1 /* 2 * TINYEXPR - Tiny recursive descent parser and evaluation engine in C 3 * 4 * Copyright (c) 2015, 2016 Lewis Van Winkle 5 * 6 * http://CodePlea.com 7 * 8 * This software is provided 'as-is', without any express or implied 9 * warranty. In no event will the authors be held liable for any damages 10 * arising from the use of this software. 11 * 12 * Permission is granted to anyone to use this software for any purpose, 13 * including commercial applications, and to alter it and redistribute it 14 * freely, subject to the following restrictions: 15 * 16 * 1. The origin of this software must not be misrepresented; you must not 17 * claim that you wrote the original software. If you use this software 18 * in a product, an acknowledgement in the product documentation would be 19 * appreciated but is not required. 20 * 2. Altered source versions must be plainly marked as such, and must not be 21 * misrepresented as being the original software. 22 * 3. This notice may not be removed or altered from any source distribution. 23 */ 24 25 #ifndef __TINYEXPR_H__ 26 #define __TINYEXPR_H__ 27 28 29 #ifdef __cplusplus 30 extern "C" { 31 #endif 32 33 34 35 typedef struct te_expr { 36 int type; 37 union {double value; const double *bound; const void *function;}; 38 void *parameters[1]; 39 } te_expr; 40 41 42 enum { 43 TE_VARIABLE = 0, 44 45 TE_FUNCTION0 = 8, TE_FUNCTION1, TE_FUNCTION2, TE_FUNCTION3, 46 TE_FUNCTION4, TE_FUNCTION5, TE_FUNCTION6, TE_FUNCTION7, 47 48 TE_CLOSURE0 = 16, TE_CLOSURE1, TE_CLOSURE2, TE_CLOSURE3, 49 TE_CLOSURE4, TE_CLOSURE5, TE_CLOSURE6, TE_CLOSURE7, 50 51 TE_FLAG_PURE = 32 52 }; 53 54 typedef struct te_variable { 55 const char *name; 56 const void *address; 57 int type; 58 void *context; 59 } te_variable; 60 61 62 63 /* Parses the input expression, evaluates it, and frees it. */ 64 /* Returns NaN on error. */ 65 double te_interp(const char *expression, int *error); 66 67 /* Parses the input expression and binds variables. */ 68 /* Returns NULL on error. */ 69 te_expr *te_compile(const char *expression, const te_variable *variables, int var_count, int *error); 70 71 /* Evaluates the expression. */ 72 double te_eval(const te_expr *n); 73 74 /* Prints debugging information on the syntax tree. */ 75 void te_print(const te_expr *n); 76 77 /* Frees the expression. */ 78 /* This is safe to call on NULL pointers. */ 79 void te_free(te_expr *n); 80 81 82 #ifdef __cplusplus 83 } 84 #endif 85 86 #endif /*__TINYEXPR_H__*/
