jx_eval.h File Reference

Implements evaluation of JX expressions. More...

#include "jx.h"

Go to the source code of this file.

Functions
struct jx *	jx_eval (struct jx *j, struct jx *context)
	Evaluate an expression. More...
struct jx *	jx_eval_with_defines (struct jx *j, struct jx *context)
	Evaluate an expression with embedded definitions. More...
void	jx_eval_enable_external (int enable)
	Enable external functions. More...

Detailed Description

Implements evaluation of JX expressions.

Function Documentation

struct jx* jx_eval	(	struct jx *	j,
		struct jx *	context
	)

Evaluate an expression.

Traverses the expression, evaluates all operators and evalutes unbound symbols by looking for matches in the context object.

Parameters

j	The expression to evaluate.
context	An object in which values will be found.

Returns

A newly created result expression, which must be deleted with jx_delete. If the expression is invalid in some way, an object of type JX_NULL is returned.

struct jx* jx_eval_with_defines	(	struct jx *	j,
		struct jx *	context
	)

Evaluate an expression with embedded definitions.

Same as jx_eval, except first looks for a "defines" clause and combines that with the context. Allows an expression to have its own bound values, for convenience.

Parameters

j	The expression to evaluate, which may contain a "defines" clause.
context	An object in which values will be found.

Returns

A newly created result expression, which must be deleted with jx_delete. If the expression is invalid in some way, an object of type JX_NULL is returned.

void jx_eval_enable_external

(

int

enable

)

Enable external functions.

A small number of JX functions make use of "external" context, For safety, these functions are not enabled unless the user first calls jx_eval_enable_external(1).

Parameters

enable

If non-zero, enable external functions, otherwise disable.