/*

 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */



/**

 * @file

 * simple arithmetic expression evaluator

 */



#ifndef AVUTIL_EVAL_H

#define AVUTIL_EVAL_H



#include "avutil.h"



typedef struct AVExpr AVExpr;



/**

 * Parse and evaluate an expression.

 * Note, this is significantly slower than av_expr_eval().

 *

 * @param res a pointer to a double where is put the result value of

 * the expression, or NAN in case of error

 * @param s expression as a zero terminated string, for example "1+2^3+5*5+sin(2/3)"

 * @param const_names NULL terminated array of zero terminated strings of constant identifiers, for example {"PI", "E", 0}

 * @param const_values a zero terminated array of values for the identifiers from const_names

 * @param func1_names NULL terminated array of zero terminated strings of funcs1 identifiers

 * @param funcs1 NULL terminated array of function pointers for functions which take 1 argument

 * @param func2_names NULL terminated array of zero terminated strings of funcs2 identifiers

 * @param funcs2 NULL terminated array of function pointers for functions which take 2 arguments

 * @param opaque a pointer which will be passed to all functions from funcs1 and funcs2

 * @param log_ctx parent logging context

 * @return 0 in case of success, a negative value corresponding to an

 * AVERROR code otherwise

 */

int av_expr_parse_and_eval(double *res, const char *s,

                           const char * const *const_names, const double *const_values,

                           const char * const *func1_names, double (* const *funcs1)(void *, double),

                           const char * const *func2_names, double (* const *funcs2)(void *, double, double),

                           void *opaque, int log_offset, void *log_ctx);



/**

 * Parse an expression.

 *

 * @param expr a pointer where is put an AVExpr containing the parsed

 * value in case of successfull parsing, or NULL otherwise.

 * The pointed to AVExpr must be freed with av_expr_free() by the user

 * when it is not needed anymore.

 * @param s expression as a zero terminated string, for example "1+2^3+5*5+sin(2/3)"

 * @param const_names NULL terminated array of zero terminated strings of constant identifiers, for example {"PI", "E", 0}

 * @param func1_names NULL terminated array of zero terminated strings of funcs1 identifiers

 * @param funcs1 NULL terminated array of function pointers for functions which take 1 argument

 * @param func2_names NULL terminated array of zero terminated strings of funcs2 identifiers

 * @param funcs2 NULL terminated array of function pointers for functions which take 2 arguments

 * @param log_ctx parent logging context

 * @return 0 in case of success, a negative value corresponding to an

 * AVERROR code otherwise

 */

int av_expr_parse(AVExpr **expr, const char *s,

                  const char * const *const_names,

                  const char * const *func1_names, double (* const *funcs1)(void *, double),

                  const char * const *func2_names, double (* const *funcs2)(void *, double, double),

                  int log_offset, void *log_ctx);



/**

 * Evaluate a previously parsed expression.

 *

 * @param const_values a zero terminated array of values for the identifiers from av_expr_parse() const_names

 * @param opaque a pointer which will be passed to all functions from funcs1 and funcs2

 * @return the value of the expression

 */

double av_expr_eval(AVExpr *e, const double *const_values, void *opaque);



/**

 * Free a parsed expression previously created with av_expr_parse().

 */

void av_expr_free(AVExpr *e);



#if FF_API_OLD_EVAL_NAMES

/**

 * @deprecated Deprecated in favor of av_expr_parse_and_eval().

 */

attribute_deprecated

int av_parse_and_eval_expr(double *res, const char *s,

                           const char * const *const_names, const double *const_values,

                           const char * const *func1_names, double (* const *funcs1)(void *, double),

                           const char * const *func2_names, double (* const *funcs2)(void *, double, double),

                           void *opaque, int log_offset, void *log_ctx);



/**

 * @deprecated Deprecated in favor of av_expr_parse().

 */

attribute_deprecated

int av_parse_expr(AVExpr **expr, const char *s,

                  const char * const *const_names,

                  const char * const *func1_names, double (* const *funcs1)(void *, double),

                  const char * const *func2_names, double (* const *funcs2)(void *, double, double),

                  int log_offset, void *log_ctx);

/**

 * @deprecated Deprecated in favor of av_expr_eval().

 */

attribute_deprecated

double av_eval_expr(AVExpr *e, const double *const_values, void *opaque);



/**

 * @deprecated Deprecated in favor of av_expr_free().

 */

attribute_deprecated

void av_free_expr(AVExpr *e);

#endif /* FF_API_OLD_EVAL_NAMES */



/**

 * Parse the string in numstr and return its value as a double. If

 * the string is empty, contains only whitespaces, or does not contain

 * an initial substring that has the expected syntax for a

 * floating-point number, no conversion is performed. In this case,

 * returns a value of zero and the value returned in tail is the value

 * of numstr.

 *

 * @param numstr a string representing a number, may contain one of

 * the International System number postfixes, for example 'K', 'M',

 * 'G'. If 'i' is appended after the postfix, powers of 2 are used

 * instead of powers of 10. The 'B' postfix multiplies the value for

 * 8, and can be appended after another postfix or used alone. This

 * allows using for example 'KB', 'MiB', 'G' and 'B' as postfix.

 * @param tail if non-NULL puts here the pointer to the char next

 * after the last parsed character

 */

double av_strtod(const char *numstr, char **tail);



#endif /* AVUTIL_EVAL_H */

