1/* Iterate over previous character in UTF-32 string.
2   Copyright (C) 2002, 2006-2007, 2009-2010 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 <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19
20/* Specification.  */
21#include "unistr.h"
22
23const uint32_t *
24u32_prev (ucs4_t *puc, const uint32_t *s, const uint32_t *start)
25{
26  if (s != start)
27    {
28      uint32_t c_1 = s[-1];
29
30#if CONFIG_UNICODE_SAFETY
31      if (c_1 < 0xd800 || (c_1 >= 0xe000 && c_1 < 0x110000))
32#endif
33        {
34          *puc = c_1;
35          return s - 1;
36        }
37    }
38  return NULL;
39}
40