/**
*******************************************************************************
* Copyright (C) 2006-2012, International Business Machines Corporation
* and others. All Rights Reserved.
*******************************************************************************
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_BREAK_ITERATION
#include "brkeng.h"
#include "dictbe.h"
#include "unicode/uniset.h"
#include "unicode/chariter.h"
#include "unicode/ubrk.h"
#include "uvector.h"
#include "uassert.h"
#include "unicode/normlzr.h"
#include "cmemory.h"
#include "dictionarydata.h"
U_NAMESPACE_BEGIN
/*
******************************************************************
*/
DictionaryBreakEngine::DictionaryBreakEngine(uint32_t breakTypes) {
fTypes = breakTypes;
}
DictionaryBreakEngine::~DictionaryBreakEngine() {
}
UBool
DictionaryBreakEngine::handles(UChar32 c, int32_t breakType) const {
return (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes)
&& fSet.contains(c));
}
int32_t
DictionaryBreakEngine::findBreaks( UText *text,
int32_t startPos,
int32_t endPos,
UBool reverse,
int32_t breakType,
UStack &foundBreaks ) const {
int32_t result = 0;
// Find the span of characters included in the set.
int32_t start = (int32_t)utext_getNativeIndex(text);
int32_t current;
int32_t rangeStart;
int32_t rangeEnd;
UChar32 c = utext_current32(text);
if (reverse) {
UBool isDict = fSet.contains(c);
while((current = (int32_t)utext_getNativeIndex(text)) > startPos && isDict) {
c = utext_previous32(text);
isDict = fSet.contains(c);
}
rangeStart = (current < startPos) ? startPos : current+(isDict ? 0 : 1);
rangeEnd = start + 1;
}
else {
while((current = (int32_t)utext_getNativeIndex(text)) < endPos && fSet.contains(c)) {
utext_next32(text); // TODO: recast loop for postincrement
c = utext_current32(text);
}
rangeStart = start;
rangeEnd = current;
}
if (breakType >= 0 && breakType < 32 && (((uint32_t)1 << breakType) & fTypes)) {
result = divideUpDictionaryRange(text, rangeStart, rangeEnd, foundBreaks);
utext_setNativeIndex(text, current);
}
return result;
}
void
DictionaryBreakEngine::setCharacters( const UnicodeSet &set ) {
fSet = set;
// Compact for caching
fSet.compact();
}
/*
******************************************************************
*/
// 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];
int32_t count; // Count of candidates
int32_t prefix; // The longest match with a dictionary word
int32_t offset; // Offset in the text of these candidates
int mark; // The preferred candidate's offset
int current; // The candidate we're currently looking at
public:
PossibleWord();
~PossibleWord();
// Fill the list of candidates if needed, select the longest, and return the number found
int candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd );
// Select the currently marked candidate, point after it in the text, and invalidate self
int32_t acceptMarked( UText *text );
// Back up from the current candidate to the next shorter one; return TRUE if that exists
// and point the text after it
UBool backUp( UText *text );
// Return the longest prefix this candidate location shares with a dictionary word
int32_t longestPrefix();
// Mark the current candidate as the one we like
void markCurrent();
};
inline
PossibleWord::PossibleWord() {
offset = -1;
}
inline
PossibleWord::~PossibleWord() {
}
inline int
PossibleWord::candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd ) {
// TODO: If getIndex is too slow, use offset < 0 and add discardAll()
int32_t start = (int32_t)utext_getNativeIndex(text);
if (start != offset) {
offset = start;
prefix = dict->matches(text, rangeEnd-start, lengths, count, sizeof(lengths)/sizeof(lengths[0]));
// Dictionary leaves text after longest prefix, not longest word. Back up.
if (count <= 0) {
utext_setNativeIndex(text, start);
}
}
if (count > 0) {
utext_setNativeIndex(text, start+lengths[count-1]);
}
current = count-1;
mark = current;
return count;
}
inline int32_t
PossibleWord::acceptMarked( UText *text ) {
utext_setNativeIndex(text, offset + lengths[mark]);
return lengths[mark];
}
inline UBool
PossibleWord::backUp( UText *text ) {
if (current > 0) {
utext_setNativeIndex(text, offset + lengths[--current]);
return TRUE;
}
return FALSE;
}
inline int32_t
PossibleWord::longestPrefix() {
return prefix;
}
inline void
PossibleWord::markCurrent() {
mark = current;
}
// How many words in a row are "good enough"?
#define THAI_LOOKAHEAD 3
// Will not combine a non-word with a preceding dictionary word longer than this
#define THAI_ROOT_COMBINE_THRESHOLD 3
// Will not combine a non-word that shares at least this much prefix with a
// dictionary word, with a preceding word
#define THAI_PREFIX_COMBINE_THRESHOLD 3
// Ellision character
#define THAI_PAIYANNOI 0x0E2F
// Repeat character
#define THAI_MAIYAMOK 0x0E46
// Minimum word size
#define THAI_MIN_WORD 2
// Minimum number of characters for two words
#define THAI_MIN_WORD_SPAN (THAI_MIN_WORD * 2)
ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
: DictionaryBreakEngine((1<<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(DictionaryMatcher *adoptDictionary, UErrorCode &status)
: DictionaryBreakEngine((1 << UBRK_WORD) | (1 << UBRK_LINE)),
fDictionary(adoptDictionary)
{
fKhmerWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]]"), status);
if (U_SUCCESS(status)) {
setCharacters(fKhmerWordSet);
}
fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Khmr:]&[:LineBreak=SA:]&[:M:]]"), status);
fMarkSet.add(0x0020);
fEndWordSet = fKhmerWordSet;
fBeginWordSet.add(0x1780, 0x17B3);
//fBeginWordSet.add(0x17A3, 0x17A4); // deprecated vowels
//fEndWordSet.remove(0x17A5, 0x17A9); // Khmer independent vowels that can't end a word
//fEndWordSet.remove(0x17B2); // Khmer independent vowel that can't end a word
fEndWordSet.remove(0x17D2); // KHMER SIGN COENG that combines some following characters
//fEndWordSet.remove(0x17B6, 0x17C5); // Remove dependent vowels
// fEndWordSet.remove(0x0E31); // MAI HAN-AKAT
// fEndWordSet.remove(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
// fBeginWordSet.add(0x0E01, 0x0E2E); // KO KAI through HO NOKHUK
// fBeginWordSet.add(0x0E40, 0x0E44); // SARA E through SARA AI MAIMALAI
// fSuffixSet.add(THAI_PAIYANNOI);
// fSuffixSet.add(THAI_MAIYAMOK);
// Compact for caching.
fMarkSet.compact();
fEndWordSet.compact();
fBeginWordSet.compact();
// fSuffixSet.compact();
}
KhmerBreakEngine::~KhmerBreakEngine() {
delete fDictionary;
}
int32_t
KhmerBreakEngine::divideUpDictionaryRange( UText *text,
int32_t rangeStart,
int32_t rangeEnd,
UStack &foundBreaks ) const {
if ((rangeEnd - rangeStart) < KHMER_MIN_WORD_SPAN) {
return 0; // Not enough characters for two words
}
uint32_t wordsFound = 0;
int32_t wordLength;
int32_t current;
UErrorCode status = U_ZERO_ERROR;
PossibleWord words[KHMER_LOOKAHEAD];
UChar32 uc;
utext_setNativeIndex(text, rangeStart);
while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
wordLength = 0;
// Look for candidate words at the current position
int candidates = words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
// If we found exactly one, use that
if (candidates == 1) {
wordLength = words[wordsFound%KHMER_LOOKAHEAD].acceptMarked(text);
wordsFound += 1;
}
// If there was more than one, see which one can take us forward the most words
else if (candidates > 1) {
// If we're already at the end of the range, we're done
if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
goto foundBest;
}
do {
int wordsMatched = 1;
if (words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) {
if (wordsMatched < 2) {
// Followed by another dictionary word; mark first word as a good candidate
words[wordsFound % KHMER_LOOKAHEAD].markCurrent();
wordsMatched = 2;
}
// If we're already at the end of the range, we're done
if ((int32_t)utext_getNativeIndex(text) >= rangeEnd) {
goto foundBest;
}
// See if any of the possible second words is followed by a third word
do {
// If we find a third word, stop right away
if (words[(wordsFound + 2) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) {
words[wordsFound % KHMER_LOOKAHEAD].markCurrent();
goto foundBest;
}
}
while (words[(wordsFound + 1) % KHMER_LOOKAHEAD].backUp(text));
}
}
while (words[wordsFound % KHMER_LOOKAHEAD].backUp(text));
foundBest:
wordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text);
wordsFound += 1;
}
// We come here after having either found a word or not. We look ahead to the
// next word. If it's not a dictionary word, we will combine it with the word we
// just found (if there is one), but only if the preceding word does not exceed
// the threshold.
// The text iterator should now be positioned at the end of the word we found.
if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength < KHMER_ROOT_COMBINE_THRESHOLD) {
// if it is a dictionary word, do nothing. If it isn't, then if there is
// no preceding word, or the non-word shares less than the minimum threshold
// of characters with a dictionary word, then scan to resynchronize
if (words[wordsFound % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
&& (wordLength == 0
|| words[wordsFound % KHMER_LOOKAHEAD].longestPrefix() < KHMER_PREFIX_COMBINE_THRESHOLD)) {
// Look for a plausible word boundary
//TODO: This section will need a rework for UText.
int32_t remaining = rangeEnd - (current+wordLength);
UChar32 pc = utext_current32(text);
int32_t chars = 0;
for (;;) {
utext_next32(text);
uc = utext_current32(text);
// TODO: Here we're counting on the fact that the SA languages are all
// in the BMP. This should get fixed with the UText rework.
chars += 1;
if (--remaining <= 0) {
break;
}
if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
// Maybe. See if it's in the dictionary.
int candidates = words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
utext_setNativeIndex(text, current+wordLength+chars);
if (candidates > 0) {
break;
}
}
pc = uc;
}
// Bump the word count if there wasn't already one
if (wordLength <= 0) {
wordsFound += 1;
}
// Update the length with the passed-over characters
wordLength += chars;
}
else {
// Back up to where we were for next iteration
utext_setNativeIndex(text, current+wordLength);
}
}
// Never stop before a combining mark.
int32_t currPos;
while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
utext_next32(text);
wordLength += (int32_t)utext_getNativeIndex(text) - currPos;
}
// Look ahead for possible suffixes if a dictionary word does not follow.
// We do this in code rather than using a rule so that the heuristic
// resynch continues to function. For example, one of the suffix characters
// could be a typo in the middle of a word.
// if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) {
// if (words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
// && fSuffixSet.contains(uc = utext_current32(text))) {
// if (uc == KHMER_PAIYANNOI) {
// if (!fSuffixSet.contains(utext_previous32(text))) {
// // Skip over previous end and PAIYANNOI
// utext_next32(text);
// utext_next32(text);
// wordLength += 1; // Add PAIYANNOI to word
// uc = utext_current32(text); // Fetch next character
// }
// else {
// // Restore prior position
// utext_next32(text);
// }
// }
// if (uc == KHMER_MAIYAMOK) {
// if (utext_previous32(text) != KHMER_MAIYAMOK) {
// // Skip over previous end and MAIYAMOK
// utext_next32(text);
// utext_next32(text);
// wordLength += 1; // Add MAIYAMOK to word
// }
// else {
// // Restore prior position
// utext_next32(text);
// }
// }
// }
// else {
// utext_setNativeIndex(text, current+wordLength);
// }
// }
// Did we find a word on this iteration? If so, push it on the break stack
if (wordLength > 0) {
foundBreaks.push((current+wordLength), status);
}
}
// Don't return a break for the end of the dictionary range if there is one there.
if (foundBreaks.peeki() >= rangeEnd) {
(void) foundBreaks.popi();
wordsFound -= 1;
}
return wordsFound;
}
#if !UCONFIG_NO_NORMALIZATION
/*
******************************************************************
* CjkBreakEngine
*/
static const uint32_t kuint32max = 0xFFFFFFFF;
CjkBreakEngine::CjkBreakEngine(DictionaryMatcher *adoptDictionary, LanguageType type, UErrorCode &status)
: DictionaryBreakEngine(1 << UBRK_WORD), fDictionary(adoptDictionary) {
// Korean dictionary only includes Hangul syllables
fHangulWordSet.applyPattern(UNICODE_STRING_SIMPLE("[\\uac00-\\ud7a3]"), status);
fHanWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Han:]"), status);
fKatakanaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Katakana:]\\uff9e\\uff9f]"), status);
fHiraganaWordSet.applyPattern(UNICODE_STRING_SIMPLE("[:Hiragana:]"), status);
if (U_SUCCESS(status)) {
// handle Korean and Japanese/Chinese using different dictionaries
if (type == kKorean) {
setCharacters(fHangulWordSet);
} else { //Chinese and Japanese
UnicodeSet cjSet;
cjSet.addAll(fHanWordSet);
cjSet.addAll(fKatakanaWordSet);
cjSet.addAll(fHiraganaWordSet);
cjSet.add(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 (int32_t i = 0; i < numChars; ++i) {
//utext_setNativeIndex(text, rangeStart + i);
utext_setNativeIndex(&normalizedText, i);
if (bestSnlp[i] == kuint32max)
continue;
int32_t count;
// limit maximum word length matched to size of current substring
int32_t maxSearchLength = (i + maxWordSize < (size_t) numChars)? maxWordSize : (numChars - i);
fDictionary->matches(&normalizedText, maxSearchLength, lengths.elems(), count, maxSearchLength, values.elems());
// if there are no single character matches found in the dictionary
// starting with this charcter, treat character as a 1-character word
// with the highest value possible, i.e. the least likely to occur.
// Exclude Korean characters from this treatment, as they should be left
// together by default.
if((count == 0 || lengths[0] != 1) &&
!fHangulWordSet.contains(utext_current32(&normalizedText))) {
values[count] = maxSnlp;
lengths[count++] = 1;
}
for (int j = 0; j < count; j++) {
uint32_t newSnlp = bestSnlp[i] + values[j];
if (newSnlp < bestSnlp[lengths[j] + i]) {
bestSnlp[lengths[j] + i] = newSnlp;
prev[lengths[j] + i] = i;
}
}
// In Japanese,
// Katakana word in single character is pretty rare. So we apply
// the following heuristic to Katakana: any continuous run of Katakana
// characters is considered a candidate word with a default cost
// specified in the katakanaCost table according to its length.
//utext_setNativeIndex(text, rangeStart + i);
utext_setNativeIndex(&normalizedText, i);
bool is_katakana = isKatakana(utext_current32(&normalizedText));
if (!is_prev_katakana && is_katakana) {
int j = i + 1;
utext_next32(&normalizedText);
// Find the end of the continuous run of Katakana characters
while (j < numChars && (j - i) < kMaxKatakanaGroupLength &&
isKatakana(utext_current32(&normalizedText))) {
utext_next32(&normalizedText);
++j;
}
if ((j - i) < kMaxKatakanaGroupLength) {
uint32_t newSnlp = bestSnlp[i] + getKatakanaCost(j - i);
if (newSnlp < bestSnlp[j]) {
bestSnlp[j] = newSnlp;
prev[j] = i;
}
}
}
is_prev_katakana = is_katakana;
}
// Start pushing the optimal offset index into t_boundary (t for tentative).
// prev[numChars] is guaranteed to be meaningful.
// We'll first push in the reverse order, i.e.,
// t_boundary[0] = numChars, and afterwards do a swap.
// TODO: Replace by UVector32.
AutoBuffer<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 */