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Diffstat (limited to 'intl/icu/source/i18n/utf16collationiterator.cpp')
| -rw-r--r-- | intl/icu/source/i18n/utf16collationiterator.cpp | 494 |
1 files changed, 494 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/utf16collationiterator.cpp b/intl/icu/source/i18n/utf16collationiterator.cpp new file mode 100644 index 0000000000..7598b0ee52 --- /dev/null +++ b/intl/icu/source/i18n/utf16collationiterator.cpp @@ -0,0 +1,494 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +******************************************************************************* +* Copyright (C) 2010-2014, International Business Machines +* Corporation and others. All Rights Reserved. +******************************************************************************* +* utf16collationiterator.cpp +* +* created on: 2010oct27 +* created by: Markus W. Scherer +*/ + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_COLLATION + +#include "charstr.h" +#include "cmemory.h" +#include "collation.h" +#include "collationdata.h" +#include "collationfcd.h" +#include "collationiterator.h" +#include "normalizer2impl.h" +#include "uassert.h" +#include "utf16collationiterator.h" + +U_NAMESPACE_BEGIN + +UTF16CollationIterator::UTF16CollationIterator(const UTF16CollationIterator &other, + const UChar *newText) + : CollationIterator(other), + start(newText), + pos(newText + (other.pos - other.start)), + limit(other.limit == NULL ? NULL : newText + (other.limit - other.start)) { +} + +UTF16CollationIterator::~UTF16CollationIterator() {} + +UBool +UTF16CollationIterator::operator==(const CollationIterator &other) const { + if(!CollationIterator::operator==(other)) { return FALSE; } + const UTF16CollationIterator &o = static_cast<const UTF16CollationIterator &>(other); + // Compare the iterator state but not the text: Assume that the caller does that. + return (pos - start) == (o.pos - o.start); +} + +void +UTF16CollationIterator::resetToOffset(int32_t newOffset) { + reset(); + pos = start + newOffset; +} + +int32_t +UTF16CollationIterator::getOffset() const { + return (int32_t)(pos - start); +} + +uint32_t +UTF16CollationIterator::handleNextCE32(UChar32 &c, UErrorCode & /*errorCode*/) { + if(pos == limit) { + c = U_SENTINEL; + return Collation::FALLBACK_CE32; + } + c = *pos++; + return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c); +} + +UChar +UTF16CollationIterator::handleGetTrailSurrogate() { + if(pos == limit) { return 0; } + UChar trail; + if(U16_IS_TRAIL(trail = *pos)) { ++pos; } + return trail; +} + +UBool +UTF16CollationIterator::foundNULTerminator() { + if(limit == NULL) { + limit = --pos; + return TRUE; + } else { + return FALSE; + } +} + +UChar32 +UTF16CollationIterator::nextCodePoint(UErrorCode & /*errorCode*/) { + if(pos == limit) { + return U_SENTINEL; + } + UChar32 c = *pos; + if(c == 0 && limit == NULL) { + limit = pos; + return U_SENTINEL; + } + ++pos; + UChar trail; + if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(trail = *pos)) { + ++pos; + return U16_GET_SUPPLEMENTARY(c, trail); + } else { + return c; + } +} + +UChar32 +UTF16CollationIterator::previousCodePoint(UErrorCode & /*errorCode*/) { + if(pos == start) { + return U_SENTINEL; + } + UChar32 c = *--pos; + UChar lead; + if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(lead = *(pos - 1))) { + --pos; + return U16_GET_SUPPLEMENTARY(lead, c); + } else { + return c; + } +} + +void +UTF16CollationIterator::forwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) { + while(num > 0 && pos != limit) { + UChar32 c = *pos; + if(c == 0 && limit == NULL) { + limit = pos; + break; + } + ++pos; + --num; + if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(*pos)) { + ++pos; + } + } +} + +void +UTF16CollationIterator::backwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) { + while(num > 0 && pos != start) { + UChar32 c = *--pos; + --num; + if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(*(pos-1))) { + --pos; + } + } +} + +// FCDUTF16CollationIterator ----------------------------------------------- *** + +FCDUTF16CollationIterator::FCDUTF16CollationIterator(const FCDUTF16CollationIterator &other, + const UChar *newText) + : UTF16CollationIterator(other), + rawStart(newText), + segmentStart(newText + (other.segmentStart - other.rawStart)), + segmentLimit(other.segmentLimit == NULL ? NULL : newText + (other.segmentLimit - other.rawStart)), + rawLimit(other.rawLimit == NULL ? NULL : newText + (other.rawLimit - other.rawStart)), + nfcImpl(other.nfcImpl), + normalized(other.normalized), + checkDir(other.checkDir) { + if(checkDir != 0 || other.start == other.segmentStart) { + start = newText + (other.start - other.rawStart); + pos = newText + (other.pos - other.rawStart); + limit = other.limit == NULL ? NULL : newText + (other.limit - other.rawStart); + } else { + start = normalized.getBuffer(); + pos = start + (other.pos - other.start); + limit = start + normalized.length(); + } +} + +FCDUTF16CollationIterator::~FCDUTF16CollationIterator() {} + +UBool +FCDUTF16CollationIterator::operator==(const CollationIterator &other) const { + // Skip the UTF16CollationIterator and call its parent. + if(!CollationIterator::operator==(other)) { return FALSE; } + const FCDUTF16CollationIterator &o = static_cast<const FCDUTF16CollationIterator &>(other); + // Compare the iterator state but not the text: Assume that the caller does that. + if(checkDir != o.checkDir) { return FALSE; } + if(checkDir == 0 && (start == segmentStart) != (o.start == o.segmentStart)) { return FALSE; } + if(checkDir != 0 || start == segmentStart) { + return (pos - rawStart) == (o.pos - o.rawStart); + } else { + return (segmentStart - rawStart) == (o.segmentStart - o.rawStart) && + (pos - start) == (o.pos - o.start); + } +} + +void +FCDUTF16CollationIterator::resetToOffset(int32_t newOffset) { + reset(); + start = segmentStart = pos = rawStart + newOffset; + limit = rawLimit; + checkDir = 1; +} + +int32_t +FCDUTF16CollationIterator::getOffset() const { + if(checkDir != 0 || start == segmentStart) { + return (int32_t)(pos - rawStart); + } else if(pos == start) { + return (int32_t)(segmentStart - rawStart); + } else { + return (int32_t)(segmentLimit - rawStart); + } +} + +uint32_t +FCDUTF16CollationIterator::handleNextCE32(UChar32 &c, UErrorCode &errorCode) { + for(;;) { + if(checkDir > 0) { + if(pos == limit) { + c = U_SENTINEL; + return Collation::FALLBACK_CE32; + } + c = *pos++; + if(CollationFCD::hasTccc(c)) { + if(CollationFCD::maybeTibetanCompositeVowel(c) || + (pos != limit && CollationFCD::hasLccc(*pos))) { + --pos; + if(!nextSegment(errorCode)) { + c = U_SENTINEL; + return Collation::FALLBACK_CE32; + } + c = *pos++; + } + } + break; + } else if(checkDir == 0 && pos != limit) { + c = *pos++; + break; + } else { + switchToForward(); + } + } + return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c); +} + +UBool +FCDUTF16CollationIterator::foundNULTerminator() { + if(limit == NULL) { + limit = rawLimit = --pos; + return TRUE; + } else { + return FALSE; + } +} + +UChar32 +FCDUTF16CollationIterator::nextCodePoint(UErrorCode &errorCode) { + UChar32 c; + for(;;) { + if(checkDir > 0) { + if(pos == limit) { + return U_SENTINEL; + } + c = *pos++; + if(CollationFCD::hasTccc(c)) { + if(CollationFCD::maybeTibetanCompositeVowel(c) || + (pos != limit && CollationFCD::hasLccc(*pos))) { + --pos; + if(!nextSegment(errorCode)) { + return U_SENTINEL; + } + c = *pos++; + } + } else if(c == 0 && limit == NULL) { + limit = rawLimit = --pos; + return U_SENTINEL; + } + break; + } else if(checkDir == 0 && pos != limit) { + c = *pos++; + break; + } else { + switchToForward(); + } + } + UChar trail; + if(U16_IS_LEAD(c) && pos != limit && U16_IS_TRAIL(trail = *pos)) { + ++pos; + return U16_GET_SUPPLEMENTARY(c, trail); + } else { + return c; + } +} + +UChar32 +FCDUTF16CollationIterator::previousCodePoint(UErrorCode &errorCode) { + UChar32 c; + for(;;) { + if(checkDir < 0) { + if(pos == start) { + return U_SENTINEL; + } + c = *--pos; + if(CollationFCD::hasLccc(c)) { + if(CollationFCD::maybeTibetanCompositeVowel(c) || + (pos != start && CollationFCD::hasTccc(*(pos - 1)))) { + ++pos; + if(!previousSegment(errorCode)) { + return U_SENTINEL; + } + c = *--pos; + } + } + break; + } else if(checkDir == 0 && pos != start) { + c = *--pos; + break; + } else { + switchToBackward(); + } + } + UChar lead; + if(U16_IS_TRAIL(c) && pos != start && U16_IS_LEAD(lead = *(pos - 1))) { + --pos; + return U16_GET_SUPPLEMENTARY(lead, c); + } else { + return c; + } +} + +void +FCDUTF16CollationIterator::forwardNumCodePoints(int32_t num, UErrorCode &errorCode) { + // Specify the class to avoid a virtual-function indirection. + // In Java, we would declare this class final. + while(num > 0 && FCDUTF16CollationIterator::nextCodePoint(errorCode) >= 0) { + --num; + } +} + +void +FCDUTF16CollationIterator::backwardNumCodePoints(int32_t num, UErrorCode &errorCode) { + // Specify the class to avoid a virtual-function indirection. + // In Java, we would declare this class final. + while(num > 0 && FCDUTF16CollationIterator::previousCodePoint(errorCode) >= 0) { + --num; + } +} + +void +FCDUTF16CollationIterator::switchToForward() { + U_ASSERT(checkDir < 0 || (checkDir == 0 && pos == limit)); + if(checkDir < 0) { + // Turn around from backward checking. + start = segmentStart = pos; + if(pos == segmentLimit) { + limit = rawLimit; + checkDir = 1; // Check forward. + } else { // pos < segmentLimit + checkDir = 0; // Stay in FCD segment. + } + } else { + // Reached the end of the FCD segment. + if(start == segmentStart) { + // The input text segment is FCD, extend it forward. + } else { + // The input text segment needed to be normalized. + // Switch to checking forward from it. + pos = start = segmentStart = segmentLimit; + // Note: If this segment is at the end of the input text, + // then it might help to return FALSE to indicate that, so that + // we do not have to re-check and normalize when we turn around and go backwards. + // However, that would complicate the call sites for an optimization of an unusual case. + } + limit = rawLimit; + checkDir = 1; + } +} + +UBool +FCDUTF16CollationIterator::nextSegment(UErrorCode &errorCode) { + if(U_FAILURE(errorCode)) { return FALSE; } + U_ASSERT(checkDir > 0 && pos != limit); + // The input text [segmentStart..pos[ passes the FCD check. + const UChar *p = pos; + uint8_t prevCC = 0; + for(;;) { + // Fetch the next character's fcd16 value. + const UChar *q = p; + uint16_t fcd16 = nfcImpl.nextFCD16(p, rawLimit); + uint8_t leadCC = (uint8_t)(fcd16 >> 8); + if(leadCC == 0 && q != pos) { + // FCD boundary before the [q, p[ character. + limit = segmentLimit = q; + break; + } + if(leadCC != 0 && (prevCC > leadCC || CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) { + // Fails FCD check. Find the next FCD boundary and normalize. + do { + q = p; + } while(p != rawLimit && nfcImpl.nextFCD16(p, rawLimit) > 0xff); + if(!normalize(pos, q, errorCode)) { return FALSE; } + pos = start; + break; + } + prevCC = (uint8_t)fcd16; + if(p == rawLimit || prevCC == 0) { + // FCD boundary after the last character. + limit = segmentLimit = p; + break; + } + } + U_ASSERT(pos != limit); + checkDir = 0; + return TRUE; +} + +void +FCDUTF16CollationIterator::switchToBackward() { + U_ASSERT(checkDir > 0 || (checkDir == 0 && pos == start)); + if(checkDir > 0) { + // Turn around from forward checking. + limit = segmentLimit = pos; + if(pos == segmentStart) { + start = rawStart; + checkDir = -1; // Check backward. + } else { // pos > segmentStart + checkDir = 0; // Stay in FCD segment. + } + } else { + // Reached the start of the FCD segment. + if(start == segmentStart) { + // The input text segment is FCD, extend it backward. + } else { + // The input text segment needed to be normalized. + // Switch to checking backward from it. + pos = limit = segmentLimit = segmentStart; + } + start = rawStart; + checkDir = -1; + } +} + +UBool +FCDUTF16CollationIterator::previousSegment(UErrorCode &errorCode) { + if(U_FAILURE(errorCode)) { return FALSE; } + U_ASSERT(checkDir < 0 && pos != start); + // The input text [pos..segmentLimit[ passes the FCD check. + const UChar *p = pos; + uint8_t nextCC = 0; + for(;;) { + // Fetch the previous character's fcd16 value. + const UChar *q = p; + uint16_t fcd16 = nfcImpl.previousFCD16(rawStart, p); + uint8_t trailCC = (uint8_t)fcd16; + if(trailCC == 0 && q != pos) { + // FCD boundary after the [p, q[ character. + start = segmentStart = q; + break; + } + if(trailCC != 0 && ((nextCC != 0 && trailCC > nextCC) || + CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) { + // Fails FCD check. Find the previous FCD boundary and normalize. + do { + q = p; + } while(fcd16 > 0xff && p != rawStart && + (fcd16 = nfcImpl.previousFCD16(rawStart, p)) != 0); + if(!normalize(q, pos, errorCode)) { return FALSE; } + pos = limit; + break; + } + nextCC = (uint8_t)(fcd16 >> 8); + if(p == rawStart || nextCC == 0) { + // FCD boundary before the following character. + start = segmentStart = p; + break; + } + } + U_ASSERT(pos != start); + checkDir = 0; + return TRUE; +} + +UBool +FCDUTF16CollationIterator::normalize(const UChar *from, const UChar *to, UErrorCode &errorCode) { + // NFD without argument checking. + U_ASSERT(U_SUCCESS(errorCode)); + nfcImpl.decompose(from, to, normalized, (int32_t)(to - from), errorCode); + if(U_FAILURE(errorCode)) { return FALSE; } + // Switch collation processing into the FCD buffer + // with the result of normalizing [segmentStart, segmentLimit[. + segmentStart = from; + segmentLimit = to; + start = normalized.getBuffer(); + limit = start + normalized.length(); + return TRUE; +} + +U_NAMESPACE_END + +#endif // !UCONFIG_NO_COLLATION |