kc3-lang/gnulib/lib/unistr/u16-strrchr.c

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• Hash : 32a72f45
  Author :
  Date : 2023-01-01T01:14:21
  

  maint: run 'make update-copyright'
  

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• lib/unistr/u16-strrchr.c

• /* Search character in UTF-16 string.
     Copyright (C) 1999, 2002, 2006-2007, 2009-2023 Free Software Foundation,
     Inc.
     Written by Bruno Haible <bruno@clisp.org>, 2002.
  
     This file is free software.
     It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
     You can redistribute it and/or modify it under either
       - the terms of the GNU Lesser General Public License as published
         by the Free Software Foundation, either version 3, or (at your
         option) any later version, or
       - the terms of the GNU General Public License as published by the
         Free Software Foundation; either version 2, or (at your option)
         any later version, or
       - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  
     This file 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 and the GNU General Public License
     for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License and of the GNU General Public License along with this
     program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  #include <config.h>
  
  /* Specification.  */
  #include "unistr.h"
  
  uint16_t *
  u16_strrchr (const uint16_t *s, ucs4_t uc)
  {
    /* Calling u16_strlen and then searching from the other end would cause more
       memory accesses. Avoid that, at the cost of a few more comparisons.  */
    uint16_t *result = NULL;
    uint16_t c[2];
  
    if (uc < 0x10000)
      {
        uint16_t c0 = uc;
  
        for (;; s++)
          {
            if (*s == c0)
              result = (uint16_t *) s;
            if (*s == 0)
              break;
          }
      }
    else
      switch (u16_uctomb_aux (c, uc, 2))
        {
        case 2:
          if (*s)
            {
              uint16_t c0 = c[0];
              uint16_t c1 = c[1];
  
              /* FIXME: Maybe walking the string via u16_mblen is a win?  */
              for (;; s++)
                {
                  if (s[1] == 0)
                    break;
                  if (*s == c0 && s[1] == c1)
                    result = (uint16_t *) s;
                }
            }
          break;
        }
    return result;
  }
  

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