Writes JSON to a stream, indented by two spaces. More...

#include <raptor/inspect/json_writer.hpp>

Collaboration diagram for raptor::json_writer:

Classes
struct	container
	The state of an open container. More...

Public Member Functions
json_writer &	begin_array (bool const inline_elements=false)

json_writer &	begin_object (bool const inline_elements=false)

json_writer &	boolean (bool const value)

json_writer &	end_array ()

json_writer &	end_object ()

	json_writer (json_writer &&)=default

	json_writer (json_writer const &)=delete

	json_writer (std::ostream &stream)

json_writer &	key (std::string_view const name)
	Names the next value. Only valid inside an object.

json_writer &	null ()

template<std::unsigned_integral number_t>
json_writer &	number (number_t const value)

template<std::floating_point number_t>
json_writer &	number (number_t const value)
	Writes `null` if `value` is not finite.

json_writer &	operator= (json_writer &&)=delete

json_writer &	operator= (json_writer const &)=delete

json_writer &	string (std::string_view const value)

Private Member Functions
void	close (bool const is_object)

void	indent (size_t const level)

void	open (bool const is_object, bool const inline_elements)

void	prepare_value ()
	Writes what has to precede a value: a separator and indentation, or nothing after a key.

json_writer &	write_double (double const value)

void	write_separator (container &parent)
	Writes the comma and line break or space that precede an element of `parent`.

json_writer &	write_unsigned (uint64_t const value)

Private Attributes
bool	has_key {false}
	Whether raptor::json_writer::key has been called for the next value.

std::vector< container >	open_containers {}

std::ostream &	stream

Detailed Description

Writes JSON to a stream, indented by two spaces.

The caller states the structure; the writer keeps track of nesting, separators and indentation. Inside an object, every value must be preceded by raptor::json_writer::key; inside an array, it must not.

A container opened with inline_elements is written on a single line, as are all containers nested inside it. This keeps long lists of short entries, e.g. one per user bin, at one line per entry.

Strings are written as given: bytes that are not valid UTF-8, e.g. in file names, are passed through.

Raptor only writes JSON, a single small object for raptor inspect, which does not justify a library:

simdjson is a compiled dependency, and its string_builder leaves the separators to the caller as well.
The rapidjson bundled with cereal writes NaN and Infinity, which are not valid JSON, because cereal sets CEREAL_RAPIDJSON_WRITE_DEFAULT_FLAGS to kWriteNanAndInfFlag. Its PrettyWriter can only write arrays on a single line, not objects.

Attention: The output is only complete after every container has been closed. Correct nesting is checked by assertions only.

The documentation for this class was generated from the following files:

Classes

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description