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>
class nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer
lexical analysis
This class organizes the lexical analysis during JSON deserialization. The core of it is a scanner generated by re2c that processes a buffer and recognizes tokens according to RFC 7159.
Definition at line 8957 of file json.hpp.
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>
the char type to use in the lexer
Definition at line 8980 of file json.hpp.
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>
token types for the parser
| Enumerator |
|---|
| uninitialized |
indicating the scanner is uninitialized
|
| literal_true |
the true literal
|
| literal_false |
the false literal
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| literal_null |
the null literal
|
| value_string |
a string – use get_string() for actual value
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| value_number |
a number – use get_number() for actual value
|
| begin_array |
the character for array begin [
|
| begin_object |
the character for object begin {
|
| end_array |
the character for array end ]
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| end_object |
the character for object end }
|
| name_separator |
the name separator :
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| value_separator |
the value separator ,
|
| parse_error |
indicating a parse error
|
| end_of_input |
indicating the end of the input buffer
|
Definition at line 8961 of file json.hpp.
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>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::lexer |
( |
const lexer_char_t * |
buff, |
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const size_t |
len |
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) |
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inlinenoexcept |
a lexer from a buffer with given length
Definition at line 8983 of file json.hpp.
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>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::lexer |
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std::istream & |
s | ) |
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inlineexplicit |
a lexer from an input stream
Definition at line 8992 of file json.hpp.
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>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::lexer |
( |
| ) |
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delete |
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>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::lexer |
( |
const lexer & |
| ) |
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delete |
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>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::fill_line_buffer |
( |
size_t |
n = 0 | ) |
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inline |
append data from the stream to the line buffer
This function is called by the scan() function when the end of the buffer (m_limit) is reached and the m_cursor pointer cannot be incremented without leaving the limits of the line buffer. Note re2c decides when to call this function.
If the lexer reads from contiguous storage, there is no trailing null byte. Therefore, this function must make sure to add these padding null bytes.
If the lexer reads from an input stream, this function reads the next line of the input.
- Precondition
- p p p p p p u u u u u x . . . . . . ^ ^ ^ ^ m_content m_start | m_limit m_cursor
- Postcondition
- u u u u u x x x x x x x . . . . . . ^ ^ ^ | m_cursor m_limit m_start m_content
Definition at line 10121 of file json.hpp.
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>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::get_number |
( |
basic_json & |
result | ) |
const |
|
inline |
return number value for number tokens
This function translates the last token into the most appropriate number type (either integer, unsigned integer or floating point), which is passed back to the caller via the result parameter.
This function parses the integer component up to the radix point or exponent while collecting information about the 'floating point representation', which it stores in the result parameter. If there is no radix point or exponent, and the number can fit into a number_integer_t or number_unsigned_t then it sets the result parameter accordingly.
If the number is a floating point number the number is then parsed using std:strtod (or std:strtof or std::strtold).
- Parameters
-
| [out] | result | basic_json object to receive the number, or NAN if the conversion read past the current token. The latter case needs to be treated by the caller function. |
Definition at line 10445 of file json.hpp.
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>
| string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::get_string |
( |
| ) |
const |
|
inline |
return string value for string tokens
The function iterates the characters between the opening and closing quotes of the string value. The complete string is the range [m_start,m_cursor). Consequently, we iterate from m_start+1 to m_cursor-1.
We differentiate two cases:
- Escaped characters. In this case, a new character is constructed according to the nature of the escape. Some escapes create new characters (e.g.,
"\\\\n" is replaced by "\\n"), some are copied as is (e.g., "\\\\\\\\"). Furthermore, Unicode escapes of the shape "\\\\uxxxx" need special care. In this case, to_unicode takes care of the construction of the values.
- Unescaped characters are copied as is.
- Precondition
m_cursor - m_start >= 2, meaning the length of the last token is at least 2 bytes which is trivially true for any string (which consists of at least two quotes). " c1 c2 c3 ... "
^ ^
m_start m_cursor
Linear in the length of the string.
Lemma: The loop body will always terminate.
Proof (by contradiction): Assume the loop body does not terminate. As the loop body does not contain another loop, one of the called functions must never return. The called functions are std::strtoul and to_unicode. Neither function can loop forever, so the loop body will never loop forever which contradicts the assumption that the loop body does not terminate, q.e.d.
Lemma: The loop condition for the for loop is eventually false.
Proof (by contradiction): Assume the loop does not terminate. Due to the above lemma, this can only be due to a tautological loop condition; that is, the loop condition i < m_cursor - 1 must always be true. Let x be the change of i for any loop iteration. Then m_start + 1 + x < m_cursor - 1 must hold to loop indefinitely. This can be rephrased to m_cursor - m_start - 2 > x. With the precondition, we x <= 0, meaning that the loop condition holds indefinitly if i is always decreased. However, observe that the value of i is strictly increasing with each iteration, as it is incremented by 1 in the iteration expression and never decremented inside the loop body. Hence, the loop condition will eventually be false which contradicts the assumption that the loop condition is a tautology, q.e.d.
- Returns
- string value of current token without opening and closing quotes
- Exceptions
-
| std::out_of_range | if to_unicode fails |
Definition at line 10247 of file json.hpp.
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>
| string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::get_token_string |
( |
| ) |
const |
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inline |
return string representation of last read token
Definition at line 10183 of file json.hpp.
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>
| lexer nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::operator= |
( |
const lexer & |
| ) |
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delete |
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>
| token_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::scan |
( |
| ) |
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inline |
This function implements a scanner for JSON. It is specified using regular expressions that try to follow RFC 7159 as close as possible. These regular expressions are then translated into a minimized deterministic finite automaton (DFA) by the tool re2c. As a result, the translated code for this function consists of a large block of code with goto jumps.
- Returns
- the class of the next token read from the buffer
Linear in the length of the input.
Proposition: The loop below will always terminate for finite input.
Proof (by contradiction): Assume a finite input. To loop forever, the loop must never hit code with a break statement. The only code snippets without a break statement are the continue statements for whitespace and byte-order-marks. To loop forever, the input must be an infinite sequence of whitespace or byte-order-marks. This contradicts the assumption of finite input, q.e.d.
Definition at line 9167 of file json.hpp.
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>
| long double nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::str_to_float_t |
( |
long double * |
, |
|
|
char ** |
endptr |
|
) |
| const |
|
inline |
parse floating point number
This function (and its overloads) serves to select the most approprate standard floating point number parsing function based on the type supplied via the first parameter. Set this to static_cast<number_float_t*>(nullptr).
- Parameters
-
| [in,out] | endptr | recieves a pointer to the first character after the number |
- Returns
- the floating point number
Definition at line 10375 of file json.hpp.
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>
| double nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::str_to_float_t |
( |
double * |
, |
|
|
char ** |
endptr |
|
) |
| const |
|
inline |
parse floating point number
This function (and its overloads) serves to select the most approprate standard floating point number parsing function based on the type supplied via the first parameter. Set this to static_cast<number_float_t*>(nullptr).
- Parameters
-
| [in,out] | endptr | recieves a pointer to the first character after the number |
- Returns
- the floating point number
Definition at line 10397 of file json.hpp.
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>
| float nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::str_to_float_t |
( |
float * |
, |
|
|
char ** |
endptr |
|
) |
| const |
|
inline |
parse floating point number
This function (and its overloads) serves to select the most approprate standard floating point number parsing function based on the type supplied via the first parameter. Set this to static_cast<number_float_t*>(nullptr).
- Parameters
-
| [in,out] | endptr | recieves a pointer to the first character after the number |
- Returns
- the floating point number
Definition at line 10415 of file json.hpp.
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>
| static string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::to_unicode |
( |
const std::size_t |
codepoint1, |
|
|
const std::size_t |
codepoint2 = 0 |
|
) |
| |
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inlinestatic |
create a string from one or two Unicode code points
There are two cases: (1) codepoint1 is in the Basic Multilingual Plane (U+0000 through U+FFFF) and codepoint2 is 0, or (2) codepoint1 and codepoint2 are a UTF-16 surrogate pair to represent a code point above U+FFFF.
- Parameters
-
| [in] | codepoint1 | the code point (can be high surrogate) |
| [in] | codepoint2 | the code point (can be low surrogate or 0) |
- Returns
- string representation of the code point; the length of the result string is between 1 and 4 characters.
- Exceptions
-
| std::out_of_range | if code point is > 0x10ffff; example: "code
points above 0x10FFFF are invalid" |
| std::invalid_argument | if the low surrogate is invalid; example: ""missing or wrong low surrogate"" |
Constant.
- See also
- http://en.wikipedia.org/wiki/UTF-8#Sample_code
Definition at line 9041 of file json.hpp.
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>
| static std::string nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::token_type_name |
( |
const token_type |
t | ) |
|
|
inlinestatic |
return name of values of type token_type (only used for errors)
Definition at line 9106 of file json.hpp.
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<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>
| const lexer_char_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_content = nullptr |
|
private |
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>
| const lexer_char_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_cursor = nullptr |
|
private |
pointer to the current symbol
Definition at line 10566 of file json.hpp.
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>
| const lexer_char_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_limit = nullptr |
|
private |
pointer to the end of the buffer
Definition at line 10568 of file json.hpp.
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>
| string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_line_buffer {} |
|
private |
line buffer buffer for m_stream
Definition at line 10556 of file json.hpp.
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>
| string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_line_buffer_tmp {} |
|
private |
used for filling m_line_buffer
Definition at line 10558 of file json.hpp.
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>
| const lexer_char_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_marker = nullptr |
|
private |
pointer for backtracking information
Definition at line 10564 of file json.hpp.
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>
| const lexer_char_t* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_start = nullptr |
|
private |
pointer to the beginning of the current symbol
Definition at line 10562 of file json.hpp.
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>
| std::istream* nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType >::lexer::m_stream = nullptr |
|
private |