1/* Case-mapping contexts of UTF-8/UTF-16/UTF-32 substring.
2   Copyright (C) 2009-2010 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2009.
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
19/* The context of a prefix string combines the information of the "Before C"
20   conditions of the Unicode Standard,
21   <http://www.unicode.org/versions/Unicode5.0.0/ch03.pdf>, section 3.13,
22   table 3-14 "Context Specification for Casing".
23
24   casing_prefix_context_t contains the following fields:
25
26     // Helper for evaluating the FINAL_SIGMA condition:
27     //  Last character that was not case-ignorable.
28     ucs4_t last_char_except_ignorable;
29
30     // Helper for evaluating the AFTER_SOFT_DOTTED and AFTER_I conditions:
31     // Last character that was of combining class 230 ("Above") or 0.
32     ucs4_t last_char_normal_or_above;
33
34   Three bits would be sufficient to carry the context information, but
35   that would require to invoke uc_is_cased and uc_is_property_soft_dotted
36   ahead of time, more often than actually needed.  */
37
38
39/* The context of a suffix string combines the information of the "After C"
40   conditions of the Unicode Standard,
41   <http://www.unicode.org/versions/Unicode5.0.0/ch03.pdf>, section 3.13,
42   table 3-14 "Context Specification for Casing".
43
44   casing_suffix_context_t contains the following fields:
45
46     // For evaluating the FINAL_SIGMA condition:
47     //  First character that was not case-ignorable.
48     ucs4_t first_char_except_ignorable;
49
50     // For evaluating the MORE_ABOVE condition:
51     // Bit 0 is set if the suffix contains a character of combining class
52     // 230 (Above) with no character of combining class 0 or 230 (Above)
53     // before it.
54     //
55     // For evaluating the BEFORE_DOT condition:
56     // Bit 1 is set if the suffix contains a COMBINING DOT ABOVE (U+0307)
57     // with no character of combining class 0 or 230 (Above) before it.
58     //
59     uint32_t bits;
60
61   Three bits would be sufficient to carry the context information, but
62   that would require to invoke uc_is_cased ahead of time, more often than
63   actually needed.  */
64#define SCC_MORE_ABOVE_MASK  1
65#define SCC_BEFORE_DOT_MASK  2
66