1/* Count characters in UTF-16 string.
2   Copyright (C) 2007, 2009-2010 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2007.
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
23size_t
24u16_mbsnlen (const uint16_t *s, size_t n)
25{
26  size_t characters;
27
28  characters = 0;
29  while (n > 0)
30    {
31      ucs4_t uc;
32      int count = u16_mbtoucr (&uc, s, n);
33      characters++;
34      if (count == -2)
35        break;
36      if (count <= 0)
37        count = 1;
38      s += count;
39      n -= count;
40    }
41  return characters;
42}
43