// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /** ******************************************************************************* * Copyright (C) 2006-2016, 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 "uvectr32.h" #include "uvector.h" #include "uassert.h" #include "unicode/normlzr.h" #include "cmemory.h" #include "dictionarydata.h" U_NAMESPACE_BEGIN /* ****************************************************************** */ DictionaryBreakEngine::DictionaryBreakEngine() { } DictionaryBreakEngine::~DictionaryBreakEngine() { } UBool DictionaryBreakEngine::handles(UChar32 c) const { return fSet.contains(c); } int32_t DictionaryBreakEngine::findBreaks( UText *text, int32_t startPos, int32_t endPos, UVector32 &foundBreaks ) const { (void)startPos; // TODO: remove this param? int32_t result = 0; // Find the span of characters included in the set. // The span to break begins at the current position in the text, and // extends towards the start or end of the text, depending on 'reverse'. int32_t start = (int32_t)utext_getNativeIndex(text); int32_t current; int32_t rangeStart; int32_t rangeEnd; UChar32 c = utext_current32(text); 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; 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. static const int32_t POSSIBLE_WORD_LIST_MAX = 20; class PossibleWord { private: // list of word candidate lengths, in increasing length order // TODO: bytes would be sufficient for word lengths. 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 int32_t mark; // The preferred candidate's offset int32_t current; // The candidate we're currently looking at int32_t cuLengths[POSSIBLE_WORD_LIST_MAX]; // Word Lengths, in code units. int32_t cpLengths[POSSIBLE_WORD_LIST_MAX]; // Word Lengths, in code points. public: PossibleWord() : count(0), prefix(0), offset(-1), mark(0), current(0) {}; ~PossibleWord() {}; // Fill the list of candidates if needed, select the longest, and return the number found int32_t 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 // Return value is in code points. int32_t longestPrefix() { return prefix; }; // Mark the current candidate as the one we like void markCurrent() { mark = current; }; // Get length in code points of the marked word. int32_t markedCPLength() { return cpLengths[mark]; }; }; int32_t 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; count = dict->matches(text, rangeEnd-start, UPRV_LENGTHOF(cuLengths), cuLengths, cpLengths, NULL, &prefix); // 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+cuLengths[count-1]); } current = count-1; mark = current; return count; } int32_t PossibleWord::acceptMarked( UText *text ) { utext_setNativeIndex(text, offset + cuLengths[mark]); return cuLengths[mark]; } UBool PossibleWord::backUp( UText *text ) { if (current > 0) { utext_setNativeIndex(text, offset + cuLengths[--current]); return TRUE; } return FALSE; } /* ****************************************************************** * ThaiBreakEngine */ // How many words in a row are "good enough"? static const int32_t THAI_LOOKAHEAD = 3; // Will not combine a non-word with a preceding dictionary word longer than this static const int32_t 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 static const int32_t THAI_PREFIX_COMBINE_THRESHOLD = 3; // Ellision character static const int32_t THAI_PAIYANNOI = 0x0E2F; // Repeat character static const int32_t THAI_MAIYAMOK = 0x0E46; // Minimum word size static const int32_t THAI_MIN_WORD = 2; // Minimum number of characters for two words static const int32_t THAI_MIN_WORD_SPAN = THAI_MIN_WORD * 2; ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine(), fDictionary(adoptDictionary) { fThaiWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Thai:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) { setCharacters(fThaiWordSet); } fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Thai:]&[:LineBreak=SA:]&[:M:]]"), status); fMarkSet.add(0x0020); fEndWordSet = fThaiWordSet; 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(); } ThaiBreakEngine::~ThaiBreakEngine() { delete fDictionary; } int32_t ThaiBreakEngine::divideUpDictionaryRange( UText *text, int32_t rangeStart, int32_t rangeEnd, UVector32 &foundBreaks ) const { utext_setNativeIndex(text, rangeStart); utext_moveIndex32(text, THAI_MIN_WORD_SPAN); if (utext_getNativeIndex(text) >= rangeEnd) { return 0; // Not enough characters for two words } utext_setNativeIndex(text, rangeStart); uint32_t wordsFound = 0; int32_t cpWordLength = 0; // Word Length in Code Points. int32_t cuWordLength = 0; // Word length in code units (UText native indexing) int32_t current; UErrorCode status = U_ZERO_ERROR; PossibleWord words[THAI_LOOKAHEAD]; utext_setNativeIndex(text, rangeStart); while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) { cpWordLength = 0; cuWordLength = 0; // Look for candidate words at the current position int32_t candidates = words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); // If we found exactly one, use that if (candidates == 1) { cuWordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % THAI_LOOKAHEAD].markedCPLength(); 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 { int32_t 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: // Set UText position to after the accepted word. cuWordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % THAI_LOOKAHEAD].markedCPLength(); 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. UChar32 uc = 0; if ((int32_t)utext_getNativeIndex(text) < rangeEnd && cpWordLength < 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 && (cuWordLength == 0 || words[wordsFound%THAI_LOOKAHEAD].longestPrefix() < THAI_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary int32_t remaining = rangeEnd - (current+cuWordLength); UChar32 pc; int32_t chars = 0; for (;;) { int32_t pcIndex = (int32_t)utext_getNativeIndex(text); pc = utext_next32(text); int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex; chars += pcSize; remaining -= pcSize; if (remaining <= 0) { break; } uc = utext_current32(text); 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. int32_t num_candidates = words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current + cuWordLength + chars); if (num_candidates > 0) { break; } } } // Bump the word count if there wasn't already one if (cuWordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters cuWordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current+cuWordLength); } } // 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); cuWordLength += (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 && cuWordLength > 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); int32_t paiyannoiIndex = (int32_t)utext_getNativeIndex(text); utext_next32(text); cuWordLength += (int32_t)utext_getNativeIndex(text) - paiyannoiIndex; // 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); int32_t maiyamokIndex = (int32_t)utext_getNativeIndex(text); utext_next32(text); cuWordLength += (int32_t)utext_getNativeIndex(text) - maiyamokIndex; // Add MAIYAMOK to word } else { // Restore prior position utext_next32(text); } } } else { utext_setNativeIndex(text, current+cuWordLength); } } // Did we find a word on this iteration? If so, push it on the break stack if (cuWordLength > 0) { foundBreaks.push((current+cuWordLength), 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"? static const int32_t LAO_LOOKAHEAD = 3; // Will not combine a non-word with a preceding dictionary word longer than this static const int32_t 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 static const int32_t LAO_PREFIX_COMBINE_THRESHOLD = 3; // Minimum word size static const int32_t LAO_MIN_WORD = 2; // Minimum number of characters for two words static const int32_t LAO_MIN_WORD_SPAN = LAO_MIN_WORD * 2; LaoBreakEngine::LaoBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine(), fDictionary(adoptDictionary) { fLaoWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Laoo:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) { setCharacters(fLaoWordSet); } fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Laoo:]&[:LineBreak=SA:]&[:M:]]"), status); fMarkSet.add(0x0020); fEndWordSet = fLaoWordSet; fEndWordSet.remove(0x0EC0, 0x0EC4); // prefix vowels fBeginWordSet.add(0x0E81, 0x0EAE); // basic consonants (including holes for corresponding Thai characters) fBeginWordSet.add(0x0EDC, 0x0EDD); // digraph consonants (no Thai equivalent) fBeginWordSet.add(0x0EC0, 0x0EC4); // prefix vowels // Compact for caching. fMarkSet.compact(); fEndWordSet.compact(); fBeginWordSet.compact(); } LaoBreakEngine::~LaoBreakEngine() { delete fDictionary; } int32_t LaoBreakEngine::divideUpDictionaryRange( UText *text, int32_t rangeStart, int32_t rangeEnd, UVector32 &foundBreaks ) const { if ((rangeEnd - rangeStart) < LAO_MIN_WORD_SPAN) { return 0; // Not enough characters for two words } uint32_t wordsFound = 0; int32_t cpWordLength = 0; int32_t cuWordLength = 0; int32_t current; UErrorCode status = U_ZERO_ERROR; PossibleWord words[LAO_LOOKAHEAD]; utext_setNativeIndex(text, rangeStart); while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) { cuWordLength = 0; cpWordLength = 0; // Look for candidate words at the current position int32_t candidates = words[wordsFound%LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); // If we found exactly one, use that if (candidates == 1) { cuWordLength = words[wordsFound % LAO_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % LAO_LOOKAHEAD].markedCPLength(); 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 (utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } do { int32_t 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: cuWordLength = words[wordsFound % LAO_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % LAO_LOOKAHEAD].markedCPLength(); 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 && cpWordLength < 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 && (cuWordLength == 0 || words[wordsFound%LAO_LOOKAHEAD].longestPrefix() < LAO_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary int32_t remaining = rangeEnd - (current + cuWordLength); UChar32 pc; UChar32 uc; int32_t chars = 0; for (;;) { int32_t pcIndex = (int32_t)utext_getNativeIndex(text); pc = utext_next32(text); int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex; chars += pcSize; remaining -= pcSize; if (remaining <= 0) { break; } uc = utext_current32(text); if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. // TODO: this looks iffy; compare with old code. int32_t num_candidates = words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current + cuWordLength + chars); if (num_candidates > 0) { break; } } } // Bump the word count if there wasn't already one if (cuWordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters cuWordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current + cuWordLength); } } // 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); cuWordLength += (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 (cuWordLength > 0) { foundBreaks.push((current+cuWordLength), 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; } /* ****************************************************************** * BurmeseBreakEngine */ // How many words in a row are "good enough"? static const int32_t BURMESE_LOOKAHEAD = 3; // Will not combine a non-word with a preceding dictionary word longer than this static const int32_t BURMESE_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 static const int32_t BURMESE_PREFIX_COMBINE_THRESHOLD = 3; // Minimum word size static const int32_t BURMESE_MIN_WORD = 2; // Minimum number of characters for two words static const int32_t BURMESE_MIN_WORD_SPAN = BURMESE_MIN_WORD * 2; BurmeseBreakEngine::BurmeseBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine(), fDictionary(adoptDictionary) { fBurmeseWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Mymr:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) { setCharacters(fBurmeseWordSet); } fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Mymr:]&[:LineBreak=SA:]&[:M:]]"), status); fMarkSet.add(0x0020); fEndWordSet = fBurmeseWordSet; fBeginWordSet.add(0x1000, 0x102A); // basic consonants and independent vowels // Compact for caching. fMarkSet.compact(); fEndWordSet.compact(); fBeginWordSet.compact(); } BurmeseBreakEngine::~BurmeseBreakEngine() { delete fDictionary; } int32_t BurmeseBreakEngine::divideUpDictionaryRange( UText *text, int32_t rangeStart, int32_t rangeEnd, UVector32 &foundBreaks ) const { if ((rangeEnd - rangeStart) < BURMESE_MIN_WORD_SPAN) { return 0; // Not enough characters for two words } uint32_t wordsFound = 0; int32_t cpWordLength = 0; int32_t cuWordLength = 0; int32_t current; UErrorCode status = U_ZERO_ERROR; PossibleWord words[BURMESE_LOOKAHEAD]; utext_setNativeIndex(text, rangeStart); while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) { cuWordLength = 0; cpWordLength = 0; // Look for candidate words at the current position int32_t candidates = words[wordsFound%BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); // If we found exactly one, use that if (candidates == 1) { cuWordLength = words[wordsFound % BURMESE_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % BURMESE_LOOKAHEAD].markedCPLength(); 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 (utext_getNativeIndex(text) >= rangeEnd) { goto foundBest; } do { int32_t wordsMatched = 1; if (words[(wordsFound + 1) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { if (wordsMatched < 2) { // Followed by another dictionary word; mark first word as a good candidate words[wordsFound%BURMESE_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) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) { words[wordsFound % BURMESE_LOOKAHEAD].markCurrent(); goto foundBest; } } while (words[(wordsFound + 1) % BURMESE_LOOKAHEAD].backUp(text)); } } while (words[wordsFound % BURMESE_LOOKAHEAD].backUp(text)); foundBest: cuWordLength = words[wordsFound % BURMESE_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % BURMESE_LOOKAHEAD].markedCPLength(); 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 && cpWordLength < BURMESE_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 % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0 && (cuWordLength == 0 || words[wordsFound%BURMESE_LOOKAHEAD].longestPrefix() < BURMESE_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary int32_t remaining = rangeEnd - (current + cuWordLength); UChar32 pc; UChar32 uc; int32_t chars = 0; for (;;) { int32_t pcIndex = (int32_t)utext_getNativeIndex(text); pc = utext_next32(text); int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex; chars += pcSize; remaining -= pcSize; if (remaining <= 0) { break; } uc = utext_current32(text); if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. // TODO: this looks iffy; compare with old code. int32_t num_candidates = words[(wordsFound + 1) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current + cuWordLength + chars); if (num_candidates > 0) { break; } } } // Bump the word count if there wasn't already one if (cuWordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters cuWordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current + cuWordLength); } } // 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); cuWordLength += (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 BURMESE // Did we find a word on this iteration? If so, push it on the break stack if (cuWordLength > 0) { foundBreaks.push((current+cuWordLength), 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"? static const int32_t KHMER_LOOKAHEAD = 3; // Will not combine a non-word with a preceding dictionary word longer than this static const int32_t 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 static const int32_t KHMER_PREFIX_COMBINE_THRESHOLD = 3; // Minimum word size static const int32_t KHMER_MIN_WORD = 2; // Minimum number of characters for two words static const int32_t KHMER_MIN_WORD_SPAN = KHMER_MIN_WORD * 2; KhmerBreakEngine::KhmerBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status) : DictionaryBreakEngine(), 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, UVector32 &foundBreaks ) const { if ((rangeEnd - rangeStart) < KHMER_MIN_WORD_SPAN) { return 0; // Not enough characters for two words } uint32_t wordsFound = 0; int32_t cpWordLength = 0; int32_t cuWordLength = 0; int32_t current; UErrorCode status = U_ZERO_ERROR; PossibleWord words[KHMER_LOOKAHEAD]; utext_setNativeIndex(text, rangeStart); while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) { cuWordLength = 0; cpWordLength = 0; // Look for candidate words at the current position int32_t candidates = words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); // If we found exactly one, use that if (candidates == 1) { cuWordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % KHMER_LOOKAHEAD].markedCPLength(); 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 { int32_t 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: cuWordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text); cpWordLength = words[wordsFound % KHMER_LOOKAHEAD].markedCPLength(); 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 && cpWordLength < 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 && (cuWordLength == 0 || words[wordsFound % KHMER_LOOKAHEAD].longestPrefix() < KHMER_PREFIX_COMBINE_THRESHOLD)) { // Look for a plausible word boundary int32_t remaining = rangeEnd - (current+cuWordLength); UChar32 pc; UChar32 uc; int32_t chars = 0; for (;;) { int32_t pcIndex = (int32_t)utext_getNativeIndex(text); pc = utext_next32(text); int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex; chars += pcSize; remaining -= pcSize; if (remaining <= 0) { break; } uc = utext_current32(text); if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) { // Maybe. See if it's in the dictionary. int32_t num_candidates = words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); utext_setNativeIndex(text, current+cuWordLength+chars); if (num_candidates > 0) { break; } } } // Bump the word count if there wasn't already one if (cuWordLength <= 0) { wordsFound += 1; } // Update the length with the passed-over characters cuWordLength += chars; } else { // Back up to where we were for next iteration utext_setNativeIndex(text, current+cuWordLength); } } // 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); cuWordLength += (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 (cuWordLength > 0) { foundBreaks.push((current+cuWordLength), 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(), 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); nfkcNorm2 = Normalizer2::getNFKCInstance(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 int32_t kMaxKatakanaLength = 8; static const int32_t kMaxKatakanaGroupLength = 20; static const uint32_t maxSnlp = 255; static inline uint32_t getKatakanaCost(int32_t 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(UChar32 value) { return (value >= 0x30A1 && value <= 0x30FE && value != 0x30FB) || (value >= 0xFF66 && value <= 0xFF9f); } // Function for accessing internal utext flags. // Replicates an internal UText function. static inline int32_t utext_i32_flag(int32_t bitIndex) { return (int32_t)1 << bitIndex; } /* * @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 vector to receive the break positions * @return The number of breaks found */ int32_t CjkBreakEngine::divideUpDictionaryRange( UText *inText, int32_t rangeStart, int32_t rangeEnd, UVector32 &foundBreaks ) const { if (rangeStart >= rangeEnd) { return 0; } // UnicodeString version of input UText, NFKC normalized if necessary. UnicodeString inString; // inputMap[inStringIndex] = corresponding native index from UText inText. // If NULL then mapping is 1:1 LocalPointer inputMap; UErrorCode status = U_ZERO_ERROR; // if UText has the input string as one contiguous UTF-16 chunk if ((inText->providerProperties & utext_i32_flag(UTEXT_PROVIDER_STABLE_CHUNKS)) && inText->chunkNativeStart <= rangeStart && inText->chunkNativeLimit >= rangeEnd && inText->nativeIndexingLimit >= rangeEnd - inText->chunkNativeStart) { // Input UText is in one contiguous UTF-16 chunk. // Use Read-only aliasing UnicodeString. inString.setTo(FALSE, inText->chunkContents + rangeStart - inText->chunkNativeStart, rangeEnd - rangeStart); } else { // Copy the text from the original inText (UText) to inString (UnicodeString). // Create a map from UnicodeString indices -> UText offsets. utext_setNativeIndex(inText, rangeStart); int32_t limit = rangeEnd; U_ASSERT(limit <= utext_nativeLength(inText)); if (limit > utext_nativeLength(inText)) { limit = (int32_t)utext_nativeLength(inText); } inputMap.adoptInsteadAndCheckErrorCode(new UVector32(status), status); if (U_FAILURE(status)) { return 0; } while (utext_getNativeIndex(inText) < limit) { int32_t nativePosition = (int32_t)utext_getNativeIndex(inText); UChar32 c = utext_next32(inText); U_ASSERT(c != U_SENTINEL); inString.append(c); while (inputMap->size() < inString.length()) { inputMap->addElement(nativePosition, status); } } inputMap->addElement(limit, status); } if (!nfkcNorm2->isNormalized(inString, status)) { UnicodeString normalizedInput; // normalizedMap[normalizedInput position] == original UText position. LocalPointer normalizedMap(new UVector32(status), status); if (U_FAILURE(status)) { return 0; } UnicodeString fragment; UnicodeString normalizedFragment; for (int32_t srcI = 0; srcI < inString.length();) { // Once per normalization chunk fragment.remove(); int32_t fragmentStartI = srcI; UChar32 c = inString.char32At(srcI); for (;;) { fragment.append(c); srcI = inString.moveIndex32(srcI, 1); if (srcI == inString.length()) { break; } c = inString.char32At(srcI); if (nfkcNorm2->hasBoundaryBefore(c)) { break; } } nfkcNorm2->normalize(fragment, normalizedFragment, status); normalizedInput.append(normalizedFragment); // Map every position in the normalized chunk to the start of the chunk // in the original input. int32_t fragmentOriginalStart = inputMap.isValid() ? inputMap->elementAti(fragmentStartI) : fragmentStartI+rangeStart; while (normalizedMap->size() < normalizedInput.length()) { normalizedMap->addElement(fragmentOriginalStart, status); if (U_FAILURE(status)) { break; } } } U_ASSERT(normalizedMap->size() == normalizedInput.length()); int32_t nativeEnd = inputMap.isValid() ? inputMap->elementAti(inString.length()) : inString.length()+rangeStart; normalizedMap->addElement(nativeEnd, status); inputMap.moveFrom(normalizedMap); inString.moveFrom(normalizedInput); } int32_t numCodePts = inString.countChar32(); if (numCodePts != inString.length()) { // There are supplementary characters in the input. // The dictionary will produce boundary positions in terms of code point indexes, // not in terms of code unit string indexes. // Use the inputMap mechanism to take care of this in addition to indexing differences // from normalization and/or UTF-8 input. UBool hadExistingMap = inputMap.isValid(); if (!hadExistingMap) { inputMap.adoptInsteadAndCheckErrorCode(new UVector32(status), status); if (U_FAILURE(status)) { return 0; } } int32_t cpIdx = 0; for (int32_t cuIdx = 0; ; cuIdx = inString.moveIndex32(cuIdx, 1)) { U_ASSERT(cuIdx >= cpIdx); if (hadExistingMap) { inputMap->setElementAt(inputMap->elementAti(cuIdx), cpIdx); } else { inputMap->addElement(cuIdx+rangeStart, status); } cpIdx++; if (cuIdx == inString.length()) { break; } } } // bestSnlp[i] is the snlp of the best segmentation of the first i // code points in the range to be matched. UVector32 bestSnlp(numCodePts + 1, status); bestSnlp.addElement(0, status); for(int32_t i = 1; i <= numCodePts; i++) { bestSnlp.addElement(kuint32max, status); } // prev[i] is the index of the last CJK code point in the previous word in // the best segmentation of the first i characters. UVector32 prev(numCodePts + 1, status); for(int32_t i = 0; i <= numCodePts; i++){ prev.addElement(-1, status); } const int32_t maxWordSize = 20; UVector32 values(numCodePts, status); values.setSize(numCodePts); UVector32 lengths(numCodePts, status); lengths.setSize(numCodePts); UText fu = UTEXT_INITIALIZER; utext_openUnicodeString(&fu, &inString, &status); // Dynamic programming to find the best segmentation. // In outer loop, i is the code point index, // ix is the corresponding string (code unit) index. // They differ when the string contains supplementary characters. int32_t ix = 0; bool is_prev_katakana = false; for (int32_t i = 0; i < numCodePts; ++i, ix = inString.moveIndex32(ix, 1)) { if ((uint32_t)bestSnlp.elementAti(i) == kuint32max) { continue; } int32_t count; utext_setNativeIndex(&fu, ix); count = fDictionary->matches(&fu, maxWordSize, numCodePts, NULL, lengths.getBuffer(), values.getBuffer(), NULL); // Note: lengths is filled with code point lengths // The NULL parameter is the ignored code unit lengths. // if there are no single character matches found in the dictionary // starting with this character, 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.elementAti(0) != 1) && !fHangulWordSet.contains(inString.char32At(ix))) { values.setElementAt(maxSnlp, count); // 255 lengths.setElementAt(1, count++); } for (int32_t j = 0; j < count; j++) { uint32_t newSnlp = (uint32_t)bestSnlp.elementAti(i) + (uint32_t)values.elementAti(j); int32_t ln_j_i = lengths.elementAti(j) + i; if (newSnlp < (uint32_t)bestSnlp.elementAti(ln_j_i)) { bestSnlp.setElementAt(newSnlp, ln_j_i); prev.setElementAt(i, ln_j_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. bool is_katakana = isKatakana(inString.char32At(ix)); int32_t katakanaRunLength = 1; if (!is_prev_katakana && is_katakana) { int32_t j = inString.moveIndex32(ix, 1); // Find the end of the continuous run of Katakana characters while (j < inString.length() && katakanaRunLength < kMaxKatakanaGroupLength && isKatakana(inString.char32At(j))) { j = inString.moveIndex32(j, 1); katakanaRunLength++; } if (katakanaRunLength < kMaxKatakanaGroupLength) { uint32_t newSnlp = bestSnlp.elementAti(i) + getKatakanaCost(katakanaRunLength); if (newSnlp < (uint32_t)bestSnlp.elementAti(i+katakanaRunLength)) { bestSnlp.setElementAt(newSnlp, i+katakanaRunLength); prev.setElementAt(i, i+katakanaRunLength); // prev[j] = i; } } } is_prev_katakana = is_katakana; } utext_close(&fu); // Start pushing the optimal offset index into t_boundary (t for tentative). // prev[numCodePts] is guaranteed to be meaningful. // We'll first push in the reverse order, i.e., // t_boundary[0] = numCodePts, and afterwards do a swap. UVector32 t_boundary(numCodePts+1, status); int32_t numBreaks = 0; // No segmentation found, set boundary to end of range if ((uint32_t)bestSnlp.elementAti(numCodePts) == kuint32max) { t_boundary.addElement(numCodePts, status); numBreaks++; } else { for (int32_t i = numCodePts; i > 0; i = prev.elementAti(i)) { t_boundary.addElement(i, status); numBreaks++; } U_ASSERT(prev.elementAti(t_boundary.elementAti(numBreaks - 1)) == 0); } // Add a break for the start of the dictionary range if there is not one // there already. if (foundBreaks.size() == 0 || foundBreaks.peeki() < rangeStart) { t_boundary.addElement(0, status); numBreaks++; } // Now that we're done, convert positions in t_boundary[] (indices in // the normalized input string) back to indices in the original input UText // while reversing t_boundary and pushing values to foundBreaks. int32_t prevCPPos = -1; int32_t prevUTextPos = -1; for (int32_t i = numBreaks-1; i >= 0; i--) { int32_t cpPos = t_boundary.elementAti(i); U_ASSERT(cpPos > prevCPPos); int32_t utextPos = inputMap.isValid() ? inputMap->elementAti(cpPos) : cpPos + rangeStart; U_ASSERT(utextPos >= prevUTextPos); if (utextPos > prevUTextPos) { // Boundaries are added to foundBreaks output in ascending order. U_ASSERT(foundBreaks.size() == 0 || foundBreaks.peeki() < utextPos); foundBreaks.push(utextPos, status); } else { // Normalization expanded the input text, the dictionary found a boundary // within the expansion, giving two boundaries with the same index in the // original text. Ignore the second. See ticket #12918. --numBreaks; } prevCPPos = cpPos; prevUTextPos = utextPos; } (void)prevCPPos; // suppress compiler warnings about unused variable // inString goes out of scope // inputMap goes out of scope return numBreaks; } #endif U_NAMESPACE_END #endif /* #if !UCONFIG_NO_BREAK_ITERATION */