xref: /haiku/src/libs/iconv/utf16be.h (revision 68ea01249e1e2088933cb12f9c28d4e5c5d1c9ef)
1 /*
2  * Copyright (C) 1999-2001 Free Software Foundation, Inc.
3  * This file is part of the GNU LIBICONV Library.
4  *
5  * The GNU LIBICONV Library is free software; you can redistribute it
6  * and/or modify it under the terms of the GNU Library General Public
7  * License as published by the Free Software Foundation; either version 2
8  * of the License, or (at your option) any later version.
9  *
10  * The GNU LIBICONV Library is distributed in the hope that it will be
11  * useful, 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.
14  *
15  * You should have received a copy of the GNU Library General Public
16  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
17  * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
18  * Fifth Floor, Boston, MA 02110-1301, USA.
19  */
20 
21 /*
22  * UTF-16BE
23  */
24 
25 /* Specification: RFC 2781 */
26 
27 static int
28 utf16be_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
29 {
30   int count = 0;
31   if (n >= 2) {
32     ucs4_t wc = (s[0] << 8) + s[1];
33     if (wc >= 0xd800 && wc < 0xdc00) {
34       if (n >= 4) {
35         ucs4_t wc2 = (s[2] << 8) + s[3];
36         if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
37           return RET_ILSEQ;
38         *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
39         return count+4;
40       }
41     } else if (wc >= 0xdc00 && wc < 0xe000) {
42       return RET_ILSEQ;
43     } else {
44       *pwc = wc;
45       return count+2;
46     }
47   }
48   return RET_TOOFEW(count);
49 }
50 
51 static int
52 utf16be_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
53 {
54   if (!(wc >= 0xd800 && wc < 0xe000)) {
55     if (wc < 0x10000) {
56       if (n >= 2) {
57         r[0] = (unsigned char) (wc >> 8);
58         r[1] = (unsigned char) wc;
59         return 2;
60       } else
61         return RET_TOOSMALL;
62     }
63     else if (wc < 0x110000) {
64       if (n >= 4) {
65         ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
66         ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
67         r[0] = (unsigned char) (wc1 >> 8);
68         r[1] = (unsigned char) wc1;
69         r[2] = (unsigned char) (wc2 >> 8);
70         r[3] = (unsigned char) wc2;
71         return 4;
72       } else
73         return RET_TOOSMALL;
74     }
75   }
76   return RET_ILUNI;
77 }
78