tinyexpr.h

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// SPDX-License-Identifier: Zlib
/*
 * TINYEXPR - Tiny recursive descent parser and evaluation engine in C
 *
 * Copyright (c) 2015-2020 Lewis Van Winkle
 *
 * http://CodePlea.com
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgement in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
 
#ifndef TINYEXPR_H
#define TINYEXPR_H
 
#ifdef __cplusplus
extern "C" {
#endif
 
typedef struct te_expr {
   int type;
   union {
      double value;
      const double *bound;
      const void *function;
   };
   void *parameters[1];
} te_expr;
 
enum {
   TE_VARIABLE = 0,
 
   TE_FUNCTION0 = 8,
   TE_FUNCTION1,
   TE_FUNCTION2,
   TE_FUNCTION3,
   TE_FUNCTION4,
   TE_FUNCTION5,
   TE_FUNCTION6,
   TE_FUNCTION7,
 
   TE_CLOSURE0 = 16,
   TE_CLOSURE1,
   TE_CLOSURE2,
   TE_CLOSURE3,
   TE_CLOSURE4,
   TE_CLOSURE5,
   TE_CLOSURE6,
   TE_CLOSURE7,
 
   TE_FLAG_PURE = 32
};
 
typedef struct te_variable {
   const char *name;
   const void *address;
   int type;
   void *context;
} te_variable;
 
/* Parses the input expression, evaluates it, and frees it. */
/* Returns NaN on error. */
double te_interp(const char *expression, int *error);
 
/* Parses the input expression and binds variables. */
/* Returns NULL on error. */
te_expr *te_compile(const char *expression, const te_variable *variables, int var_count, int *error);
 
/* Evaluates the expression. */
double te_eval(const te_expr *n);
 
/* Prints debugging information on the syntax tree. */
void te_print(const te_expr *n);
 
/* Frees the expression. */
/* This is safe to call on NULL pointers. */
void te_free(te_expr *n);
 
#ifdef __cplusplus
}
#endif
 
#endif /*TINYEXPR_H*/