1 /* Compare UTF-16 strings.
2 Copyright (C) 1999, 2002, 2006 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2002.
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU Library General Public License as published
7 by the Free Software Foundation; either version 2, or (at your option)
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 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with this program; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
26 u16_strncmp (const uint16_t *s1, const uint16_t *s2, size_t n)
28 /* Note that the UTF-16 encoding does NOT preserve lexicographic order.
29 Namely, if uc1 is a 16-bit character and [uc2a,uc2b] is a surrogate pair,
30 we must enforce uc1 < [uc2a,uc2b], even if uc1 > uc2a. */
35 if (c1 != 0 && c1 == c2)
40 if (c1 < 0xd800 || c1 >= 0xe000)
42 if (!(c2 < 0xd800 || c2 >= 0xe000))
43 /* c2 is a surrogate, but c1 is not. */
48 if (c2 < 0xd800 || c2 >= 0xe000)
49 /* c1 is a surrogate, but c2 is not. */
52 return (int)c1 - (int)c2;
53 /* > 0 if c1 > c2, < 0 if c1 < c2, = 0 if c1 and c2 are both 0. */