/src/icu/source/common/bmpset.h
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1 | | // © 2016 and later: Unicode, Inc. and others. |
2 | | // License & terms of use: http://www.unicode.org/copyright.html |
3 | | /* |
4 | | ****************************************************************************** |
5 | | * |
6 | | * Copyright (C) 2007, International Business Machines |
7 | | * Corporation and others. All Rights Reserved. |
8 | | * |
9 | | ****************************************************************************** |
10 | | * file name: bmpset.h |
11 | | * encoding: UTF-8 |
12 | | * tab size: 8 (not used) |
13 | | * indentation:4 |
14 | | * |
15 | | * created on: 2007jan29 |
16 | | * created by: Markus W. Scherer |
17 | | */ |
18 | | |
19 | | #ifndef __BMPSET_H__ |
20 | | #define __BMPSET_H__ |
21 | | |
22 | | #include "unicode/utypes.h" |
23 | | #include "unicode/uniset.h" |
24 | | |
25 | | U_NAMESPACE_BEGIN |
26 | | |
27 | | /* |
28 | | * Helper class for frozen UnicodeSets, implements contains() and span() |
29 | | * optimized for BMP code points. Structured to be UTF-8-friendly. |
30 | | * |
31 | | * ASCII: Look up bytes. |
32 | | * 2-byte characters: Bits organized vertically. |
33 | | * 3-byte characters: Use zero/one/mixed data per 64-block in U+0000..U+FFFF, |
34 | | * with mixed for illegal ranges. |
35 | | * Supplementary characters: Call contains() on the parent set. |
36 | | */ |
37 | | class BMPSet : public UMemory { |
38 | | public: |
39 | | BMPSet(const int32_t *parentList, int32_t parentListLength); |
40 | | BMPSet(const BMPSet &otherBMPSet, const int32_t *newParentList, int32_t newParentListLength); |
41 | | virtual ~BMPSet(); |
42 | | |
43 | | virtual UBool contains(UChar32 c) const; |
44 | | |
45 | | /* |
46 | | * Span the initial substring for which each character c has spanCondition==contains(c). |
47 | | * It must be s<limit and spanCondition==0 or 1. |
48 | | * @return The string pointer which limits the span. |
49 | | */ |
50 | | const UChar *span(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; |
51 | | |
52 | | /* |
53 | | * Span the trailing substring for which each character c has spanCondition==contains(c). |
54 | | * It must be s<limit and spanCondition==0 or 1. |
55 | | * @return The string pointer which starts the span. |
56 | | */ |
57 | | const UChar *spanBack(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; |
58 | | |
59 | | /* |
60 | | * Span the initial substring for which each character c has spanCondition==contains(c). |
61 | | * It must be length>0 and spanCondition==0 or 1. |
62 | | * @return The string pointer which limits the span. |
63 | | */ |
64 | | const uint8_t *spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; |
65 | | |
66 | | /* |
67 | | * Span the trailing substring for which each character c has spanCondition==contains(c). |
68 | | * It must be length>0 and spanCondition==0 or 1. |
69 | | * @return The start of the span. |
70 | | */ |
71 | | int32_t spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; |
72 | | |
73 | | private: |
74 | | void initBits(); |
75 | | void overrideIllegal(); |
76 | | |
77 | | /** |
78 | | * Same as UnicodeSet::findCodePoint(UChar32 c) const except that the |
79 | | * binary search is restricted for finding code points in a certain range. |
80 | | * |
81 | | * For restricting the search for finding in the range start..end, |
82 | | * pass in |
83 | | * lo=findCodePoint(start) and |
84 | | * hi=findCodePoint(end) |
85 | | * with 0<=lo<=hi<len. |
86 | | * findCodePoint(c) defaults to lo=0 and hi=len-1. |
87 | | * |
88 | | * @param c a character in a subrange of MIN_VALUE..MAX_VALUE |
89 | | * @param lo The lowest index to be returned. |
90 | | * @param hi The highest index to be returned. |
91 | | * @return the smallest integer i in the range lo..hi, |
92 | | * inclusive, such that c < list[i] |
93 | | */ |
94 | | int32_t findCodePoint(UChar32 c, int32_t lo, int32_t hi) const; |
95 | | |
96 | | inline UBool containsSlow(UChar32 c, int32_t lo, int32_t hi) const; |
97 | | |
98 | | /* |
99 | | * One byte per ASCII character, or trail byte in lead position. |
100 | | * 0 or 1 for ASCII characters. |
101 | | * The value for trail bytes is the result of contains(FFFD) |
102 | | * for faster validity checking at runtime. |
103 | | */ |
104 | | UBool asciiBytes[0xc0]; |
105 | | |
106 | | /* |
107 | | * One bit per code point from U+0000..U+07FF. |
108 | | * The bits are organized vertically; consecutive code points |
109 | | * correspond to the same bit positions in consecutive table words. |
110 | | * With code point parts |
111 | | * lead=c{10..6} |
112 | | * trail=c{5..0} |
113 | | * it is set.contains(c)==(table7FF[trail] bit lead) |
114 | | * |
115 | | * Bits for 0..7F (non-shortest forms) are set to the result of contains(FFFD) |
116 | | * for faster validity checking at runtime. |
117 | | */ |
118 | | uint32_t table7FF[64]; |
119 | | |
120 | | /* |
121 | | * One bit per 64 BMP code points. |
122 | | * The bits are organized vertically; consecutive 64-code point blocks |
123 | | * correspond to the same bit position in consecutive table words. |
124 | | * With code point parts |
125 | | * lead=c{15..12} |
126 | | * t1=c{11..6} |
127 | | * test bits (lead+16) and lead in bmpBlockBits[t1]. |
128 | | * If the upper bit is 0, then the lower bit indicates if contains(c) |
129 | | * for all code points in the 64-block. |
130 | | * If the upper bit is 1, then the block is mixed and set.contains(c) |
131 | | * must be called. |
132 | | * |
133 | | * Bits for 0..7FF (non-shortest forms) and D800..DFFF are set to |
134 | | * the result of contains(FFFD) for faster validity checking at runtime. |
135 | | */ |
136 | | uint32_t bmpBlockBits[64]; |
137 | | |
138 | | /* |
139 | | * Inversion list indexes for restricted binary searches in |
140 | | * findCodePoint(), from |
141 | | * findCodePoint(U+0800, U+1000, U+2000, .., U+F000, U+10000). |
142 | | * U+0800 is the first 3-byte-UTF-8 code point. Code points below U+0800 are |
143 | | * always looked up in the bit tables. |
144 | | * The last pair of indexes is for finding supplementary code points. |
145 | | */ |
146 | | int32_t list4kStarts[18]; |
147 | | |
148 | | /* |
149 | | * The inversion list of the parent set, for the slower contains() implementation |
150 | | * for mixed BMP blocks and for supplementary code points. |
151 | | * The list is terminated with list[listLength-1]=0x110000. |
152 | | */ |
153 | | const int32_t *list; |
154 | | int32_t listLength; |
155 | | }; |
156 | | |
157 | 0 | inline UBool BMPSet::containsSlow(UChar32 c, int32_t lo, int32_t hi) const { |
158 | 0 | return (UBool)(findCodePoint(c, lo, hi) & 1); |
159 | 0 | } |
160 | | |
161 | | U_NAMESPACE_END |
162 | | |
163 | | #endif |