text: /**
   *******************************************************************************
   * 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 */
  
  