JSON_checker.h File Reference

Main header of the C interface of autojson. More...

#include <stddef.h>

Go to the source code of this file.

Classes
struct	JSON_checker_struct

Typedefs
typedef enum JSON_event	JSON_event
typedef enum JSON_result	JSON_result
typedef void(*	JSON_callback )(void *user, JSON_event type, const char *data, size_t len)
typedef struct JSON_checker_struct *	JSON_checker

Enumerations
enum	JSON_event {   JSON_array_start, JSON_array_end, JSON_object_start, JSON_object_key,   JSON_object_end, JSON_string, JSON_number, JSON_null,   JSON_true, JSON_false }
enum	JSON_result { JSON_error, JSON_ok }

Functions
JSON_checker	new_JSON_checker (int depth)
int	JSON_checker_char (JSON_checker jc, const char *chars, size_t len, JSON_callback cb, void *user)
int	JSON_checker_done (JSON_checker jc)

Detailed Description

Main header of the C interface of autojson.

This file is adapted from http://www.json.org/JSON_checker/ with modification.

Typedef Documentation

typedef void(* JSON_callback)(void *user, JSON_event type, const char *data, size_t len)

A callback function to be invoked when the parser encounter a event. See JSON_event for a detailed list of events available. You need to provide this function when you call JSON_checker_char().

Parameters

user	A user-provided pointer by JSON_checker_char(). The parser will not interpret its value. It will be pass as-is.
type	Type of event encountered.
data	Pointer to parsed data. It's only meaningful for certain events, such as JSON_string. Note that this buffer is not null-terminated. You need to refer to len to know how many bytes are there.
len	The number of bytes in the buffer pointed by data. Note that the unit is bytes, not characters, as unicode characters many need more than 1 byte to represent in UTF-8/UTF-16.

typedef enum JSON_event JSON_event

The type of JSON parse events. It is used to indicate what the parser has encountered. It is a parameter to the JSON_callback() function.

typedef enum JSON_result JSON_result

Enum to indicate success/failure of the function

Enumeration Type Documentation

enum JSON_event

The type of JSON parse events. It is used to indicate what the parser has encountered. It is a parameter to the JSON_callback() function.

Enumerator
JSON_array_start	Start of a JSON array.
JSON_array_end	End of a JSON array.
JSON_object_start	Start of a JSON object.
JSON_object_key	A key inside a JSON object. The value of the key is given by data with len bytes.
JSON_object_end	End of a JSON object.
JSON_string	String as a value. The value is given by data and len.
JSON_number	Number as a value. It's provided as a string. You need to call atoi() to obtain the real number.
JSON_null	Literal value "null".
JSON_true	Literal value "true".
JSON_false	Literal value "false".

enum JSON_result

Enum to indicate success/failure of the function

Function Documentation

int JSON_checker_char	(	JSON_checker	jc,
		const char *	chars,
		size_t	len,
		JSON_callback	cb,
		void *	user
	)

Parse JSON data. Call this function to parse some JSON data. The data does not need to be a complete JSON file. It can be a fragment of the file. The parser will parse it progressively and invoke the callback function it is can successfully parse something.

Parameters

jc	A parser created by new_JSON_checker()
chars	A block of JSON data to be parsed. It does not need to be a complete JSON document. JSON_checker_char() can parse incrementally.
len	Number of bytes in the buffer pointed by chars.
cb	A pointer to a callback function to be called when the parser encounter an event. See JSON_event for more details about the events.
user	A pointer to user data. The parser will not try to interpret this pointer. It will be passed as-is to the callback function cb.

JSON_checker new_JSON_checker

(

int

depth

)

Create a new parser. new_JSON_checker() starts the checking process by constructing a JSON_checker object. It takes the depth parameter that restricts the level of maximum nesting.

To continue the process, call JSON_checker_char() for each block of characters in the JSON text, and then call JSON_checker_done() to obtain the final result. These functions are fully reentrant.

The JSON_checker object will be deleted by JSON_checker_done(). JSON_checker_char() will auto delete the JSON_checker object if it sees an error.