diff options
Diffstat (limited to 'Build/source/libs/icu/icu-4.8.1/common/dictbe.cpp')
-rw-r--r-- | Build/source/libs/icu/icu-4.8.1/common/dictbe.cpp | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/Build/source/libs/icu/icu-4.8.1/common/dictbe.cpp b/Build/source/libs/icu/icu-4.8.1/common/dictbe.cpp new file mode 100644 index 00000000000..dbd397b2c58 --- /dev/null +++ b/Build/source/libs/icu/icu-4.8.1/common/dictbe.cpp @@ -0,0 +1,656 @@ +/** + ******************************************************************************* + * Copyright (C) 2006-2008,2011, 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 "triedict.h" + +U_NAMESPACE_BEGIN + +/* + ****************************************************************** + */ + +/*DictionaryBreakEngine::DictionaryBreakEngine() { + fTypes = 0; +}*/ + +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(); +} + +/*void +DictionaryBreakEngine::setBreakTypes( uint32_t breakTypes ) { + fTypes = breakTypes; +}*/ + +/* + ****************************************************************** + */ + + +// Helper class for improving readability of the Thai 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]; + int 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, const TrieWordDictionary *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, const TrieWordDictionary *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; +} + +// 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(const TrieWordDictionary *adoptDictionary, UErrorCode &status) + : DictionaryBreakEngine((1<<UBRK_WORD) | (1<<UBRK_LINE)), + 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, + UStack &foundBreaks ) const { + if ((rangeEnd - rangeStart) < THAI_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[THAI_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%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd); + + // If we found exactly one, use that + if (candidates == 1) { + wordLength = words[wordsFound%THAI_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)%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; +} + +// 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(const TrieWordDictionary *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; +} + +U_NAMESPACE_END + +#endif /* #if !UCONFIG_NO_BREAK_ITERATION */ |