1 /* Look at first character in UTF-16 string, returning an error code.
2 Copyright (C) 1999-2002, 2006-2007, 2009-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2001.
4
5 This file is free software.
6 It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
7 You can redistribute it and/or modify it under either
8 - the terms of the GNU Lesser General Public License as published
9 by the Free Software Foundation; either version 3, or (at your
10 option) any later version, or
11 - the terms of the GNU General Public License as published by the
12 Free Software Foundation; either version 2, or (at your option)
13 any later version, or
14 - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
15
16 This file is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License and the GNU General Public License
20 for more details.
21
22 You should have received a copy of the GNU Lesser General Public
23 License and of the GNU General Public License along with this
24 program. If not, see <https://www.gnu.org/licenses/>. */
25
26 #include <config.h>
27
28 /* Specification. */
29 #include "unistr.h"
30
31 int
32 u16_mbtoucr (ucs4_t *puc, const uint16_t *s, size_t n)
/* ![[previous]](../icons/n_left.png)
![[next]](../icons/n_right.png)
![[first]](../icons/n_first.png)
![[last]](../icons/n_last.png)
![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
33 {
34 uint16_t c = *s;
35
36 if (c < 0xd800 || c >= 0xe000)
37 {
38 *puc = c;
39 return 1;
40 }
41 if (c < 0xdc00)
42 {
43 if (n >= 2)
44 {
45 if (s[1] >= 0xdc00 && s[1] < 0xe000)
46 {
47 *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
48 return 2;
49 }
50 /* invalid multibyte character */
51 }
52 else
53 {
54 /* incomplete multibyte character */
55 *puc = 0xfffd;
56 return -2;
57 }
58 }
59 /* invalid multibyte character */
60 *puc = 0xfffd;
61 return -1;
62 }