// 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'.
// 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. staticconst 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.
// 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 = static_cast<int32_t>(utext_getNativeIndex(text)); if (start != offset) {
offset = start;
count = dict->matches(text, rangeEnd-start, UPRV_LENGTHOF(cuLengths), cuLengths, cpLengths, nullptr, &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;
}
// How many words in a row are "good enough"? staticconst int32_t THAI_LOOKAHEAD = 3;
// Will not combine a non-word with a preceding dictionary word longer than this staticconst 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 staticconst int32_t THAI_PREFIX_COMBINE_THRESHOLD = 3;
// Elision character staticconst int32_t THAI_PAIYANNOI = 0x0E2F;
// Repeat character staticconst int32_t THAI_MAIYAMOK = 0x0E46;
// Minimum word size staticconst int32_t THAI_MIN_WORD = 2;
// Minimum number of characters for two words staticconst int32_t THAI_MIN_WORD_SPAN = THAI_MIN_WORD * 2;
ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
: DictionaryBreakEngine(),
fDictionary(adoptDictionary)
{
UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Thai");
UnicodeSet thaiWordSet(UnicodeString(u"[[:Thai:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) {
setCharacters(thaiWordSet);
}
fMarkSet.applyPattern(UnicodeString(u"[[:Thai:]&[:LineBreak=SA:]&[:M:]]"), status);
fMarkSet.add(0x0020);
fEndWordSet = thaiWordSet;
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();
UTRACE_EXIT_STATUS(status);
}
// 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 elseif (candidates > 1) { // If we're already at the end of the range, we're done if (static_cast<int32_t>(utext_getNativeIndex(text)) >= rangeEnd) { goto foundBest;
} do { if (words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { // Followed by another dictionary word; mark first word as a good candidate
words[wordsFound%THAI_LOOKAHEAD].markCurrent();
// If we're already at the end of the range, we're done if (static_cast<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 (static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
pc = utext_next32(text);
int32_t pcSize = static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text))) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
utext_next32(text);
cuWordLength += static_cast<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 (static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
utext_next32(text);
cuWordLength += static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
utext_next32(text);
cuWordLength += static_cast<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;
}
// How many words in a row are "good enough"? staticconst int32_t LAO_LOOKAHEAD = 3;
// Will not combine a non-word with a preceding dictionary word longer than this staticconst 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 staticconst int32_t LAO_PREFIX_COMBINE_THRESHOLD = 3;
// Minimum word size staticconst int32_t LAO_MIN_WORD = 2;
// Minimum number of characters for two words staticconst int32_t LAO_MIN_WORD_SPAN = LAO_MIN_WORD * 2;
// 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 elseif (candidates > 1) { // If we're already at the end of the range, we're done if (utext_getNativeIndex(text) >= rangeEnd) { goto foundBest;
} do { if (words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { // Followed by another dictionary word; mark first word as a good candidate
words[wordsFound%LAO_LOOKAHEAD].markCurrent();
// If we're already at the end of the range, we're done if (static_cast<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 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 (static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
pc = utext_next32(text);
int32_t pcSize = static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text))) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
utext_next32(text);
cuWordLength += static_cast<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;
}
// How many words in a row are "good enough"? staticconst int32_t BURMESE_LOOKAHEAD = 3;
// Will not combine a non-word with a preceding dictionary word longer than this staticconst 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 staticconst int32_t BURMESE_PREFIX_COMBINE_THRESHOLD = 3;
// Minimum word size staticconst int32_t BURMESE_MIN_WORD = 2;
// Minimum number of characters for two words staticconst int32_t BURMESE_MIN_WORD_SPAN = BURMESE_MIN_WORD * 2;
// 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 elseif (candidates > 1) { // If we're already at the end of the range, we're done if (utext_getNativeIndex(text) >= rangeEnd) { goto foundBest;
} do { if (words[(wordsFound + 1) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { // Followed by another dictionary word; mark first word as a good candidate
words[wordsFound%BURMESE_LOOKAHEAD].markCurrent();
// If we're already at the end of the range, we're done if (static_cast<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 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 (static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
pc = utext_next32(text);
int32_t pcSize = static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text))) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
utext_next32(text);
cuWordLength += static_cast<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;
}
// How many words in a row are "good enough"? staticconst int32_t KHMER_LOOKAHEAD = 3;
// Will not combine a non-word with a preceding dictionary word longer than this staticconst 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 staticconst int32_t KHMER_PREFIX_COMBINE_THRESHOLD = 3;
// Minimum word size staticconst int32_t KHMER_MIN_WORD = 2;
// Minimum number of characters for two words staticconst int32_t KHMER_MIN_WORD_SPAN = KHMER_MIN_WORD * 2;
KhmerBreakEngine::KhmerBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
: DictionaryBreakEngine(),
fDictionary(adoptDictionary)
{
UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Khmr");
UnicodeSet khmerWordSet(UnicodeString(u"[[:Khmr:]&[:LineBreak=SA:]]"), status); if (U_SUCCESS(status)) {
setCharacters(khmerWordSet);
}
fMarkSet.applyPattern(UnicodeString(u"[[:Khmr:]&[:LineBreak=SA:]&[:M:]]"), status);
fMarkSet.add(0x0020);
fEndWordSet = khmerWordSet;
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);
// 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 elseif (candidates > 1) { // If we're already at the end of the range, we're done if (static_cast<int32_t>(utext_getNativeIndex(text)) >= rangeEnd) { goto foundBest;
} do { if (words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) { // Followed by another dictionary word; mark first word as a good candidate
words[wordsFound % KHMER_LOOKAHEAD].markCurrent();
// If we're already at the end of the range, we're done if (static_cast<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 (static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text));
pc = utext_next32(text);
int32_t pcSize = static_cast<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 = static_cast<int32_t>(utext_getNativeIndex(text))) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
utext_next32(text);
cuWordLength += static_cast<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;
}
// handle Korean and Japanese/Chinese using different dictionaries if (type == kKorean) { if (U_SUCCESS(status)) {
setCharacters(fHangulWordSet);
}
} else { // Chinese and Japanese
UnicodeSet cjSet(UnicodeString(u"[[:Han:][:Hiragana:][:Katakana:]\\u30fc\\uff70\\uff9e\\uff9f]"), status);
isCj = true; if (U_SUCCESS(status)) {
setCharacters(cjSet); #if UCONFIG_USE_ML_PHRASE_BREAKING
fMlBreakEngine = new MlBreakEngine(fDigitOrOpenPunctuationOrAlphabetSet,
fClosePunctuationSet, status); if (fMlBreakEngine == nullptr) {
status = U_MEMORY_ALLOCATION_ERROR;
} #else
initJapanesePhraseParameter(status); #endif
}
}
UTRACE_EXIT_STATUS(status);
}
// The katakanaCost values below are based on the length frequencies of all // katakana phrases in the dictionary staticconst int32_t kMaxKatakanaLength = 8; staticconst int32_t kMaxKatakanaGroupLength = 20; staticconst uint32_t maxSnlp = 255;
staticinline uint32_t getKatakanaCost(int32_t wordLength){ //TODO: fill array with actual values from dictionary! staticconst uint32_t katakanaCost[kMaxKatakanaLength + 1]
= {8192, 984, 408, 240, 204, 252, 300, 372, 480}; return (wordLength > kMaxKatakanaLength) ? 8192 : katakanaCost[wordLength];
}
staticinlinebool 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.
/* * @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<int32> 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,
UBool isPhraseBreaking,
UErrorCode& status) const { if (U_FAILURE(status)) return 0; 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 nullptr then mapping is 1:1
LocalPointer<UVector32> inputMap;
// 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 = static_cast<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 = static_cast<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<UVector32> 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);
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;
}
}
}
#if UCONFIG_USE_ML_PHRASE_BREAKING // PhraseBreaking is supported in ja and ko; MlBreakEngine only supports ja. if (isPhraseBreaking && isCj) { return fMlBreakEngine->divideUpRange(inText, rangeStart, rangeEnd, foundBreaks, inString,
inputMap, status);
} #endif
// 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);
}
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 (static_cast<uint32_t>(bestSnlp.elementAti(i)) == kuint32max) { continue;
}
int32_t count;
utext_setNativeIndex(&fu, ix);
count = fDictionary->matches(&fu, maxWordSize, numCodePts,
nullptr, lengths.getBuffer(), values.getBuffer(), nullptr); // Note: lengths is filled with code point lengths // The nullptr 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++);
}
// 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 < static_cast<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 (static_cast<uint32_t>(bestSnlp.elementAti(numCodePts)) == kuint32max) {
t_boundary.addElement(numCodePts, status);
numBreaks++;
} elseif (isPhraseBreaking) {
t_boundary.addElement(numCodePts, status); if(U_SUCCESS(status)) {
numBreaks++;
int32_t prevIdx = numCodePts;
int32_t codeUnitIdx = -1;
int32_t prevCodeUnitIdx = -1;
int32_t length = -1; for (int32_t i = prev.elementAti(numCodePts); i > 0; i = prev.elementAti(i)) {
codeUnitIdx = inString.moveIndex32(0, i);
prevCodeUnitIdx = inString.moveIndex32(0, prevIdx); // Calculate the length by using the code unit.
length = prevCodeUnitIdx - codeUnitIdx;
prevIdx = i; // Keep the breakpoint if the pattern is not in the fSkipSet and continuous Katakana // characters don't occur. if (!fSkipSet.containsKey(inString.tempSubString(codeUnitIdx, length))
&& (!isKatakana(inString.char32At(inString.moveIndex32(codeUnitIdx, -1)))
|| !isKatakana(inString.char32At(codeUnitIdx)))) {
t_boundary.addElement(i, 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;
int32_t correctedNumBreaks = 0; 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); // In phrase breaking, there has to be a breakpoint between Cj character and close // punctuation. // E.g.[携帯電話]正しい選択 -> [携帯▁電話]▁正しい▁選択 -> breakpoint between ] and 正 if (utextPos != rangeStart
|| (isPhraseBreaking && utextPos > 0
&& fClosePunctuationSet.contains(utext_char32At(inText, utextPos - 1)))) {
foundBreaks.push(utextPos, status);
correctedNumBreaks++;
}
} 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
UChar32 nextChar = utext_char32At(inText, rangeEnd); if (!foundBreaks.isEmpty() && foundBreaks.peeki() == rangeEnd) { // In phrase breaking, there has to be a breakpoint between Cj character and // the number/open punctuation. // E.g. る文字「そうだ、京都」->る▁文字▁「そうだ、▁京都」-> breakpoint between 字 and「 // E.g. 乗車率90%程度だろうか -> 乗車▁率▁90%▁程度だろうか -> breakpoint between 率 and 9 // E.g. しかもロゴがUnicode! -> しかも▁ロゴが▁Unicode!-> breakpoint between が and U if (isPhraseBreaking) { if (!fDigitOrOpenPunctuationOrAlphabetSet.contains(nextChar)) {
foundBreaks.popi();
correctedNumBreaks--;
}
} else {
foundBreaks.popi();
correctedNumBreaks--;
}
}
// inString goes out of scope // inputMap goes out of scope return correctedNumBreaks;
}
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