1/* Look at first character in UTF-16 string.
2   Copyright (C) 1999-2002, 2006-2007, 2009-2010 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2001.
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#if defined IN_LIBUNISTRING
21/* Tell unistr.h to declare u16_mbtouc as 'extern', not 'static inline'.  */
22# include "unistring-notinline.h"
23#endif
24
25/* Specification.  */
26#include "unistr.h"
27
28#if !HAVE_INLINE
29
30int
31u16_mbtouc (ucs4_t *puc, const uint16_t *s, size_t n)
32{
33  uint16_t c = *s;
34
35  if (c < 0xd800 || c >= 0xe000)
36    {
37      *puc = c;
38      return 1;
39    }
40  if (c < 0xdc00)
41    {
42      if (n >= 2)
43        {
44          if (s[1] >= 0xdc00 && s[1] < 0xe000)
45            {
46              *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
47              return 2;
48            }
49          /* invalid multibyte character */
50        }
51      else
52        {
53          /* incomplete multibyte character */
54        }
55    }
56  /* invalid multibyte character */
57  *puc = 0xfffd;
58  return 1;
59}
60
61#endif
62