Template Struct json_sax

Struct Documentation

template<typename BasicJsonType>
struct json_sax

SAX interface.

This class describes the SAX interface used by nlohmann::json::sax_parse. Each function is called in different situations while the input is parsed. The boolean return value informs the parser whether to continue processing the input.

Public Types

using number_integer_t = typename BasicJsonType::number_integer_t

type for (signed) integers

using number_unsigned_t = typename BasicJsonType::number_unsigned_t

type for unsigned integers

using number_float_t = typename BasicJsonType::number_float_t

type for floating-point numbers

using string_t = typename BasicJsonType::string_t

type for strings

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 binary_t = typename BasicJsonType::binary_t

Public Functions

virtual bool null() = 0

a null value was read

Returns:

whether parsing should proceed

virtual bool boolean(bool val) = 0

a boolean value was read

Parameters:

val – [in] boolean value

Returns:

whether parsing should proceed

virtual bool number_integer(number_integer_t val) = 0

an integer number was read

Parameters:

val – [in] integer value

Returns:

whether parsing should proceed

virtual bool number_unsigned(number_unsigned_t val) = 0

an unsigned integer number was read

Parameters:

val – [in] unsigned integer value

Returns:

whether parsing should proceed

virtual bool number_float(number_float_t val, const string_t &s) = 0

an floating-point number was read

Parameters:

  • val – [in] floating-point value

  • s – [in] raw token value

Returns:

whether parsing should proceed

virtual bool string(string_t &val) = 0

a string was read

Note

It is safe to move the passed string.

Parameters:

val – [in] string value

Returns:

whether parsing should proceed

virtual bool start_object(std::size_t elements) = 0

the beginning of an object was read

Note

binary formats may report the number of elements

Parameters:

elements – [in] number of object elements or -1 if unknown

Returns:

whether parsing should proceed

virtual bool key(string_t &val) = 0

an object key was read

Note

It is safe to move the passed string.

Parameters:

val – [in] object key

Returns:

whether parsing should proceed

virtual bool end_object() = 0

the end of an object was read

Returns:

whether parsing should proceed

virtual bool start_array(std::size_t elements) = 0

the beginning of an array was read

Note

binary formats may report the number of elements

Parameters:

elements – [in] number of array elements or -1 if unknown

Returns:

whether parsing should proceed

virtual bool end_array() = 0

the end of an array was read

Returns:

whether parsing should proceed

virtual bool parse_error(std::size_t position, const std::string &last_token, const detail::exception &ex) = 0

a parse error occurred

Parameters:

  • position – [in] the position in the input where the error occurs

  • last_token – [in] the last read token

  • ex – [in] an exception object describing the error

Returns:

whether parsing should proceed (must return false)

virtual ~json_sax() = default
virtual bool null() = 0

a null value was read

Returns:

whether parsing should proceed

virtual bool boolean(bool val) = 0

a boolean value was read

Parameters:

val – [in] boolean value

Returns:

whether parsing should proceed

virtual bool number_integer(number_integer_t val) = 0

an integer number was read

Parameters:

val – [in] integer value

Returns:

whether parsing should proceed

virtual bool number_unsigned(number_unsigned_t val) = 0

an unsigned integer number was read

Parameters:

val – [in] unsigned integer value

Returns:

whether parsing should proceed

virtual bool number_float(number_float_t val, const string_t &s) = 0

an floating-point number was read

Parameters:

  • val – [in] floating-point value

  • s – [in] raw token value

Returns:

whether parsing should proceed

virtual bool string(string_t &val) = 0

a string was read

Note

It is safe to move the passed string.

Parameters:

val – [in] string value

Returns:

whether parsing should proceed

virtual bool binary(binary_t &val) = 0

a binary string was read

Note

It is safe to move the passed binary.

Parameters:

val – [in] binary value

Returns:

whether parsing should proceed

virtual bool start_object(std::size_t elements) = 0

the beginning of an object was read

Note

binary formats may report the number of elements

Parameters:

elements – [in] number of object elements or -1 if unknown

Returns:

whether parsing should proceed

virtual bool key(string_t &val) = 0

an object key was read

Note

It is safe to move the passed string.

Parameters:

val – [in] object key

Returns:

whether parsing should proceed

virtual bool end_object() = 0

the end of an object was read

Returns:

whether parsing should proceed

virtual bool start_array(std::size_t elements) = 0

the beginning of an array was read

Note

binary formats may report the number of elements

Parameters:

elements – [in] number of array elements or -1 if unknown

Returns:

whether parsing should proceed

virtual bool end_array() = 0

the end of an array was read

Returns:

whether parsing should proceed

virtual bool parse_error(std::size_t position, const std::string &last_token, const detail::exception &ex) = 0

a parse error occurred

Parameters:

  • position – [in] the position in the input where the error occurs

  • last_token – [in] the last read token

  • ex – [in] an exception object describing the error

Returns:

whether parsing should proceed (must return false)

virtual ~json_sax() = default