/*
  * C99-compatible strtod() implementation
  * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
  *

  * 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
  */
 
 #include <limits.h>
 #include <stdlib.h>
 
 #include "libavutil/avstring.h"
 #include "libavutil/mathematics.h"
 

 static const char *check_nan_suffix(const char *s)

 {

     const char *start = s;

 
     if (*s++ != '(')
         return start;
 
     while ((*s >= 'a' && *s <= 'z') || (*s >= 'A' && *s <= 'Z') ||
            (*s >= '0' && *s <= '9') ||  *s == '_')
         s++;
 
     return *s == ')' ? s + 1 : start;
 }
 
 #undef strtod
 double strtod(const char *, char **);
 
 double avpriv_strtod(const char *nptr, char **endptr)
 {

     const char *end;

     double res;
 
     /* Skip leading spaces */

     while (av_isspace(*nptr))

         nptr++;
 
     if (!av_strncasecmp(nptr, "infinity", 8)) {
         end = nptr + 8;
         res = INFINITY;
     } else if (!av_strncasecmp(nptr, "inf", 3)) {
         end = nptr + 3;
         res = INFINITY;
     } else if (!av_strncasecmp(nptr, "+infinity", 9)) {
         end = nptr + 9;
         res = INFINITY;
     } else if (!av_strncasecmp(nptr, "+inf", 4)) {
         end = nptr + 4;
         res = INFINITY;
     } else if (!av_strncasecmp(nptr, "-infinity", 9)) {
         end = nptr + 9;
         res = -INFINITY;
     } else if (!av_strncasecmp(nptr, "-inf", 4)) {
         end = nptr + 4;
         res = -INFINITY;
     } else if (!av_strncasecmp(nptr, "nan", 3)) {
         end = check_nan_suffix(nptr + 3);
         res = NAN;
     } else if (!av_strncasecmp(nptr, "+nan", 4) ||
                !av_strncasecmp(nptr, "-nan", 4)) {
         end = check_nan_suffix(nptr + 4);
         res = NAN;
     } else if (!av_strncasecmp(nptr, "0x", 2) ||
                !av_strncasecmp(nptr, "-0x", 3) ||
                !av_strncasecmp(nptr, "+0x", 3)) {
         /* FIXME this doesn't handle exponents, non-integers (float/double)
          * and numbers too large for long long */

         res = strtoll(nptr, (char **)&end, 16);

     } else {

         res = strtod(nptr, (char **)&end);

     }
 
     if (endptr)

         *endptr = (char *)end;

 
     return res;
 }