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Diffstat (limited to 'intl/icu/source/common/bmpset.h')
| -rw-r--r-- | intl/icu/source/common/bmpset.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/intl/icu/source/common/bmpset.h b/intl/icu/source/common/bmpset.h new file mode 100644 index 000000000..8975cd61d --- /dev/null +++ b/intl/icu/source/common/bmpset.h @@ -0,0 +1,163 @@ +// Copyright (C) 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +****************************************************************************** +* +* Copyright (C) 2007, International Business Machines +* Corporation and others. All Rights Reserved. +* +****************************************************************************** +* file name: bmpset.h +* encoding: US-ASCII +* tab size: 8 (not used) +* indentation:4 +* +* created on: 2007jan29 +* created by: Markus W. Scherer +*/ + +#ifndef __BMPSET_H__ +#define __BMPSET_H__ + +#include "unicode/utypes.h" +#include "unicode/uniset.h" + +U_NAMESPACE_BEGIN + +/* + * Helper class for frozen UnicodeSets, implements contains() and span() + * optimized for BMP code points. Structured to be UTF-8-friendly. + * + * ASCII: Look up bytes. + * 2-byte characters: Bits organized vertically. + * 3-byte characters: Use zero/one/mixed data per 64-block in U+0000..U+FFFF, + * with mixed for illegal ranges. + * Supplementary characters: Call contains() on the parent set. + */ +class BMPSet : public UMemory { +public: + BMPSet(const int32_t *parentList, int32_t parentListLength); + BMPSet(const BMPSet &otherBMPSet, const int32_t *newParentList, int32_t newParentListLength); + virtual ~BMPSet(); + + virtual UBool contains(UChar32 c) const; + + /* + * Span the initial substring for which each character c has spanCondition==contains(c). + * It must be s<limit and spanCondition==0 or 1. + * @return The string pointer which limits the span. + */ + const UChar *span(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; + + /* + * Span the trailing substring for which each character c has spanCondition==contains(c). + * It must be s<limit and spanCondition==0 or 1. + * @return The string pointer which starts the span. + */ + const UChar *spanBack(const UChar *s, const UChar *limit, USetSpanCondition spanCondition) const; + + /* + * Span the initial substring for which each character c has spanCondition==contains(c). + * It must be length>0 and spanCondition==0 or 1. + * @return The string pointer which limits the span. + */ + const uint8_t *spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; + + /* + * Span the trailing substring for which each character c has spanCondition==contains(c). + * It must be length>0 and spanCondition==0 or 1. + * @return The start of the span. + */ + int32_t spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const; + +private: + void initBits(); + void overrideIllegal(); + + /** + * Same as UnicodeSet::findCodePoint(UChar32 c) const except that the + * binary search is restricted for finding code points in a certain range. + * + * For restricting the search for finding in the range start..end, + * pass in + * lo=findCodePoint(start) and + * hi=findCodePoint(end) + * with 0<=lo<=hi<len. + * findCodePoint(c) defaults to lo=0 and hi=len-1. + * + * @param c a character in a subrange of MIN_VALUE..MAX_VALUE + * @param lo The lowest index to be returned. + * @param hi The highest index to be returned. + * @return the smallest integer i in the range lo..hi, + * inclusive, such that c < list[i] + */ + int32_t findCodePoint(UChar32 c, int32_t lo, int32_t hi) const; + + inline UBool containsSlow(UChar32 c, int32_t lo, int32_t hi) const; + + /* + * One byte per ASCII character, or trail byte in lead position. + * 0 or 1 for ASCII characters. + * The value for trail bytes is the result of contains(FFFD) + * for faster validity checking at runtime. + */ + UBool asciiBytes[0xc0]; + + /* + * One bit per code point from U+0000..U+07FF. + * The bits are organized vertically; consecutive code points + * correspond to the same bit positions in consecutive table words. + * With code point parts + * lead=c{10..6} + * trail=c{5..0} + * it is set.contains(c)==(table7FF[trail] bit lead) + * + * Bits for 0..7F (non-shortest forms) are set to the result of contains(FFFD) + * for faster validity checking at runtime. + */ + uint32_t table7FF[64]; + + /* + * One bit per 64 BMP code points. + * The bits are organized vertically; consecutive 64-code point blocks + * correspond to the same bit position in consecutive table words. + * With code point parts + * lead=c{15..12} + * t1=c{11..6} + * test bits (lead+16) and lead in bmpBlockBits[t1]. + * If the upper bit is 0, then the lower bit indicates if contains(c) + * for all code points in the 64-block. + * If the upper bit is 1, then the block is mixed and set.contains(c) + * must be called. + * + * Bits for 0..7FF (non-shortest forms) and D800..DFFF are set to + * the result of contains(FFFD) for faster validity checking at runtime. + */ + uint32_t bmpBlockBits[64]; + + /* + * Inversion list indexes for restricted binary searches in + * findCodePoint(), from + * findCodePoint(U+0800, U+1000, U+2000, .., U+F000, U+10000). + * U+0800 is the first 3-byte-UTF-8 code point. Code points below U+0800 are + * always looked up in the bit tables. + * The last pair of indexes is for finding supplementary code points. + */ + int32_t list4kStarts[18]; + + /* + * The inversion list of the parent set, for the slower contains() implementation + * for mixed BMP blocks and for supplementary code points. + * The list is terminated with list[listLength-1]=0x110000. + */ + const int32_t *list; + int32_t listLength; +}; + +inline UBool BMPSet::containsSlow(UChar32 c, int32_t lo, int32_t hi) const { + return (UBool)(findCodePoint(c, lo, hi) & 1); +} + +U_NAMESPACE_END + +#endif |