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/* evaluate.h (C) 2000-2002 Kyzer/CSG. */
/* Released under the terms of the GNU General Public Licence version 2. */
/* http://www.kyzer.me.uk/code/evaluate/ */
#include <stddef.h>
#include <stdlib.h>
#define T_INT 0
#define T_REAL 1
/* value */
struct val {
long ival; /* if type = T_INT, this is the result */
double rval; /* if type = T_REAL, this is the result */
char type; /* either T_INT or T_REAL */
};
/* variable */
struct var {
struct var *next; /* next variable in table or NULL */
struct val val; /* value of variable */
char *name; /* name of variable */
};
/* variable table */
struct vartable {
struct var *first; /* first entry in variable table */
struct memh *mh;
};
/* creates a new variable table (NULL if no memory) */
struct vartable *create_vartable(void);
/* frees a variable table */
void free_vartable(struct vartable *vt);
/* gets a variable from a variable table (NULL if not found) */
struct var *get_var(struct vartable *vt, char *name);
/* puts a variable into a variable table (NULL if no memory) */
struct var *put_var(struct vartable *vt, char *name, struct val *value);
/* callbacks */
typedef struct val*(*get_var_cb_t)(char*, struct val*);
typedef struct val*(*get_func_result_cb_t)(char*, struct val*, struct val*);
void eval_set_cb_get_var(get_var_cb_t cb);
void eval_set_cb_get_func_result(get_func_result_cb_t cb);
/* THE FUNCTION YOU WANT TO CALL */
/* given a string to evaluate (not NULL), a result to put the answer in
* (not NULL) and optionally your own variable table (NULL for 'internal
* only' vartable), will return an error code (and result, etc)
*/
int evaluate(char *eval, struct val *result, struct vartable *variables);
/* errors */
#define RESULT_OK 0 /* all OK */
#define ERROR_SYNTAX 2 /* invalid expression */
#define ERROR_VARNOTFOUND 3 /* variable not found */
#define ERROR_FUNCNOTFOUND 4 /* function not found */
#define ERROR_NOMEM 8 /* not enough memory available */
#define ERROR_DIV0 9 /* division by zero */
#define ERROR_BUSY 10 /* busy now */
/* configuration */
#define TOKEN_DEBUG 0
#define EVAL_DEBUG 0
#define EVAL_MALLOC 0
#define USE_MATH_LIB 0
#define MEM_DEBUG 0
#define MEM_LOW_FOOTPRINT 1
#define VAR_FROM_ENV 0
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