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Diffstat (limited to '')
| -rw-r--r-- | intl/icu/source/i18n/nortrans.cpp | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/intl/icu/source/i18n/nortrans.cpp b/intl/icu/source/i18n/nortrans.cpp new file mode 100644 index 0000000000..d793433b3d --- /dev/null +++ b/intl/icu/source/i18n/nortrans.cpp @@ -0,0 +1,178 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +********************************************************************** +* Copyright (C) 2001-2011, International Business Machines +* Corporation and others. All Rights Reserved. +********************************************************************** +* Date Name Description +* 07/03/01 aliu Creation. +********************************************************************** +*/ + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_TRANSLITERATION + +#include "unicode/normalizer2.h" +#include "unicode/utf16.h" +#include "cstring.h" +#include "nortrans.h" + +U_NAMESPACE_BEGIN + +UOBJECT_DEFINE_RTTI_IMPLEMENTATION(NormalizationTransliterator) + +static inline Transliterator::Token cstrToken(const char *s) { + return Transliterator::pointerToken((void *)s); +} + +/** + * System registration hook. + */ +void NormalizationTransliterator::registerIDs() { + // In the Token, the byte after the NUL is the UNormalization2Mode. + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFC"), + _create, cstrToken("nfc\0\0")); + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFKC"), + _create, cstrToken("nfkc\0\0")); + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFD"), + _create, cstrToken("nfc\0\1")); + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFKD"), + _create, cstrToken("nfkc\0\1")); + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-FCD"), + _create, cstrToken("nfc\0\2")); + Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-FCC"), + _create, cstrToken("nfc\0\3")); + Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("NFC"), + UNICODE_STRING_SIMPLE("NFD"), true); + Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("NFKC"), + UNICODE_STRING_SIMPLE("NFKD"), true); + Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("FCC"), + UNICODE_STRING_SIMPLE("NFD"), false); + Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("FCD"), + UNICODE_STRING_SIMPLE("FCD"), false); +} + +/** + * Factory methods + */ +Transliterator* NormalizationTransliterator::_create(const UnicodeString& ID, + Token context) { + const char *name = (const char *)context.pointer; + UNormalization2Mode mode = (UNormalization2Mode)uprv_strchr(name, 0)[1]; + UErrorCode errorCode = U_ZERO_ERROR; + const Normalizer2 *norm2 = Normalizer2::getInstance(nullptr, name, mode, errorCode); + if(U_SUCCESS(errorCode)) { + return new NormalizationTransliterator(ID, *norm2); + } else { + return nullptr; + } +} + +/** + * Constructs a transliterator. + */ +NormalizationTransliterator::NormalizationTransliterator(const UnicodeString& id, + const Normalizer2 &norm2) : + Transliterator(id, 0), fNorm2(norm2) {} + +/** + * Destructor. + */ +NormalizationTransliterator::~NormalizationTransliterator() { +} + +/** + * Copy constructor. + */ +NormalizationTransliterator::NormalizationTransliterator(const NormalizationTransliterator& o) : + Transliterator(o), fNorm2(o.fNorm2) {} + +/** + * Transliterator API. + */ +NormalizationTransliterator* NormalizationTransliterator::clone() const { + return new NormalizationTransliterator(*this); +} + +/** + * Implements {@link Transliterator#handleTransliterate}. + */ +void NormalizationTransliterator::handleTransliterate(Replaceable& text, UTransPosition& offsets, + UBool isIncremental) const { + // start and limit of the input range + int32_t start = offsets.start; + int32_t limit = offsets.limit; + if(start >= limit) { + return; + } + + /* + * Normalize as short chunks at a time as possible even in + * bulk mode, so that styled text is minimally disrupted. + * In incremental mode, a chunk that ends with offsets.limit + * must not be normalized. + * + * If it was known that the input text is not styled, then + * a bulk mode normalization could look like this: + + UnicodeString input, normalized; + int32_t length = limit - start; + _Replaceable_extractBetween(text, start, limit, input.getBuffer(length)); + input.releaseBuffer(length); + + UErrorCode status = U_ZERO_ERROR; + fNorm2.normalize(input, normalized, status); + + text.handleReplaceBetween(start, limit, normalized); + + int32_t delta = normalized.length() - length; + offsets.contextLimit += delta; + offsets.limit += delta; + offsets.start = limit + delta; + + */ + UErrorCode errorCode = U_ZERO_ERROR; + UnicodeString segment; + UnicodeString normalized; + UChar32 c = text.char32At(start); + do { + int32_t prev = start; + // Skip at least one character so we make progress. + // c holds the character at start. + segment.remove(); + do { + segment.append(c); + start += U16_LENGTH(c); + } while(start < limit && !fNorm2.hasBoundaryBefore(c = text.char32At(start))); + if(start == limit && isIncremental && !fNorm2.hasBoundaryAfter(c)) { + // stop in incremental mode when we reach the input limit + // in case there are additional characters that could change the + // normalization result + start=prev; + break; + } + fNorm2.normalize(segment, normalized, errorCode); + if(U_FAILURE(errorCode)) { + break; + } + if(segment != normalized) { + // replace the input chunk with its normalized form + text.handleReplaceBetween(prev, start, normalized); + + // update all necessary indexes accordingly + int32_t delta = normalized.length() - (start - prev); + start += delta; + limit += delta; + } + } while(start < limit); + + offsets.start = start; + offsets.contextLimit += limit - offsets.limit; + offsets.limit = limit; +} + +U_NAMESPACE_END + +#endif /* #if !UCONFIG_NO_TRANSLITERATION */ |