lib/unistr/u-strspn.h

   1 /* Search for some characters in UTF-8/UTF-16/UTF-32 string.
   2    Copyright (C) 1999, 2002, 2006, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2002.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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 GNU
  13    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 size_t
  19 FUNC (const UNIT *str, const UNIT *accept)
  20 {
  21   /* Optimize two cases.  */
  22   if (accept[0] == 0)
  23     return 0;
  24   {
  25     ucs4_t uc;
  26     int count = U_STRMBTOUC (&uc, accept);
  27     if (count >= 0 && accept[count] == 0)
  28       {
  29         const UNIT *ptr = str;
  30         for (; *ptr != 0; ptr += count)
  31           if (U_CMP (ptr, accept, count) != 0)
  32             break;
  33         return ptr - str;
  34       }
  35   }
  36   /* General case.  */
  37   {
  38     const UNIT *ptr = str;
  39
  40     for (;;)
  41       {
  42         ucs4_t uc;
  43         int count = U_STRMBTOUC (&uc, ptr);
  44         if (count == 0)
  45           return ptr - str;
  46         if (count < 0)
  47           break;
  48         if (!U_STRCHR (accept, uc))
  49           return ptr - str;
  50         ptr += count;
  51       }
  52     return U_STRLEN (str);
  53   }
  54 }