943 lines
36 KiB
C++
943 lines
36 KiB
C++
/**
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*******************************************************************************
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* Copyright (C) 2006-2008,2012, International Business Machines Corporation *
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* and others. All Rights Reserved. *
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*******************************************************************************
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*/
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#include "unicode/utypes.h"
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#if !UCONFIG_NO_BREAK_ITERATION
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#include "brkeng.h"
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#include "dictbe.h"
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#include "unicode/uniset.h"
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#include "unicode/chariter.h"
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#include "unicode/ubrk.h"
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#include "uvector.h"
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#include "uassert.h"
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#include "unicode/normlzr.h"
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#include "cmemory.h"
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#include "dictionarydata.h"
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U_NAMESPACE_BEGIN
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/*
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******************************************************************
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*/
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DictionaryBreakEngine::DictionaryBreakEngine(uint32_t breakTypes) {
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fTypes = breakTypes;
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}
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DictionaryBreakEngine::~DictionaryBreakEngine() {
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}
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UBool
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DictionaryBreakEngine::handles(UChar32 c, int32_t breakType) const {
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return (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes)
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&& fSet.contains(c));
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}
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int32_t
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DictionaryBreakEngine::findBreaks( UText *text,
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int32_t startPos,
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int32_t endPos,
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UBool reverse,
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int32_t breakType,
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UStack &foundBreaks ) const {
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int32_t result = 0;
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// Find the span of characters included in the set.
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int32_t start = (int32_t)utext_getNativeIndex(text);
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int32_t current;
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int32_t rangeStart;
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int32_t rangeEnd;
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UChar32 c = utext_current32(text);
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if (reverse) {
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UBool isDict = fSet.contains(c);
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while((current = (int32_t)utext_getNativeIndex(text)) > startPos && isDict) {
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c = utext_previous32(text);
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isDict = fSet.contains(c);
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}
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rangeStart = (current < startPos) ? startPos : current+(isDict ? 0 : 1);
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rangeEnd = start + 1;
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}
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else {
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while((current = (int32_t)utext_getNativeIndex(text)) < endPos && fSet.contains(c)) {
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utext_next32(text); // TODO: recast loop for postincrement
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c = utext_current32(text);
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}
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rangeStart = start;
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rangeEnd = current;
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}
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if (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes)) {
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result = divideUpDictionaryRange(text, rangeStart, rangeEnd, foundBreaks);
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utext_setNativeIndex(text, current);
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}
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return result;
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}
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void
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DictionaryBreakEngine::setCharacters( const UnicodeSet &set ) {
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fSet = set;
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// Compact for caching
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fSet.compact();
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}
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/*
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******************************************************************
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*/
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// Helper class for improving readability of the Thai word break
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// algorithm. The implementation is completely inline.
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// List size, limited by the maximum number of words in the dictionary
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// that form a nested sequence.
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#define POSSIBLE_WORD_LIST_MAX 20
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class PossibleWord {
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private:
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// list of word candidate lengths, in increasing length order
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int32_t lengths[POSSIBLE_WORD_LIST_MAX];
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int count; // Count of candidates
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int32_t prefix; // The longest match with a dictionary word
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int32_t offset; // Offset in the text of these candidates
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int mark; // The preferred candidate's offset
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int current; // The candidate we're currently looking at
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public:
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PossibleWord();
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~PossibleWord();
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// Fill the list of candidates if needed, select the longest, and return the number found
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int candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd );
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// Select the currently marked candidate, point after it in the text, and invalidate self
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int32_t acceptMarked( UText *text );
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// Back up from the current candidate to the next shorter one; return TRUE if that exists
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// and point the text after it
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UBool backUp( UText *text );
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// Return the longest prefix this candidate location shares with a dictionary word
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int32_t longestPrefix();
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// Mark the current candidate as the one we like
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void markCurrent();
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};
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inline
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PossibleWord::PossibleWord() {
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offset = -1;
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}
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inline
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PossibleWord::~PossibleWord() {
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}
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inline int
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PossibleWord::candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd ) {
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// TODO: If getIndex is too slow, use offset < 0 and add discardAll()
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int32_t start = (int32_t)utext_getNativeIndex(text);
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if (start != offset) {
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offset = start;
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prefix = dict->matches(text, rangeEnd-start, lengths, count, sizeof(lengths)/sizeof(lengths[0]));
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// Dictionary leaves text after longest prefix, not longest word. Back up.
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if (count <= 0) {
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utext_setNativeIndex(text, start);
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}
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}
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if (count > 0) {
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utext_setNativeIndex(text, start+lengths[count-1]);
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}
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current = count-1;
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mark = current;
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return count;
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}
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inline int32_t
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PossibleWord::acceptMarked( UText *text ) {
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utext_setNativeIndex(text, offset + lengths[mark]);
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return lengths[mark];
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}
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inline UBool
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PossibleWord::backUp( UText *text ) {
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if (current > 0) {
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utext_setNativeIndex(text, offset + lengths[--current]);
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return TRUE;
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}
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return FALSE;
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}
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inline int32_t
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PossibleWord::longestPrefix() {
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return prefix;
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}
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inline void
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PossibleWord::markCurrent() {
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mark = current;
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}
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// How many words in a row are "good enough"?
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#define THAI_LOOKAHEAD 3
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// Will not combine a non-word with a preceding dictionary word longer than this
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#define THAI_ROOT_COMBINE_THRESHOLD 3
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// Will not combine a non-word that shares at least this much prefix with a
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// dictionary word, with a preceding word
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#define THAI_PREFIX_COMBINE_THRESHOLD 3
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// Ellision character
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#define THAI_PAIYANNOI 0x0E2F
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// Repeat character
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#define THAI_MAIYAMOK 0x0E46
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// Minimum word size
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#define THAI_MIN_WORD 2
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// Minimum number of characters for two words
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#define THAI_MIN_WORD_SPAN (THAI_MIN_WORD * 2)
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ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
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: DictionaryBreakEngine((1<<UBRK_WORD) | (1<<UBRK_LINE)),
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fDictionary(adoptDictionary)
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{
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fThaiWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Thai:]&[:LineBreak=SA:]]"), status);
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if (U_SUCCESS(status)) {
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setCharacters(fThaiWordSet);
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}
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fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Thai:]&[:LineBreak=SA:]&[:M:]]"), status);
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fMarkSet.add(0x0020);
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fEndWordSet = fThaiWordSet;
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fEndWordSet.remove(0x0E31); // MAI HAN-AKAT
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fEndWordSet.remove(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
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fBeginWordSet.add(0x0E01, 0x0E2E); // KO KAI through HO NOKHUK
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fBeginWordSet.add(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
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fSuffixSet.add(THAI_PAIYANNOI);
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fSuffixSet.add(THAI_MAIYAMOK);
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// Compact for caching.
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fMarkSet.compact();
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fEndWordSet.compact();
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fBeginWordSet.compact();
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fSuffixSet.compact();
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}
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ThaiBreakEngine::~ThaiBreakEngine() {
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delete fDictionary;
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}
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int32_t
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ThaiBreakEngine::divideUpDictionaryRange( UText *text,
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int32_t rangeStart,
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int32_t rangeEnd,
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UStack &foundBreaks ) const {
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if ((rangeEnd - rangeStart) < THAI_MIN_WORD_SPAN) {
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return 0; // Not enough characters for two words
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}
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uint32_t wordsFound = 0;
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int32_t wordLength;
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int32_t current;
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UErrorCode status = U_ZERO_ERROR;
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PossibleWord words[THAI_LOOKAHEAD];
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UChar32 uc;
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utext_setNativeIndex(text, rangeStart);
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while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
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wordLength = 0;
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// Look for candidate words at the current position
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int candidates = words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
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// If we found exactly one, use that
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if (candidates == 1) {
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wordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text);
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wordsFound += 1;
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}
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// If there was more than one, see which one can take us forward the most words
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else if (candidates > 1) {
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// If we're already at the end of the range, we're done
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if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
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goto foundBest;
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}
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do {
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int wordsMatched = 1;
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if (words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) {
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if (wordsMatched < 2) {
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// Followed by another dictionary word; mark first word as a good candidate
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words[wordsFound%THAI_LOOKAHEAD].markCurrent();
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wordsMatched = 2;
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}
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// If we're already at the end of the range, we're done
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if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
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goto foundBest;
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}
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// See if any of the possible second words is followed by a third word
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do {
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// If we find a third word, stop right away
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if (words[(wordsFound + 2) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) {
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words[wordsFound % THAI_LOOKAHEAD].markCurrent();
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goto foundBest;
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}
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}
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while (words[(wordsFound + 1) % THAI_LOOKAHEAD].backUp(text));
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}
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}
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while (words[wordsFound % THAI_LOOKAHEAD].backUp(text));
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foundBest:
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wordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text);
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wordsFound += 1;
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}
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// We come here after having either found a word or not. We look ahead to the
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// next word. If it's not a dictionary word, we will combine it withe the word we
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// just found (if there is one), but only if the preceding word does not exceed
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// the threshold.
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// The text iterator should now be positioned at the end of the word we found.
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if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < THAI_ROOT_COMBINE_THRESHOLD) {
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// if it is a dictionary word, do nothing. If it isn't, then if there is
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// no preceding word, or the non-word shares less than the minimum threshold
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// of characters with a dictionary word, then scan to resynchronize
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if (words[wordsFound % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
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&& (wordLength == 0
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|| words[wordsFound%THAI_LOOKAHEAD].longestPrefix() < THAI_PREFIX_COMBINE_THRESHOLD)) {
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// Look for a plausible word boundary
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//TODO: This section will need a rework for UText.
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int32_t remaining = rangeEnd - (current+wordLength);
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UChar32 pc = utext_current32(text);
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int32_t chars = 0;
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for (;;) {
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utext_next32(text);
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uc = utext_current32(text);
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// TODO: Here we're counting on the fact that the SA languages are all
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// in the BMP. This should get fixed with the UText rework.
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chars += 1;
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if (--remaining <= 0) {
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break;
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}
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if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
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// Maybe. See if it's in the dictionary.
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// NOTE: In the original Apple code, checked that the next
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// two characters after uc were not 0x0E4C THANTHAKHAT before
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// checking the dictionary. That is just a performance filter,
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// but it's not clear it's faster than checking the trie.
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int candidates = words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
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utext_setNativeIndex(text, current + wordLength + chars);
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if (candidates > 0) {
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break;
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}
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}
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pc = uc;
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}
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// Bump the word count if there wasn't already one
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if (wordLength <= 0) {
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wordsFound += 1;
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}
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// Update the length with the passed-over characters
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wordLength += chars;
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}
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else {
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// Back up to where we were for next iteration
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utext_setNativeIndex(text, current+wordLength);
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}
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}
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// Never stop before a combining mark.
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int32_t currPos;
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while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
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utext_next32(text);
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wordLength += (int32_t)utext_getNativeIndex(text) - currPos;
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}
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// Look ahead for possible suffixes if a dictionary word does not follow.
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// We do this in code rather than using a rule so that the heuristic
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// resynch continues to function. For example, one of the suffix characters
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// could be a typo in the middle of a word.
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if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) {
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if (words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
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&& fSuffixSet.contains(uc = utext_current32(text))) {
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if (uc == THAI_PAIYANNOI) {
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if (!fSuffixSet.contains(utext_previous32(text))) {
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// Skip over previous end and PAIYANNOI
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utext_next32(text);
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utext_next32(text);
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wordLength += 1; // Add PAIYANNOI to word
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uc = utext_current32(text); // Fetch next character
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}
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else {
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// Restore prior position
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utext_next32(text);
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}
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}
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if (uc == THAI_MAIYAMOK) {
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if (utext_previous32(text) != THAI_MAIYAMOK) {
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// Skip over previous end and MAIYAMOK
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utext_next32(text);
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utext_next32(text);
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wordLength += 1; // Add MAIYAMOK to word
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}
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else {
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// Restore prior position
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utext_next32(text);
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}
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}
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}
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else {
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utext_setNativeIndex(text, current+wordLength);
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}
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}
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// Did we find a word on this iteration? If so, push it on the break stack
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if (wordLength > 0) {
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foundBreaks.push((current+wordLength), status);
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}
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}
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// Don't return a break for the end of the dictionary range if there is one there.
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if (foundBreaks.peeki() >= rangeEnd) {
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(void) foundBreaks.popi();
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wordsFound -= 1;
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}
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return wordsFound;
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}
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// How many words in a row are "good enough"?
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#define KHMER_LOOKAHEAD 3
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|
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// Will not combine a non-word with a preceding dictionary word longer than this
|
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#define KHMER_ROOT_COMBINE_THRESHOLD 3
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|
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// Will not combine a non-word that shares at least this much prefix with a
|
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// dictionary word, with a preceding word
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#define KHMER_PREFIX_COMBINE_THRESHOLD 3
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// Minimum word size
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#define KHMER_MIN_WORD 2
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|
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// Minimum number of characters for two words
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#define KHMER_MIN_WORD_SPAN (KHMER_MIN_WORD * 2)
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|
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KhmerBreakEngine::KhmerBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
|
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: DictionaryBreakEngine((1 << UBRK_WORD) | (1 << UBRK_LINE)),
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fDictionary(adoptDictionary)
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{
|
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fKhmerWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]]"), status);
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if (U_SUCCESS(status)) {
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setCharacters(fKhmerWordSet);
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}
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fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]&[:M:]]"), status);
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fMarkSet.add(0x0020);
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fEndWordSet = fKhmerWordSet;
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fBeginWordSet.add(0x1780, 0x17B3);
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//fBeginWordSet.add(0x17A3, 0x17A4); // deprecated vowels
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//fEndWordSet.remove(0x17A5, 0x17A9); // Khmer independent vowels that can't end a word
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//fEndWordSet.remove(0x17B2); // Khmer independent vowel that can't end a word
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fEndWordSet.remove(0x17D2); // KHMER SIGN COENG that combines some following characters
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//fEndWordSet.remove(0x17B6, 0x17C5); // Remove dependent vowels
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// fEndWordSet.remove(0x0E31); // MAI HAN-AKAT
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// fEndWordSet.remove(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
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// fBeginWordSet.add(0x0E01, 0x0E2E); // KO KAI through HO NOKHUK
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// fBeginWordSet.add(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
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// fSuffixSet.add(THAI_PAIYANNOI);
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// fSuffixSet.add(THAI_MAIYAMOK);
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|
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// Compact for caching.
|
|
fMarkSet.compact();
|
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fEndWordSet.compact();
|
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fBeginWordSet.compact();
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// fSuffixSet.compact();
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}
|
|
|
|
KhmerBreakEngine::~KhmerBreakEngine() {
|
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delete fDictionary;
|
|
}
|
|
|
|
int32_t
|
|
KhmerBreakEngine::divideUpDictionaryRange( UText *text,
|
|
int32_t rangeStart,
|
|
int32_t rangeEnd,
|
|
UStack &foundBreaks ) const {
|
|
if ((rangeEnd - rangeStart) < KHMER_MIN_WORD_SPAN) {
|
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return 0; // Not enough characters for two words
|
|
}
|
|
|
|
uint32_t wordsFound = 0;
|
|
int32_t wordLength;
|
|
int32_t current;
|
|
UErrorCode status = U_ZERO_ERROR;
|
|
PossibleWord words[KHMER_LOOKAHEAD];
|
|
UChar32 uc;
|
|
|
|
utext_setNativeIndex(text, rangeStart);
|
|
|
|
while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
|
|
wordLength = 0;
|
|
|
|
// Look for candidate words at the current position
|
|
int candidates = words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
|
|
|
|
// If we found exactly one, use that
|
|
if (candidates == 1) {
|
|
wordLength = words[wordsFound%KHMER_LOOKAHEAD].acceptMarked(text);
|
|
wordsFound += 1;
|
|
}
|
|
|
|
// If there was more than one, see which one can take us forward the most words
|
|
else if (candidates > 1) {
|
|
// If we're already at the end of the range, we're done
|
|
if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
|
|
goto foundBest;
|
|
}
|
|
do {
|
|
int wordsMatched = 1;
|
|
if (words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) {
|
|
if (wordsMatched < 2) {
|
|
// Followed by another dictionary word; mark first word as a good candidate
|
|
words[wordsFound % KHMER_LOOKAHEAD].markCurrent();
|
|
wordsMatched = 2;
|
|
}
|
|
|
|
// If we're already at the end of the range, we're done
|
|
if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
|
|
goto foundBest;
|
|
}
|
|
|
|
// See if any of the possible second words is followed by a third word
|
|
do {
|
|
// If we find a third word, stop right away
|
|
if (words[(wordsFound + 2) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) {
|
|
words[wordsFound % KHMER_LOOKAHEAD].markCurrent();
|
|
goto foundBest;
|
|
}
|
|
}
|
|
while (words[(wordsFound + 1) % KHMER_LOOKAHEAD].backUp(text));
|
|
}
|
|
}
|
|
while (words[wordsFound % KHMER_LOOKAHEAD].backUp(text));
|
|
foundBest:
|
|
wordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text);
|
|
wordsFound += 1;
|
|
}
|
|
|
|
// We come here after having either found a word or not. We look ahead to the
|
|
// next word. If it's not a dictionary word, we will combine it with the word we
|
|
// just found (if there is one), but only if the preceding word does not exceed
|
|
// the threshold.
|
|
// The text iterator should now be positioned at the end of the word we found.
|
|
if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < KHMER_ROOT_COMBINE_THRESHOLD) {
|
|
// if it is a dictionary word, do nothing. If it isn't, then if there is
|
|
// no preceding word, or the non-word shares less than the minimum threshold
|
|
// of characters with a dictionary word, then scan to resynchronize
|
|
if (words[wordsFound % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
|
|
&& (wordLength == 0
|
|
|| words[wordsFound % KHMER_LOOKAHEAD].longestPrefix() < KHMER_PREFIX_COMBINE_THRESHOLD)) {
|
|
// Look for a plausible word boundary
|
|
//TODO: This section will need a rework for UText.
|
|
int32_t remaining = rangeEnd - (current+wordLength);
|
|
UChar32 pc = utext_current32(text);
|
|
int32_t chars = 0;
|
|
for (;;) {
|
|
utext_next32(text);
|
|
uc = utext_current32(text);
|
|
// TODO: Here we're counting on the fact that the SA languages are all
|
|
// in the BMP. This should get fixed with the UText rework.
|
|
chars += 1;
|
|
if (--remaining <= 0) {
|
|
break;
|
|
}
|
|
if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
|
|
// Maybe. See if it's in the dictionary.
|
|
int candidates = words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
|
|
utext_setNativeIndex(text, current+wordLength+chars);
|
|
if (candidates > 0) {
|
|
break;
|
|
}
|
|
}
|
|
pc = uc;
|
|
}
|
|
|
|
// Bump the word count if there wasn't already one
|
|
if (wordLength <= 0) {
|
|
wordsFound += 1;
|
|
}
|
|
|
|
// Update the length with the passed-over characters
|
|
wordLength += chars;
|
|
}
|
|
else {
|
|
// Back up to where we were for next iteration
|
|
utext_setNativeIndex(text, current+wordLength);
|
|
}
|
|
}
|
|
|
|
// Never stop before a combining mark.
|
|
int32_t currPos;
|
|
while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
|
|
utext_next32(text);
|
|
wordLength += (int32_t)utext_getNativeIndex(text) - currPos;
|
|
}
|
|
|
|
// Look ahead for possible suffixes if a dictionary word does not follow.
|
|
// We do this in code rather than using a rule so that the heuristic
|
|
// resynch continues to function. For example, one of the suffix characters
|
|
// could be a typo in the middle of a word.
|
|
// if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) {
|
|
// if (words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
|
|
// && fSuffixSet.contains(uc = utext_current32(text))) {
|
|
// if (uc == KHMER_PAIYANNOI) {
|
|
// if (!fSuffixSet.contains(utext_previous32(text))) {
|
|
// // Skip over previous end and PAIYANNOI
|
|
// utext_next32(text);
|
|
// utext_next32(text);
|
|
// wordLength += 1; // Add PAIYANNOI to word
|
|
// uc = utext_current32(text); // Fetch next character
|
|
// }
|
|
// else {
|
|
// // Restore prior position
|
|
// utext_next32(text);
|
|
// }
|
|
// }
|
|
// if (uc == KHMER_MAIYAMOK) {
|
|
// if (utext_previous32(text) != KHMER_MAIYAMOK) {
|
|
// // Skip over previous end and MAIYAMOK
|
|
// utext_next32(text);
|
|
// utext_next32(text);
|
|
// wordLength += 1; // Add MAIYAMOK to word
|
|
// }
|
|
// else {
|
|
// // Restore prior position
|
|
// utext_next32(text);
|
|
// }
|
|
// }
|
|
// }
|
|
// else {
|
|
// utext_setNativeIndex(text, current+wordLength);
|
|
// }
|
|
// }
|
|
|
|
// Did we find a word on this iteration? If so, push it on the break stack
|
|
if (wordLength > 0) {
|
|
foundBreaks.push((current+wordLength), status);
|
|
}
|
|
}
|
|
|
|
// Don't return a break for the end of the dictionary range if there is one there.
|
|
if (foundBreaks.peeki() >= rangeEnd) {
|
|
(void) foundBreaks.popi();
|
|
wordsFound -= 1;
|
|
}
|
|
|
|
return wordsFound;
|
|
}
|
|
|
|
#if !UCONFIG_NO_NORMALIZATION
|
|
/*
|
|
******************************************************************
|
|
* CjkBreakEngine
|
|
*/
|
|
static const uint32_t kuint32max = 0xFFFFFFFF;
|
|
CjkBreakEngine::CjkBreakEngine(DictionaryMatcher *adoptDictionary, LanguageType type, UErrorCode &status)
|
|
: DictionaryBreakEngine(1 << UBRK_WORD), fDictionary(adoptDictionary) {
|
|
// Korean dictionary only includes Hangul syllables
|
|
fHangulWordSet.applyPattern(UNICODE_STRING_SIMPLE("[\\uac00-\\ud7a3]"), status);
|
|
fHanWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Han:]"), status);
|
|
fKatakanaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Katakana:]\\uff9e\\uff9f]"), status);
|
|
fHiraganaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Hiragana:]"), status);
|
|
|
|
if (U_SUCCESS(status)) {
|
|
// handle Korean and Japanese/Chinese using different dictionaries
|
|
if (type == kKorean) {
|
|
setCharacters(fHangulWordSet);
|
|
} else { //Chinese and Japanese
|
|
UnicodeSet cjSet;
|
|
cjSet.addAll(fHanWordSet);
|
|
cjSet.addAll(fKatakanaWordSet);
|
|
cjSet.addAll(fHiraganaWordSet);
|
|
cjSet.add(UNICODE_STRING_SIMPLE("\\uff70\\u30fc"));
|
|
setCharacters(cjSet);
|
|
}
|
|
}
|
|
}
|
|
|
|
CjkBreakEngine::~CjkBreakEngine(){
|
|
delete fDictionary;
|
|
}
|
|
|
|
// The katakanaCost values below are based on the length frequencies of all
|
|
// katakana phrases in the dictionary
|
|
static const int kMaxKatakanaLength = 8;
|
|
static const int kMaxKatakanaGroupLength = 20;
|
|
static const uint32_t maxSnlp = 255;
|
|
|
|
static inline uint32_t getKatakanaCost(int wordLength){
|
|
//TODO: fill array with actual values from dictionary!
|
|
static const uint32_t katakanaCost[kMaxKatakanaLength + 1]
|
|
= {8192, 984, 408, 240, 204, 252, 300, 372, 480};
|
|
return (wordLength > kMaxKatakanaLength) ? 8192 : katakanaCost[wordLength];
|
|
}
|
|
|
|
static inline bool isKatakana(uint16_t value) {
|
|
return (value >= 0x30A1u && value <= 0x30FEu && value != 0x30FBu) ||
|
|
(value >= 0xFF66u && value <= 0xFF9fu);
|
|
}
|
|
|
|
// A very simple helper class to streamline the buffer handling in
|
|
// divideUpDictionaryRange.
|
|
template<class T, size_t N>
|
|
class AutoBuffer {
|
|
public:
|
|
AutoBuffer(size_t size) : buffer(stackBuffer), capacity(N) {
|
|
if (size > N) {
|
|
buffer = reinterpret_cast<T*>(uprv_malloc(sizeof(T)*size));
|
|
capacity = size;
|
|
}
|
|
}
|
|
~AutoBuffer() {
|
|
if (buffer != stackBuffer)
|
|
uprv_free(buffer);
|
|
}
|
|
|
|
T* elems() {
|
|
return buffer;
|
|
}
|
|
|
|
const T& operator[] (size_t i) const {
|
|
return buffer[i];
|
|
}
|
|
|
|
T& operator[] (size_t i) {
|
|
return buffer[i];
|
|
}
|
|
|
|
// resize without copy
|
|
void resize(size_t size) {
|
|
if (size <= capacity)
|
|
return;
|
|
if (buffer != stackBuffer)
|
|
uprv_free(buffer);
|
|
buffer = reinterpret_cast<T*>(uprv_malloc(sizeof(T)*size));
|
|
capacity = size;
|
|
}
|
|
|
|
private:
|
|
T stackBuffer[N];
|
|
T* buffer;
|
|
AutoBuffer();
|
|
size_t capacity;
|
|
};
|
|
|
|
|
|
/*
|
|
* @param text A UText representing the text
|
|
* @param rangeStart The start of the range of dictionary characters
|
|
* @param rangeEnd The end of the range of dictionary characters
|
|
* @param foundBreaks Output of C array of int32_t break positions, or 0
|
|
* @return The number of breaks found
|
|
*/
|
|
int32_t
|
|
CjkBreakEngine::divideUpDictionaryRange( UText *text,
|
|
int32_t rangeStart,
|
|
int32_t rangeEnd,
|
|
UStack &foundBreaks ) const {
|
|
if (rangeStart >= rangeEnd) {
|
|
return 0;
|
|
}
|
|
|
|
const size_t defaultInputLength = 80;
|
|
size_t inputLength = rangeEnd - rangeStart;
|
|
// TODO: Replace by UnicodeString.
|
|
AutoBuffer<UChar, defaultInputLength> charString(inputLength);
|
|
|
|
// Normalize the input string and put it in normalizedText.
|
|
// The map from the indices of the normalized input to the raw
|
|
// input is kept in charPositions.
|
|
UErrorCode status = U_ZERO_ERROR;
|
|
utext_extract(text, rangeStart, rangeEnd, charString.elems(), inputLength, &status);
|
|
if (U_FAILURE(status)) {
|
|
return 0;
|
|
}
|
|
|
|
UnicodeString inputString(charString.elems(), inputLength);
|
|
// TODO: Use Normalizer2.
|
|
UNormalizationMode norm_mode = UNORM_NFKC;
|
|
UBool isNormalized =
|
|
Normalizer::quickCheck(inputString, norm_mode, status) == UNORM_YES ||
|
|
Normalizer::isNormalized(inputString, norm_mode, status);
|
|
|
|
// TODO: Replace by UVector32.
|
|
AutoBuffer<int32_t, defaultInputLength> charPositions(inputLength + 1);
|
|
int numChars = 0;
|
|
UText normalizedText = UTEXT_INITIALIZER;
|
|
// Needs to be declared here because normalizedText holds onto its buffer.
|
|
UnicodeString normalizedString;
|
|
if (isNormalized) {
|
|
int32_t index = 0;
|
|
charPositions[0] = 0;
|
|
while(index < inputString.length()) {
|
|
index = inputString.moveIndex32(index, 1);
|
|
charPositions[++numChars] = index;
|
|
}
|
|
utext_openUnicodeString(&normalizedText, &inputString, &status);
|
|
}
|
|
else {
|
|
Normalizer::normalize(inputString, norm_mode, 0, normalizedString, status);
|
|
if (U_FAILURE(status)) {
|
|
return 0;
|
|
}
|
|
charPositions.resize(normalizedString.length() + 1);
|
|
Normalizer normalizer(charString.elems(), inputLength, norm_mode);
|
|
int32_t index = 0;
|
|
charPositions[0] = 0;
|
|
while(index < normalizer.endIndex()){
|
|
UChar32 uc = normalizer.next();
|
|
charPositions[++numChars] = index = normalizer.getIndex();
|
|
}
|
|
utext_openUnicodeString(&normalizedText, &normalizedString, &status);
|
|
}
|
|
|
|
if (U_FAILURE(status)) {
|
|
return 0;
|
|
}
|
|
|
|
// From this point on, all the indices refer to the indices of
|
|
// the normalized input string.
|
|
|
|
// bestSnlp[i] is the snlp of the best segmentation of the first i
|
|
// characters in the range to be matched.
|
|
// TODO: Replace by UVector32.
|
|
AutoBuffer<uint32_t, defaultInputLength> bestSnlp(numChars + 1);
|
|
bestSnlp[0] = 0;
|
|
for(int i = 1; i <= numChars; i++) {
|
|
bestSnlp[i] = kuint32max;
|
|
}
|
|
|
|
// prev[i] is the index of the last CJK character in the previous word in
|
|
// the best segmentation of the first i characters.
|
|
// TODO: Replace by UVector32.
|
|
AutoBuffer<int, defaultInputLength> prev(numChars + 1);
|
|
for(int i = 0; i <= numChars; i++){
|
|
prev[i] = -1;
|
|
}
|
|
|
|
const size_t maxWordSize = 20;
|
|
// TODO: Replace both with UVector32.
|
|
AutoBuffer<int32_t, maxWordSize> values(numChars);
|
|
AutoBuffer<int32_t, maxWordSize> lengths(numChars);
|
|
|
|
// Dynamic programming to find the best segmentation.
|
|
bool is_prev_katakana = false;
|
|
for (int i = 0; i < numChars; ++i) {
|
|
//utext_setNativeIndex(text, rangeStart + i);
|
|
utext_setNativeIndex(&normalizedText, i);
|
|
if (bestSnlp[i] == kuint32max)
|
|
continue;
|
|
|
|
int count;
|
|
// limit maximum word length matched to size of current substring
|
|
int maxSearchLength = (i + maxWordSize < (size_t) numChars)? maxWordSize : (numChars - i);
|
|
|
|
fDictionary->matches(&normalizedText, maxSearchLength, lengths.elems(), count, maxSearchLength, values.elems());
|
|
|
|
// if there are no single character matches found in the dictionary
|
|
// starting with this charcter, treat character as a 1-character word
|
|
// with the highest value possible, i.e. the least likely to occur.
|
|
// Exclude Korean characters from this treatment, as they should be left
|
|
// together by default.
|
|
if((count == 0 || lengths[0] != 1) &&
|
|
!fHangulWordSet.contains(utext_current32(&normalizedText))) {
|
|
values[count] = maxSnlp;
|
|
lengths[count++] = 1;
|
|
}
|
|
|
|
for (int j = 0; j < count; j++) {
|
|
uint32_t newSnlp = bestSnlp[i] + values[j];
|
|
if (newSnlp < bestSnlp[lengths[j] + i]) {
|
|
bestSnlp[lengths[j] + i] = newSnlp;
|
|
prev[lengths[j] + i] = i;
|
|
}
|
|
}
|
|
|
|
// In Japanese,
|
|
// Katakana word in single character is pretty rare. So we apply
|
|
// the following heuristic to Katakana: any continuous run of Katakana
|
|
// characters is considered a candidate word with a default cost
|
|
// specified in the katakanaCost table according to its length.
|
|
//utext_setNativeIndex(text, rangeStart + i);
|
|
utext_setNativeIndex(&normalizedText, i);
|
|
bool is_katakana = isKatakana(utext_current32(&normalizedText));
|
|
if (!is_prev_katakana && is_katakana) {
|
|
int j = i + 1;
|
|
utext_next32(&normalizedText);
|
|
// Find the end of the continuous run of Katakana characters
|
|
while (j < numChars && (j - i) < kMaxKatakanaGroupLength &&
|
|
isKatakana(utext_current32(&normalizedText))) {
|
|
utext_next32(&normalizedText);
|
|
++j;
|
|
}
|
|
if ((j - i) < kMaxKatakanaGroupLength) {
|
|
uint32_t newSnlp = bestSnlp[i] + getKatakanaCost(j - i);
|
|
if (newSnlp < bestSnlp[j]) {
|
|
bestSnlp[j] = newSnlp;
|
|
prev[j] = i;
|
|
}
|
|
}
|
|
}
|
|
is_prev_katakana = is_katakana;
|
|
}
|
|
|
|
// Start pushing the optimal offset index into t_boundary (t for tentative).
|
|
// prev[numChars] is guaranteed to be meaningful.
|
|
// We'll first push in the reverse order, i.e.,
|
|
// t_boundary[0] = numChars, and afterwards do a swap.
|
|
// TODO: Replace by UVector32.
|
|
AutoBuffer<int, maxWordSize> t_boundary(numChars + 1);
|
|
|
|
int numBreaks = 0;
|
|
// No segmentation found, set boundary to end of range
|
|
if (bestSnlp[numChars] == kuint32max) {
|
|
t_boundary[numBreaks++] = numChars;
|
|
} else {
|
|
for (int i = numChars; i > 0; i = prev[i]) {
|
|
t_boundary[numBreaks++] = i;
|
|
}
|
|
U_ASSERT(prev[t_boundary[numBreaks - 1]] == 0);
|
|
}
|
|
|
|
// Reverse offset index in t_boundary.
|
|
// Don't add a break for the start of the dictionary range if there is one
|
|
// there already.
|
|
if (foundBreaks.size() == 0 || foundBreaks.peeki() < rangeStart) {
|
|
t_boundary[numBreaks++] = 0;
|
|
}
|
|
|
|
// Now that we're done, convert positions in t_bdry[] (indices in
|
|
// the normalized input string) back to indices in the raw input string
|
|
// while reversing t_bdry and pushing values to foundBreaks.
|
|
for (int i = numBreaks-1; i >= 0; i--) {
|
|
foundBreaks.push(charPositions[t_boundary[i]] + rangeStart, status);
|
|
}
|
|
|
|
utext_close(&normalizedText);
|
|
return numBreaks;
|
|
}
|
|
#endif
|
|
|
|
U_NAMESPACE_END
|
|
|
|
#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
|
|
|