// SPDX-License-Identifier: Zlib
/*
 * TINYEXPR - Tiny recursive descent parser and evaluation engine in C
 * 
 * Maintained by SollyBunny at https://github.com/SollyBunny/tinyexpr
 * Created by codeplea at https://github.com/codeplea/tinyexpr
 */
/*
 * 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 union te_function {
    void *any;
    double (*f0)(void);
    double (*f1)(double);
    double (*f2)(double,double);
    double (*f3)(double,double,double);
    double (*f4)(double,double,double,double);
    double (*f5)(double,double,double,double,double);
    double (*f6)(double,double,double,double,double,double);
    double (*f7)(double,double,double,double,double,double,double);
    double (*cl0)(void*);
    double (*cl1)(void*,double);
    double (*cl2)(void*,double,double);
    double (*cl3)(void*,double,double,double);
    double (*cl4)(void*,double,double,double,double);
    double (*cl5)(void*,double,double,double,double,double);
    double (*cl6)(void*,double,double,double,double,double,double);
    double (*cl7)(void*,double,double,double,double,double,double,double);
} te_function;

typedef union te_value {
    double value;
    const double *bound;
    te_function f;
} te_value;

typedef struct te_expr {
    int type;
    te_value v;
    struct te_expr *parameters[];
} 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 te_function 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*/
