jx_parse.h File Reference

Parse JSON strings and files into JX expressions. More...

#include "jx.h"
#include "link.h"
#include <stdbool.h>
#include <stdio.h>

Go to the source code of this file.

Functions
struct jx *	jx_parse_string (const char *str)
	Parse a JSON string to a JX expression. More...
struct jx *	jx_parse_stream (FILE *file)
	Parse a standard IO stream to a JX expression. More...
struct jx *	jx_parse_file (const char *name)
	Parse a file to a JX expression. More...
struct jx *	jx_parse_link (struct link *l, time_t stoptime)
	Parse a network link to a JX expression. More...
struct jx *	jx_parse_cmd_args (struct jx *jx_args, char *args_file)
	Parse a jx argument file from a commandline option. More...
int	jx_parse_cmd_define (struct jx *jx_args, char *define_stmt)
	Parse a jx define statement from a commandline option. More...
struct jx_parser *	jx_parser_create (bool strict_mode)
	Create a JX parser object. More...
void	jx_parser_read_stream (struct jx_parser *p, FILE *file)
	Attach parser to a file. More...
void	jx_parser_read_string (struct jx_parser *p, const char *str)
	Attach parser to a string. More...
void	jx_parser_read_link (struct jx_parser *p, struct link *l, time_t stoptime)
	Attach parser to a link. More...
struct jx *	jx_parser_yield (struct jx_parser *p)
	Parse and return a single value. More...
struct jx *	jx_parse (struct jx_parser *p)
	Parse a JX expression. More...
int	jx_parser_errors (struct jx_parser *p)
	Return number of parse errors. More...
const char *	jx_parser_error_string (struct jx_parser *p)
	Return text of first parse error encountered. More...
void	jx_parser_delete (struct jx_parser *p)
	Delete a parser. More...

Detailed Description

Parse JSON strings and files into JX expressions.

This module parses arbirary JSON expressions according to the definition at json.org, with the following exceptions:

1. Atomic values are limited to 4KB in size.
2. Bare identifiers are permitted, to enable expression evaluation.

Function Documentation

struct jx* jx_parse_string

(

const char *

str

)

Parse a JSON string to a JX expression.

Parameters

str	A C string containing JSON data.

Returns

A JX expression which must be deleted with jx_delete. If the parse fails or no JSON value is present, null is returned.

struct jx* jx_parse_stream

(

FILE *

file

)

Parse a standard IO stream to a JX expression.

Parameters

file	A stream containing JSON data.

Returns

A JX expression which must be deleted with jx_delete. If the parse fails or no JSON value is present, null is returned.

struct jx* jx_parse_file

(

const char *

name

)

Parse a file to a JX expression.

Parameters

name	The name of a file containing JSON data.

Returns

A JX expression which must be deleted with jx_delete. If the parse fails or no JSON value is present, null is returned.

struct jx* jx_parse_link	(	struct link *	l,
		time_t	stoptime
	)

Parse a network link to a JX expression.

Parameters

l	A link pointer (opaque struct).
stoptime	The absolute time at which to stop.

Returns

A JX expression which must be deleted with jx_delete. If the parse fails or no JSON value is present, null is returned.

struct jx* jx_parse_cmd_args	(	struct jx *	jx_args,
		char *	args_file
	)

Parse a jx argument file from a commandline option.

The passed-in object is consumed.

Parameters

jx_args	A JX object to add args to.
args_file	Name of the jx_args file that will be read in.

Returns

An augmented JX object.

NULL on failure.

int jx_parse_cmd_define	(	struct jx *	jx_args,
		char *	define_stmt
	)

Parse a jx define statement from a commandline option.

Parameters

jx_args	A JX object to add args to.
define_stmt	Command line value of from VAR=EXPR.

Returns

1 on success.

0 on failure.

struct jx_parser* jx_parser_create

(

bool

strict_mode

)

Create a JX parser object.

Returns

A parser object.

void jx_parser_read_stream	(	struct jx_parser *	p,
		FILE *	file
	)

Attach parser to a file.

Parameters

p	A parser object.
file	A standard IO stream.

void jx_parser_read_string	(	struct jx_parser *	p,
		const char *	str
	)

Attach parser to a string.

Parameters

p	A parser object.
str	A JSON string to parse.

void jx_parser_read_link	(	struct jx_parser *	p,
		struct link *	l,
		time_t	stoptime
	)

Attach parser to a link.

Parameters

p	A parser object.
l	A link object.
stoptime	The absolute time at which to stop.

struct jx* jx_parser_yield

(

struct jx_parser *

p

)

Parse and return a single value.

This function is useful for streaming multiple independent values from a single source.

Parameters

p	A parser object

Returns

A JX expression which must be deleted with jx_delete. If the parse fails or no JSON value is present, null is returned.

struct jx* jx_parse

(

struct jx_parser *

p

)

Parse a JX expression.

Note that in the event of a parse error, this function can return a partial result, reflecting the text that was parseable. You must call jx_parser_errors to determine if the parse was successul.

Parameters

p	A parser created by jx_parser_create.

Returns

A JX expression, or null if nothing was parsed.

int jx_parser_errors

(

struct jx_parser *

p

)

Return number of parse errors.

Parameters

p	A parser object.

Returns

Number of parse errors encountered.

const char* jx_parser_error_string

(

struct jx_parser *

p

)

Return text of first parse error encountered.

Parameters

p	A parser object.

Returns

Error string, if available, null otherwise.

void jx_parser_delete

(

struct jx_parser *

p

)

Delete a parser.

Parameters

p	The parser to delete.