverse_iterator crbegin() const noexcept + { + return const_reverse_iterator(cend()); + } + + /*! + @brief returns a const reverse iterator to one before the first + + Returns a const reverse iterator to the reverse-end; that is, one before + the first element. + + @image html range-rbegin-rend.svg "Illustration from cppreference.com" + + @complexity Constant. + + @requirement This function helps `basic_json` satisfying the + [ReversibleContainer](https://en.cppreference.com/w/cpp/named_req/ReversibleContainer) + requirements: + - The complexity is constant. + - Has the semantics of `const_cast(*this).rend()`. + + @liveexample{The following code shows an example for `crend()`.,crend} + + @sa @ref rend() -- returns a reverse iterator to the end + @sa @ref rbegin() -- returns a reverse iterator to the beginning + @sa @ref crbegin() -- returns a const reverse iterator to the beginning + + @since version 1.0.0 + */ + const_reverse_iterator crend() const noexcept + { + return const_reverse_iterator(cbegin()); + } + + public: + /*! + @brief wrapper to access iterator member functions in range-based for + + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. + + For loop without iterator_wrapper: + + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + Range-based for loop without iterator proxy: + + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode + + Range-based for loop with iterator proxy: + + @code{cpp} + for (auto it : json::iterator_wrapper(j_object)) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + @note When iterating over an array, `key()` will return the index of the + element as string (see example). + + @param[in] ref reference to a JSON value + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops + + @liveexample{The following code shows how the wrapper is used,iterator_wrapper} + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @note The name of this function is not yet final and may change in the + future. + + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use @ref items() instead; + that is, replace `json::iterator_wrapper(j)` with `j.items()`. + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(reference ref) noexcept + { + return ref.items(); + } + + /*! + @copydoc iterator_wrapper(reference) + */ + JSON_DEPRECATED + static iteration_proxy iterator_wrapper(const_reference ref) noexcept + { + return ref.items(); + } + + /*! + @brief helper to access iterator member functions in range-based for + + This function allows to access @ref iterator::key() and @ref + iterator::value() during range-based for loops. In these loops, a + reference to the JSON values is returned, so there is no access to the + underlying iterator. + + For loop without `items()` function: + + @code{cpp} + for (auto it = j_object.begin(); it != j_object.end(); ++it) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + Range-based for loop without `items()` function: + + @code{cpp} + for (auto it : j_object) + { + // "it" is of type json::reference and has no key() member + std::cout << "value: " << it << '\n'; + } + @endcode + + Range-based for loop with `items()` function: + + @code{cpp} + for (auto it : j_object.items()) + { + std::cout << "key: " << it.key() << ", value:" << it.value() << '\n'; + } + @endcode + + @note When iterating over an array, `key()` will return the index of the + element as string (see example). For primitive types (e.g., numbers), + `key()` returns an empty string. + + @return iteration proxy object wrapping @a ref with an interface to use in + range-based for loops + + @liveexample{The following code shows how the function is used.,items} + + @exceptionsafety Strong guarantee: if an exception is thrown, there are no + changes in the JSON value. + + @complexity Constant. + + @since version 3.1.0. + */ + iteration_proxy items() noexcept + { + return iteration_proxy(*this); + } + + /*! + @copydoc items() + */ + iteration_proxy items() const noexcept + { + return iteration_proxy(*this); + } + + /// @} + + + ////////////// + // capacity // + ////////////// + + /// @name capacity + /// @{ + + /*! + @brief checks whether the container is empty. + + Checks if a JSON value has no elements (i.e. whether its @ref size is `0`). + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `true` + boolean | `false` + string | `false` + number | `false` + object | result of function `object_t::empty()` + array | result of function `array_t::empty()` + + @liveexample{The following code uses `empty()` to check if a JSON + object contains any elements.,empty} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `empty()` functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @note This function does not return whether a string stored as JSON value + is empty - it returns whether the JSON container itself is empty which is + false in the case of a string. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + - Has the semantics of `begin() == end()`. + + @sa @ref size() -- returns the number of elements + + @since version 1.0.0 + */ + bool empty() const noexcept + { + switch (m_type) + { + case value_t::null: + { + // null values are empty + return true; + } + + case value_t::array: + { + // delegate call to array_t::empty() + return m_value.array->empty(); + } + + case value_t::object: + { + // delegate call to object_t::empty() + return m_value.object->empty(); + } + + default: + { + // all other types are nonempty + return false; + } + } + } + + /*! + @brief returns the number of elements + + Returns the number of elements in a JSON value. + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` + boolean | `1` + string | `1` + number | `1` + object | result of function object_t::size() + array | result of function array_t::size() + + @liveexample{The following code calls `size()` on the different value + types.,size} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their size() functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @note This function does not return the length of a string stored as JSON + value - it returns the number of elements in the JSON value which is 1 in + the case of a string. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + - Has the semantics of `std::distance(begin(), end())`. + + @sa @ref empty() -- checks whether the container is empty + @sa @ref max_size() -- returns the maximal number of elements + + @since version 1.0.0 + */ + size_type size() const noexcept + { + switch (m_type) + { + case value_t::null: + { + // null values are empty + return 0; + } + + case value_t::array: + { + // delegate call to array_t::size() + return m_value.array->size(); + } + + case value_t::object: + { + // delegate call to object_t::size() + return m_value.object->size(); + } + + default: + { + // all other types have size 1 + return 1; + } + } + } + + /*! + @brief returns the maximum possible number of elements + + Returns the maximum number of elements a JSON value is able to hold due to + system or library implementation limitations, i.e. `std::distance(begin(), + end())` for the JSON value. + + @return The return value depends on the different types and is + defined as follows: + Value type | return value + ----------- | ------------- + null | `0` (same as `size()`) + boolean | `1` (same as `size()`) + string | `1` (same as `size()`) + number | `1` (same as `size()`) + object | result of function `object_t::max_size()` + array | result of function `array_t::max_size()` + + @liveexample{The following code calls `max_size()` on the different value + types. Note the output is implementation specific.,max_size} + + @complexity Constant, as long as @ref array_t and @ref object_t satisfy + the Container concept; that is, their `max_size()` functions have constant + complexity. + + @iterators No changes. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @requirement This function helps `basic_json` satisfying the + [Container](https://en.cppreference.com/w/cpp/named_req/Container) + requirements: + - The complexity is constant. + - Has the semantics of returning `b.size()` where `b` is the largest + possible JSON value. + + @sa @ref size() -- returns the number of elements + + @since version 1.0.0 + */ + size_type max_size() const noexcept + { + switch (m_type) + { + case value_t::array: + { + // delegate call to array_t::max_size() + return m_value.array->max_size(); + } + + case value_t::object: + { + // delegate call to object_t::max_size() + return m_value.object->max_size(); + } + + default: + { + // all other types have max_size() == size() + return size(); + } + } + } + + /// @} + + + /////////////// + // modifiers // + /////////////// + + /// @name modifiers + /// @{ + + /*! + @brief clears the contents + + Clears the content of a JSON value and resets it to the default value as + if @ref basic_json(value_t) would have been called with the current value + type from @ref type(): + + Value type | initial value + ----------- | ------------- + null | `null` + boolean | `false` + string | `""` + number | `0` + object | `{}` + array | `[]` + + @post Has the same effect as calling + @code {.cpp} + *this = basic_json(type()); + @endcode + + @liveexample{The example below shows the effect of `clear()` to different + JSON types.,clear} + + @complexity Linear in the size of the JSON value. + + @iterators All iterators, pointers and references related to this container + are invalidated. + + @exceptionsafety No-throw guarantee: this function never throws exceptions. + + @sa @ref basic_json(value_t) -- constructor that creates an object with the + same value than calling `clear()` + + @since version 1.0.0 + */ + void clear() noexcept + { + switch (m_type) + { + case value_t::number_integer: + { + m_value.number_integer = 0; + break; + } + + case value_t::number_unsigned: + { + m_value.number_unsigned = 0; + break; + } + + case value_t::number_float: + { + m_value.number_float = 0.0; + break; + } + + case value_t::boolean: + { + m_value.boolean = false; + break; + } + + case value_t::string: + { + m_value.string->clear(); + break; + } + + case value_t::array: + { + m_value.array->clear(); + break; + } + + case value_t::object: + { + m_value.object->clear(); + break; + } + + default: + break; + } + } + + /*! + @brief add an object to an array + + Appends the given element @a val to the end of the JSON value. If the + function is called on a JSON null value, an empty array is created before + appending @a val. + + @param[in] val the value to add to the JSON array + + @throw type_error.308 when called on a type other than JSON array or + null; example: `"cannot use push_back() with number"` + + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON array. Note how the `null` value was silently + converted to a JSON array.,push_back} + + @since version 1.0.0 + */ + void push_back(basic_json&& val) + { + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } + + // add element to array (move semantics) + m_value.array->push_back(std::move(val)); + // invalidate object + val.m_type = value_t::null; + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(basic_json&& val) + { + push_back(std::move(val)); + return *this; + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + void push_back(const basic_json& val) + { + // push_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } + + // add element to array + m_value.array->push_back(val); + } + + /*! + @brief add an object to an array + @copydoc push_back(basic_json&&) + */ + reference operator+=(const basic_json& val) + { + push_back(val); + return *this; + } + + /*! + @brief add an object to an object - /*! - @brief[in] j JSON value to serialize - */ - void write_msgpack(const basic_json& j) - { - switch (j.type()) - { - case value_t::null: - { - // nil - oa->write_character(0xc0); - break; - } + Inserts the given element @a val to the JSON object. If the function is + called on a JSON null value, an empty object is created before inserting + @a val. - case value_t::boolean: - { - // true and false - oa->write_character(j.m_value.boolean ? 0xc3 : 0xc2); - break; - } + @param[in] val the value to add to the JSON object - case value_t::number_integer: - { - if (j.m_value.number_integer >= 0) - { - // MessagePack does not differentiate between positive - // signed integers and unsigned integers. Therefore, we - // used the code from the value_t::number_unsigned case - // here. - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - } - else - { - if (j.m_value.number_integer >= -32) - { - // negative fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 8 - oa->write_character(0xd0); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 16 - oa->write_character(0xd1); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 32 - oa->write_character(0xd2); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_integer >= (std::numeric_limits::min)() and j.m_value.number_integer <= (std::numeric_limits::max)()) - { - // int 64 - oa->write_character(0xd3); - write_number(static_cast(j.m_value.number_integer)); - } - } - break; - } + @throw type_error.308 when called on a type other than JSON object or + null; example: `"cannot use push_back() with number"` - case value_t::number_unsigned: - { - if (j.m_value.number_unsigned < 128) - { - // positive fixnum - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 8 - oa->write_character(0xcc); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 16 - oa->write_character(0xcd); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 32 - oa->write_character(0xce); - write_number(static_cast(j.m_value.number_integer)); - } - else if (j.m_value.number_unsigned <= (std::numeric_limits::max)()) - { - // uint 64 - oa->write_character(0xcf); - write_number(static_cast(j.m_value.number_integer)); - } - break; - } + @complexity Logarithmic in the size of the container, O(log(`size()`)). - case value_t::number_float: - { - // float 64 - oa->write_character(0xcb); - write_number(j.m_value.number_float); - break; - } + @liveexample{The example shows how `push_back()` and `+=` can be used to + add elements to a JSON object. Note how the `null` value was silently + converted to a JSON object.,push_back__object_t__value} - case value_t::string: - { - // step 1: write control byte and the string length - const auto N = j.m_value.string->size(); - if (N <= 31) - { - // fixstr - write_number(static_cast(0xa0 | N)); - } - else if (N <= 255) - { - // str 8 - oa->write_character(0xd9); - write_number(static_cast(N)); - } - else if (N <= 65535) - { - // str 16 - oa->write_character(0xda); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // str 32 - oa->write_character(0xdb); - write_number(static_cast(N)); - } + @since version 1.0.0 + */ + void push_back(const typename object_t::value_type& val) + { + // push_back only works for null objects or objects + if (JSON_UNLIKELY(not(is_null() or is_object()))) + { + JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name()))); + } - // step 2: write the string - oa->write_characters(reinterpret_cast(j.m_value.string->c_str()), - j.m_value.string->size()); - break; - } + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } - case value_t::array: - { - // step 1: write control byte and the array size - const auto N = j.m_value.array->size(); - if (N <= 15) - { - // fixarray - write_number(static_cast(0x90 | N)); - } - else if (N <= 0xffff) - { - // array 16 - oa->write_character(0xdc); - write_number(static_cast(N)); - } - else if (N <= 0xffffffff) - { - // array 32 - oa->write_character(0xdd); - write_number(static_cast(N)); - } + // add element to array + m_value.object->insert(val); + } - // step 2: write each element - for (const auto& el : *j.m_value.array) - { - write_msgpack(el); - } - break; - } + /*! + @brief add an object to an object + @copydoc push_back(const typename object_t::value_type&) + */ + reference operator+=(const typename object_t::value_type& val) + { + push_back(val); + return *this; + } - case value_t::object: - { - // step 1: write control byte and the object size - const auto N = j.m_value.object->size(); - if (N <= 15) - { - // fixmap - write_number(static_cast(0x80 | (N & 0xf))); - } - else if (N <= 65535) - { - // map 16 - oa->write_character(0xde); - write_number(static_cast(N)); - } - else if (N <= 4294967295) - { - // map 32 - oa->write_character(0xdf); - write_number(static_cast(N)); - } + /*! + @brief add an object to an object - // step 2: write each element - for (const auto& el : *j.m_value.object) - { - write_msgpack(el.first); - write_msgpack(el.second); - } - break; - } + This function allows to use `push_back` with an initializer list. In case - default: - { - break; - } - } - } + 1. the current value is an object, + 2. the initializer list @a init contains only two elements, and + 3. the first element of @a init is a string, - private: - /* - @brief write a number to output input + @a init is converted into an object element and added using + @ref push_back(const typename object_t::value_type&). Otherwise, @a init + is converted to a JSON value and added using @ref push_back(basic_json&&). - @param[in] n number of type @a T - @tparam T the type of the number + @param[in] init an initializer list - @note This function needs to respect the system's endianess, because - bytes in CBOR and MessagePack are stored in network order (big - endian) and therefore need reordering on little endian systems. - */ - template - void write_number(T n) - { - // step 1: write number to array of length T - std::array vec; - std::memcpy(vec.data(), &n, sizeof(T)); + @complexity Linear in the size of the initializer list @a init. - // step 2: write array to output (with possible reordering) - for (size_t i = 0; i < sizeof(T); ++i) - { - // reverse byte order prior to conversion if necessary - if (is_little_endian) - { - oa->write_character(vec[sizeof(T) - i - 1]); - } - else - { - oa->write_character(vec[i]); - } - } - } + @note This function is required to resolve an ambiguous overload error, + because pairs like `{"key", "value"}` can be both interpreted as + `object_t::value_type` or `std::initializer_list`, see + https://github.com/nlohmann/json/issues/235 for more information. - private: - /// whether we can assume little endianess - const bool is_little_endian = true; + @liveexample{The example shows how initializer lists are treated as + objects when possible.,push_back__initializer_list} + */ + void push_back(initializer_list_t init) + { + if (is_object() and init.size() == 2 and (*init.begin())->is_string()) + { + basic_json&& key = init.begin()->moved_or_copied(); + push_back(typename object_t::value_type( + std::move(key.get_ref()), (init.begin() + 1)->moved_or_copied())); + } + else + { + push_back(basic_json(init)); + } + } - /// the output - output_adapter_t oa = nullptr; - }; + /*! + @brief add an object to an object + @copydoc push_back(initializer_list_t) + */ + reference operator+=(initializer_list_t init) + { + push_back(init); + return *this; + } - public: /*! - @brief create a CBOR serialization of a given JSON value + @brief add an object to an array - Serializes a given JSON value @a j to a byte vector using the CBOR (Concise - Binary Object Representation) serialization format. CBOR is a binary - serialization format which aims to be more compact than JSON itself, yet - more efficient to parse. + Creates a JSON value from the passed parameters @a args to the end of the + JSON value. If the function is called on a JSON null value, an empty array + is created before appending the value created from @a args. - The library uses the following mapping from JSON values types to - CBOR types according to the CBOR specification (RFC 7049): + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object - JSON value type | value/range | CBOR type | first byte - --------------- | ------------------------------------------ | ---------------------------------- | --------------- - null | `null` | Null | 0xf6 - boolean | `true` | True | 0xf5 - boolean | `false` | False | 0xf4 - number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3b - number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3a - number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 - number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 - number_integer | -24..-1 | Negative integer | 0x20..0x37 - number_integer | 0..23 | Integer | 0x00..0x17 - number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_unsigned | 0..23 | Integer | 0x00..0x17 - number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 - number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 - number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1a - number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1b - number_float | *any value* | Double-Precision Float | 0xfb - string | *length*: 0..23 | UTF-8 string | 0x60..0x77 - string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 - string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 - string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7a - string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7b - array | *size*: 0..23 | array | 0x80..0x97 - array | *size*: 23..255 | array (1 byte follow) | 0x98 - array | *size*: 256..65535 | array (2 bytes follow) | 0x99 - array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9a - array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9b - object | *size*: 0..23 | map | 0xa0..0xb7 - object | *size*: 23..255 | map (1 byte follow) | 0xb8 - object | *size*: 256..65535 | map (2 bytes follow) | 0xb9 - object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xba - object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xbb + @throw type_error.311 when called on a type other than JSON array or + null; example: `"cannot use emplace_back() with number"` + + @complexity Amortized constant. + + @liveexample{The example shows how `push_back()` can be used to add + elements to a JSON array. Note how the `null` value was silently converted + to a JSON array.,emplace_back} + + @since version 2.0.8 + */ + template + void emplace_back(Args&& ... args) + { + // emplace_back only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_array()))) + { + JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + std::string(type_name()))); + } + + // transform null object into an array + if (is_null()) + { + m_type = value_t::array; + m_value = value_t::array; + assert_invariant(); + } - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a CBOR value. + // add element to array (perfect forwarding) + m_value.array->emplace_back(std::forward(args)...); + } - @note The following CBOR types are not used in the conversion: - - byte strings (0x40..0x5f) - - UTF-8 strings terminated by "break" (0x7f) - - arrays terminated by "break" (0x9f) - - maps terminated by "break" (0xbf) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) - - half and single-precision floats (0xf9-0xfa) - - break (0xff) + /*! + @brief add an object to an object if key does not exist - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + Inserts a new element into a JSON object constructed in-place with the + given @a args if there is no element with the key in the container. If the + function is called on a JSON null value, an empty object is created before + appending the value created from @a args. - @complexity Linear in the size of the JSON value @a j. + @param[in] args arguments to forward to a constructor of @ref basic_json + @tparam Args compatible types to create a @ref basic_json object - @liveexample{The example shows the serialization of a JSON value to a byte - vector in CBOR format.,to_cbor} + @return a pair consisting of an iterator to the inserted element, or the + already-existing element if no insertion happened, and a bool + denoting whether the insertion took place. - @sa http://cbor.io - @sa @ref from_cbor(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_msgpack(const basic_json& for the related MessagePack format + @throw type_error.311 when called on a type other than JSON object or + null; example: `"cannot use emplace() with number"` - @since version 2.0.9 + @complexity Logarithmic in the size of the container, O(log(`size()`)). + + @liveexample{The example shows how `emplace()` can be used to add elements + to a JSON object. Note how the `null` value was silently converted to a + JSON object. Further note how no value is added if there was already one + value stored with the same key.,emplace} + + @since version 2.0.8 */ - static std::vector to_cbor(const basic_json& j) + template + std::pair emplace(Args&& ... args) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_cbor(j); - return result; - } + // emplace only works for null objects or arrays + if (JSON_UNLIKELY(not(is_null() or is_object()))) + { + JSON_THROW(type_error::create(311, "cannot use emplace() with " + std::string(type_name()))); + } - /*! - @brief create a MessagePack serialization of a given JSON value + // transform null object into an object + if (is_null()) + { + m_type = value_t::object; + m_value = value_t::object; + assert_invariant(); + } - Serializes a given JSON value @a j to a byte vector using the MessagePack - serialization format. MessagePack is a binary serialization format which - aims to be more compact than JSON itself, yet more efficient to parse. + // add element to array (perfect forwarding) + auto res = m_value.object->emplace(std::forward(args)...); + // create result iterator and set iterator to the result of emplace + auto it = begin(); + it.m_it.object_iterator = res.first; - The library uses the following mapping from JSON values types to - MessagePack types according to the MessagePack specification: + // return pair of iterator and boolean + return {it, res.second}; + } - JSON value type | value/range | MessagePack type | first byte - --------------- | --------------------------------- | ---------------- | ---------- - null | `null` | nil | 0xc0 - boolean | `true` | true | 0xc3 - boolean | `false` | false | 0xc2 - number_integer | -9223372036854775808..-2147483649 | int64 | 0xd3 - number_integer | -2147483648..-32769 | int32 | 0xd2 - number_integer | -32768..-129 | int16 | 0xd1 - number_integer | -128..-33 | int8 | 0xd0 - number_integer | -32..-1 | negative fixint | 0xe0..0xff - number_integer | 0..127 | positive fixint | 0x00..0x7f - number_integer | 128..255 | uint 8 | 0xcc - number_integer | 256..65535 | uint 16 | 0xcd - number_integer | 65536..4294967295 | uint 32 | 0xce - number_integer | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_unsigned | 0..127 | positive fixint | 0x00..0x7f - number_unsigned | 128..255 | uint 8 | 0xcc - number_unsigned | 256..65535 | uint 16 | 0xcd - number_unsigned | 65536..4294967295 | uint 32 | 0xce - number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xcf - number_float | *any value* | float 64 | 0xcb - string | *length*: 0..31 | fixstr | 0xa0..0xbf - string | *length*: 32..255 | str 8 | 0xd9 - string | *length*: 256..65535 | str 16 | 0xda - string | *length*: 65536..4294967295 | str 32 | 0xdb - array | *size*: 0..15 | fixarray | 0x90..0x9f - array | *size*: 16..65535 | array 16 | 0xdc - array | *size*: 65536..4294967295 | array 32 | 0xdd - object | *size*: 0..15 | fix map | 0x80..0x8f - object | *size*: 16..65535 | map 16 | 0xde - object | *size*: 65536..4294967295 | map 32 | 0xdf + /*! + @brief inserts element - @note The mapping is **complete** in the sense that any JSON value type - can be converted to a MessagePack value. + Inserts element @a val before iterator @a pos. - @note The following values can **not** be converted to a MessagePack value: - - strings with more than 4294967295 bytes - - arrays with more than 4294967295 elements - - objects with more than 4294967295 elements + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] val element to insert + @return iterator pointing to the inserted @a val. - @note The following MessagePack types are not used in the conversion: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - float 32 (0xca) - - fixext 1 - fixext 16 (0xd4..0xd8) + @throw type_error.309 if called on JSON values other than arrays; + example: `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + @complexity Constant plus linear in the distance between @a pos and end of + the container. - @param[in] j JSON value to serialize - @return MessagePack serialization as byte vector + @liveexample{The example shows how `insert()` is used.,insert} - @complexity Linear in the size of the JSON value @a j. + @since version 1.0.0 + */ + iterator insert(const_iterator pos, const basic_json& val) + { + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @liveexample{The example shows the serialization of a JSON value to a byte - vector in MessagePack format.,to_msgpack} + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, val); + return result; + } - @sa http://msgpack.org - @sa @ref from_msgpack(const std::vector&, const size_t) for the - analogous deserialization - @sa @ref to_cbor(const basic_json& for the related CBOR format + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @since version 2.0.9 + /*! + @brief inserts element + @copydoc insert(const_iterator, const basic_json&) */ - static std::vector to_msgpack(const basic_json& j) + iterator insert(const_iterator pos, basic_json&& val) { - std::vector result; - binary_writer bw(output_adapter::create(result)); - bw.write_msgpack(j); - return result; + return insert(pos, val); } /*! - @brief create a JSON value from a byte vector in CBOR format + @brief inserts elements - Deserializes a given byte vector @a v to a JSON value using the CBOR - (Concise Binary Object Representation) serialization format. + Inserts @a cnt copies of @a val before iterator @a pos. - The library maps CBOR types to JSON value types as follows: + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] cnt number of copies of @a val to insert + @param[in] val element to insert + @return iterator pointing to the first element inserted, or @a pos if + `cnt==0` - CBOR type | JSON value type | first byte - ---------------------- | --------------- | ---------- - Integer | number_unsigned | 0x00..0x17 - Unsigned integer | number_unsigned | 0x18 - Unsigned integer | number_unsigned | 0x19 - Unsigned integer | number_unsigned | 0x1a - Unsigned integer | number_unsigned | 0x1b - Negative integer | number_integer | 0x20..0x37 - Negative integer | number_integer | 0x38 - Negative integer | number_integer | 0x39 - Negative integer | number_integer | 0x3a - Negative integer | number_integer | 0x3b - Negative integer | number_integer | 0x40..0x57 - UTF-8 string | string | 0x60..0x77 - UTF-8 string | string | 0x78 - UTF-8 string | string | 0x79 - UTF-8 string | string | 0x7a - UTF-8 string | string | 0x7b - UTF-8 string | string | 0x7f - array | array | 0x80..0x97 - array | array | 0x98 - array | array | 0x99 - array | array | 0x9a - array | array | 0x9b - array | array | 0x9f - map | object | 0xa0..0xb7 - map | object | 0xb8 - map | object | 0xb9 - map | object | 0xba - map | object | 0xbb - map | object | 0xbf - False | `false` | 0xf4 - True | `true` | 0xf5 - Nill | `null` | 0xf6 - Half-Precision Float | number_float | 0xf9 - Single-Precision Float | number_float | 0xfa - Double-Precision Float | number_float | 0xfb + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @warning The mapping is **incomplete** in the sense that not all CBOR - types can be converted to a JSON value. The following CBOR types - are not supported and will yield parse errors (parse_error.112): - - byte strings (0x40..0x5f) - - date/time (0xc0..0xc1) - - bignum (0xc2..0xc3) - - decimal fraction (0xc4) - - bigfloat (0xc5) - - tagged items (0xc6..0xd4, 0xd8..0xdb) - - expected conversions (0xd5..0xd7) - - simple values (0xe0..0xf3, 0xf8) - - undefined (0xf7) + @complexity Linear in @a cnt plus linear in the distance between @a pos + and end of the container. - @warning CBOR allows map keys of any type, whereas JSON only allows - strings as keys in object values. Therefore, CBOR maps with keys - other than UTF-8 strings are rejected (parse_error.113). + @liveexample{The example shows how `insert()` is used.,insert__count} - @note Any CBOR output created @ref to_cbor can be successfully parsed by - @ref from_cbor. + @since version 1.0.0 + */ + iterator insert(const_iterator pos, size_type cnt, const basic_json& val) + { + // insert only works for arrays + if (JSON_LIKELY(is_array())) + { + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @param[in] v a byte vector in CBOR format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, cnt, val); + return result; + } - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from CBOR were - used in the given vector @a v or if the input is not valid CBOR - @throw parse_error.113 if a string was expected as map key, but not found + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - @complexity Linear in the size of the byte vector @a v. + /*! + @brief inserts elements - @liveexample{The example shows the deserialization of a byte vector in CBOR - format to a JSON value.,from_cbor} + Inserts elements from range `[first, last)` before iterator @a pos. - @sa http://cbor.io - @sa @ref to_cbor(const basic_json&) for the analogous serialization - @sa @ref from_msgpack(const std::vector&, const size_t) for the - related MessagePack format + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - @since version 2.0.9, parameter @a start_index since 2.1.1 - */ - static basic_json from_cbor(const std::vector& v, - const size_t start_index = 0) - { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_cbor(); - } + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` + @throw invalid_iterator.211 if @a first or @a last are iterators into + container for which insert is called; example: `"passed iterators may not + belong to container"` + @return iterator pointing to the first element inserted, or @a pos if + `first==last` - /*! - @brief create a JSON value from a byte vector in MessagePack format + @complexity Linear in `std::distance(first, last)` plus linear in the + distance between @a pos and end of the container. - Deserializes a given byte vector @a v to a JSON value using the MessagePack - serialization format. + @liveexample{The example shows how `insert()` is used.,insert__range} - The library maps MessagePack types to JSON value types as follows: + @since version 1.0.0 + */ + iterator insert(const_iterator pos, const_iterator first, const_iterator last) + { + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - MessagePack type | JSON value type | first byte - ---------------- | --------------- | ---------- - positive fixint | number_unsigned | 0x00..0x7f - fixmap | object | 0x80..0x8f - fixarray | array | 0x90..0x9f - fixstr | string | 0xa0..0xbf - nil | `null` | 0xc0 - false | `false` | 0xc2 - true | `true` | 0xc3 - float 32 | number_float | 0xca - float 64 | number_float | 0xcb - uint 8 | number_unsigned | 0xcc - uint 16 | number_unsigned | 0xcd - uint 32 | number_unsigned | 0xce - uint 64 | number_unsigned | 0xcf - int 8 | number_integer | 0xd0 - int 16 | number_integer | 0xd1 - int 32 | number_integer | 0xd2 - int 64 | number_integer | 0xd3 - str 8 | string | 0xd9 - str 16 | string | 0xda - str 32 | string | 0xdb - array 16 | array | 0xdc - array 32 | array | 0xdd - map 16 | object | 0xde - map 32 | object | 0xdf - negative fixint | number_integer | 0xe0-0xff + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - @warning The mapping is **incomplete** in the sense that not all - MessagePack types can be converted to a JSON value. The following - MessagePack types are not supported and will yield parse errors: - - bin 8 - bin 32 (0xc4..0xc6) - - ext 8 - ext 32 (0xc7..0xc9) - - fixext 1 - fixext 16 (0xd4..0xd8) + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - @note Any MessagePack output created @ref to_msgpack can be successfully - parsed by @ref from_msgpack. + if (JSON_UNLIKELY(first.m_object == this)) + { + JSON_THROW(invalid_iterator::create(211, "passed iterators may not belong to container")); + } + + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert( + pos.m_it.array_iterator, + first.m_it.array_iterator, + last.m_it.array_iterator); + return result; + } + + /*! + @brief inserts elements - @param[in] v a byte vector in MessagePack format - @param[in] start_index the index to start reading from @a v (0 by default) - @return deserialized JSON value + Inserts elements from initializer list @a ilist before iterator @a pos. - @throw parse_error.110 if the given vector ends prematurely - @throw parse_error.112 if unsupported features from MessagePack were - used in the given vector @a v or if the input is not valid MessagePack - @throw parse_error.113 if a string was expected as map key, but not found + @param[in] pos iterator before which the content will be inserted; may be + the end() iterator + @param[in] ilist initializer list to insert the values from - @complexity Linear in the size of the byte vector @a v. + @throw type_error.309 if called on JSON values other than arrays; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if @a pos is not an iterator of *this; + example: `"iterator does not fit current value"` - @liveexample{The example shows the deserialization of a byte vector in - MessagePack format to a JSON value.,from_msgpack} + @return iterator pointing to the first element inserted, or @a pos if + `ilist` is empty - @sa http://msgpack.org - @sa @ref to_msgpack(const basic_json&) for the analogous serialization - @sa @ref from_cbor(const std::vector&, const size_t) for the - related CBOR format + @complexity Linear in `ilist.size()` plus linear in the distance between + @a pos and end of the container. - @since version 2.0.9, parameter @a start_index since 2.1.1 + @liveexample{The example shows how `insert()` is used.,insert__ilist} + + @since version 1.0.0 */ - static basic_json from_msgpack(const std::vector& v, - const size_t start_index = 0) + iterator insert(const_iterator pos, initializer_list_t ilist) { - binary_reader br(input_adapter::create(v.begin() + static_cast(start_index), v.end())); - return br.parse_msgpack(); - } + // insert only works for arrays + if (JSON_UNLIKELY(not is_array())) + { + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); + } - /// @} + // check if iterator pos fits to this JSON value + if (JSON_UNLIKELY(pos.m_object != this)) + { + JSON_THROW(invalid_iterator::create(202, "iterator does not fit current value")); + } - ////////////////////// - // lexer and parser // - ////////////////////// + // insert to array and return iterator + iterator result(this); + result.m_it.array_iterator = m_value.array->insert(pos.m_it.array_iterator, ilist.begin(), ilist.end()); + return result; + } - private: /*! - @brief lexical analysis + @brief inserts elements + + Inserts elements from range `[first, last)`. + + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert + + @throw type_error.309 if called on JSON values other than objects; example: + `"cannot use insert() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` + + @complexity Logarithmic: `O(N*log(size() + N))`, where `N` is the number + of elements to insert. - This class organizes the lexical analysis during JSON deserialization. + @liveexample{The example shows how `insert()` is used.,insert__range_object} + + @since version 3.0.0 */ - class lexer + void insert(const_iterator first, const_iterator last) { - public: - /// token types for the parser - enum class token_type - { - uninitialized, ///< indicating the scanner is uninitialized - literal_true, ///< the `true` literal - literal_false, ///< the `false` literal - literal_null, ///< the `null` literal - value_string, ///< a string -- use get_string() for actual value - value_unsigned, ///< an unsigned integer -- use get_number_unsigned() for actual value - value_integer, ///< a signed integer -- use get_number_integer() for actual value - value_float, ///< an floating point number -- use get_number_float() for actual value - begin_array, ///< the character for array begin `[` - begin_object, ///< the character for object begin `{` - end_array, ///< the character for array end `]` - end_object, ///< the character for object end `}` - name_separator, ///< the name separator `:` - value_separator, ///< the value separator `,` - parse_error, ///< indicating a parse error - end_of_input ///< indicating the end of the input buffer - }; - - /// return name of values of type token_type (only used for errors) - static const char* token_type_name(const token_type t) noexcept + // insert only works for objects + if (JSON_UNLIKELY(not is_object())) { - switch (t) - { - case token_type::uninitialized: - return ""; - case token_type::literal_true: - return "true literal"; - case token_type::literal_false: - return "false literal"; - case token_type::literal_null: - return "null literal"; - case token_type::value_string: - return "string literal"; - case lexer::token_type::value_unsigned: - case lexer::token_type::value_integer: - case lexer::token_type::value_float: - return "number literal"; - case token_type::begin_array: - return "'['"; - case token_type::begin_object: - return "'{'"; - case token_type::end_array: - return "']'"; - case token_type::end_object: - return "'}'"; - case token_type::name_separator: - return "':'"; - case token_type::value_separator: - return "','"; - case token_type::parse_error: - return ""; - case token_type::end_of_input: - return "end of input"; - default: - { - // catch non-enum values - return "unknown token"; // LCOV_EXCL_LINE - } - } + JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name()))); } - explicit lexer(input_adapter_t adapter) - : ia(adapter), decimal_point_char(get_decimal_point()) - {} - - private: - ///////////////////// - // locales - ///////////////////// + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - /// return the locale-dependent decimal point - static char get_decimal_point() noexcept + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object())) { - const auto loc = localeconv(); - assert(loc != nullptr); - return (loc->decimal_point == nullptr) ? '.' : loc->decimal_point[0]; + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); } - ///////////////////// - // scan functions - ///////////////////// + m_value.object->insert(first.m_it.object_iterator, last.m_it.object_iterator); + } - /*! - @brief get codepoint from 4 hex characters following `\u` + /*! + @brief updates a JSON object from another object, overwriting existing keys - @return codepoint or -1 in case of an error (e.g. EOF or non-hex - character) - */ - int get_codepoint() - { - // this function only makes sense after reading `\u` - assert(current == 'u'); - int codepoint = 0; + Inserts all values from JSON object @a j and overwrites existing keys. - // byte 1: \uXxxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x1000; - break; - case '2': - codepoint += 0x2000; - break; - case '3': - codepoint += 0x3000; - break; - case '4': - codepoint += 0x4000; - break; - case '5': - codepoint += 0x5000; - break; - case '6': - codepoint += 0x6000; - break; - case '7': - codepoint += 0x7000; - break; - case '8': - codepoint += 0x8000; - break; - case '9': - codepoint += 0x9000; - break; - case 'A': - case 'a': - codepoint += 0xa000; - break; - case 'B': - case 'b': - codepoint += 0xb000; - break; - case 'C': - case 'c': - codepoint += 0xc000; - break; - case 'D': - case 'd': - codepoint += 0xd000; - break; - case 'E': - case 'e': - codepoint += 0xe000; - break; - case 'F': - case 'f': - codepoint += 0xf000; - break; - default: - return -1; - } + @param[in] j JSON object to read values from - // byte 2: \uxXxx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0100; - break; - case '2': - codepoint += 0x0200; - break; - case '3': - codepoint += 0x0300; - break; - case '4': - codepoint += 0x0400; - break; - case '5': - codepoint += 0x0500; - break; - case '6': - codepoint += 0x0600; - break; - case '7': - codepoint += 0x0700; - break; - case '8': - codepoint += 0x0800; - break; - case '9': - codepoint += 0x0900; - break; - case 'A': - case 'a': - codepoint += 0x0a00; - break; - case 'B': - case 'b': - codepoint += 0x0b00; - break; - case 'C': - case 'c': - codepoint += 0x0c00; - break; - case 'D': - case 'd': - codepoint += 0x0d00; - break; - case 'E': - case 'e': - codepoint += 0x0e00; - break; - case 'F': - case 'f': - codepoint += 0x0f00; - break; - default: - return -1; - } + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` - // byte 3: \uxxXx - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0010; - break; - case '2': - codepoint += 0x0020; - break; - case '3': - codepoint += 0x0030; - break; - case '4': - codepoint += 0x0040; - break; - case '5': - codepoint += 0x0050; - break; - case '6': - codepoint += 0x0060; - break; - case '7': - codepoint += 0x0070; - break; - case '8': - codepoint += 0x0080; - break; - case '9': - codepoint += 0x0090; - break; - case 'A': - case 'a': - codepoint += 0x00a0; - break; - case 'B': - case 'b': - codepoint += 0x00b0; - break; - case 'C': - case 'c': - codepoint += 0x00c0; - break; - case 'D': - case 'd': - codepoint += 0x00d0; - break; - case 'E': - case 'e': - codepoint += 0x00e0; - break; - case 'F': - case 'f': - codepoint += 0x00f0; - break; - default: - return -1; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // byte 4: \uxxxX - switch (get()) - { - case '0': - break; - case '1': - codepoint += 0x0001; - break; - case '2': - codepoint += 0x0002; - break; - case '3': - codepoint += 0x0003; - break; - case '4': - codepoint += 0x0004; - break; - case '5': - codepoint += 0x0005; - break; - case '6': - codepoint += 0x0006; - break; - case '7': - codepoint += 0x0007; - break; - case '8': - codepoint += 0x0008; - break; - case '9': - codepoint += 0x0009; - break; - case 'A': - case 'a': - codepoint += 0x000a; - break; - case 'B': - case 'b': - codepoint += 0x000b; - break; - case 'C': - case 'c': - codepoint += 0x000c; - break; - case 'D': - case 'd': - codepoint += 0x000d; - break; - case 'E': - case 'e': - codepoint += 0x000e; - break; - case 'F': - case 'f': - codepoint += 0x000f; - break; - default: - return -1; - } + @liveexample{The example shows how `update()` is used.,update} - return codepoint; - } + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - /*! - @brief create diagnostic representation of a codepoint - @return string "U+XXXX" for codepoint XXXX - */ - static std::string codepoint_to_string(int codepoint) + @since version 3.0.0 + */ + void update(const_reference j) + { + // implicitly convert null value to an empty object + if (is_null()) { - std::stringstream ss; - ss << "U+" << std::setw(4) << std::uppercase << std::setfill('0') << std::hex << codepoint; - return ss.str(); + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); } - /*! - @brief scan a string literal + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } + if (JSON_UNLIKELY(not j.is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(j.type_name()))); + } - This function scans a string according to Sect. 7 of RFC 7159. While - scanning, bytes are escaped and copied into buffer yytext. Then the - function returns successfully, yytext is null-terminated and yylen - contains the number of bytes in the string. + for (auto it = j.cbegin(); it != j.cend(); ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - @return token_type::value_string if string could be successfully - scanned, token_type::parse_error otherwise + /*! + @brief updates a JSON object from another object, overwriting existing keys - @note In case of errors, variable error_message contains a textual - description. - */ - token_type scan_string() - { - // reset yytext (ignore opening quote) - reset(); + Inserts all values from from range `[first, last)` and overwrites existing + keys. - // we entered the function by reading an open quote - assert(current == '\"'); + @param[in] first begin of the range of elements to insert + @param[in] last end of the range of elements to insert - while (true) - { - // get next character - get(); + @throw type_error.312 if called on JSON values other than objects; example: + `"cannot use update() with string"` + @throw invalid_iterator.202 if iterator @a first or @a last does does not + point to an object; example: `"iterators first and last must point to + objects"` + @throw invalid_iterator.210 if @a first and @a last do not belong to the + same JSON value; example: `"iterators do not fit"` - switch (current) - { - // end of file while parsing string - case std::char_traits::eof(): - { - error_message = "invalid string: missing closing quote"; - return token_type::parse_error; - } + @complexity O(N*log(size() + N)), where N is the number of elements to + insert. - // closing quote - case '\"': - { - // terminate yytext - add('\0'); - --yylen; - return token_type::value_string; - } + @liveexample{The example shows how `update()` is used__range.,update} - // escapes - case '\\': - { - switch (get()) - { - // quotation mark - case '\"': - add('\"'); - break; - // reverse solidus - case '\\': - add('\\'); - break; - // solidus - case '/': - add('/'); - break; - // backspace - case 'b': - add('\b'); - break; - // form feed - case 'f': - add('\f'); - break; - // line feed - case 'n': - add('\n'); - break; - // carriage return - case 'r': - add('\r'); - break; - // tab - case 't': - add('\t'); - break; - - // unicode escapes - case 'u': - { - int codepoint; - int codepoint1 = get_codepoint(); + @sa https://docs.python.org/3.6/library/stdtypes.html#dict.update - if (JSON_UNLIKELY(codepoint1 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } + @since version 3.0.0 + */ + void update(const_iterator first, const_iterator last) + { + // implicitly convert null value to an empty object + if (is_null()) + { + m_type = value_t::object; + m_value.object = create(); + assert_invariant(); + } - // check if code point is a high surrogate - if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF) - { - // expect next \uxxxx entry - if (JSON_LIKELY(get() == '\\' and get() == 'u')) - { - const int codepoint2 = get_codepoint(); - - if (JSON_UNLIKELY(codepoint2 == -1)) - { - error_message = "invalid string: '\\u' must be followed by 4 hex digits"; - return token_type::parse_error; - } - - // check if codepoint2 is a low surrogate - if (JSON_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF)) - { - codepoint = - // high surrogate occupies the most significant 22 bits - (codepoint1 << 10) - // low surrogate occupies the least significant 15 bits - + codepoint2 - // there is still the 0xD800, 0xDC00 and 0x10000 noise - // in the result so we have to subtract with: - // (0xD800 << 10) + DC00 - 0x10000 = 0x35FDC00 - - 0x35FDC00; - } - else - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must be followed by U+DC00..U+DFFF instead of " + codepoint_to_string(codepoint2); - return token_type::parse_error; - } - } - else - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must be followed by U+DC00..U+DFFF"; - return token_type::parse_error; - } - } - else - { - if (JSON_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF)) - { - error_message = "invalid string: surrogate " + codepoint_to_string(codepoint1) + " must follow U+D800..U+DBFF"; - return token_type::parse_error; - } + if (JSON_UNLIKELY(not is_object())) + { + JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name()))); + } - // only work with first code point - codepoint = codepoint1; - } + // check if range iterators belong to the same JSON object + if (JSON_UNLIKELY(first.m_object != last.m_object)) + { + JSON_THROW(invalid_iterator::create(210, "iterators do not fit")); + } - // result of the above calculation yields a proper codepoint - assert(0x00 <= codepoint and codepoint <= 0x10FFFF); + // passed iterators must belong to objects + if (JSON_UNLIKELY(not first.m_object->is_object() + or not last.m_object->is_object())) + { + JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects")); + } - // translate code point to bytes - if (codepoint < 0x80) - { - // 1-byte characters: 0xxxxxxx (ASCII) - add(codepoint); - } - else if (codepoint <= 0x7ff) - { - // 2-byte characters: 110xxxxx 10xxxxxx - add(0xC0 | (codepoint >> 6)); - add(0x80 | (codepoint & 0x3F)); - } - else if (codepoint <= 0xffff) - { - // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx - add(0xE0 | (codepoint >> 12)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } - else - { - // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx - add(0xF0 | (codepoint >> 18)); - add(0x80 | ((codepoint >> 12) & 0x3F)); - add(0x80 | ((codepoint >> 6) & 0x3F)); - add(0x80 | (codepoint & 0x3F)); - } + for (auto it = first; it != last; ++it) + { + m_value.object->operator[](it.key()) = it.value(); + } + } - break; - } + /*! + @brief exchanges the values - // other characters after escape - default: - error_message = "invalid string: forbidden character after backslash"; - return token_type::parse_error; - } + Exchanges the contents of the JSON value with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - break; - } + @param[in,out] other JSON value to exchange the contents with - // invalid control characters - case 0x00: - case 0x01: - case 0x02: - case 0x03: - case 0x04: - case 0x05: - case 0x06: - case 0x07: - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - case 0x10: - case 0x11: - case 0x12: - case 0x13: - case 0x14: - case 0x15: - case 0x16: - case 0x17: - case 0x18: - case 0x19: - case 0x1a: - case 0x1b: - case 0x1c: - case 0x1d: - case 0x1e: - case 0x1f: - { - error_message = "invalid string: control character " + codepoint_to_string(current) + " must be escaped"; - return token_type::parse_error; - } + @complexity Constant. - // U+0020..U+007F (except U+0022 (quote) and U+005C (backspace)) - case 0x20: - case 0x21: - case 0x23: - case 0x24: - case 0x25: - case 0x26: - case 0x27: - case 0x28: - case 0x29: - case 0x2a: - case 0x2b: - case 0x2c: - case 0x2d: - case 0x2e: - case 0x2f: - case 0x30: - case 0x31: - case 0x32: - case 0x33: - case 0x34: - case 0x35: - case 0x36: - case 0x37: - case 0x38: - case 0x39: - case 0x3a: - case 0x3b: - case 0x3c: - case 0x3d: - case 0x3e: - case 0x3f: - case 0x40: - case 0x41: - case 0x42: - case 0x43: - case 0x44: - case 0x45: - case 0x46: - case 0x47: - case 0x48: - case 0x49: - case 0x4a: - case 0x4b: - case 0x4c: - case 0x4d: - case 0x4e: - case 0x4f: - case 0x50: - case 0x51: - case 0x52: - case 0x53: - case 0x54: - case 0x55: - case 0x56: - case 0x57: - case 0x58: - case 0x59: - case 0x5a: - case 0x5b: - case 0x5d: - case 0x5e: - case 0x5f: - case 0x60: - case 0x61: - case 0x62: - case 0x63: - case 0x64: - case 0x65: - case 0x66: - case 0x67: - case 0x68: - case 0x69: - case 0x6a: - case 0x6b: - case 0x6c: - case 0x6d: - case 0x6e: - case 0x6f: - case 0x70: - case 0x71: - case 0x72: - case 0x73: - case 0x74: - case 0x75: - case 0x76: - case 0x77: - case 0x78: - case 0x79: - case 0x7a: - case 0x7b: - case 0x7c: - case 0x7d: - case 0x7e: - case 0x7f: - { - add(current); - break; - } + @liveexample{The example below shows how JSON values can be swapped with + `swap()`.,swap__reference} - // U+0080..U+07FF: bytes C2..DF 80..BF - case 0xc2: - case 0xc3: - case 0xc4: - case 0xc5: - case 0xc6: - case 0xc7: - case 0xc8: - case 0xc9: - case 0xca: - case 0xcb: - case 0xcc: - case 0xcd: - case 0xce: - case 0xcf: - case 0xd0: - case 0xd1: - case 0xd2: - case 0xd3: - case 0xd4: - case 0xd5: - case 0xd6: - case 0xd7: - case 0xd8: - case 0xd9: - case 0xda: - case 0xdb: - case 0xdc: - case 0xdd: - case 0xde: - case 0xdf: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } + @since version 1.0.0 + */ + void swap(reference other) noexcept ( + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value and + std::is_nothrow_move_constructible::value and + std::is_nothrow_move_assignable::value + ) + { + std::swap(m_type, other.m_type); + std::swap(m_value, other.m_value); + assert_invariant(); + } - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + /*! + @brief exchanges the values - // U+0800..U+0FFF: bytes E0 A0..BF 80..BF - case 0xe0: - { - add(current); - get(); - if (JSON_LIKELY(0xa0 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + Exchanges the contents of a JSON array with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @param[in,out] other array to exchange the contents with - // U+1000..U+CFFF: bytes E1..EC 80..BF 80..BF - // U+E000..U+FFFF: bytes EE..EF 80..BF 80..BF - case 0xe1: - case 0xe2: - case 0xe3: - case 0xe4: - case 0xe5: - case 0xe6: - case 0xe7: - case 0xe8: - case 0xe9: - case 0xea: - case 0xeb: - case 0xec: - case 0xee: - case 0xef: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @throw type_error.310 when JSON value is not an array; example: `"cannot + use swap() with string"` - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @complexity Constant. - // U+D000..U+D7FF: bytes ED 80..9F 80..BF - case 0xed: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x9f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } + @liveexample{The example below shows how arrays can be swapped with + `swap()`.,swap__array_t} - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @since version 1.0.0 + */ + void swap(array_t& other) + { + // swap only works for arrays + if (JSON_LIKELY(is_array())) + { + std::swap(*(m_value.array), other); + } + else + { + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); + } + } - // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF - case 0xf0: - { - add(current); - get(); - if (JSON_LIKELY(0x90 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + /*! + @brief exchanges the values - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + Exchanges the contents of a JSON object with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. - // U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF - case 0xf1: - case 0xf2: - case 0xf3: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @param[in,out] other object to exchange the contents with - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @throw type_error.310 when JSON value is not an object; example: + `"cannot use swap() with string"` - // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF - case 0xf4: - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0x8f)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - get(); - if (JSON_LIKELY(0x80 <= current and current <= 0xbf)) - { - add(current); - continue; - } - } - } + @complexity Constant. - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } + @liveexample{The example below shows how objects can be swapped with + `swap()`.,swap__object_t} - // remaining bytes (80..C1 and F5..FF) are ill-formed - default: - { - error_message = "invalid string: ill-formed UTF-8 byte"; - return token_type::parse_error; - } - } - } + @since version 1.0.0 + */ + void swap(object_t& other) + { + // swap only works for objects + if (JSON_LIKELY(is_object())) + { + std::swap(*(m_value.object), other); } - - static void strtof(float& f, const char* str, char** endptr) noexcept + else { - f = std::strtof(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } + + /*! + @brief exchanges the values + + Exchanges the contents of a JSON string with those of @a other. Does not + invoke any move, copy, or swap operations on individual elements. All + iterators and references remain valid. The past-the-end iterator is + invalidated. + + @param[in,out] other string to exchange the contents with + + @throw type_error.310 when JSON value is not a string; example: `"cannot + use swap() with boolean"` - static void strtof(double& f, const char* str, char** endptr) noexcept + @complexity Constant. + + @liveexample{The example below shows how strings can be swapped with + `swap()`.,swap__string_t} + + @since version 1.0.0 + */ + void swap(string_t& other) + { + // swap only works for strings + if (JSON_LIKELY(is_string())) { - f = std::strtod(str, endptr); + std::swap(*(m_value.string), other); } - - static void strtof(long double& f, const char* str, char** endptr) noexcept + else { - f = std::strtold(str, endptr); + JSON_THROW(type_error::create(310, "cannot use swap() with " + std::string(type_name()))); } + } + + /// @} - /*! - @brief scan a number literal + public: + ////////////////////////////////////////// + // lexicographical comparison operators // + ////////////////////////////////////////// + + /// @name lexicographical comparison operators + /// @{ + + /*! + @brief comparison: equal - This function scans a string according to Sect. 6 of RFC 7159. + Compares two JSON values for equality according to the following rules: + - Two JSON values are equal if (1) they are from the same type and (2) + their stored values are the same according to their respective + `operator==`. + - Integer and floating-point numbers are automatically converted before + comparison. Note than two NaN values are always treated as unequal. + - Two JSON null values are equal. - The function is realized with a deterministic finite state machine - derived from the grammar described in RFC 7159. Starting in state - "init", the input is read and used to determined the next state. Only - state "done" accepts the number. State "error" is a trap state to model - errors. In the table below, "anything" means any character but the ones - listed before. + @note Floating-point inside JSON values numbers are compared with + `json::number_float_t::operator==` which is `double::operator==` by + default. To compare floating-point while respecting an epsilon, an alternative + [comparison function](https://github.com/mariokonrad/marnav/blob/master/src/marnav/math/floatingpoint.hpp#L34-#L39) + could be used, for instance + @code {.cpp} + template::value, T>::type> + inline bool is_same(T a, T b, T epsilon = std::numeric_limits::epsilon()) noexcept + { + return std::abs(a - b) <= epsilon; + } + @endcode - state | 0 | 1-9 | e E | + | - | . | anything - ---------|----------|----------|----------|---------|---------|----------|----------- - init | zero | any1 | [error] | [error] | minus | [error] | [error] - minus | zero | any1 | [error] | [error] | [error] | [error] | [error] - zero | done | done | exponent | done | done | decimal1 | done - any1 | any1 | any1 | exponent | done | done | decimal1 | done - decimal1 | decimal2 | [error] | [error] | [error] | [error] | [error] | [error] - decimal2 | decimal2 | decimal2 | exponent | done | done | done | done - exponent | any2 | any2 | [error] | sign | sign | [error] | [error] - sign | any2 | any2 | [error] | [error] | [error] | [error] | [error] - any2 | any2 | any2 | done | done | done | done | done + @note NaN values never compare equal to themselves or to other NaN values. - The state machine is realized with one label per state (prefixed with - "scan_number_") and `goto` statements between them. The state machine - contains cycles, but any cycle can be left when EOF is read. Therefore, - the function is guaranteed to terminate. + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are equal - During scanning, the read bytes are stored in yytext. This string is - then converted to a signed integer, an unsigned integer, or a - floating-point number. + @exceptionsafety No-throw guarantee: this function never throws exceptions. - @return token_type::value_unsigned, token_type::value_integer, or - token_type::value_float if number could be successfully scanned, - token_type::parse_error otherwise + @complexity Linear. - @note The scanner is independent of the current locale. Internally, the - locale's decimal point is used instead of `.` to work with the - locale-dependent converters. - */ - token_type scan_number() - { - // reset yytext to store the number's bytes - reset(); + @liveexample{The example demonstrates comparing several JSON + types.,operator__equal} - // the type of the parsed number; initially set to unsigned; will be - // changed if minus sign, decimal point or exponent is read - token_type number_type = token_type::value_unsigned; + @since version 1.0.0 + */ + friend bool operator==(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); - // state (init): we just found out we need to scan a number - switch (current) + if (lhs_type == rhs_type) + { + switch (lhs_type) { - case '-': - { - add(current); - goto scan_number_minus; - } + case value_t::array: + return (*lhs.m_value.array == *rhs.m_value.array); - case '0': - { - add(current); - goto scan_number_zero; - } + case value_t::object: + return (*lhs.m_value.object == *rhs.m_value.object); - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + case value_t::null: + return true; - default: - { - // all other characters are rejected outside scan_number() - assert(false); // LCOV_EXCL_LINE - } - } + case value_t::string: + return (*lhs.m_value.string == *rhs.m_value.string); -scan_number_minus: - // state: we just parsed a leading minus sign - number_type = token_type::value_integer; - switch (get()) - { - case '0': - { - add(current); - goto scan_number_zero; - } + case value_t::boolean: + return (lhs.m_value.boolean == rhs.m_value.boolean); - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + case value_t::number_integer: + return (lhs.m_value.number_integer == rhs.m_value.number_integer); + + case value_t::number_unsigned: + return (lhs.m_value.number_unsigned == rhs.m_value.number_unsigned); + + case value_t::number_float: + return (lhs.m_value.number_float == rhs.m_value.number_float); default: - { - error_message = "invalid number; expected digit after '-'"; - return token_type::parse_error; - } + return false; } + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_integer) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_integer)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_float); + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_float == static_cast(rhs.m_value.number_unsigned)); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) + { + return (static_cast(lhs.m_value.number_unsigned) == rhs.m_value.number_integer); + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) + { + return (lhs.m_value.number_integer == static_cast(rhs.m_value.number_unsigned)); + } + + return false; + } -scan_number_zero: - // state: we just parse a zero (maybe with a leading minus sign) - switch (get()) - { - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs == basic_json(rhs)); + } - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + /*! + @brief comparison: equal + @copydoc operator==(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator==(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) == rhs); + } - default: - { - goto scan_number_done; - } - } + /*! + @brief comparison: not equal -scan_number_any1: - // state: we just parsed a number 0-9 (maybe with a leading minus sign) - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any1; - } + Compares two JSON values for inequality by calculating `not (lhs == rhs)`. - case '.': - { - add(decimal_point_char); - goto scan_number_decimal1; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether the values @a lhs and @a rhs are not equal - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + @complexity Linear. - default: - { - goto scan_number_done; - } - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. -scan_number_decimal1: - // state: we just parsed a decimal point - number_type = token_type::value_float; - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__notequal} - default: - { - error_message = "invalid number; expected digit after '.'"; - return token_type::parse_error; - } - } + @since version 1.0.0 + */ + friend bool operator!=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs == rhs); + } -scan_number_decimal2: - // we just parsed at least one number after a decimal point - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_decimal2; - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs != basic_json(rhs)); + } - case 'e': - case 'E': - { - add(current); - goto scan_number_exponent; - } + /*! + @brief comparison: not equal + @copydoc operator!=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator!=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) != rhs); + } - default: - { - goto scan_number_done; - } - } + /*! + @brief comparison: less than -scan_number_exponent: - // we just parsed an exponent - number_type = token_type::value_float; - switch (get()) - { - case '+': - case '-': - { - add(current); - goto scan_number_sign; - } + Compares whether one JSON value @a lhs is less than another JSON value @a + rhs according to the following rules: + - If @a lhs and @a rhs have the same type, the values are compared using + the default `<` operator. + - Integer and floating-point numbers are automatically converted before + comparison + - In case @a lhs and @a rhs have different types, the values are ignored + and the order of the types is considered, see + @ref operator<(const value_t, const value_t). - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than @a rhs - default: - { - error_message = "invalid number; expected '+', '-', or digit after exponent"; - return token_type::parse_error; - } - } + @complexity Linear. -scan_number_sign: - // we just parsed an exponent sign - switch (get()) - { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - default: - { - error_message = "invalid number; expected digit after exponent sign"; - return token_type::parse_error; - } - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__less} -scan_number_any2: - // we just parsed a number after the exponent or exponent sign - switch (get()) + @since version 1.0.0 + */ + friend bool operator<(const_reference lhs, const_reference rhs) noexcept + { + const auto lhs_type = lhs.type(); + const auto rhs_type = rhs.type(); + + if (lhs_type == rhs_type) + { + switch (lhs_type) { - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - { - add(current); - goto scan_number_any2; - } + case value_t::array: + return (*lhs.m_value.array) < (*rhs.m_value.array); - default: - { - goto scan_number_done; - } - } + case value_t::object: + return *lhs.m_value.object < *rhs.m_value.object; -scan_number_done: - // unget the character after the number (we only read it to know - // that we are done scanning a number) - --chars_read; - next_unget = true; + case value_t::null: + return false; - // terminate token - add('\0'); - --yylen; + case value_t::string: + return *lhs.m_value.string < *rhs.m_value.string; - // try to parse integers first and fall back to floats - if (number_type == token_type::value_unsigned) - { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoull(yytext.data(), &endptr, 10); + case value_t::boolean: + return lhs.m_value.boolean < rhs.m_value.boolean; - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::number_integer: + return lhs.m_value.number_integer < rhs.m_value.number_integer; - if (errno == 0) - { - value_unsigned = static_cast(x); - if (value_unsigned == x) - { - return token_type::value_unsigned; - } - } - } - else if (number_type == token_type::value_integer) - { - char* endptr = nullptr; - errno = 0; - const auto x = std::strtoll(yytext.data(), &endptr, 10); + case value_t::number_unsigned: + return lhs.m_value.number_unsigned < rhs.m_value.number_unsigned; - // we checked the number format before - assert(endptr == yytext.data() + yylen); + case value_t::number_float: + return lhs.m_value.number_float < rhs.m_value.number_float; - if (errno == 0) - { - value_integer = static_cast(x); - if (value_integer == x) - { - return token_type::value_integer; - } - } + default: + return false; } - - // this code is reached if we parse a floating-point number or if - // an integer conversion above failed - strtof(value_float, yytext.data(), nullptr); - return token_type::value_float; } - - token_type scan_true() + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float) { - assert(current == 't'); - if (JSON_LIKELY((get() == 'r' and get() == 'u' and get() == 'e'))) - { - return token_type::literal_true; - } - - error_message = "invalid literal; expected 'true'"; - return token_type::parse_error; + return static_cast(lhs.m_value.number_integer) < rhs.m_value.number_float; } - - token_type scan_false() + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer) { - assert(current == 'f'); - if (JSON_LIKELY((get() == 'a' and get() == 'l' and get() == 's' and get() == 'e'))) - { - return token_type::literal_false; - } - - error_message = "invalid literal; expected 'false'"; - return token_type::parse_error; + return lhs.m_value.number_float < static_cast(rhs.m_value.number_integer); } - - token_type scan_null() + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float) { - assert(current == 'n'); - if (JSON_LIKELY((get() == 'u' and get() == 'l' and get() == 'l'))) - { - return token_type::literal_null; - } - - error_message = "invalid literal; expected 'null'"; - return token_type::parse_error; + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_float; + } + else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned) + { + return lhs.m_value.number_float < static_cast(rhs.m_value.number_unsigned); + } + else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned) + { + return lhs.m_value.number_integer < static_cast(rhs.m_value.number_unsigned); + } + else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer) + { + return static_cast(lhs.m_value.number_unsigned) < rhs.m_value.number_integer; } - ///////////////////// - // input management - ///////////////////// + // We only reach this line if we cannot compare values. In that case, + // we compare types. Note we have to call the operator explicitly, + // because MSVC has problems otherwise. + return operator<(lhs_type, rhs_type); + } + + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs < basic_json(rhs)); + } + + /*! + @brief comparison: less than + @copydoc operator<(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) < rhs); + } - /// reset yytext - void reset() noexcept - { - yylen = 0; - start_pos = chars_read - 1; - } + /*! + @brief comparison: less than or equal - /// get a character from the input - int get() - { - ++chars_read; - return next_unget - ? (next_unget = false, current) - : (current = ia->get_character()); - } + Compares whether one JSON value @a lhs is less than or equal to another + JSON value by calculating `not (rhs < lhs)`. - /// add a character to yytext - void add(int c) - { - // resize yytext if necessary; this condition is deemed unlikely, - // because we start with a 1024-byte buffer - if (JSON_UNLIKELY((yylen + 1 > yytext.capacity()))) - { - yytext.resize(2 * yytext.capacity(), '\0'); - } - yytext[yylen++] = static_cast(c); - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is less than or equal to @a rhs - public: - ///////////////////// - // value getters - ///////////////////// + @complexity Linear. - /// return integer value - constexpr number_integer_t get_number_integer() const noexcept - { - return value_integer; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - /// return unsigned integer value - constexpr number_unsigned_t get_number_unsigned() const noexcept - { - return value_unsigned; - } + @liveexample{The example demonstrates comparing several JSON + types.,operator__greater} - /// return floating-point value - constexpr number_float_t get_number_float() const noexcept - { - return value_float; - } + @since version 1.0.0 + */ + friend bool operator<=(const_reference lhs, const_reference rhs) noexcept + { + return not (rhs < lhs); + } - /// return string value - const std::string get_string() - { - // yytext cannot be returned as char*, because it may contain a - // null byte (parsed as "\u0000") - return std::string(yytext.data(), yylen); - } + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs <= basic_json(rhs)); + } - ///////////////////// - // diagnostics - ///////////////////// + /*! + @brief comparison: less than or equal + @copydoc operator<=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator<=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) <= rhs); + } - /// return position of last read token - constexpr size_t get_position() const noexcept - { - return chars_read; - } + /*! + @brief comparison: greater than - /// return the last read token (for errors only) - std::string get_token_string() const - { - // get the raw byte sequence of the last token - std::string s = ia->read(start_pos, chars_read - start_pos); + Compares whether one JSON value @a lhs is greater than another + JSON value by calculating `not (lhs <= rhs)`. - // escape control characters - std::string result; - for (auto c : s) - { - if (c == '\0' or c == std::char_traits::eof()) - { - // ignore EOF - continue; - } - else if ('\x00' <= c and c <= '\x1f') - { - // escape control characters - result += "<" + codepoint_to_string(c) + ">"; - } - else - { - // add character as is - result.append(1, c); - } - } + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than to @a rhs - return result; - } + @complexity Linear. - /// return syntax error message - const std::string& get_error_message() const noexcept - { - return error_message; - } + @exceptionsafety No-throw guarantee: this function never throws exceptions. - ///////////////////// - // actual scanner - ///////////////////// + @liveexample{The example demonstrates comparing several JSON + types.,operator__lessequal} - token_type scan() - { - // read next character and ignore whitespace - do - { - get(); - } - while (current == ' ' or current == '\t' or current == '\n' or current == '\r'); - - switch (current) - { - // structural characters - case '[': - return token_type::begin_array; - case ']': - return token_type::end_array; - case '{': - return token_type::begin_object; - case '}': - return token_type::end_object; - case ':': - return token_type::name_separator; - case ',': - return token_type::value_separator; - - // literals - case 't': - return scan_true(); - case 'f': - return scan_false(); - case 'n': - return scan_null(); - - // string - case '\"': - return scan_string(); - - // number - case '-': - case '0': - case '1': - case '2': - case '3': - case '4': - case '5': - case '6': - case '7': - case '8': - case '9': - return scan_number(); - - // end of input (the null byte is needed when parsing from - // string literals) - case '\0': - case std::char_traits::eof(): - return token_type::end_of_input; + @since version 1.0.0 + */ + friend bool operator>(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs <= rhs); + } - // error - default: - error_message = "invalid literal"; - return token_type::parse_error; - } - } + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const_reference lhs, const ScalarType rhs) noexcept + { + return (lhs > basic_json(rhs)); + } - private: - /// input adapter - input_adapter_t ia = nullptr; + /*! + @brief comparison: greater than + @copydoc operator>(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) > rhs); + } - /// the current character - int current = std::char_traits::eof(); + /*! + @brief comparison: greater than or equal - /// whether get() should return the last character again - bool next_unget = false; + Compares whether one JSON value @a lhs is greater than or equal to another + JSON value by calculating `not (lhs < rhs)`. - /// the number of characters read - size_t chars_read = 0; - /// the start position of the current token - size_t start_pos = 0; + @param[in] lhs first JSON value to consider + @param[in] rhs second JSON value to consider + @return whether @a lhs is greater than or equal to @a rhs - /// buffer for variable-length tokens (numbers, strings) - std::vector yytext = std::vector(1024, '\0'); - /// current index in yytext - size_t yylen = 0; + @complexity Linear. - /// a description of occurred lexer errors - std::string error_message = ""; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - // number values - number_integer_t value_integer = 0; - number_unsigned_t value_unsigned = 0; - number_float_t value_float = 0; + @liveexample{The example demonstrates comparing several JSON + types.,operator__greaterequal} - /// the decimal point - const char decimal_point_char = '.'; - }; + @since version 1.0.0 + */ + friend bool operator>=(const_reference lhs, const_reference rhs) noexcept + { + return not (lhs < rhs); + } /*! - @brief syntax analysis - - This class implements a recursive decent parser. + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) */ - class parser + template::value, int>::type = 0> + friend bool operator>=(const_reference lhs, const ScalarType rhs) noexcept { - public: - /// a parser reading from an input adapter - explicit parser(input_adapter_t adapter, - const parser_callback_t cb = nullptr) - : callback(cb), m_lexer(adapter) - {} - - /*! - @brief public parser interface + return (lhs >= basic_json(rhs)); + } - @param[in] strict whether to expect the last token to be EOF - @return parsed JSON value + /*! + @brief comparison: greater than or equal + @copydoc operator>=(const_reference, const_reference) + */ + template::value, int>::type = 0> + friend bool operator>=(const ScalarType lhs, const_reference rhs) noexcept + { + return (basic_json(lhs) >= rhs); + } - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse(const bool strict = true) - { - // read first token - get_token(); + /// @} - basic_json result = parse_internal(true); - result.assert_invariant(); + /////////////////// + // serialization // + /////////////////// - if (strict) - { - get_token(); - expect(lexer::token_type::end_of_input); - } + /// @name serialization + /// @{ - // return parser result and replace it with null in case the - // top-level value was discarded by the callback function - return result.is_discarded() ? basic_json() : std::move(result); - } + /*! + @brief serialize to stream - /*! - @brief public accept interface + Serialize the given JSON value @a j to the output stream @a o. The JSON + value will be serialized using the @ref dump member function. - @param[in] strict whether to expect the last token to be EOF - @return whether the input is a proper JSON text - */ - bool accept(const bool strict = true) - { - // read first token - get_token(); + - The indentation of the output can be controlled with the member variable + `width` of the output stream @a o. For instance, using the manipulator + `std::setw(4)` on @a o sets the indentation level to `4` and the + serialization result is the same as calling `dump(4)`. - if (not accept_internal()) - { - return false; - } + - The indentation character can be controlled with the member variable + `fill` of the output stream @a o. For instance, the manipulator + `std::setfill('\\t')` sets indentation to use a tab character rather than + the default space character. - if (strict and get_token() != lexer::token_type::end_of_input) - { - return false; - } + @param[in,out] o stream to serialize to + @param[in] j JSON value to serialize - return true; - } + @return the stream @a o - private: - /*! - @brief the actual parser - @throw parse_error.101 in case of an unexpected token - @throw parse_error.102 if to_unicode fails or surrogate error - @throw parse_error.103 if to_unicode fails - */ - basic_json parse_internal(bool keep) - { - auto result = basic_json(value_t::discarded); + @throw type_error.316 if a string stored inside the JSON value is not + UTF-8 encoded - switch (last_token) - { - case lexer::token_type::begin_object: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::object_start, result)) != 0))) - { - // explicitly set result to object to cope with {} - result.m_type = value_t::object; - result.m_value = value_t::object; - } + @complexity Linear. - // read next token - get_token(); + @liveexample{The example below shows the serialization with different + parameters to `width` to adjust the indentation level.,operator_serialize} - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @since version 1.0.0; indentation character added in version 3.0.0 + */ + friend std::ostream& operator<<(std::ostream& o, const basic_json& j) + { + // read width member and use it as indentation parameter if nonzero + const bool pretty_print = (o.width() > 0); + const auto indentation = (pretty_print ? o.width() : 0); - // parse values - while (true) - { - // store key - expect(lexer::token_type::value_string); - const auto key = m_lexer.get_string(); + // reset width to 0 for subsequent calls to this stream + o.width(0); - bool keep_tag = false; - if (keep) - { - if (callback) - { - basic_json k(key); - keep_tag = callback(depth, parse_event_t::key, k); - } - else - { - keep_tag = true; - } - } + // do the actual serialization + serializer s(detail::output_adapter(o), o.fill()); + s.dump(j, pretty_print, false, static_cast(indentation)); + return o; + } - // parse separator (:) - get_token(); - expect(lexer::token_type::name_separator); + /*! + @brief serialize to stream + @deprecated This stream operator is deprecated and will be removed in + future 4.0.0 of the library. Please use + @ref operator<<(std::ostream&, const basic_json&) + instead; that is, replace calls like `j >> o;` with `o << j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::ostream& operator>>(const basic_json& j, std::ostream& o) + { + return o << j; + } - // parse and add value - get_token(); - auto value = parse_internal(keep); - if (keep and keep_tag and not value.is_discarded()) - { - result[key] = std::move(value); - } + /// @} - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } - // closing } - expect(lexer::token_type::end_object); - break; - } + ///////////////////// + // deserialization // + ///////////////////// - if (keep and callback and not callback(--depth, parse_event_t::object_end, result)) - { - result = basic_json(value_t::discarded); - } + /// @name deserialization + /// @{ - return result; - } + /*! + @brief deserialize from a compatible input + + This function reads from a compatible input. Examples are: + - an array of 1-byte values + - strings with character/literal type with size of 1 byte + - input streams + - container with contiguous storage of 1-byte values. Compatible container + types include `std::vector`, `std::string`, `std::array`, + `std::valarray`, and `std::initializer_list`. Furthermore, C-style + arrays can be used with `std::begin()`/`std::end()`. User-defined + containers can be used as long as they implement random-access iterators + and a contiguous storage. - case lexer::token_type::begin_array: - { - if (keep and (not callback - or ((keep = callback(depth++, parse_event_t::array_start, result)) != 0))) - { - // explicitly set result to object to cope with [] - result.m_type = value_t::array; - result.m_value = value_t::array; - } + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - // read next token - get_token(); + @pre The container storage is contiguous. Violating this precondition + yields undefined behavior. **This precondition is enforced with an + assertion.** + @pre Each element of the container has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - if (callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with a noncompliant container and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - // parse values - while (true) - { - // parse value - auto value = parse_internal(keep); - if (keep and not value.is_discarded()) - { - result.push_back(std::move(value)); - } + @param[in] i input to read from + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + @return result of the deserialization - // closing ] - expect(lexer::token_type::end_array); - break; - } + @throw parse_error.101 if a parse error occurs; example: `""unexpected end + of input; expected string literal""` + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - if (keep and callback and not callback(--depth, parse_event_t::array_end, result)) - { - result = basic_json(value_t::discarded); - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - return result; - } + @note A UTF-8 byte order mark is silently ignored. - case lexer::token_type::literal_null: - { - result.m_type = value_t::null; - break; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an array.,parse__array__parser_callback_t} - case lexer::token_type::value_string: - { - result = basic_json(m_lexer.get_string()); - break; - } + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__string__parser_callback_t} - case lexer::token_type::literal_true: - { - result.m_type = value_t::boolean; - result.m_value = true; - break; - } + @liveexample{The example below demonstrates the `parse()` function with + and without callback function.,parse__istream__parser_callback_t} - case lexer::token_type::literal_false: - { - result.m_type = value_t::boolean; - result.m_value = false; - break; - } + @liveexample{The example below demonstrates the `parse()` function reading + from a contiguous container.,parse__contiguouscontainer__parser_callback_t} - case lexer::token_type::value_unsigned: - { - result.m_type = value_t::number_unsigned; - result.m_value = m_lexer.get_number_unsigned(); - break; - } + @since version 2.0.3 (contiguous containers) + */ + static basic_json parse(detail::input_adapter&& i, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(i, cb, allow_exceptions).parse(true, result); + return result; + } - case lexer::token_type::value_integer: - { - result.m_type = value_t::number_integer; - result.m_value = m_lexer.get_number_integer(); - break; - } + static bool accept(detail::input_adapter&& i) + { + return parser(i).accept(true); + } - case lexer::token_type::value_float: - { - result.m_type = value_t::number_float; - result.m_value = m_lexer.get_number_float(); + static bool sax_parse(detail::input_adapter&& i, json_sax_t* sax, + input_format_t format = input_format_t::json, + const bool strict = true) + { + assert(sax); + switch (format) + { + case input_format_t::json: + return parser(std::move(i)).sax_parse(sax, strict); + default: + return binary_reader(std::move(i)).sax_parse(format, sax, strict); + } + } - // throw in case of infinity or NAN - if (JSON_UNLIKELY(not std::isfinite(result.m_value.number_float))) - { - JSON_THROW(out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'")); - } + /*! + @brief deserialize from an iterator range with contiguous storage - break; - } + This function reads from an iterator range of a container with contiguous + storage of 1-byte values. Compatible container types include + `std::vector`, `std::string`, `std::array`, `std::valarray`, and + `std::initializer_list`. Furthermore, C-style arrays can be used with + `std::begin()`/`std::end()`. User-defined containers can be used as long + as they implement random-access iterators and a contiguous storage. - default: - { - // the last token was unexpected - unexpect(last_token); - } - } + @pre The iterator range is contiguous. Violating this precondition yields + undefined behavior. **This precondition is enforced with an assertion.** + @pre Each element in the range has a size of 1 byte. Violating this + precondition yields undefined behavior. **This precondition is enforced + with a static assertion.** - if (keep and callback and not callback(depth, parse_event_t::value, result)) - { - result = basic_json(value_t::discarded); - } - return result; - } + @warning There is no way to enforce all preconditions at compile-time. If + the function is called with noncompliant iterators and with + assertions switched off, the behavior is undefined and will most + likely yield segmentation violation. - /*! - @brief the acutal acceptor + @tparam IteratorType iterator of container with contiguous storage + @param[in] first begin of the range to parse (included) + @param[in] last end of the range to parse (excluded) + @param[in] cb a parser callback function of type @ref parser_callback_t + which is used to control the deserialization by filtering unwanted values + (optional) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - @invariant 1. The last token is not yet processed. Therefore, the - caller of this function must make sure a token has - been read. - 2. When this function returns, the last token is processed. - That is, the last read character was already considered. + @return result of the deserialization - This invariant makes sure that no token needs to be "unput". - */ - bool accept_internal() - { - switch (last_token) - { - case lexer::token_type::begin_object: - { - // read next token - get_token(); + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - // closing } -> we are done - if (last_token == lexer::token_type::end_object) - { - return true; - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. The complexity can be higher if the parser callback function + @a cb has a super-linear complexity. - // parse values - while (true) - { - // parse key - if (last_token != lexer::token_type::value_string) - { - return false; - } + @note A UTF-8 byte order mark is silently ignored. - // parse separator (:) - get_token(); - if (last_token != lexer::token_type::name_separator) - { - return false; - } + @liveexample{The example below demonstrates the `parse()` function reading + from an iterator range.,parse__iteratortype__parser_callback_t} - // parse value - get_token(); - if (not accept_internal()) - { - return false; - } + @since version 2.0.3 + */ + template::iterator_category>::value, int>::type = 0> + static basic_json parse(IteratorType first, IteratorType last, + const parser_callback_t cb = nullptr, + const bool allow_exceptions = true) + { + basic_json result; + parser(detail::input_adapter(first, last), cb, allow_exceptions).parse(true, result); + return result; + } - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + template::iterator_category>::value, int>::type = 0> + static bool accept(IteratorType first, IteratorType last) + { + return parser(detail::input_adapter(first, last)).accept(true); + } - // closing } - if (last_token != lexer::token_type::end_object) - { - return false; - } + template::iterator_category>::value, int>::type = 0> + static bool sax_parse(IteratorType first, IteratorType last, json_sax_t* sax) + { + return parser(detail::input_adapter(first, last)).sax_parse(sax); + } - return true; - } - } + /*! + @brief deserialize from stream + @deprecated This stream operator is deprecated and will be removed in + version 4.0.0 of the library. Please use + @ref operator>>(std::istream&, basic_json&) + instead; that is, replace calls like `j << i;` with `i >> j;`. + @since version 1.0.0; deprecated since version 3.0.0 + */ + JSON_DEPRECATED + friend std::istream& operator<<(basic_json& j, std::istream& i) + { + return operator>>(i, j); + } - case lexer::token_type::begin_array: - { - // read next token - get_token(); + /*! + @brief deserialize from stream - // closing ] -> we are done - if (last_token == lexer::token_type::end_array) - { - return true; - } + Deserializes an input stream to a JSON value. - // parse values - while (true) - { - // parse value - if (not accept_internal()) - { - return false; - } + @param[in,out] i input stream to read a serialized JSON value from + @param[in,out] j JSON value to write the deserialized input to - // comma -> next value - get_token(); - if (last_token == lexer::token_type::value_separator) - { - get_token(); - continue; - } + @throw parse_error.101 in case of an unexpected token + @throw parse_error.102 if to_unicode fails or surrogate error + @throw parse_error.103 if to_unicode fails - // closing ] - if (last_token != lexer::token_type::end_array) - { - return false; - } + @complexity Linear in the length of the input. The parser is a predictive + LL(1) parser. - return true; - } - } + @note A UTF-8 byte order mark is silently ignored. - case lexer::token_type::literal_false: - case lexer::token_type::literal_null: - case lexer::token_type::literal_true: - case lexer::token_type::value_float: - case lexer::token_type::value_integer: - case lexer::token_type::value_string: - case lexer::token_type::value_unsigned: - { - return true; - } + @liveexample{The example below shows how a JSON value is constructed by + reading a serialization from a stream.,operator_deserialize} - default: - { - // the last token was unexpected - return false; - } - } - } + @sa parse(std::istream&, const parser_callback_t) for a variant with a + parser callback function to filter values while parsing - /// get next token from lexer - typename lexer::token_type get_token() - { - last_token = m_lexer.scan(); - return last_token; - } + @since version 1.0.0 + */ + friend std::istream& operator>>(std::istream& i, basic_json& j) + { + parser(detail::input_adapter(i)).parse(false, j); + return i; + } - /*! - @throw parse_error.101 if expected token did not occur - */ - void expect(typename lexer::token_type t) const - { - if (JSON_UNLIKELY(t != last_token)) - { - std::string error_msg = "syntax error - "; - if (last_token == lexer::token_type::parse_error) - { - error_msg += m_lexer.get_error_message() + "; last read: '" + m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer::token_type_name(last_token)); - } + /// @} - error_msg += "; expected " + std::string(lexer::token_type_name(t)); - JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); - } - } + /////////////////////////// + // convenience functions // + /////////////////////////// - /*! - @throw parse_error.101 if unexpected token occurred - */ - void unexpect(typename lexer::token_type t) const - { - if (JSON_UNLIKELY(t == last_token)) - { - std::string error_msg = "syntax error - "; - if (last_token == lexer::token_type::parse_error) - { - error_msg += m_lexer.get_error_message() + "; last read '" + m_lexer.get_token_string() + "'"; - } - else - { - error_msg += "unexpected " + std::string(lexer::token_type_name(last_token)); - } + /*! + @brief return the type as string - JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg)); - } - } + Returns the type name as string to be used in error messages - usually to + indicate that a function was called on a wrong JSON type. + + @return a string representation of a the @a m_type member: + Value type | return value + ----------- | ------------- + null | `"null"` + boolean | `"boolean"` + string | `"string"` + number | `"number"` (for all number types) + object | `"object"` + array | `"array"` + discarded | `"discarded"` - private: - /// current level of recursion - int depth = 0; - /// callback function - const parser_callback_t callback = nullptr; - /// the type of the last read token - typename lexer::token_type last_token = lexer::token_type::uninitialized; - /// the lexer - lexer m_lexer; - }; + @exceptionsafety No-throw guarantee: this function never throws exceptions. - public: - /*! - @brief JSON Pointer + @complexity Constant. - A JSON pointer defines a string syntax for identifying a specific value - within a JSON document. It can be used with functions `at` and - `operator[]`. Furthermore, JSON pointers are the base for JSON patches. + @liveexample{The following code exemplifies `type_name()` for all JSON + types.,type_name} - @sa [RFC 6901](https://tools.ietf.org/html/rfc6901) + @sa @ref type() -- return the type of the JSON value + @sa @ref operator value_t() -- return the type of the JSON value (implicit) - @since version 2.0.0 + @since version 1.0.0, public since 2.1.0, `const char*` and `noexcept` + since 3.0.0 */ - class json_pointer + const char* type_name() const noexcept { - /// allow basic_json to access private members - friend class basic_json; - - public: - /*! - @brief create JSON pointer - - Create a JSON pointer according to the syntax described in - [Section 3 of RFC6901](https://tools.ietf.org/html/rfc6901#section-3). - - @param[in] s string representing the JSON pointer; if omitted, the - empty string is assumed which references the whole JSON - value + { + switch (m_type) + { + case value_t::null: + return "null"; + case value_t::object: + return "object"; + case value_t::array: + return "array"; + case value_t::string: + return "string"; + case value_t::boolean: + return "boolean"; + case value_t::discarded: + return "discarded"; + default: + return "number"; + } + } + } - @throw parse_error.107 if the given JSON pointer @a s is nonempty and - does not begin with a slash (`/`); see example below - @throw parse_error.108 if a tilde (`~`) in the given JSON pointer @a s - is not followed by `0` (representing `~`) or `1` (representing `/`); - see example below + private: + ////////////////////// + // member variables // + ////////////////////// - @liveexample{The example shows the construction several valid JSON - pointers as well as the exceptional behavior.,json_pointer} + /// the type of the current element + value_t m_type = value_t::null; - @since version 2.0.0 - */ - explicit json_pointer(const std::string& s = "") - : reference_tokens(split(s)) - {} + /// the value of the current element + json_value m_value = {}; - /*! - @brief return a string representation of the JSON pointer + ////////////////////////////////////////// + // binary serialization/deserialization // + ////////////////////////////////////////// - @invariant For each JSON pointer `ptr`, it holds: - @code {.cpp} - ptr == json_pointer(ptr.to_string()); - @endcode + /// @name binary serialization/deserialization support + /// @{ - @return a string representation of the JSON pointer + public: + /*! + @brief create a CBOR serialization of a given JSON value - @liveexample{The example shows the result of `to_string`., - json_pointer__to_string} + Serializes a given JSON value @a j to a byte vector using the CBOR (Concise + Binary Object Representation) serialization format. CBOR is a binary + serialization format which aims to be more compact than JSON itself, yet + more efficient to parse. - @since version 2.0.0 - */ - std::string to_string() const noexcept - { - return std::accumulate(reference_tokens.begin(), - reference_tokens.end(), std::string{}, - [](const std::string & a, const std::string & b) - { - return a + "/" + escape(b); - }); - } + The library uses the following mapping from JSON values types to + CBOR types according to the CBOR specification (RFC 7049): - /// @copydoc to_string() - operator std::string() const - { - return to_string(); - } + JSON value type | value/range | CBOR type | first byte + --------------- | ------------------------------------------ | ---------------------------------- | --------------- + null | `null` | Null | 0xF6 + boolean | `true` | True | 0xF5 + boolean | `false` | False | 0xF4 + number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3B + number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3A + number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 + number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 + number_integer | -24..-1 | Negative integer | 0x20..0x37 + number_integer | 0..23 | Integer | 0x00..0x17 + number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_unsigned | 0..23 | Integer | 0x00..0x17 + number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 + number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 + number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A + number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B + number_float | *any value* | Double-Precision Float | 0xFB + string | *length*: 0..23 | UTF-8 string | 0x60..0x77 + string | *length*: 23..255 | UTF-8 string (1 byte follow) | 0x78 + string | *length*: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 + string | *length*: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7A + string | *length*: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7B + array | *size*: 0..23 | array | 0x80..0x97 + array | *size*: 23..255 | array (1 byte follow) | 0x98 + array | *size*: 256..65535 | array (2 bytes follow) | 0x99 + array | *size*: 65536..4294967295 | array (4 bytes follow) | 0x9A + array | *size*: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9B + object | *size*: 0..23 | map | 0xA0..0xB7 + object | *size*: 23..255 | map (1 byte follow) | 0xB8 + object | *size*: 256..65535 | map (2 bytes follow) | 0xB9 + object | *size*: 65536..4294967295 | map (4 bytes follow) | 0xBA + object | *size*: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xBB - private: - /*! - @brief remove and return last reference pointer - @throw out_of_range.405 if JSON pointer has no parent - */ - std::string pop_back() - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a CBOR value. - auto last = reference_tokens.back(); - reference_tokens.pop_back(); - return last; - } + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - /// return whether pointer points to the root document - bool is_root() const - { - return reference_tokens.empty(); - } + @note The following CBOR types are not used in the conversion: + - byte strings (0x40..0x5F) + - UTF-8 strings terminated by "break" (0x7F) + - arrays terminated by "break" (0x9F) + - maps terminated by "break" (0xBF) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) + - half and single-precision floats (0xF9-0xFA) + - break (0xFF) - json_pointer top() const - { - if (is_root()) - { - JSON_THROW(out_of_range::create(405, "JSON pointer has no parent")); - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - json_pointer result = *this; - result.reference_tokens = {reference_tokens[0]}; - return result; - } + @complexity Linear in the size of the JSON value @a j. - /*! - @brief create and return a reference to the pointed to value + @liveexample{The example shows the serialization of a JSON value to a byte + vector in CBOR format.,to_cbor} - @complexity Linear in the number of reference tokens. + @sa http://cbor.io + @sa @ref from_cbor(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format - @throw parse_error.109 if array index is not a number - @throw type_error.313 if value cannot be unflattened - */ - reference get_and_create(reference j) const - { - pointer result = &j; + @since version 2.0.9 + */ + static std::vector to_cbor(const basic_json& j) + { + std::vector result; + to_cbor(j, result); + return result; + } - // in case no reference tokens exist, return a reference to the - // JSON value j which will be overwritten by a primitive value - for (const auto& reference_token : reference_tokens) - { - switch (result->m_type) - { - case value_t::null: - { - if (reference_token == "0") - { - // start a new array if reference token is 0 - result = &result->operator[](0); - } - else - { - // start a new object otherwise - result = &result->operator[](reference_token); - } - break; - } + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - case value_t::object: - { - // create an entry in the object - result = &result->operator[](reference_token); - break; - } + static void to_cbor(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_cbor(j); + } - case value_t::array: - { - // create an entry in the array - JSON_TRY - { - result = &result->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + /*! + @brief create a MessagePack serialization of a given JSON value - /* - The following code is only reached if there exists a - reference token _and_ the current value is primitive. In - this case, we have an error situation, because primitive - values may only occur as single value; that is, with an - empty list of reference tokens. - */ - default: - { - JSON_THROW(type_error::create(313, "invalid value to unflatten")); - } - } - } + Serializes a given JSON value @a j to a byte vector using the MessagePack + serialization format. MessagePack is a binary serialization format which + aims to be more compact than JSON itself, yet more efficient to parse. - return *result; - } + The library uses the following mapping from JSON values types to + MessagePack types according to the MessagePack specification: - /*! - @brief return a reference to the pointed to value + JSON value type | value/range | MessagePack type | first byte + --------------- | --------------------------------- | ---------------- | ---------- + null | `null` | nil | 0xC0 + boolean | `true` | true | 0xC3 + boolean | `false` | false | 0xC2 + number_integer | -9223372036854775808..-2147483649 | int64 | 0xD3 + number_integer | -2147483648..-32769 | int32 | 0xD2 + number_integer | -32768..-129 | int16 | 0xD1 + number_integer | -128..-33 | int8 | 0xD0 + number_integer | -32..-1 | negative fixint | 0xE0..0xFF + number_integer | 0..127 | positive fixint | 0x00..0x7F + number_integer | 128..255 | uint 8 | 0xCC + number_integer | 256..65535 | uint 16 | 0xCD + number_integer | 65536..4294967295 | uint 32 | 0xCE + number_integer | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_unsigned | 0..127 | positive fixint | 0x00..0x7F + number_unsigned | 128..255 | uint 8 | 0xCC + number_unsigned | 256..65535 | uint 16 | 0xCD + number_unsigned | 65536..4294967295 | uint 32 | 0xCE + number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF + number_float | *any value* | float 64 | 0xCB + string | *length*: 0..31 | fixstr | 0xA0..0xBF + string | *length*: 32..255 | str 8 | 0xD9 + string | *length*: 256..65535 | str 16 | 0xDA + string | *length*: 65536..4294967295 | str 32 | 0xDB + array | *size*: 0..15 | fixarray | 0x90..0x9F + array | *size*: 16..65535 | array 16 | 0xDC + array | *size*: 65536..4294967295 | array 32 | 0xDD + object | *size*: 0..15 | fix map | 0x80..0x8F + object | *size*: 16..65535 | map 16 | 0xDE + object | *size*: 65536..4294967295 | map 32 | 0xDF - @note This version does not throw if a value is not present, but tries - to create nested values instead. For instance, calling this function - with pointer `"/this/that"` on a null value is equivalent to calling - `operator[]("this").operator[]("that")` on that value, effectively - changing the null value to an object. + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a MessagePack value. - @param[in] ptr a JSON value + @note The following values can **not** be converted to a MessagePack value: + - strings with more than 4294967295 bytes + - arrays with more than 4294967295 elements + - objects with more than 4294967295 elements - @return reference to the JSON value pointed to by the JSON pointer + @note The following MessagePack types are not used in the conversion: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - float 32 (0xCA) + - fixext 1 - fixext 16 (0xD4..0xD8) - @complexity Linear in the length of the JSON pointer. + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_unchecked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - // convert null values to arrays or objects before continuing - if (ptr->m_type == value_t::null) - { - // check if reference token is a number - const bool nums = std::all_of(reference_token.begin(), - reference_token.end(), - [](const char x) - { - return (x >= '0' and x <= '9'); - }); + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - // change value to array for numbers or "-" or to object - // otherwise - if (nums or reference_token == "-") - { - *ptr = value_t::array; - } - else - { - *ptr = value_t::object; - } - } + @param[in] j JSON value to serialize + @return MessagePack serialization as byte vector - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + @complexity Linear in the size of the JSON value @a j. - case value_t::array: - { - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in MessagePack format.,to_msgpack} - if (reference_token == "-") - { - // explicitly treat "-" as index beyond the end - ptr = &ptr->operator[](ptr->m_value.array->size()); - } - else - { - // convert array index to number; unchecked access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - } - break; - } + @sa http://msgpack.org + @sa @ref from_msgpack(const std::vector&, const size_t) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + related UBJSON format - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @since version 2.0.9 + */ + static std::vector to_msgpack(const basic_json& j) + { + std::vector result; + to_msgpack(j, result); + return result; + } - return *ptr; - } + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - reference get_checked(pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + static void to_msgpack(const basic_json& j, detail::output_adapter o) + { + binary_writer(o).write_msgpack(j); + } - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + /*! + @brief create a UBJSON serialization of a given JSON value - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + Serializes a given JSON value @a j to a byte vector using the UBJSON + (Universal Binary JSON) serialization format. UBJSON aims to be more compact + than JSON itself, yet more efficient to parse. - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + The library uses the following mapping from JSON values types to + UBJSON types according to the UBJSON specification: + + JSON value type | value/range | UBJSON type | marker + --------------- | --------------------------------- | ----------- | ------ + null | `null` | null | `Z` + boolean | `true` | true | `T` + boolean | `false` | false | `F` + number_integer | -9223372036854775808..-2147483649 | int64 | `L` + number_integer | -2147483648..-32769 | int32 | `l` + number_integer | -32768..-129 | int16 | `I` + number_integer | -128..127 | int8 | `i` + number_integer | 128..255 | uint8 | `U` + number_integer | 256..32767 | int16 | `I` + number_integer | 32768..2147483647 | int32 | `l` + number_integer | 2147483648..9223372036854775807 | int64 | `L` + number_unsigned | 0..127 | int8 | `i` + number_unsigned | 128..255 | uint8 | `U` + number_unsigned | 256..32767 | int16 | `I` + number_unsigned | 32768..2147483647 | int32 | `l` + number_unsigned | 2147483648..9223372036854775807 | int64 | `L` + number_float | *any value* | float64 | `D` + string | *with shortest length indicator* | string | `S` + array | *see notes on optimized format* | array | `[` + object | *see notes on optimized format* | map | `{` - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @note The mapping is **complete** in the sense that any JSON value type + can be converted to a UBJSON value. - return *ptr; - } + @note The following values can **not** be converted to a UBJSON value: + - strings with more than 9223372036854775807 bytes (theoretical) + - unsigned integer numbers above 9223372036854775807 - /*! - @brief return a const reference to the pointed to value + @note The following markers are not used in the conversion: + - `Z`: no-op values are not created. + - `C`: single-byte strings are serialized with `S` markers. - @param[in] ptr a JSON value + @note Any UBJSON output created @ref to_ubjson can be successfully parsed + by @ref from_ubjson. - @return const reference to the JSON value pointed to by the JSON - pointer + @note If NaN or Infinity are stored inside a JSON number, they are + serialized properly. This behavior differs from the @ref dump() + function which serializes NaN or Infinity to `null`. - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_unchecked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // use unchecked object access - ptr = &ptr->operator[](reference_token); - break; - } + @note The optimized formats for containers are supported: Parameter + @a use_size adds size information to the beginning of a container and + removes the closing marker. Parameter @a use_type further checks + whether all elements of a container have the same type and adds the + type marker to the beginning of the container. The @a use_type + parameter must only be used together with @a use_size = true. Note + that @a use_size = true alone may result in larger representations - + the benefit of this parameter is that the receiving side is + immediately informed on the number of elements of the container. - case value_t::array: - { - if (reference_token == "-") - { - // "-" cannot be used for const access - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + @param[in] j JSON value to serialize + @param[in] use_size whether to add size annotations to container types + @param[in] use_type whether to add type annotations to container types + (must be combined with @a use_size = true) + @return UBJSON serialization as byte vector - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + @complexity Linear in the size of the JSON value @a j. - // use unchecked array access - JSON_TRY - { - ptr = &ptr->operator[](static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + @liveexample{The example shows the serialization of a JSON value to a byte + vector in UBJSON format.,to_ubjson} - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + @sa http://ubjson.org + @sa @ref from_ubjson(detail::input_adapter, const bool strict) for the + analogous deserialization + @sa @ref to_cbor(const basic_json& for the related CBOR format + @sa @ref to_msgpack(const basic_json&) for the related MessagePack format - return *ptr; - } + @since version 3.1.0 + */ + static std::vector to_ubjson(const basic_json& j, + const bool use_size = false, + const bool use_type = false) + { + std::vector result; + to_ubjson(j, result, use_size, use_type); + return result; + } - /*! - @throw parse_error.106 if an array index begins with '0' - @throw parse_error.109 if an array index was not a number - @throw out_of_range.402 if the array index '-' is used - @throw out_of_range.404 if the JSON pointer can not be resolved - */ - const_reference get_checked(const_pointer ptr) const - { - for (const auto& reference_token : reference_tokens) - { - switch (ptr->m_type) - { - case value_t::object: - { - // note: at performs range check - ptr = &ptr->at(reference_token); - break; - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - case value_t::array: - { - if (reference_token == "-") - { - // "-" always fails the range check - JSON_THROW(out_of_range::create(402, "array index '-' (" + - std::to_string(ptr->m_value.array->size()) + - ") is out of range")); - } + static void to_ubjson(const basic_json& j, detail::output_adapter o, + const bool use_size = false, const bool use_type = false) + { + binary_writer(o).write_ubjson(j, use_size, use_type); + } - // error condition (cf. RFC 6901, Sect. 4) - if (reference_token.size() > 1 and reference_token[0] == '0') - { - JSON_THROW(parse_error::create(106, 0, "array index '" + reference_token + "' must not begin with '0'")); - } + /*! + @brief create a JSON value from an input in CBOR format - // note: at performs range check - JSON_TRY - { - ptr = &ptr->at(static_cast(std::stoi(reference_token))); - } - JSON_CATCH (std::invalid_argument&) - { - JSON_THROW(parse_error::create(109, 0, "array index '" + reference_token + "' is not a number")); - } - break; - } + Deserializes a given input @a i to a JSON value using the CBOR (Concise + Binary Object Representation) serialization format. - default: - { - JSON_THROW(out_of_range::create(404, "unresolved reference token '" + reference_token + "'")); - } - } - } + The library maps CBOR types to JSON value types as follows: - return *ptr; - } + CBOR type | JSON value type | first byte + ---------------------- | --------------- | ---------- + Integer | number_unsigned | 0x00..0x17 + Unsigned integer | number_unsigned | 0x18 + Unsigned integer | number_unsigned | 0x19 + Unsigned integer | number_unsigned | 0x1A + Unsigned integer | number_unsigned | 0x1B + Negative integer | number_integer | 0x20..0x37 + Negative integer | number_integer | 0x38 + Negative integer | number_integer | 0x39 + Negative integer | number_integer | 0x3A + Negative integer | number_integer | 0x3B + Negative integer | number_integer | 0x40..0x57 + UTF-8 string | string | 0x60..0x77 + UTF-8 string | string | 0x78 + UTF-8 string | string | 0x79 + UTF-8 string | string | 0x7A + UTF-8 string | string | 0x7B + UTF-8 string | string | 0x7F + array | array | 0x80..0x97 + array | array | 0x98 + array | array | 0x99 + array | array | 0x9A + array | array | 0x9B + array | array | 0x9F + map | object | 0xA0..0xB7 + map | object | 0xB8 + map | object | 0xB9 + map | object | 0xBA + map | object | 0xBB + map | object | 0xBF + False | `false` | 0xF4 + True | `true` | 0xF5 + Nill | `null` | 0xF6 + Half-Precision Float | number_float | 0xF9 + Single-Precision Float | number_float | 0xFA + Double-Precision Float | number_float | 0xFB - /*! - @brief split the string input to reference tokens + @warning The mapping is **incomplete** in the sense that not all CBOR + types can be converted to a JSON value. The following CBOR types + are not supported and will yield parse errors (parse_error.112): + - byte strings (0x40..0x5F) + - date/time (0xC0..0xC1) + - bignum (0xC2..0xC3) + - decimal fraction (0xC4) + - bigfloat (0xC5) + - tagged items (0xC6..0xD4, 0xD8..0xDB) + - expected conversions (0xD5..0xD7) + - simple values (0xE0..0xF3, 0xF8) + - undefined (0xF7) - @note This function is only called by the json_pointer constructor. - All exceptions below are documented there. + @warning CBOR allows map keys of any type, whereas JSON only allows + strings as keys in object values. Therefore, CBOR maps with keys + other than UTF-8 strings are rejected (parse_error.113). - @throw parse_error.107 if the pointer is not empty or begins with '/' - @throw parse_error.108 if character '~' is not followed by '0' or '1' - */ - static std::vector split(const std::string& reference_string) - { - std::vector result; + @note Any CBOR output created @ref to_cbor can be successfully parsed by + @ref from_cbor. - // special case: empty reference string -> no reference tokens - if (reference_string.empty()) - { - return result; - } + @param[in] i an input in CBOR format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - // check if nonempty reference string begins with slash - if (reference_string[0] != '/') - { - JSON_THROW(parse_error::create(107, 1, "JSON pointer must be empty or begin with '/' - was: '" + reference_string + "'")); - } + @return deserialized JSON value - // extract the reference tokens: - // - slash: position of the last read slash (or end of string) - // - start: position after the previous slash - for ( - // search for the first slash after the first character - size_t slash = reference_string.find_first_of('/', 1), - // set the beginning of the first reference token - start = 1; - // we can stop if start == string::npos+1 = 0 - start != 0; - // set the beginning of the next reference token - // (will eventually be 0 if slash == std::string::npos) - start = slash + 1, - // find next slash - slash = reference_string.find_first_of('/', start)) - { - // use the text between the beginning of the reference token - // (start) and the last slash (slash). - auto reference_token = reference_string.substr(start, slash - start); + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from CBOR were + used in the given input @a v or if the input is not valid CBOR + @throw parse_error.113 if a string was expected as map key, but not found - // check reference tokens are properly escaped - for (size_t pos = reference_token.find_first_of('~'); - pos != std::string::npos; - pos = reference_token.find_first_of('~', pos + 1)) - { - assert(reference_token[pos] == '~'); + @complexity Linear in the size of the input @a i. - // ~ must be followed by 0 or 1 - if (pos == reference_token.size() - 1 or - (reference_token[pos + 1] != '0' and - reference_token[pos + 1] != '1')) - { - JSON_THROW(parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'")); - } - } + @liveexample{The example shows the deserialization of a byte vector in CBOR + format to a JSON value.,from_cbor} - // finally, store the reference token - unescape(reference_token); - result.push_back(reference_token); - } + @sa http://cbor.io + @sa @ref to_cbor(const basic_json&) for the analogous serialization + @sa @ref from_msgpack(detail::input_adapter, const bool, const bool) for the + related MessagePack format + @sa @ref from_ubjson(detail::input_adapter, const bool, const bool) for the + related UBJSON format - return result; - } + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0; added @allow_exceptions parameter + since 3.2.0 + */ + static basic_json from_cbor(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::cbor, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - /*! - @brief replace all occurrences of a substring by another string + /*! + @copydoc from_cbor(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_cbor(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::cbor, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - @param[in,out] s the string to manipulate; changed so that all - occurrences of @a f are replaced with @a t - @param[in] f the substring to replace with @a t - @param[in] t the string to replace @a f + /*! + @brief create a JSON value from an input in MessagePack format - @pre The search string @a f must not be empty. **This precondition is - enforced with an assertion.** + Deserializes a given input @a i to a JSON value using the MessagePack + serialization format. - @since version 2.0.0 - */ - static void replace_substring(std::string& s, - const std::string& f, - const std::string& t) - { - assert(not f.empty()); + The library maps MessagePack types to JSON value types as follows: - for ( - size_t pos = s.find(f); // find first occurrence of f - pos != std::string::npos; // make sure f was found - s.replace(pos, f.size(), t), // replace with t - pos = s.find(f, pos + t.size()) // find next occurrence of f - ); - } + MessagePack type | JSON value type | first byte + ---------------- | --------------- | ---------- + positive fixint | number_unsigned | 0x00..0x7F + fixmap | object | 0x80..0x8F + fixarray | array | 0x90..0x9F + fixstr | string | 0xA0..0xBF + nil | `null` | 0xC0 + false | `false` | 0xC2 + true | `true` | 0xC3 + float 32 | number_float | 0xCA + float 64 | number_float | 0xCB + uint 8 | number_unsigned | 0xCC + uint 16 | number_unsigned | 0xCD + uint 32 | number_unsigned | 0xCE + uint 64 | number_unsigned | 0xCF + int 8 | number_integer | 0xD0 + int 16 | number_integer | 0xD1 + int 32 | number_integer | 0xD2 + int 64 | number_integer | 0xD3 + str 8 | string | 0xD9 + str 16 | string | 0xDA + str 32 | string | 0xDB + array 16 | array | 0xDC + array 32 | array | 0xDD + map 16 | object | 0xDE + map 32 | object | 0xDF + negative fixint | number_integer | 0xE0-0xFF - /// escape tilde and slash - static std::string escape(std::string s) - { - // escape "~"" to "~0" and "/" to "~1" - replace_substring(s, "~", "~0"); - replace_substring(s, "/", "~1"); - return s; - } + @warning The mapping is **incomplete** in the sense that not all + MessagePack types can be converted to a JSON value. The following + MessagePack types are not supported and will yield parse errors: + - bin 8 - bin 32 (0xC4..0xC6) + - ext 8 - ext 32 (0xC7..0xC9) + - fixext 1 - fixext 16 (0xD4..0xD8) - /// unescape tilde and slash - static void unescape(std::string& s) - { - // first transform any occurrence of the sequence '~1' to '/' - replace_substring(s, "~1", "/"); - // then transform any occurrence of the sequence '~0' to '~' - replace_substring(s, "~0", "~"); - } + @note Any MessagePack output created @ref to_msgpack can be successfully + parsed by @ref from_msgpack. - /*! - @param[in] reference_string the reference string to the current value - @param[in] value the value to consider - @param[in,out] result the result object to insert values to + @param[in] i an input in MessagePack format convertible to an input + adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - @note Empty objects or arrays are flattened to `null`. - */ - static void flatten(const std::string& reference_string, - const basic_json& value, - basic_json& result) - { - switch (value.m_type) - { - case value_t::array: - { - if (value.m_value.array->empty()) - { - // flatten empty array as null - result[reference_string] = nullptr; - } - else - { - // iterate array and use index as reference string - for (size_t i = 0; i < value.m_value.array->size(); ++i) - { - flatten(reference_string + "/" + std::to_string(i), - value.m_value.array->operator[](i), result); - } - } - break; - } + @return deserialized JSON value - case value_t::object: - { - if (value.m_value.object->empty()) - { - // flatten empty object as null - result[reference_string] = nullptr; - } - else - { - // iterate object and use keys as reference string - for (const auto& element : *value.m_value.object) - { - flatten(reference_string + "/" + escape(element.first), - element.second, result); - } - } - break; - } + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if unsupported features from MessagePack were + used in the given input @a i or if the input is not valid MessagePack + @throw parse_error.113 if a string was expected as map key, but not found - default: - { - // add primitive value with its reference string - result[reference_string] = value; - break; - } - } - } + @complexity Linear in the size of the input @a i. - /*! - @param[in] value flattened JSON + @liveexample{The example shows the deserialization of a byte vector in + MessagePack format to a JSON value.,from_msgpack} - @return unflattened JSON + @sa http://msgpack.org + @sa @ref to_msgpack(const basic_json&) for the analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool, const bool) for the + related CBOR format + @sa @ref from_ubjson(detail::input_adapter, const bool, const bool) for + the related UBJSON format - @throw parse_error.109 if array index is not a number - @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitive - @throw type_error.313 if value cannot be unflattened - */ - static basic_json unflatten(const basic_json& value) - { - if (not value.is_object()) - { - JSON_THROW(type_error::create(314, "only objects can be unflattened")); - } + @since version 2.0.9; parameter @a start_index since 2.1.1; changed to + consume input adapters, removed start_index parameter, and added + @a strict parameter since 3.0.0; added @allow_exceptions parameter + since 3.2.0 + */ + static basic_json from_msgpack(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::msgpack, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - basic_json result; + /*! + @copydoc from_msgpack(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_msgpack(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::msgpack, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } - // iterate the JSON object values - for (const auto& element : *value.m_value.object) - { - if (not element.second.is_primitive()) - { - JSON_THROW(type_error::create(315, "values in object must be primitive")); - } + /*! + @brief create a JSON value from an input in UBJSON format + + Deserializes a given input @a i to a JSON value using the UBJSON (Universal + Binary JSON) serialization format. + + The library maps UBJSON types to JSON value types as follows: + + UBJSON type | JSON value type | marker + ----------- | --------------------------------------- | ------ + no-op | *no value, next value is read* | `N` + null | `null` | `Z` + false | `false` | `F` + true | `true` | `T` + float32 | number_float | `d` + float64 | number_float | `D` + uint8 | number_unsigned | `U` + int8 | number_integer | `i` + int16 | number_integer | `I` + int32 | number_integer | `l` + int64 | number_integer | `L` + string | string | `S` + char | string | `C` + array | array (optimized values are supported) | `[` + object | object (optimized values are supported) | `{` + + @note The mapping is **complete** in the sense that any UBJSON value can + be converted to a JSON value. + + @param[in] i an input in UBJSON format convertible to an input adapter + @param[in] strict whether to expect the input to be consumed until EOF + (true by default) + @param[in] allow_exceptions whether to throw exceptions in case of a + parse error (optional, true by default) - // assign value to reference pointed to by JSON pointer; Note - // that if the JSON pointer is "" (i.e., points to the whole - // value), function get_and_create returns a reference to - // result itself. An assignment will then create a primitive - // value. - json_pointer(element.first).get_and_create(result) = element.second; - } + @return deserialized JSON value - return result; - } + @throw parse_error.110 if the given input ends prematurely or the end of + file was not reached when @a strict was set to true + @throw parse_error.112 if a parse error occurs + @throw parse_error.113 if a string could not be parsed successfully - friend bool operator==(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return lhs.reference_tokens == rhs.reference_tokens; - } + @complexity Linear in the size of the input @a i. - friend bool operator!=(json_pointer const& lhs, - json_pointer const& rhs) noexcept - { - return !(lhs == rhs); - } + @liveexample{The example shows the deserialization of a byte vector in + UBJSON format to a JSON value.,from_ubjson} - /// the reference tokens - std::vector reference_tokens {}; - }; + @sa http://ubjson.org + @sa @ref to_ubjson(const basic_json&, const bool, const bool) for the + analogous serialization + @sa @ref from_cbor(detail::input_adapter, const bool, const bool) for the + related CBOR format + @sa @ref from_msgpack(detail::input_adapter, const bool, const bool) for + the related MessagePack format + + @since version 3.1.0; added @allow_exceptions parameter since 3.2.0 + */ + static basic_json from_ubjson(detail::input_adapter&& i, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::ubjson, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } + + /*! + @copydoc from_ubjson(detail::input_adapter, const bool, const bool) + */ + template::value, int> = 0> + static basic_json from_ubjson(A1 && a1, A2 && a2, + const bool strict = true, + const bool allow_exceptions = true) + { + basic_json result; + detail::json_sax_dom_parser sdp(result, allow_exceptions); + const bool res = binary_reader(detail::input_adapter(std::forward(a1), std::forward(a2))).sax_parse(input_format_t::ubjson, &sdp, strict); + return res ? result : basic_json(value_t::discarded); + } + + /// @} ////////////////////////// // JSON Pointer support // @@ -13750,6 +17782,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13790,6 +17825,9 @@ scan_number_done: pointer @a ptr. As `at` provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. + @throw out_of_range.403 if the JSON pointer describes a key of an object + which cannot be found. See example below. + @throw out_of_range.404 if the JSON pointer @a ptr can not be resolved. See example below. @@ -13857,7 +17895,7 @@ scan_number_done: @complexity Linear in the size the JSON value. @throw type_error.314 if value is not an object - @throw type_error.315 if object values are not primitve + @throw type_error.315 if object values are not primitive @liveexample{The following code shows how a flattened JSON object is unflattened into the original nested JSON object.,unflatten} @@ -14005,8 +18043,8 @@ scan_number_done: } else { - const auto idx = std::stoi(last_path); - if (static_cast(idx) > parent.size()) + const auto idx = json_pointer::array_index(last_path); + if (JSON_UNLIKELY(static_cast(idx) > parent.size())) { // avoid undefined behavior JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range")); @@ -14041,7 +18079,7 @@ scan_number_done: { // perform range check auto it = parent.find(last_path); - if (it != parent.end()) + if (JSON_LIKELY(it != parent.end())) { parent.erase(it); } @@ -14053,12 +18091,12 @@ scan_number_done: else if (parent.is_array()) { // note erase performs range check - parent.erase(static_cast(std::stoi(last_path))); + parent.erase(static_cast(json_pointer::array_index(last_path))); } }; // type check: top level value must be an array - if (not json_patch.is_array()) + if (JSON_UNLIKELY(not json_patch.is_array())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14069,7 +18107,7 @@ scan_number_done: // wrapper to get a value for an operation const auto get_value = [&val](const std::string & op, const std::string & member, - bool string_type) -> basic_json& + bool string_type) -> basic_json & { // find value auto it = val.m_value.object->find(member); @@ -14078,13 +18116,13 @@ scan_number_done: const auto error_msg = (op == "op") ? "operation" : "operation '" + op + "'"; // check if desired value is present - if (it == val.m_value.object->end()) + if (JSON_UNLIKELY(it == val.m_value.object->end())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have member '" + member + "'")); } // check if result is of type string - if (string_type and not it->second.is_string()) + if (JSON_UNLIKELY(string_type and not it->second.is_string())) { JSON_THROW(parse_error::create(105, 0, error_msg + " must have string member '" + member + "'")); } @@ -14094,7 +18132,7 @@ scan_number_done: }; // type check: every element of the array must be an object - if (not val.is_object()) + if (JSON_UNLIKELY(not val.is_object())) { JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects")); } @@ -14144,11 +18182,16 @@ scan_number_done: case patch_operations::copy: { - const std::string from_path = get_value("copy", "from", true);; + const std::string from_path = get_value("copy", "from", true); const json_pointer from_ptr(from_path); // the "from" location must exist - use at() - result[ptr] = result.at(from_ptr); + basic_json v = result.at(from_ptr); + + // The copy is functionally identical to an "add" + // operation at the target location using the value + // specified in the "from" member. + operation_add(ptr, v); break; } @@ -14167,7 +18210,7 @@ scan_number_done: } // throw an exception if test fails - if (not success) + if (JSON_UNLIKELY(not success)) { JSON_THROW(other_error::create(501, "unsuccessful: " + val.dump())); } @@ -14214,13 +18257,13 @@ scan_number_done: diff for two JSON values.,diff} @sa @ref patch -- apply a JSON patch + @sa @ref merge_patch -- apply a JSON Merge Patch @sa [RFC 6902 (JSON Patch)](https://tools.ietf.org/html/rfc6902) @since version 2.0.0 */ - static basic_json diff(const basic_json& source, - const basic_json& target, + static basic_json diff(const basic_json& source, const basic_json& target, const std::string& path = "") { // the patch @@ -14237,9 +18280,7 @@ scan_number_done: // different types: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); } else @@ -14249,7 +18290,7 @@ scan_number_done: case value_t::array: { // first pass: traverse common elements - size_t i = 0; + std::size_t i = 0; while (i < source.size() and i < target.size()) { // recursive call to compare array values at index i @@ -14293,7 +18334,7 @@ scan_number_done: case value_t::object: { // first pass: traverse this object's elements - for (auto it = source.begin(); it != source.end(); ++it) + for (auto it = source.cbegin(); it != source.cend(); ++it) { // escape the key name to be used in a JSON patch const auto key = json_pointer::escape(it.key()); @@ -14309,14 +18350,13 @@ scan_number_done: // found a key that is not in o -> remove it result.push_back(object( { - {"op", "remove"}, - {"path", path + "/" + key} + {"op", "remove"}, {"path", path + "/" + key} })); } } // second pass: traverse other object's elements - for (auto it = target.begin(); it != target.end(); ++it) + for (auto it = target.cbegin(); it != target.cend(); ++it) { if (source.find(it.key()) == source.end()) { @@ -14324,8 +18364,7 @@ scan_number_done: const auto key = json_pointer::escape(it.key()); result.push_back( { - {"op", "add"}, - {"path", path + "/" + key}, + {"op", "add"}, {"path", path + "/" + key}, {"value", it.value()} }); } @@ -14339,9 +18378,7 @@ scan_number_done: // both primitive type: replace value result.push_back( { - {"op", "replace"}, - {"path", path}, - {"value", target} + {"op", "replace"}, {"path", path}, {"value", target} }); break; } @@ -14352,23 +18389,85 @@ scan_number_done: } /// @} -}; -///////////// -// presets // -///////////// + //////////////////////////////// + // JSON Merge Patch functions // + //////////////////////////////// -/*! -@brief default JSON class + /// @name JSON Merge Patch functions + /// @{ -This type is the default specialization of the @ref basic_json class which -uses the standard template types. + /*! + @brief applies a JSON Merge Patch + + The merge patch format is primarily intended for use with the HTTP PATCH + method as a means of describing a set of modifications to a target + resource's content. This function applies a merge patch to the current + JSON value. + + The function implements the following algorithm from Section 2 of + [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396): + + ``` + define MergePatch(Target, Patch): + if Patch is an Object: + if Target is not an Object: + Target = {} // Ignore the contents and set it to an empty Object + for each Name/Value pair in Patch: + if Value is null: + if Name exists in Target: + remove the Name/Value pair from Target + else: + Target[Name] = MergePatch(Target[Name], Value) + return Target + else: + return Patch + ``` + + Thereby, `Target` is the current object; that is, the patch is applied to + the current value. + + @param[in] patch the patch to apply + + @complexity Linear in the lengths of @a patch. + + @liveexample{The following code shows how a JSON Merge Patch is applied to + a JSON document.,merge_patch} -@since version 1.0.0 -*/ -using json = basic_json<>; -} // namespace nlohmann + @sa @ref patch -- apply a JSON patch + @sa [RFC 7396 (JSON Merge Patch)](https://tools.ietf.org/html/rfc7396) + + @since version 3.0.0 + */ + void merge_patch(const basic_json& patch) + { + if (patch.is_object()) + { + if (not is_object()) + { + *this = object(); + } + for (auto it = patch.begin(); it != patch.end(); ++it) + { + if (it.value().is_null()) + { + erase(it.key()); + } + else + { + operator[](it.key()).merge_patch(it.value()); + } + } + } + else + { + *this = patch; + } + } + /// @} +}; +} // namespace nlohmann /////////////////////// // nonmember support // @@ -14383,11 +18482,10 @@ namespace std @since version 1.0.0 */ template<> -inline void swap(nlohmann::json& j1, - nlohmann::json& j2) noexcept( - is_nothrow_move_constructible::value and - is_nothrow_move_assignable::value - ) +inline void swap(nlohmann::json& j1, nlohmann::json& j2) noexcept( + is_nothrow_move_constructible::value and + is_nothrow_move_assignable::value +) { j1.swap(j2); } @@ -14410,8 +18508,10 @@ struct hash }; /// specialization for std::less -template <> -struct less<::nlohmann::detail::value_t> +/// @note: do not remove the space after '<', +/// see https://github.com/nlohmann/json/pull/679 +template<> +struct less< ::nlohmann::detail::value_t> { /*! @brief compare two value_t enum values @@ -14462,6 +18562,9 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std return nlohmann::json::json_pointer(std::string(s, n)); } +// #include + + // restore GCC/clang diagnostic settings #if defined(__clang__) || defined(__GNUC__) || defined(__GNUG__) #pragma GCC diagnostic pop @@ -14477,5 +18580,11 @@ inline nlohmann::json::json_pointer operator "" _json_pointer(const char* s, std #undef JSON_LIKELY #undef JSON_UNLIKELY #undef JSON_DEPRECATED +#undef JSON_HAS_CPP_14 +#undef JSON_HAS_CPP_17 +#undef NLOHMANN_BASIC_JSON_TPL_DECLARATION +#undef NLOHMANN_BASIC_JSON_TPL +#undef NLOHMANN_JSON_HAS_HELPER + #endif diff --git a/src/CurrentBlockchainStatus.h b/src/CurrentBlockchainStatus.h index 8f64520..a46cd69 100755 --- a/src/CurrentBlockchainStatus.h +++ b/src/CurrentBlockchainStatus.h @@ -1,5 +1,4 @@ -#ifndef RESTBED_XMR_CURRENTBLOCKCHAINSTATUS_H -#define RESTBED_XMR_CURRENTBLOCKCHAINSTATUS_H +#pragma once #define MYSQLPP_SSQLS_NO_STATICS 1 @@ -293,4 +292,3 @@ protected: } -#endif //RESTBED_XMR_CURRENTBLOCKCHAINSTATUS_H diff --git a/src/TxSearch.cpp b/src/TxSearch.cpp index 89c19f3..3d611ec 100755 --- a/src/TxSearch.cpp +++ b/src/TxSearch.cpp @@ -589,8 +589,7 @@ TxSearch::get_known_outputs_keys() }; json -TxSearch::find_txs_in_mempool( - vector> mempool_txs) +TxSearch::find_txs_in_mempool(TxSearch::pool_txs_t mempool_txs) { json j_transactions = json::array(); @@ -605,9 +604,9 @@ TxSearch::find_txs_in_mempool( // time in a single connection. // so we create local connection here, only to be used in this method. - shared_ptr local_xmr_accounts = make_shared(current_bc_status); + auto local_xmr_accounts = make_shared(current_bc_status); - for (const pair& mtx: mempool_txs) + for (auto const& mtx: mempool_txs) { uint64_t recieve_time = mtx.first; @@ -683,7 +682,8 @@ TxSearch::find_txs_in_mempool( // tx public key and its index in that tx XmrOutput out; - if (local_xmr_accounts->output_exists(pod_to_hex(in_info.out_pub_key), out)) + if (local_xmr_accounts->output_exists( + pod_to_hex(in_info.out_pub_key), out)) { total_sent += out.amount; diff --git a/src/TxSearch.h b/src/TxSearch.h index 64e0cf1..f54d7f0 100755 --- a/src/TxSearch.h +++ b/src/TxSearch.h @@ -1,17 +1,10 @@ -// -// Created by mwo on 8/01/17. -// - -#ifndef RESTBED_XMR_TXSEARCH_H -#define RESTBED_XMR_TXSEARCH_H +#pragma once #include "MySqlAccounts.h" #include "OutputInputIdentification.h" -#include #include #include -#include #include #include #include @@ -37,6 +30,7 @@ public: // out_pk , amount using known_outputs_t = std::unordered_map; using addr_view_t = std::pair; + using pool_txs_t = std::vector>; private: @@ -139,7 +133,7 @@ public: * @return json */ virtual json - find_txs_in_mempool(vector> mempool_txs); + find_txs_in_mempool(pool_txs_t mempool_txs); virtual addr_view_t get_xmr_address_viewkey() const; @@ -157,4 +151,3 @@ public: } -#endif //RESTBED_XMR_TXSEARCH_H diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt index 524b115..54469fa 100644 --- a/tests/CMakeLists.txt +++ b/tests/CMakeLists.txt @@ -24,14 +24,14 @@ add_om_test(microcore) add_om_test(bcstatus) SETUP_TARGET_FOR_COVERAGE( - NAME mysql_cov # New target name + NAME mysql_cov EXECUTABLE mysql_tests) SETUP_TARGET_FOR_COVERAGE( - NAME microcore_cov # New target name + NAME microcore_cov EXECUTABLE microcore_tests) SETUP_TARGET_FOR_COVERAGE( - NAME bcstatus_cov # New target name + NAME bcstatus_cov EXECUTABLE bcstatus_tests) diff --git a/tests/bcstatus_tests.cpp b/tests/bcstatus_tests.cpp index a83b538..628df36 100644 --- a/tests/bcstatus_tests.cpp +++ b/tests/bcstatus_tests.cpp @@ -132,6 +132,9 @@ public: MOCK_CONST_METHOD0(get_xmr_address_viewkey, xmreg::TxSearch::addr_view_t()); + + MOCK_METHOD1(find_txs_in_mempool, + json(xmreg::TxSearch::pool_txs_t mempool_txs)); }; @@ -1038,7 +1041,44 @@ TEST_P(BCSTATUS_TEST, GetSearchedBlkOutputsAndAddrViewkey) EXPECT_FALSE(bcs->get_xmr_address_viewkey(acc.address, address_returned, viewkey_returned)); +} + +TEST_P(BCSTATUS_TEST, FindTxsInMempool) +{ + xmreg::XmrAccount acc; // empty, mock account + + acc.address = "whatever mock address"; + + auto tx_search = std::make_unique(); + + json txs_to_return = json::array(); + + txs_to_return.push_back(json {"tx_hash1", "some_tx_hash1"}); + txs_to_return.push_back(json {"tx_hash2", "some_tx_hash2"}); + txs_to_return.push_back(json {"tx_hash3", "some_tx_hash3"}); + + EXPECT_CALL(*tx_search, find_txs_in_mempool(_)) + .WillRepeatedly(Return(txs_to_return)); + + EXPECT_CALL(*tx_search, operator_fcall()) // mock operator() + .WillRepeatedly(MockSearchWhile2()); + ASSERT_TRUE(bcs->start_tx_search_thread(acc, std::move(tx_search))); + + json txs; + + EXPECT_TRUE(bcs->find_txs_in_mempool(acc.address, txs)); + + while(bcs->search_thread_exist(acc.address)) + { + cout << "\nsearch thread still exists\n"; + std::this_thread::sleep_for(1s); + bcs->clean_search_thread_map(); + } + + // once we removed the search thread as it finshed, + // we should be getting false now + EXPECT_FALSE(bcs->find_txs_in_mempool(acc.address, txs)); }