1 /* Decomposition of Unicode characters.
2 Copyright (C) 2001-2003, 2009-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2009.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file 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
13 GNU 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 <https://www.gnu.org/licenses/>. */
17
18
19 #include "unitypes.h"
20
21 /* The decomposition table is made of two parts:
22 - A table containing the actual arrays of decomposed equivalents.
23 (This table is separate because the maximum length of a decomposition
24 is 18, much larger than the average length 1.497 of a decomposition).
25 - A 3-level table of indices into this array. */
26
27 #include "decomposition-table1.h"
28
29 static inline unsigned short
30 decomp_index (ucs4_t uc)
/* ![[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)
*/
31 {
32 unsigned int index1 = uc >> decomp_header_0;
33 if (index1 < decomp_header_1)
34 {
35 int lookup1 = gl_uninorm_decomp_index_table.level1[index1];
36 if (lookup1 >= 0)
37 {
38 unsigned int index2 = (uc >> decomp_header_2) & decomp_header_3;
39 int lookup2 = gl_uninorm_decomp_index_table.level2[lookup1 + index2];
40 if (lookup2 >= 0)
41 {
42 unsigned int index3 = uc & decomp_header_4;
43 return gl_uninorm_decomp_index_table.level3[lookup2 + index3];
44 }
45 }
46 }
47 return (unsigned short)(-1);
48 }