/** ******************************************************************************* * Copyright (C) 2006-2013, International Business Machines Corporation * and others. All Rights Reserved. ******************************************************************************* */ #include "unicode/utypes.h" #if !UCONFIG_NO_BREAK_ITERATION #include "brkeng.h" #include "dictbe.h" #include "unicode/uniset.h" #include "unicode/chariter.h" #include "unicode/ubrk.h" #include "uvector.h" #include "uassert.h" #include "unicode/normlzr.h" #include "cmemory.h" #include "dictionarydata.h" U_NAMESPACE_BEGIN /* ****************************************************************** */ DictionaryBreakEngine::DictionaryBreakEngine(uint32_t breakTypes) { fTypes = breakTypes; } DictionaryBreakEngine::~DictionaryBreakEngine() { } UBool DictionaryBreakEngine::handles(UChar32 c, int32_t breakType) const { return (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes) && fSet.contains(c)); } int32_t DictionaryBreakEngine::findBreaks( UText *text, int32_t startPos, int32_t endPos, UBool reverse, int32_t breakType, UStack &foundBreaks ) const { int32_t result = 0; // Find the span of characters included in the set. int32_t start = (int32_t)utext_getNativeIndex(text); int32_t current; int32_t rangeStart; int32_t rangeEnd; UChar32 c = utext_current32(text); if (reverse) { UBool isDict = fSet.contains(c); while((current = (int32_t)utext_getNativeIndex(text)) > startPos && isDict) { c = utext_previous32(text); isDict = fSet.contains(c); } rangeStart = (current < startPos) ? startPos : current+(isDict ? 0 : 1); rangeEnd = start + 1; } else { while((current = (int32_t)utext_getNativeIndex(text)) < endPos && fSet.contains(c)) { utext_next32(text); // TODO: recast loop for postincrement c = utext_current32(text); } rangeStart = start; rangeEnd = current; } if (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes)) { result = divideUpDictionaryRange(text, rangeStart, rangeEnd, foundBreaks); utext_setNativeIndex(text, current); } return result; } void DictionaryBreakEngine::setCharacters( const UnicodeSet &set ) { fSet = set; // Compact for caching fSet.compact(); } /* ****************************************************************** * PossibleWord */ // Helper class for improving readability of the Thai/Lao/Khmer word break // algorithm. The implementation is completely inline. // List size, limited by the maximum number of words in the dictionary // that form a nested sequence. #define POSSIBLE_WORD_LIST_MAX 20 class PossibleWord { private: // list of word candidate lengths, in increasing length order int32_t lengths[POSSIBLE_WORD_LIST_MAX]; int32_t count; // Count of candidates int32_t prefix; // The longest match with a dictionary word int32_t offset; // Offset in the text of these candidates int mark; // The preferred candidate's offset int current; // The candidate we're currently looking at public: PossibleWord(); ~PossibleWord(); // Fill the list of candidates if needed, select the longest, and return the number found int candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd ); // Select the currently marked candidate, point after it in the text, and invalidate self int32_t acceptMarked( UText *text ); // Back up from the current candidate to the next shorter one; return TRUE if that exists // and point the text after it UBool backUp( UText *text ); // Return the longest prefix this candidate location shares with a dictionary word int32_t longestPrefix(); // Mark the current candidate as the one we like void markCurrent(); }; inline PossibleWord::PossibleWord() { offset = -1; } inline PossibleWord::~PossibleWord() { } inline int PossibleWord::candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd ) { // TODO: If getIndex is too slow, use offset < 0 and add discardAll() int32_t start = (int32_t)utext_getNativeIndex(text); if (start != offset) { offset = start; prefix = dict->matches(text, rangeEnd-start, lengths, count, sizeof(lengths)/sizeof(lengths[0])); // Dictionary leaves text after longest prefix, not longest word. Back up. if (count <= 0) { utext_setNativeIndex(text, start); } } if (count > 0) { utext_setNativeIndex(text, start+lengths[count-1]); } current = count-1; mark = current; return count; } inline int32_t PossibleWord::acceptMarked( UText *text ) { utext_setNativeIndex(text, offset + lengths[mark]); return lengths[mark]; } inline UBool PossibleWord::backUp( UText *text ) { if (current > 0) { utext_setNativeIndex(text, offset + lengths[--current]); return TRUE; } return FALSE; } inline int32_t PossibleWord::longestPrefix() { return prefix; } inline void PossibleWord::markCurrent() { mark = current; } /* ****************************************************************** * ThaiBreakEngine */ // How many words in a row are "good enough"? #define THAI_LOOKAHEAD 3 // Will not combine a non-word with a preceding dictionary word longer than this #define THAI_ROOT_COMBINE_THRESHOLD 3 // Will not combine a non-word that shares at least this much prefix with a // dictionary word, with a preceding word #define THAI_PREFIX_COMBINE_THRESHOLD 3 // Ellision character #define THAI_PAIYANNOI 0x0E2F // Repeat character #define THAI_MAIYAMOK 0x0E46 // Minimum word size #define THAI_MIN_WORD 2 // Minimum number of characters for two words #define THAI_MIN_WORD_SPAN (THAI_MIN_WORD * 2) ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine((1< 1) { // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } do { int wordsMatched = 1; if (words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { if (wordsMatched < 2) { // Followed by another dictionary word; mark first word as a good candidate words[wordsFound%THAI_LOOKAHEAD].markCurrent(); wordsMatched = 2; } // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } // See if any of the possible second words is followed by a third word do { // If we find a third word, stop right away if (words[(wordsFound + 2) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) { words[wordsFound % THAI_LOOKAHEAD].markCurrent(); goto foundBest; } } while (words[(wordsFound + 1) % THAI_LOOKAHEAD].backUp(text)); } } while (words[wordsFound % THAI_LOOKAHEAD].backUp(text)); foundBest: wordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text); wordsFound += 1; } // We come here after having either found a word or not. We look ahead to the // next word. If it's not a dictionary word, we will combine it withe the word we // just found (if there is one), but only if the preceding word does not exceed // the threshold. // The text iterator should now be positioned at the end of the word we found. if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < THAI_ROOT_COMBINE_THRESHOLD) { // if it is a dictionary word, do nothing. If it isn't, then if there is // no preceding word, or the non-word shares less than the minimum threshold // of characters with a dictionary word, then scan to resynchronize if (words[wordsFound % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 && (wordLength == 0 || words[wordsFound%THAI_LOOKAHEAD].longestPrefix() < THAI_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary //TODO: This section will need a rework for UText. int32_t remaining = rangeEnd - (current+wordLength); UChar32 pc = utext_current32(text); int32_t chars = 0; for (;;) { utext_next32(text); uc = utext_current32(text); // TODO: Here we're counting on the fact that the SA languages are all // in the BMP. This should get fixed with the UText rework. chars += 1; if (--remaining <= 0) { break; } if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. // NOTE: In the original Apple code, checked that the next // two characters after uc were not 0x0E4C THANTHAKHAT before // checking the dictionary. That is just a performance filter, // but it's not clear it's faster than checking the trie. int candidates = words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current + wordLength + chars); if (candidates > 0) { break; } } pc = uc; } // Bump the word count if there wasn't already one if (wordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters wordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current+wordLength); } } // Never stop before a combining mark. int32_t currPos; while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) { utext_next32(text); wordLength += (int32_t)utext_getNativeIndex(text) - currPos; } // Look ahead for possible suffixes if a dictionary word does not follow. // We do this in code rather than using a rule so that the heuristic // resynch continues to function. For example, one of the suffix characters // could be a typo in the middle of a word. if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) { if (words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 && fSuffixSet.contains(uc = utext_current32(text))) { if (uc == THAI_PAIYANNOI) { if (!fSuffixSet.contains(utext_previous32(text))) { // Skip over previous end and PAIYANNOI utext_next32(text); utext_next32(text); wordLength += 1; // Add PAIYANNOI to word uc = utext_current32(text); // Fetch next character } else { // Restore prior position utext_next32(text); } } if (uc == THAI_MAIYAMOK) { if (utext_previous32(text) != THAI_MAIYAMOK) { // Skip over previous end and MAIYAMOK utext_next32(text); utext_next32(text); wordLength += 1; // Add MAIYAMOK to word } else { // Restore prior position utext_next32(text); } } } else { utext_setNativeIndex(text, current+wordLength); } } // Did we find a word on this iteration? If so, push it on the break stack if (wordLength > 0) { foundBreaks.push((current+wordLength), status); } } // Don't return a break for the end of the dictionary range if there is one there. if (foundBreaks.peeki() >= rangeEnd) { (void) foundBreaks.popi(); wordsFound -= 1; } return wordsFound; } /* ****************************************************************** * LaoBreakEngine */ // How many words in a row are "good enough"? #define LAO_LOOKAHEAD 3 // Will not combine a non-word with a preceding dictionary word longer than this #define LAO_ROOT_COMBINE_THRESHOLD 3 // Will not combine a non-word that shares at least this much prefix with a // dictionary word, with a preceding word #define LAO_PREFIX_COMBINE_THRESHOLD 3 // Minimum word size #define LAO_MIN_WORD 2 // Minimum number of characters for two words #define LAO_MIN_WORD_SPAN (LAO_MIN_WORD * 2) LaoBreakEngine::LaoBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine((1< 1) { // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } do { int wordsMatched = 1; if (words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { if (wordsMatched < 2) { // Followed by another dictionary word; mark first word as a good candidate words[wordsFound%LAO_LOOKAHEAD].markCurrent(); wordsMatched = 2; } // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } // See if any of the possible second words is followed by a third word do { // If we find a third word, stop right away if (words[(wordsFound + 2) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) { words[wordsFound % LAO_LOOKAHEAD].markCurrent(); goto foundBest; } } while (words[(wordsFound + 1) % LAO_LOOKAHEAD].backUp(text)); } } while (words[wordsFound % LAO_LOOKAHEAD].backUp(text)); foundBest: wordLength = words[wordsFound % LAO_LOOKAHEAD].acceptMarked(text); wordsFound += 1; } // We come here after having either found a word or not. We look ahead to the // next word. If it's not a dictionary word, we will combine it withe the word we // just found (if there is one), but only if the preceding word does not exceed // the threshold. // The text iterator should now be positioned at the end of the word we found. if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < LAO_ROOT_COMBINE_THRESHOLD) { // if it is a dictionary word, do nothing. If it isn't, then if there is // no preceding word, or the non-word shares less than the minimum threshold // of characters with a dictionary word, then scan to resynchronize if (words[wordsFound % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 && (wordLength == 0 || words[wordsFound%LAO_LOOKAHEAD].longestPrefix() < LAO_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary //TODO: This section will need a rework for UText. int32_t remaining = rangeEnd - (current+wordLength); UChar32 pc = utext_current32(text); int32_t chars = 0; for (;;) { utext_next32(text); uc = utext_current32(text); // TODO: Here we're counting on the fact that the SA languages are all // in the BMP. This should get fixed with the UText rework. chars += 1; if (--remaining <= 0) { break; } if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. int candidates = words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current + wordLength + chars); if (candidates > 0) { break; } } pc = uc; } // Bump the word count if there wasn't already one if (wordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters wordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current+wordLength); } } // Never stop before a combining mark. int32_t currPos; while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) { utext_next32(text); wordLength += (int32_t)utext_getNativeIndex(text) - currPos; } // Look ahead for possible suffixes if a dictionary word does not follow. // We do this in code rather than using a rule so that the heuristic // resynch continues to function. For example, one of the suffix characters // could be a typo in the middle of a word. // NOT CURRENTLY APPLICABLE TO LAO // Did we find a word on this iteration? If so, push it on the break stack if (wordLength > 0) { foundBreaks.push((current+wordLength), status); } } // Don't return a break for the end of the dictionary range if there is one there. if (foundBreaks.peeki() >= rangeEnd) { (void) foundBreaks.popi(); wordsFound -= 1; } return wordsFound; } /* ****************************************************************** * KhmerBreakEngine */ // How many words in a row are "good enough"? #define KHMER_LOOKAHEAD 3 // Will not combine a non-word with a preceding dictionary word longer than this #define KHMER_ROOT_COMBINE_THRESHOLD 3 // Will not combine a non-word that shares at least this much prefix with a // dictionary word, with a preceding word #define KHMER_PREFIX_COMBINE_THRESHOLD 3 // Minimum word size #define KHMER_MIN_WORD 2 // Minimum number of characters for two words #define KHMER_MIN_WORD_SPAN (KHMER_MIN_WORD * 2) KhmerBreakEngine::KhmerBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine((1 << UBRK_WORD) | (1 << UBRK_LINE)), fDictionary(adoptDictionary) { fKhmerWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) { setCharacters(fKhmerWordSet); } fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]&[:M:]]"), status); fMarkSet.add(0x0020); fEndWordSet = fKhmerWordSet; fBeginWordSet.add(0x1780, 0x17B3); //fBeginWordSet.add(0x17A3, 0x17A4); // deprecated vowels //fEndWordSet.remove(0x17A5, 0x17A9); // Khmer independent vowels that can't end a word //fEndWordSet.remove(0x17B2); // Khmer independent vowel that can't end a word fEndWordSet.remove(0x17D2); // KHMER SIGN COENG that combines some following characters //fEndWordSet.remove(0x17B6, 0x17C5); // Remove dependent vowels // fEndWordSet.remove(0x0E31); // MAI HAN-AKAT // fEndWordSet.remove(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI // fBeginWordSet.add(0x0E01, 0x0E2E); // KO KAI through HO NOKHUK // fBeginWordSet.add(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI // fSuffixSet.add(THAI_PAIYANNOI); // fSuffixSet.add(THAI_MAIYAMOK); // Compact for caching. fMarkSet.compact(); fEndWordSet.compact(); fBeginWordSet.compact(); // fSuffixSet.compact(); } KhmerBreakEngine::~KhmerBreakEngine() { delete fDictionary; } int32_t KhmerBreakEngine::divideUpDictionaryRange( UText *text, int32_t rangeStart, int32_t rangeEnd, UStack &foundBreaks ) const { if ((rangeEnd - rangeStart) < KHMER_MIN_WORD_SPAN) { return 0; // Not enough characters for two words } uint32_t wordsFound = 0; int32_t wordLength; int32_t current; UErrorCode status = U_ZERO_ERROR; PossibleWord words[KHMER_LOOKAHEAD]; UChar32 uc; utext_setNativeIndex(text, rangeStart); while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) { wordLength = 0; // Look for candidate words at the current position int candidates = words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); // If we found exactly one, use that if (candidates == 1) { wordLength = words[wordsFound%KHMER_LOOKAHEAD].acceptMarked(text); wordsFound += 1; } // If there was more than one, see which one can take us forward the most words else if (candidates > 1) { // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } do { int wordsMatched = 1; if (words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { if (wordsMatched < 2) { // Followed by another dictionary word; mark first word as a good candidate words[wordsFound % KHMER_LOOKAHEAD].markCurrent(); wordsMatched = 2; } // If we're already at the end of the range, we're done if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } // See if any of the possible second words is followed by a third word do { // If we find a third word, stop right away if (words[(wordsFound + 2) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) { words[wordsFound % KHMER_LOOKAHEAD].markCurrent(); goto foundBest; } } while (words[(wordsFound + 1) % KHMER_LOOKAHEAD].backUp(text)); } } while (words[wordsFound % KHMER_LOOKAHEAD].backUp(text)); foundBest: wordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text); wordsFound += 1; } // We come here after having either found a word or not. We look ahead to the // next word. If it's not a dictionary word, we will combine it with the word we // just found (if there is one), but only if the preceding word does not exceed // the threshold. // The text iterator should now be positioned at the end of the word we found. if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < KHMER_ROOT_COMBINE_THRESHOLD) { // if it is a dictionary word, do nothing. If it isn't, then if there is // no preceding word, or the non-word shares less than the minimum threshold // of characters with a dictionary word, then scan to resynchronize if (words[wordsFound % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 && (wordLength == 0 || words[wordsFound % KHMER_LOOKAHEAD].longestPrefix() < KHMER_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary //TODO: This section will need a rework for UText. int32_t remaining = rangeEnd - (current+wordLength); UChar32 pc = utext_current32(text); int32_t chars = 0; for (;;) { utext_next32(text); uc = utext_current32(text); // TODO: Here we're counting on the fact that the SA languages are all // in the BMP. This should get fixed with the UText rework. chars += 1; if (--remaining <= 0) { break; } if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. int candidates = words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current+wordLength+chars); if (candidates > 0) { break; } } pc = uc; } // Bump the word count if there wasn't already one if (wordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters wordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current+wordLength); } } // Never stop before a combining mark. int32_t currPos; while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) { utext_next32(text); wordLength += (int32_t)utext_getNativeIndex(text) - currPos; } // Look ahead for possible suffixes if a dictionary word does not follow. // We do this in code rather than using a rule so that the heuristic // resynch continues to function. For example, one of the suffix characters // could be a typo in the middle of a word. // if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) { // if (words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 // && fSuffixSet.contains(uc = utext_current32(text))) { // if (uc == KHMER_PAIYANNOI) { // if (!fSuffixSet.contains(utext_previous32(text))) { // // Skip over previous end and PAIYANNOI // utext_next32(text); // utext_next32(text); // wordLength += 1; // Add PAIYANNOI to word // uc = utext_current32(text); // Fetch next character // } // else { // // Restore prior position // utext_next32(text); // } // } // if (uc == KHMER_MAIYAMOK) { // if (utext_previous32(text) != KHMER_MAIYAMOK) { // // Skip over previous end and MAIYAMOK // utext_next32(text); // utext_next32(text); // wordLength += 1; // Add MAIYAMOK to word // } // else { // // Restore prior position // utext_next32(text); // } // } // } // else { // utext_setNativeIndex(text, current+wordLength); // } // } // Did we find a word on this iteration? If so, push it on the break stack if (wordLength > 0) { foundBreaks.push((current+wordLength), status); } } // Don't return a break for the end of the dictionary range if there is one there. if (foundBreaks.peeki() >= rangeEnd) { (void) foundBreaks.popi(); wordsFound -= 1; } return wordsFound; } #if !UCONFIG_NO_NORMALIZATION /* ****************************************************************** * CjkBreakEngine */ static const uint32_t kuint32max = 0xFFFFFFFF; CjkBreakEngine::CjkBreakEngine(DictionaryMatcher *adoptDictionary, LanguageType type, UErrorCode &status) : DictionaryBreakEngine(1 << UBRK_WORD), fDictionary(adoptDictionary) { // Korean dictionary only includes Hangul syllables fHangulWordSet.applyPattern(UNICODE_STRING_SIMPLE("[\\uac00-\\ud7a3]"), status); fHanWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Han:]"), status); fKatakanaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Katakana:]\\uff9e\\uff9f]"), status); fHiraganaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Hiragana:]"), status); if (U_SUCCESS(status)) { // handle Korean and Japanese/Chinese using different dictionaries if (type == kKorean) { setCharacters(fHangulWordSet); } else { //Chinese and Japanese UnicodeSet cjSet; cjSet.addAll(fHanWordSet); cjSet.addAll(fKatakanaWordSet); cjSet.addAll(fHiraganaWordSet); cjSet.add(0xFF70); // HALFWIDTH KATAKANA-HIRAGANA PROLONGED SOUND MARK cjSet.add(0x30FC); // KATAKANA-HIRAGANA PROLONGED SOUND MARK setCharacters(cjSet); } } } CjkBreakEngine::~CjkBreakEngine(){ delete fDictionary; } // The katakanaCost values below are based on the length frequencies of all // katakana phrases in the dictionary static const int kMaxKatakanaLength = 8; static const int kMaxKatakanaGroupLength = 20; static const uint32_t maxSnlp = 255; static inline uint32_t getKatakanaCost(int wordLength){ //TODO: fill array with actual values from dictionary! static const uint32_t katakanaCost[kMaxKatakanaLength + 1] = {8192, 984, 408, 240, 204, 252, 300, 372, 480}; return (wordLength > kMaxKatakanaLength) ? 8192 : katakanaCost[wordLength]; } static inline bool isKatakana(uint16_t value) { return (value >= 0x30A1u && value <= 0x30FEu && value != 0x30FBu) || (value >= 0xFF66u && value <= 0xFF9fu); } // A very simple helper class to streamline the buffer handling in // divideUpDictionaryRange. template class AutoBuffer { public: AutoBuffer(size_t size) : buffer(stackBuffer), capacity(N) { if (size > N) { buffer = reinterpret_cast(uprv_malloc(sizeof(T)*size)); capacity = size; } } ~AutoBuffer() { if (buffer != stackBuffer) uprv_free(buffer); } T* elems() { return buffer; } const T& operator[] (size_t i) const { return buffer[i]; } T& operator[] (size_t i) { return buffer[i]; } // resize without copy void resize(size_t size) { if (size <= capacity) return; if (buffer != stackBuffer) uprv_free(buffer); buffer = reinterpret_cast(uprv_malloc(sizeof(T)*size)); capacity = size; } private: T stackBuffer[N]; T* buffer; AutoBuffer(); size_t capacity; }; /* * @param text A UText representing the text * @param rangeStart The start of the range of dictionary characters * @param rangeEnd The end of the range of dictionary characters * @param foundBreaks Output of C array of int32_t break positions, or 0 * @return The number of breaks found */ int32_t CjkBreakEngine::divideUpDictionaryRange( UText *text, int32_t rangeStart, int32_t rangeEnd, UStack &foundBreaks ) const { if (rangeStart >= rangeEnd) { return 0; } const size_t defaultInputLength = 80; size_t inputLength = rangeEnd - rangeStart; // TODO: Replace by UnicodeString. AutoBuffer charString(inputLength); // Normalize the input string and put it in normalizedText. // The map from the indices of the normalized input to the raw // input is kept in charPositions. UErrorCode status = U_ZERO_ERROR; utext_extract(text, rangeStart, rangeEnd, charString.elems(), inputLength, &status); if (U_FAILURE(status)) { return 0; } UnicodeString inputString(charString.elems(), inputLength); // TODO: Use Normalizer2. UNormalizationMode norm_mode = UNORM_NFKC; UBool isNormalized = Normalizer::quickCheck(inputString, norm_mode, status) == UNORM_YES || Normalizer::isNormalized(inputString, norm_mode, status); // TODO: Replace by UVector32. AutoBuffer charPositions(inputLength + 1); int numChars = 0; UText normalizedText = UTEXT_INITIALIZER; // Needs to be declared here because normalizedText holds onto its buffer. UnicodeString normalizedString; if (isNormalized) { int32_t index = 0; charPositions[0] = 0; while(index < inputString.length()) { index = inputString.moveIndex32(index, 1); charPositions[++numChars] = index; } utext_openUnicodeString(&normalizedText, &inputString, &status); } else { Normalizer::normalize(inputString, norm_mode, 0, normalizedString, status); if (U_FAILURE(status)) { return 0; } charPositions.resize(normalizedString.length() + 1); Normalizer normalizer(charString.elems(), inputLength, norm_mode); int32_t index = 0; charPositions[0] = 0; while(index < normalizer.endIndex()){ /* UChar32 uc = */ normalizer.next(); charPositions[++numChars] = index = normalizer.getIndex(); } utext_openUnicodeString(&normalizedText, &normalizedString, &status); } if (U_FAILURE(status)) { return 0; } // From this point on, all the indices refer to the indices of // the normalized input string. // bestSnlp[i] is the snlp of the best segmentation of the first i // characters in the range to be matched. // TODO: Replace by UVector32. AutoBuffer bestSnlp(numChars + 1); bestSnlp[0] = 0; for(int i = 1; i <= numChars; i++) { bestSnlp[i] = kuint32max; } // prev[i] is the index of the last CJK character in the previous word in // the best segmentation of the first i characters. // TODO: Replace by UVector32. AutoBuffer prev(numChars + 1); for(int i = 0; i <= numChars; i++){ prev[i] = -1; } const size_t maxWordSize = 20; // TODO: Replace both with UVector32. AutoBuffer values(numChars); AutoBuffer lengths(numChars); // Dynamic programming to find the best segmentation. bool is_prev_katakana = false; for (int32_t i = 0; i < numChars; ++i) { //utext_setNativeIndex(text, rangeStart + i); utext_setNativeIndex(&normalizedText, i); if (bestSnlp[i] == kuint32max) continue; int32_t count; // limit maximum word length matched to size of current substring int32_t maxSearchLength = (i + maxWordSize < (size_t) numChars)? maxWordSize : (numChars - i); fDictionary->matches(&normalizedText, maxSearchLength, lengths.elems(), count, maxSearchLength, values.elems()); // if there are no single character matches found in the dictionary // starting with this charcter, treat character as a 1-character word // with the highest value possible, i.e. the least likely to occur. // Exclude Korean characters from this treatment, as they should be left // together by default. if((count == 0 || lengths[0] != 1) && !fHangulWordSet.contains(utext_current32(&normalizedText))) { values[count] = maxSnlp; lengths[count++] = 1; } for (int j = 0; j < count; j++) { uint32_t newSnlp = bestSnlp[i] + values[j]; if (newSnlp < bestSnlp[lengths[j] + i]) { bestSnlp[lengths[j] + i] = newSnlp; prev[lengths[j] + i] = i; } } // In Japanese, // Katakana word in single character is pretty rare. So we apply // the following heuristic to Katakana: any continuous run of Katakana // characters is considered a candidate word with a default cost // specified in the katakanaCost table according to its length. //utext_setNativeIndex(text, rangeStart + i); utext_setNativeIndex(&normalizedText, i); bool is_katakana = isKatakana(utext_current32(&normalizedText)); if (!is_prev_katakana && is_katakana) { int j = i + 1; utext_next32(&normalizedText); // Find the end of the continuous run of Katakana characters while (j < numChars && (j - i) < kMaxKatakanaGroupLength && isKatakana(utext_current32(&normalizedText))) { utext_next32(&normalizedText); ++j; } if ((j - i) < kMaxKatakanaGroupLength) { uint32_t newSnlp = bestSnlp[i] + getKatakanaCost(j - i); if (newSnlp < bestSnlp[j]) { bestSnlp[j] = newSnlp; prev[j] = i; } } } is_prev_katakana = is_katakana; } // Start pushing the optimal offset index into t_boundary (t for tentative). // prev[numChars] is guaranteed to be meaningful. // We'll first push in the reverse order, i.e., // t_boundary[0] = numChars, and afterwards do a swap. // TODO: Replace by UVector32. AutoBuffer t_boundary(numChars + 1); int numBreaks = 0; // No segmentation found, set boundary to end of range if (bestSnlp[numChars] == kuint32max) { t_boundary[numBreaks++] = numChars; } else { for (int i = numChars; i > 0; i = prev[i]) { t_boundary[numBreaks++] = i; } U_ASSERT(prev[t_boundary[numBreaks - 1]] == 0); } // Reverse offset index in t_boundary. // Don't add a break for the start of the dictionary range if there is one // there already. if (foundBreaks.size() == 0 || foundBreaks.peeki() < rangeStart) { t_boundary[numBreaks++] = 0; } // Now that we're done, convert positions in t_bdry[] (indices in // the normalized input string) back to indices in the raw input string // while reversing t_bdry and pushing values to foundBreaks. for (int i = numBreaks-1; i >= 0; i--) { foundBreaks.push(charPositions[t_boundary[i]] + rangeStart, status); } utext_close(&normalizedText); return numBreaks; } #endif U_NAMESPACE_END #endif /* #if !UCONFIG_NO_BREAK_ITERATION */