1 /* Look at first character in UTF-16 string, returning an error code.
2 Copyright (C) 1999-2002, 2006-2007, 2009-2014 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 /* Specification. */
21 #include "unistr.h"
22
23 int
u16_mbtoucr(ucs4_t * puc,const uint16_t * s,size_t n)24 u16_mbtoucr (ucs4_t *puc, const uint16_t *s, size_t n)
25 {
26 uint16_t c = *s;
27
28 if (c < 0xd800 || c >= 0xe000)
29 {
30 *puc = c;
31 return 1;
32 }
33 if (c < 0xdc00)
34 {
35 if (n >= 2)
36 {
37 if (s[1] >= 0xdc00 && s[1] < 0xe000)
38 {
39 *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
40 return 2;
41 }
42 /* invalid multibyte character */
43 }
44 else
45 {
46 /* incomplete multibyte character */
47 *puc = 0xfffd;
48 return -2;
49 }
50 }
51 /* invalid multibyte character */
52 *puc = 0xfffd;
53 return -1;
54 }
55