/*
  * 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 successful 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);
 

 /**

  * 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 by

  * 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 */