lib/mbscspn.c

   1 /* Searching a string for a character among a given set of characters.
   2    Copyright (C) 1999, 2002, 2006-2025 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2007.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation, either version 3 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <string.h>
  22
  23 #include <stdlib.h>
  24
  25 #if GNULIB_MCEL_PREFER
  26 # include "mcel.h"
  27 #else
  28 # include "mbuiterf.h"
  29 #endif
  30
  31 /* Find the first occurrence in the character string STRING of any character
  32    in the character string ACCEPT.  Return the number of bytes from the
  33    beginning of the string to this occurrence, or to the end of the string
  34    if none exists.  */
  35 size_t
  36 mbscspn (const char *string, const char *accept)
  37 {
  38   /* Optimize two cases.  */
  39   if (accept[0] == '\0')
  40     return strlen (string);
  41   if (accept[1] == '\0')
  42     {
  43       const char *ptr = mbschr (string, accept[0]);
  44       return (ptr != NULL ? ptr - string : strlen (string));
  45     }
  46   /* General case.  */
  47   if (MB_CUR_MAX > 1)
  48     {
  49 #if GNULIB_MCEL_PREFER
  50       mcel_t a, g;
  51       size_t i;
  52       for (i = 0; string[i]; i += g.len)
  53         {
  54           g = mcel_scanz (string + i);
  55           if (g.len == 1)
  56             {
  57               if (mbschr (accept, string[i]))
  58                 return i;
  59             }
  60           else
  61             for (char const *aiter = accept; *aiter; aiter += a.len)
  62               {
  63                 a = mcel_scanz (aiter);
  64                 if (mcel_cmp (g, a) == 0)
  65                   return i;
  66               }
  67         }
  68       return i;
  69 #else
  70       mbuif_state_t state;
  71       const char *iter;
  72       for (mbuif_init (state), iter = string; mbuif_avail (state, iter); )
  73         {
  74           mbchar_t cur = mbuif_next (state, iter);
  75           if (mb_len (cur) == 1)
  76             {
  77               if (mbschr (accept, *iter))
  78                 goto found;
  79             }
  80           else
  81             {
  82               mbuif_state_t astate;
  83               const char *aiter;
  84               for (mbuif_init (astate), aiter = accept;
  85                    mbuif_avail (astate, aiter); )
  86                 {
  87                   mbchar_t acur = mbuif_next (astate, aiter);
  88                   if (mb_equal (acur, cur))
  89                     goto found;
  90                   aiter += mb_len (acur);
  91                 }
  92             }
  93           iter += mb_len (cur);
  94         }
  95      found:
  96       return iter - string;
  97 #endif
  98     }
  99   else
 100     return strcspn (string, accept);
 101 }