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◆ parse() [1/6]
template< template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > 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< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE= void > class JSONSerializer = adl_serializer>
- Template Parameters
-
CharT | character/literal type with size of 1 byte |
- Parameters
-
[in] | s | string literal to read a serialized JSON value from |
[in] | cb | a parser callback function of type parser_callback_t which is used to control the deserialization by filtering unwanted values (optional) |
- Returns
- result of the deserialization
- Complexity\n 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 cb has a super-linear complexity.
- Note
- A UTF-8 byte order mark is silently ignored.
-
String containers like
std::string or string_t can be parsed with parse(const ContiguousContainer&, const parser_callback_t)
- Example\n The example below demonstrates the
parse() function with - and without callback function.
13 "Title": "View from 15th Floor",
15 "Url": "http://www.example.com/image/481989943",
20 "IDs": [116, 943, 234, 38793]
27 std::cout << std::setw(4) << j_complete << "\n\n";
46 std::cout << std::setw(4) << j_filtered << '\n';
static basic_json array(std::initializer_list< basic_json > init=std::initializer_list< basic_json >()) explicitly create an array from an initializer list
static basic_json parse(T(&array)[N], const parser_callback_t cb=nullptr) deserialize from an array
parse_event_t JSON callback events.
@ key the parser read a key of a value in an object
std::function< bool(int depth, parse_event_t event, basic_json &parsed)> parser_callback_t per-element parser callback type
a class to store JSON values
basic_json<> json default JSON class
Output (play with this example online):
{
"Image": {
"Animated": false,
"Height": 600,
"IDs": [
116,
943,
234,
38793
],
"Thumbnail": {
"Height": 125,
"Url": "http://www.example.com/image/481989943",
"Width": 100
},
"Title": "View from 15th Floor",
"Width": 800
}
}
{
"Image": {
"Animated": false,
"Height": 600,
"IDs": [
116,
943,
234,
38793
],
"Title": "View from 15th Floor",
"Width": 800
}
}
The example code above can be translated with g++ -std=c++11 -Isrc doc/examples/parse__string__parser_callback_t.cpp -o parse__string__parser_callback_t
- See also
- parse(std::istream&, const parser_callback_t) for a version that reads from an input stream
- Since
- version 1.0.0 (originally for string_t)
Definition at line 6322 of file json.hpp.
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