[Complex Text Layouts] Add third-party TextServer dependencies (ICU, HarfBuzz, Graphite).

1 files changed, 1410 insertions, 0 deletions

diff --git a/thirdparty/icu4c/common/dictbe.cpp b/thirdparty/icu4c/common/dictbe.cpp
new file mode 100644
index 0000000000..b42cdf03fa
--- /dev/null
+++ b/thirdparty/icu4c/common/dictbe.cpp
@@ -0,0 +1,1410 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/**
+ *******************************************************************************
+ * Copyright (C) 2006-2016, International Business Machines Corporation
+ * and others. All Rights Reserved.
+ *******************************************************************************
+ */
+
+#include <utility>
+
+#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 "utracimp.h"
+#include "uvectr32.h"
+#include "uvector.h"
+#include "uassert.h"
+#include "unicode/normlzr.h"
+#include "cmemory.h"
+#include "dictionarydata.h"
+
+U_NAMESPACE_BEGIN
+
+/*
+ ******************************************************************
+ */
+
+DictionaryBreakEngine::DictionaryBreakEngine() {
+}
+
+DictionaryBreakEngine::~DictionaryBreakEngine() {
+}
+
+UBool
+DictionaryBreakEngine::handles(UChar32 c) const {
+    return fSet.contains(c);
+}
+
+int32_t
+DictionaryBreakEngine::findBreaks( UText *text,
+                                 int32_t startPos,
+                                 int32_t endPos,
+                                 UVector32 &foundBreaks ) const {
+    (void)startPos;            // TODO: remove this param?
+    int32_t result = 0;
+
+    // Find the span of characters included in the set.
+    //   The span to break begins at the current position in the text, and
+    //   extends towards the start or end of the text, depending on 'reverse'.
+
+    int32_t start = (int32_t)utext_getNativeIndex(text);
+    int32_t current;
+    int32_t rangeStart;
+    int32_t rangeEnd;
+    UChar32 c = utext_current32(text);
+    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;
+    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();
+}
+
+/*
+ ******************************************************************
+ * PossibleWord
+ */
+
+// Helper class for improving readability of the Thai/Lao/Khmer word break
+// algorithm. The implementation is completely inline.
+
+// List size, limited by the maximum number of words in the dictionary
+// that form a nested sequence.
+static const int32_t POSSIBLE_WORD_LIST_MAX = 20;
+
+class PossibleWord {
+private:
+    // list of word candidate lengths, in increasing length order
+    // TODO: bytes would be sufficient for word lengths.
+    int32_t   count;      // Count of candidates
+    int32_t   prefix;     // The longest match with a dictionary word
+    int32_t   offset;     // Offset in the text of these candidates
+    int32_t   mark;       // The preferred candidate's offset
+    int32_t   current;    // The candidate we're currently looking at
+    int32_t   cuLengths[POSSIBLE_WORD_LIST_MAX];   // Word Lengths, in code units.
+    int32_t   cpLengths[POSSIBLE_WORD_LIST_MAX];   // Word Lengths, in code points.
+
+public:
+    PossibleWord() : count(0), prefix(0), offset(-1), mark(0), current(0) {}
+    ~PossibleWord() {}
+  
+    // Fill the list of candidates if needed, select the longest, and return the number found
+    int32_t   candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd );
+  
+    // Select the currently marked candidate, point after it in the text, and invalidate self
+    int32_t   acceptMarked( UText *text );
+  
+    // Back up from the current candidate to the next shorter one; return TRUE if that exists
+    // and point the text after it
+    UBool     backUp( UText *text );
+  
+    // Return the longest prefix this candidate location shares with a dictionary word
+    // Return value is in code points.
+    int32_t   longestPrefix() { return prefix; }
+  
+    // Mark the current candidate as the one we like
+    void      markCurrent() { mark = current; }
+    
+    // Get length in code points of the marked word.
+    int32_t   markedCPLength() { return cpLengths[mark]; }
+};
+
+
+int32_t PossibleWord::candidates( UText *text, DictionaryMatcher *dict, int32_t rangeEnd ) {
+    // TODO: If getIndex is too slow, use offset < 0 and add discardAll()
+    int32_t start = (int32_t)utext_getNativeIndex(text);
+    if (start != offset) {
+        offset = start;
+        count = dict->matches(text, rangeEnd-start, UPRV_LENGTHOF(cuLengths), cuLengths, cpLengths, NULL, &prefix);
+        // Dictionary leaves text after longest prefix, not longest word. Back up.
+        if (count <= 0) {
+            utext_setNativeIndex(text, start);
+        }
+    }
+    if (count > 0) {
+        utext_setNativeIndex(text, start+cuLengths[count-1]);
+    }
+    current = count-1;
+    mark = current;
+    return count;
+}
+
+int32_t
+PossibleWord::acceptMarked( UText *text ) {
+    utext_setNativeIndex(text, offset + cuLengths[mark]);
+    return cuLengths[mark];
+}
+
+
+UBool
+PossibleWord::backUp( UText *text ) {
+    if (current > 0) {
+        utext_setNativeIndex(text, offset + cuLengths[--current]);
+        return TRUE;
+    }
+    return FALSE;
+}
+
+/*
+ ******************************************************************
+ * ThaiBreakEngine
+ */
+
+// How many words in a row are "good enough"?
+static const int32_t THAI_LOOKAHEAD = 3;
+
+// Will not combine a non-word with a preceding dictionary word longer than this
+static const int32_t THAI_ROOT_COMBINE_THRESHOLD = 3;
+
+// Will not combine a non-word that shares at least this much prefix with a
+// dictionary word, with a preceding word
+static const int32_t THAI_PREFIX_COMBINE_THRESHOLD = 3;
+
+// Ellision character
+static const int32_t THAI_PAIYANNOI = 0x0E2F;
+
+// Repeat character
+static const int32_t THAI_MAIYAMOK = 0x0E46;
+
+// Minimum word size
+static const int32_t THAI_MIN_WORD = 2;
+
+// Minimum number of characters for two words
+static const int32_t THAI_MIN_WORD_SPAN = THAI_MIN_WORD * 2;
+
+ThaiBreakEngine::ThaiBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
+    : DictionaryBreakEngine(),
+      fDictionary(adoptDictionary)
+{
+    UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
+    UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Thai");
+    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();
+    UTRACE_EXIT_STATUS(status);
+}
+
+ThaiBreakEngine::~ThaiBreakEngine() {
+    delete fDictionary;
+}
+
+int32_t
+ThaiBreakEngine::divideUpDictionaryRange( UText *text,
+                                                int32_t rangeStart,
+                                                int32_t rangeEnd,
+                                                UVector32 &foundBreaks ) const {
+    utext_setNativeIndex(text, rangeStart);
+    utext_moveIndex32(text, THAI_MIN_WORD_SPAN);
+    if (utext_getNativeIndex(text) >= rangeEnd) {
+        return 0;       // Not enough characters for two words
+    }
+    utext_setNativeIndex(text, rangeStart);
+
+
+    uint32_t wordsFound = 0;
+    int32_t cpWordLength = 0;    // Word Length in Code Points.
+    int32_t cuWordLength = 0;    // Word length in code units (UText native indexing)
+    int32_t current;
+    UErrorCode status = U_ZERO_ERROR;
+    PossibleWord words[THAI_LOOKAHEAD];
+    
+    utext_setNativeIndex(text, rangeStart);
+    
+    while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
+        cpWordLength = 0;
+        cuWordLength = 0;
+
+        // Look for candidate words at the current position
+        int32_t candidates = words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+        
+        // If we found exactly one, use that
+        if (candidates == 1) {
+            cuWordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % THAI_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        // If there was more than one, see which one can take us forward the most words
+        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 {
+                int32_t 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:
+            // Set UText position to after the accepted word.
+            cuWordLength = words[wordsFound % THAI_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % THAI_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        
+        // We come here after having either found a word or not. We look ahead to the
+        // next word. If it's not a dictionary word, we will combine it with the word we
+        // just found (if there is one), but only if the preceding word does not exceed
+        // the threshold.
+        // The text iterator should now be positioned at the end of the word we found.
+        
+        UChar32 uc = 0;
+        if ((int32_t)utext_getNativeIndex(text) < rangeEnd &&  cpWordLength < THAI_ROOT_COMBINE_THRESHOLD) {
+            // if it is a dictionary word, do nothing. If it isn't, then if there is
+            // no preceding word, or the non-word shares less than the minimum threshold
+            // of characters with a dictionary word, then scan to resynchronize
+            if (words[wordsFound % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+                  && (cuWordLength == 0
+                      || words[wordsFound%THAI_LOOKAHEAD].longestPrefix() < THAI_PREFIX_COMBINE_THRESHOLD)) {
+                // Look for a plausible word boundary
+                int32_t remaining = rangeEnd - (current+cuWordLength);
+                UChar32 pc;
+                int32_t chars = 0;
+                for (;;) {
+                    int32_t pcIndex = (int32_t)utext_getNativeIndex(text);
+                    pc = utext_next32(text);
+                    int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex;
+                    chars += pcSize;
+                    remaining -= pcSize;
+                    if (remaining <= 0) {
+                        break;
+                    }
+                    uc = utext_current32(text);
+                    if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
+                        // Maybe. See if it's in the dictionary.
+                        // NOTE: In the original Apple code, checked that the next
+                        // two characters after uc were not 0x0E4C THANTHAKHAT before
+                        // checking the dictionary. That is just a performance filter,
+                        // but it's not clear it's faster than checking the trie.
+                        int32_t num_candidates = words[(wordsFound + 1) % THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+                        utext_setNativeIndex(text, current + cuWordLength + chars);
+                        if (num_candidates > 0) {
+                            break;
+                        }
+                    }
+                }
+                
+                // Bump the word count if there wasn't already one
+                if (cuWordLength <= 0) {
+                    wordsFound += 1;
+                }
+                
+                // Update the length with the passed-over characters
+                cuWordLength += chars;
+            }
+            else {
+                // Back up to where we were for next iteration
+                utext_setNativeIndex(text, current+cuWordLength);
+            }
+        }
+        
+        // Never stop before a combining mark.
+        int32_t currPos;
+        while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
+            utext_next32(text);
+            cuWordLength += (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 && cuWordLength > 0) {
+            if (words[wordsFound%THAI_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+                && fSuffixSet.contains(uc = utext_current32(text))) {
+                if (uc == THAI_PAIYANNOI) {
+                    if (!fSuffixSet.contains(utext_previous32(text))) {
+                        // Skip over previous end and PAIYANNOI
+                        utext_next32(text);
+                        int32_t paiyannoiIndex = (int32_t)utext_getNativeIndex(text);
+                        utext_next32(text);
+                        cuWordLength += (int32_t)utext_getNativeIndex(text) - paiyannoiIndex;    // Add PAIYANNOI to word
+                        uc = utext_current32(text);     // Fetch next character
+                    }
+                    else {
+                        // Restore prior position
+                        utext_next32(text);
+                    }
+                }
+                if (uc == THAI_MAIYAMOK) {
+                    if (utext_previous32(text) != THAI_MAIYAMOK) {
+                        // Skip over previous end and MAIYAMOK
+                        utext_next32(text);
+                        int32_t maiyamokIndex = (int32_t)utext_getNativeIndex(text);
+                        utext_next32(text);
+                        cuWordLength += (int32_t)utext_getNativeIndex(text) - maiyamokIndex;    // Add MAIYAMOK to word
+                    }
+                    else {
+                        // Restore prior position
+                        utext_next32(text);
+                    }
+                }
+            }
+            else {
+                utext_setNativeIndex(text, current+cuWordLength);
+            }
+        }
+
+        // Did we find a word on this iteration? If so, push it on the break stack
+        if (cuWordLength > 0) {
+            foundBreaks.push((current+cuWordLength), status);
+        }
+    }
+
+    // Don't return a break for the end of the dictionary range if there is one there.
+    if (foundBreaks.peeki() >= rangeEnd) {
+        (void) foundBreaks.popi();
+        wordsFound -= 1;
+    }
+
+    return wordsFound;
+}
+
+/*
+ ******************************************************************
+ * LaoBreakEngine
+ */
+
+// How many words in a row are "good enough"?
+static const int32_t LAO_LOOKAHEAD = 3;
+
+// Will not combine a non-word with a preceding dictionary word longer than this
+static const int32_t LAO_ROOT_COMBINE_THRESHOLD = 3;
+
+// Will not combine a non-word that shares at least this much prefix with a
+// dictionary word, with a preceding word
+static const int32_t LAO_PREFIX_COMBINE_THRESHOLD = 3;
+
+// Minimum word size
+static const int32_t LAO_MIN_WORD = 2;
+
+// Minimum number of characters for two words
+static const int32_t LAO_MIN_WORD_SPAN = LAO_MIN_WORD * 2;
+
+LaoBreakEngine::LaoBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
+    : DictionaryBreakEngine(),
+      fDictionary(adoptDictionary)
+{
+    UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
+    UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Laoo");
+    fLaoWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Laoo:]&[:LineBreak=SA:]]"), status);
+    if (U_SUCCESS(status)) {
+        setCharacters(fLaoWordSet);
+    }
+    fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Laoo:]&[:LineBreak=SA:]&[:M:]]"), status);
+    fMarkSet.add(0x0020);
+    fEndWordSet = fLaoWordSet;
+    fEndWordSet.remove(0x0EC0, 0x0EC4);     // prefix vowels
+    fBeginWordSet.add(0x0E81, 0x0EAE);      // basic consonants (including holes for corresponding Thai characters)
+    fBeginWordSet.add(0x0EDC, 0x0EDD);      // digraph consonants (no Thai equivalent)
+    fBeginWordSet.add(0x0EC0, 0x0EC4);      // prefix vowels
+
+    // Compact for caching.
+    fMarkSet.compact();
+    fEndWordSet.compact();
+    fBeginWordSet.compact();
+    UTRACE_EXIT_STATUS(status);
+}
+
+LaoBreakEngine::~LaoBreakEngine() {
+    delete fDictionary;
+}
+
+int32_t
+LaoBreakEngine::divideUpDictionaryRange( UText *text,
+                                                int32_t rangeStart,
+                                                int32_t rangeEnd,
+                                                UVector32 &foundBreaks ) const {
+    if ((rangeEnd - rangeStart) < LAO_MIN_WORD_SPAN) {
+        return 0;       // Not enough characters for two words
+    }
+
+    uint32_t wordsFound = 0;
+    int32_t cpWordLength = 0;
+    int32_t cuWordLength = 0;
+    int32_t current;
+    UErrorCode status = U_ZERO_ERROR;
+    PossibleWord words[LAO_LOOKAHEAD];
+    
+    utext_setNativeIndex(text, rangeStart);
+    
+    while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
+        cuWordLength = 0;
+        cpWordLength = 0;
+
+        // Look for candidate words at the current position
+        int32_t candidates = words[wordsFound%LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+        
+        // If we found exactly one, use that
+        if (candidates == 1) {
+            cuWordLength = words[wordsFound % LAO_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % LAO_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        // If there was more than one, see which one can take us forward the most words
+        else if (candidates > 1) {
+            // If we're already at the end of the range, we're done
+            if (utext_getNativeIndex(text) >= rangeEnd) {
+                goto foundBest;
+            }
+            do {
+                int32_t wordsMatched = 1;
+                if (words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) {
+                    if (wordsMatched < 2) {
+                        // Followed by another dictionary word; mark first word as a good candidate
+                        words[wordsFound%LAO_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) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) {
+                            words[wordsFound % LAO_LOOKAHEAD].markCurrent();
+                            goto foundBest;
+                        }
+                    }
+                    while (words[(wordsFound + 1) % LAO_LOOKAHEAD].backUp(text));
+                }
+            }
+            while (words[wordsFound % LAO_LOOKAHEAD].backUp(text));
+foundBest:
+            cuWordLength = words[wordsFound % LAO_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % LAO_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        
+        // We come here after having either found a word or not. We look ahead to the
+        // next word. If it's not a dictionary word, we will combine it 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 && cpWordLength < LAO_ROOT_COMBINE_THRESHOLD) {
+            // if it is a dictionary word, do nothing. If it isn't, then if there is
+            // no preceding word, or the non-word shares less than the minimum threshold
+            // of characters with a dictionary word, then scan to resynchronize
+            if (words[wordsFound % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+                  && (cuWordLength == 0
+                      || words[wordsFound%LAO_LOOKAHEAD].longestPrefix() < LAO_PREFIX_COMBINE_THRESHOLD)) {
+                // Look for a plausible word boundary
+                int32_t remaining = rangeEnd - (current + cuWordLength);
+                UChar32 pc;
+                UChar32 uc;
+                int32_t chars = 0;
+                for (;;) {
+                    int32_t pcIndex = (int32_t)utext_getNativeIndex(text);
+                    pc = utext_next32(text);
+                    int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex;
+                    chars += pcSize;
+                    remaining -= pcSize;
+                    if (remaining <= 0) {
+                        break;
+                    }
+                    uc = utext_current32(text);
+                    if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
+                        // Maybe. See if it's in the dictionary.
+                        // TODO: this looks iffy; compare with old code.
+                        int32_t num_candidates = words[(wordsFound + 1) % LAO_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+                        utext_setNativeIndex(text, current + cuWordLength + chars);
+                        if (num_candidates > 0) {
+                            break;
+                        }
+                    }
+                }
+                
+                // Bump the word count if there wasn't already one
+                if (cuWordLength <= 0) {
+                    wordsFound += 1;
+                }
+                
+                // Update the length with the passed-over characters
+                cuWordLength += chars;
+            }
+            else {
+                // Back up to where we were for next iteration
+                utext_setNativeIndex(text, current + cuWordLength);
+            }
+        }
+        
+        // Never stop before a combining mark.
+        int32_t currPos;
+        while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
+            utext_next32(text);
+            cuWordLength += (int32_t)utext_getNativeIndex(text) - currPos;
+        }
+        
+        // Look ahead for possible suffixes if a dictionary word does not follow.
+        // We do this in code rather than using a rule so that the heuristic
+        // resynch continues to function. For example, one of the suffix characters
+        // could be a typo in the middle of a word.
+        // NOT CURRENTLY APPLICABLE TO LAO
+
+        // Did we find a word on this iteration? If so, push it on the break stack
+        if (cuWordLength > 0) {
+            foundBreaks.push((current+cuWordLength), status);
+        }
+    }
+
+    // Don't return a break for the end of the dictionary range if there is one there.
+    if (foundBreaks.peeki() >= rangeEnd) {
+        (void) foundBreaks.popi();
+        wordsFound -= 1;
+    }
+
+    return wordsFound;
+}
+
+/*
+ ******************************************************************
+ * BurmeseBreakEngine
+ */
+
+// How many words in a row are "good enough"?
+static const int32_t BURMESE_LOOKAHEAD = 3;
+
+// Will not combine a non-word with a preceding dictionary word longer than this
+static const int32_t BURMESE_ROOT_COMBINE_THRESHOLD = 3;
+
+// Will not combine a non-word that shares at least this much prefix with a
+// dictionary word, with a preceding word
+static const int32_t BURMESE_PREFIX_COMBINE_THRESHOLD = 3;
+
+// Minimum word size
+static const int32_t BURMESE_MIN_WORD = 2;
+
+// Minimum number of characters for two words
+static const int32_t BURMESE_MIN_WORD_SPAN = BURMESE_MIN_WORD * 2;
+
+BurmeseBreakEngine::BurmeseBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
+    : DictionaryBreakEngine(),
+      fDictionary(adoptDictionary)
+{
+    UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
+    UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Mymr");
+    fBurmeseWordSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Mymr:]&[:LineBreak=SA:]]"), status);
+    if (U_SUCCESS(status)) {
+        setCharacters(fBurmeseWordSet);
+    }
+    fMarkSet.applyPattern(UNICODE_STRING_SIMPLE("[[:Mymr:]&[:LineBreak=SA:]&[:M:]]"), status);
+    fMarkSet.add(0x0020);
+    fEndWordSet = fBurmeseWordSet;
+    fBeginWordSet.add(0x1000, 0x102A);      // basic consonants and independent vowels
+
+    // Compact for caching.
+    fMarkSet.compact();
+    fEndWordSet.compact();
+    fBeginWordSet.compact();
+    UTRACE_EXIT_STATUS(status);
+}
+
+BurmeseBreakEngine::~BurmeseBreakEngine() {
+    delete fDictionary;
+}
+
+int32_t
+BurmeseBreakEngine::divideUpDictionaryRange( UText *text,
+                                                int32_t rangeStart,
+                                                int32_t rangeEnd,
+                                                UVector32 &foundBreaks ) const {
+    if ((rangeEnd - rangeStart) < BURMESE_MIN_WORD_SPAN) {
+        return 0;       // Not enough characters for two words
+    }
+
+    uint32_t wordsFound = 0;
+    int32_t cpWordLength = 0;
+    int32_t cuWordLength = 0;
+    int32_t current;
+    UErrorCode status = U_ZERO_ERROR;
+    PossibleWord words[BURMESE_LOOKAHEAD];
+    
+    utext_setNativeIndex(text, rangeStart);
+    
+    while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
+        cuWordLength = 0;
+        cpWordLength = 0;
+
+        // Look for candidate words at the current position
+        int32_t candidates = words[wordsFound%BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+        
+        // If we found exactly one, use that
+        if (candidates == 1) {
+            cuWordLength = words[wordsFound % BURMESE_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % BURMESE_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        // If there was more than one, see which one can take us forward the most words
+        else if (candidates > 1) {
+            // If we're already at the end of the range, we're done
+            if (utext_getNativeIndex(text) >= rangeEnd) {
+                goto foundBest;
+            }
+            do {
+                int32_t wordsMatched = 1;
+                if (words[(wordsFound + 1) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) > 0) {
+                    if (wordsMatched < 2) {
+                        // Followed by another dictionary word; mark first word as a good candidate
+                        words[wordsFound%BURMESE_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) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd)) {
+                            words[wordsFound % BURMESE_LOOKAHEAD].markCurrent();
+                            goto foundBest;
+                        }
+                    }
+                    while (words[(wordsFound + 1) % BURMESE_LOOKAHEAD].backUp(text));
+                }
+            }
+            while (words[wordsFound % BURMESE_LOOKAHEAD].backUp(text));
+foundBest:
+            cuWordLength = words[wordsFound % BURMESE_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % BURMESE_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+        
+        // We come here after having either found a word or not. We look ahead to the
+        // next word. If it's not a dictionary word, we will combine it 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 && cpWordLength < BURMESE_ROOT_COMBINE_THRESHOLD) {
+            // if it is a dictionary word, do nothing. If it isn't, then if there is
+            // no preceding word, or the non-word shares less than the minimum threshold
+            // of characters with a dictionary word, then scan to resynchronize
+            if (words[wordsFound % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+                  && (cuWordLength == 0
+                      || words[wordsFound%BURMESE_LOOKAHEAD].longestPrefix() < BURMESE_PREFIX_COMBINE_THRESHOLD)) {
+                // Look for a plausible word boundary
+                int32_t remaining = rangeEnd - (current + cuWordLength);
+                UChar32 pc;
+                UChar32 uc;
+                int32_t chars = 0;
+                for (;;) {
+                    int32_t pcIndex = (int32_t)utext_getNativeIndex(text);
+                    pc = utext_next32(text);
+                    int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex;
+                    chars += pcSize;
+                    remaining -= pcSize;
+                    if (remaining <= 0) {
+                        break;
+                    }
+                    uc = utext_current32(text);
+                    if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
+                        // Maybe. See if it's in the dictionary.
+                        // TODO: this looks iffy; compare with old code.
+                        int32_t num_candidates = words[(wordsFound + 1) % BURMESE_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+                        utext_setNativeIndex(text, current + cuWordLength + chars);
+                        if (num_candidates > 0) {
+                            break;
+                        }
+                    }
+                }
+                
+                // Bump the word count if there wasn't already one
+                if (cuWordLength <= 0) {
+                    wordsFound += 1;
+                }
+                
+                // Update the length with the passed-over characters
+                cuWordLength += chars;
+            }
+            else {
+                // Back up to where we were for next iteration
+                utext_setNativeIndex(text, current + cuWordLength);
+            }
+        }
+        
+        // Never stop before a combining mark.
+        int32_t currPos;
+        while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
+            utext_next32(text);
+            cuWordLength += (int32_t)utext_getNativeIndex(text) - currPos;
+        }
+        
+        // Look ahead for possible suffixes if a dictionary word does not follow.
+        // We do this in code rather than using a rule so that the heuristic
+        // resynch continues to function. For example, one of the suffix characters
+        // could be a typo in the middle of a word.
+        // NOT CURRENTLY APPLICABLE TO BURMESE
+
+        // Did we find a word on this iteration? If so, push it on the break stack
+        if (cuWordLength > 0) {
+            foundBreaks.push((current+cuWordLength), status);
+        }
+    }
+
+    // Don't return a break for the end of the dictionary range if there is one there.
+    if (foundBreaks.peeki() >= rangeEnd) {
+        (void) foundBreaks.popi();
+        wordsFound -= 1;
+    }
+
+    return wordsFound;
+}
+
+/*
+ ******************************************************************
+ * KhmerBreakEngine
+ */
+
+// How many words in a row are "good enough"?
+static const int32_t KHMER_LOOKAHEAD = 3;
+
+// Will not combine a non-word with a preceding dictionary word longer than this
+static const int32_t KHMER_ROOT_COMBINE_THRESHOLD = 3;
+
+// Will not combine a non-word that shares at least this much prefix with a
+// dictionary word, with a preceding word
+static const int32_t KHMER_PREFIX_COMBINE_THRESHOLD = 3;
+
+// Minimum word size
+static const int32_t KHMER_MIN_WORD = 2;
+
+// Minimum number of characters for two words
+static const int32_t KHMER_MIN_WORD_SPAN = KHMER_MIN_WORD * 2;
+
+KhmerBreakEngine::KhmerBreakEngine(DictionaryMatcher *adoptDictionary, UErrorCode &status)
+    : DictionaryBreakEngine(),
+      fDictionary(adoptDictionary)
+{
+    UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
+    UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Khmr");
+    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();
+    UTRACE_EXIT_STATUS(status);
+}
+
+KhmerBreakEngine::~KhmerBreakEngine() {
+    delete fDictionary;
+}
+
+int32_t
+KhmerBreakEngine::divideUpDictionaryRange( UText *text,
+                                                int32_t rangeStart,
+                                                int32_t rangeEnd,
+                                                UVector32 &foundBreaks ) const {
+    if ((rangeEnd - rangeStart) < KHMER_MIN_WORD_SPAN) {
+        return 0;       // Not enough characters for two words
+    }
+
+    uint32_t wordsFound = 0;
+    int32_t cpWordLength = 0;
+    int32_t cuWordLength = 0;
+    int32_t current;
+    UErrorCode status = U_ZERO_ERROR;
+    PossibleWord words[KHMER_LOOKAHEAD];
+
+    utext_setNativeIndex(text, rangeStart);
+
+    while (U_SUCCESS(status) && (current = (int32_t)utext_getNativeIndex(text)) < rangeEnd) {
+        cuWordLength = 0;
+        cpWordLength = 0;
+
+        // Look for candidate words at the current position
+        int32_t candidates = words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+
+        // If we found exactly one, use that
+        if (candidates == 1) {
+            cuWordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % KHMER_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+
+        // If there was more than one, see which one can take us forward the most words
+        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 {
+                int32_t 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:
+            cuWordLength = words[wordsFound % KHMER_LOOKAHEAD].acceptMarked(text);
+            cpWordLength = words[wordsFound % KHMER_LOOKAHEAD].markedCPLength();
+            wordsFound += 1;
+        }
+
+        // We come here after having either found a word or not. We look ahead to the
+        // next word. If it's not a dictionary word, we will combine it with the word we
+        // just found (if there is one), but only if the preceding word does not exceed
+        // the threshold.
+        // The text iterator should now be positioned at the end of the word we found.
+        if ((int32_t)utext_getNativeIndex(text) < rangeEnd && cpWordLength < KHMER_ROOT_COMBINE_THRESHOLD) {
+            // if it is a dictionary word, do nothing. If it isn't, then if there is
+            // no preceding word, or the non-word shares less than the minimum threshold
+            // of characters with a dictionary word, then scan to resynchronize
+            if (words[wordsFound % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+                  && (cuWordLength == 0
+                      || words[wordsFound % KHMER_LOOKAHEAD].longestPrefix() < KHMER_PREFIX_COMBINE_THRESHOLD)) {
+                // Look for a plausible word boundary
+                int32_t remaining = rangeEnd - (current+cuWordLength);
+                UChar32 pc;
+                UChar32 uc;
+                int32_t chars = 0;
+                for (;;) {
+                    int32_t pcIndex = (int32_t)utext_getNativeIndex(text);
+                    pc = utext_next32(text);
+                    int32_t pcSize = (int32_t)utext_getNativeIndex(text) - pcIndex;
+                    chars += pcSize;
+                    remaining -= pcSize;
+                    if (remaining <= 0) {
+                        break;
+                    }
+                    uc = utext_current32(text);
+                    if (fEndWordSet.contains(pc) && fBeginWordSet.contains(uc)) {
+                        // Maybe. See if it's in the dictionary.
+                        int32_t num_candidates = words[(wordsFound + 1) % KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd);
+                        utext_setNativeIndex(text, current+cuWordLength+chars);
+                        if (num_candidates > 0) {
+                            break;
+                        }
+                    }
+                }
+
+                // Bump the word count if there wasn't already one
+                if (cuWordLength <= 0) {
+                    wordsFound += 1;
+                }
+
+                // Update the length with the passed-over characters
+                cuWordLength += chars;
+            }
+            else {
+                // Back up to where we were for next iteration
+                utext_setNativeIndex(text, current+cuWordLength);
+            }
+        }
+
+        // Never stop before a combining mark.
+        int32_t currPos;
+        while ((currPos = (int32_t)utext_getNativeIndex(text)) < rangeEnd && fMarkSet.contains(utext_current32(text))) {
+            utext_next32(text);
+            cuWordLength += (int32_t)utext_getNativeIndex(text) - currPos;
+        }
+
+        // Look ahead for possible suffixes if a dictionary word does not follow.
+        // We do this in code rather than using a rule so that the heuristic
+        // resynch continues to function. For example, one of the suffix characters
+        // could be a typo in the middle of a word.
+//        if ((int32_t)utext_getNativeIndex(text) < rangeEnd && wordLength > 0) {
+//            if (words[wordsFound%KHMER_LOOKAHEAD].candidates(text, fDictionary, rangeEnd) <= 0
+//                && fSuffixSet.contains(uc = utext_current32(text))) {
+//                if (uc == KHMER_PAIYANNOI) {
+//                    if (!fSuffixSet.contains(utext_previous32(text))) {
+//                        // Skip over previous end and PAIYANNOI
+//                        utext_next32(text);
+//                        utext_next32(text);
+//                        wordLength += 1;            // Add PAIYANNOI to word
+//                        uc = utext_current32(text);     // Fetch next character
+//                    }
+//                    else {
+//                        // Restore prior position
+//                        utext_next32(text);
+//                    }
+//                }
+//                if (uc == KHMER_MAIYAMOK) {
+//                    if (utext_previous32(text) != KHMER_MAIYAMOK) {
+//                        // Skip over previous end and MAIYAMOK
+//                        utext_next32(text);
+//                        utext_next32(text);
+//                        wordLength += 1;            // Add MAIYAMOK to word
+//                    }
+//                    else {
+//                        // Restore prior position
+//                        utext_next32(text);
+//                    }
+//                }
+//            }
+//            else {
+//                utext_setNativeIndex(text, current+wordLength);
+//            }
+//        }
+
+        // Did we find a word on this iteration? If so, push it on the break stack
+        if (cuWordLength > 0) {
+            foundBreaks.push((current+cuWordLength), status);
+        }
+    }
+    
+    // Don't return a break for the end of the dictionary range if there is one there.
+    if (foundBreaks.peeki() >= rangeEnd) {
+        (void) foundBreaks.popi();
+        wordsFound -= 1;
+    }
+
+    return wordsFound;
+}
+
+#if !UCONFIG_NO_NORMALIZATION
+/*
+ ******************************************************************
+ * CjkBreakEngine
+ */
+static const uint32_t kuint32max = 0xFFFFFFFF;
+CjkBreakEngine::CjkBreakEngine(DictionaryMatcher *adoptDictionary, LanguageType type, UErrorCode &status)
+: DictionaryBreakEngine(), fDictionary(adoptDictionary) {
+    UTRACE_ENTRY(UTRACE_UBRK_CREATE_BREAK_ENGINE);
+    UTRACE_DATA1(UTRACE_INFO, "dictbe=%s", "Hani");
+    // 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);
+    nfkcNorm2 = Normalizer2::getNFKCInstance(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(0xFF70); // HALFWIDTH KATAKANA-HIRAGANA PROLONGED SOUND MARK
+            cjSet.add(0x30FC); // KATAKANA-HIRAGANA PROLONGED SOUND MARK
+            setCharacters(cjSet);
+        }
+    }
+    UTRACE_EXIT_STATUS(status);
+}
+
+CjkBreakEngine::~CjkBreakEngine(){
+    delete fDictionary;
+}
+
+// The katakanaCost values below are based on the length frequencies of all
+// katakana phrases in the dictionary
+static const int32_t kMaxKatakanaLength = 8;
+static const int32_t kMaxKatakanaGroupLength = 20;
+static const uint32_t maxSnlp = 255;
+
+static inline uint32_t getKatakanaCost(int32_t 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(UChar32 value) {
+    return (value >= 0x30A1 && value <= 0x30FE && value != 0x30FB) ||
+            (value >= 0xFF66 && value <= 0xFF9f);
+}
+
+
+// Function for accessing internal utext flags.
+//   Replicates an internal UText function.
+
+static inline int32_t utext_i32_flag(int32_t bitIndex) {
+    return (int32_t)1 << bitIndex;
+}
+
+       
+/*
+ * @param text A UText representing the text
+ * @param rangeStart The start of the range of dictionary characters
+ * @param rangeEnd The end of the range of dictionary characters
+ * @param foundBreaks vector<int32> to receive the break positions
+ * @return The number of breaks found
+ */
+int32_t 
+CjkBreakEngine::divideUpDictionaryRange( UText *inText,
+        int32_t rangeStart,
+        int32_t rangeEnd,
+        UVector32 &foundBreaks ) const {
+    if (rangeStart >= rangeEnd) {
+        return 0;
+    }
+
+    // UnicodeString version of input UText, NFKC normalized if necessary.
+    UnicodeString inString;
+
+    // inputMap[inStringIndex] = corresponding native index from UText inText.
+    // If NULL then mapping is 1:1
+    LocalPointer<UVector32>     inputMap;
+
+    UErrorCode     status      = U_ZERO_ERROR;
+
+
+    // if UText has the input string as one contiguous UTF-16 chunk
+    if ((inText->providerProperties & utext_i32_flag(UTEXT_PROVIDER_STABLE_CHUNKS)) &&
+         inText->chunkNativeStart <= rangeStart &&
+         inText->chunkNativeLimit >= rangeEnd   &&
+         inText->nativeIndexingLimit >= rangeEnd - inText->chunkNativeStart) {
+
+        // Input UText is in one contiguous UTF-16 chunk.
+        // Use Read-only aliasing UnicodeString.
+        inString.setTo(FALSE,
+                       inText->chunkContents + rangeStart - inText->chunkNativeStart,
+                       rangeEnd - rangeStart);
+    } else {
+        // Copy the text from the original inText (UText) to inString (UnicodeString).
+        // Create a map from UnicodeString indices -> UText offsets.
+        utext_setNativeIndex(inText, rangeStart);
+        int32_t limit = rangeEnd;
+        U_ASSERT(limit <= utext_nativeLength(inText));
+        if (limit > utext_nativeLength(inText)) {
+            limit = (int32_t)utext_nativeLength(inText);
+        }
+        inputMap.adoptInsteadAndCheckErrorCode(new UVector32(status), status);
+        if (U_FAILURE(status)) {
+            return 0;
+        }
+        while (utext_getNativeIndex(inText) < limit) {
+            int32_t nativePosition = (int32_t)utext_getNativeIndex(inText);
+            UChar32 c = utext_next32(inText);
+            U_ASSERT(c != U_SENTINEL);
+            inString.append(c);
+            while (inputMap->size() < inString.length()) {
+                inputMap->addElement(nativePosition, status);
+            }
+        }
+        inputMap->addElement(limit, status);
+    }
+
+
+    if (!nfkcNorm2->isNormalized(inString, status)) {
+        UnicodeString normalizedInput;
+        //  normalizedMap[normalizedInput position] ==  original UText position.
+        LocalPointer<UVector32> normalizedMap(new UVector32(status), status);
+        if (U_FAILURE(status)) {
+            return 0;
+        }
+        
+        UnicodeString fragment;
+        UnicodeString normalizedFragment;
+        for (int32_t srcI = 0; srcI < inString.length();) {  // Once per normalization chunk
+            fragment.remove();
+            int32_t fragmentStartI = srcI;
+            UChar32 c = inString.char32At(srcI);
+            for (;;) {
+                fragment.append(c);
+                srcI = inString.moveIndex32(srcI, 1);
+                if (srcI == inString.length()) {
+                    break;
+                }
+                c = inString.char32At(srcI);
+                if (nfkcNorm2->hasBoundaryBefore(c)) {
+                    break;
+                }
+            }
+            nfkcNorm2->normalize(fragment, normalizedFragment, status);
+            normalizedInput.append(normalizedFragment);
+
+            // Map every position in the normalized chunk to the start of the chunk
+            //   in the original input.
+            int32_t fragmentOriginalStart = inputMap.isValid() ?
+                    inputMap->elementAti(fragmentStartI) : fragmentStartI+rangeStart;
+            while (normalizedMap->size() < normalizedInput.length()) {
+                normalizedMap->addElement(fragmentOriginalStart, status);
+                if (U_FAILURE(status)) {
+                    break;
+                }
+            }
+        }
+        U_ASSERT(normalizedMap->size() == normalizedInput.length());
+        int32_t nativeEnd = inputMap.isValid() ?
+                inputMap->elementAti(inString.length()) : inString.length()+rangeStart;
+        normalizedMap->addElement(nativeEnd, status);
+
+        inputMap = std::move(normalizedMap);
+        inString = std::move(normalizedInput);
+    }
+
+    int32_t numCodePts = inString.countChar32();
+    if (numCodePts != inString.length()) {
+        // There are supplementary characters in the input.
+        // The dictionary will produce boundary positions in terms of code point indexes,
+        //   not in terms of code unit string indexes.
+        // Use the inputMap mechanism to take care of this in addition to indexing differences
+        //    from normalization and/or UTF-8 input.
+        UBool hadExistingMap = inputMap.isValid();
+        if (!hadExistingMap) {
+            inputMap.adoptInsteadAndCheckErrorCode(new UVector32(status), status);
+            if (U_FAILURE(status)) {
+                return 0;
+            }
+        }
+        int32_t cpIdx = 0;
+        for (int32_t cuIdx = 0; ; cuIdx = inString.moveIndex32(cuIdx, 1)) {
+            U_ASSERT(cuIdx >= cpIdx);
+            if (hadExistingMap) {
+                inputMap->setElementAt(inputMap->elementAti(cuIdx), cpIdx);
+            } else {
+                inputMap->addElement(cuIdx+rangeStart, status);
+            }
+            cpIdx++;
+            if (cuIdx == inString.length()) {
+               break;
+            }
+        }
+    }
+                
+    // bestSnlp[i] is the snlp of the best segmentation of the first i
+    // code points in the range to be matched.
+    UVector32 bestSnlp(numCodePts + 1, status);
+    bestSnlp.addElement(0, status);
+    for(int32_t i = 1; i <= numCodePts; i++) {
+        bestSnlp.addElement(kuint32max, status);
+    }
+
+
+    // prev[i] is the index of the last CJK code point in the previous word in 
+    // the best segmentation of the first i characters.
+    UVector32 prev(numCodePts + 1, status);
+    for(int32_t i = 0; i <= numCodePts; i++){
+        prev.addElement(-1, status);
+    }
+
+    const int32_t maxWordSize = 20;
+    UVector32 values(numCodePts, status);
+    values.setSize(numCodePts);
+    UVector32 lengths(numCodePts, status);
+    lengths.setSize(numCodePts);
+
+    UText fu = UTEXT_INITIALIZER;
+    utext_openUnicodeString(&fu, &inString, &status);
+
+    // Dynamic programming to find the best segmentation.
+
+    // In outer loop, i  is the code point index,
+    //                ix is the corresponding string (code unit) index.
+    //    They differ when the string contains supplementary characters.
+    int32_t ix = 0;
+    bool is_prev_katakana = false;
+    for (int32_t i = 0;  i < numCodePts;  ++i, ix = inString.moveIndex32(ix, 1)) {
+        if ((uint32_t)bestSnlp.elementAti(i) == kuint32max) {
+            continue;
+        }
+
+        int32_t count;
+        utext_setNativeIndex(&fu, ix);
+        count = fDictionary->matches(&fu, maxWordSize, numCodePts,
+                             NULL, lengths.getBuffer(), values.getBuffer(), NULL);
+                             // Note: lengths is filled with code point lengths
+                             //       The NULL parameter is the ignored code unit lengths.
+
+        // if there are no single character matches found in the dictionary 
+        // starting with this character, treat character as a 1-character word 
+        // with the highest value possible, i.e. the least likely to occur.
+        // Exclude Korean characters from this treatment, as they should be left
+        // together by default.
+        if ((count == 0 || lengths.elementAti(0) != 1) &&
+                !fHangulWordSet.contains(inString.char32At(ix))) {
+            values.setElementAt(maxSnlp, count);   // 255
+            lengths.setElementAt(1, count++);
+        }
+
+        for (int32_t j = 0; j < count; j++) {
+            uint32_t newSnlp = (uint32_t)bestSnlp.elementAti(i) + (uint32_t)values.elementAti(j);
+            int32_t ln_j_i = lengths.elementAti(j) + i;
+            if (newSnlp < (uint32_t)bestSnlp.elementAti(ln_j_i)) {
+                bestSnlp.setElementAt(newSnlp, ln_j_i);
+                prev.setElementAt(i, ln_j_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.
+
+        bool is_katakana = isKatakana(inString.char32At(ix));
+        int32_t katakanaRunLength = 1;
+        if (!is_prev_katakana && is_katakana) {
+            int32_t j = inString.moveIndex32(ix, 1);
+            // Find the end of the continuous run of Katakana characters
+            while (j < inString.length() && katakanaRunLength < kMaxKatakanaGroupLength &&
+                    isKatakana(inString.char32At(j))) {
+                j = inString.moveIndex32(j, 1);
+                katakanaRunLength++;
+            }
+            if (katakanaRunLength < kMaxKatakanaGroupLength) {
+                uint32_t newSnlp = bestSnlp.elementAti(i) + getKatakanaCost(katakanaRunLength);
+                if (newSnlp < (uint32_t)bestSnlp.elementAti(i+katakanaRunLength)) {
+                    bestSnlp.setElementAt(newSnlp, i+katakanaRunLength);
+                    prev.setElementAt(i, i+katakanaRunLength);  // prev[j] = i;
+                }
+            }
+        }
+        is_prev_katakana = is_katakana;
+    }
+    utext_close(&fu);
+
+    // Start pushing the optimal offset index into t_boundary (t for tentative).
+    // prev[numCodePts] is guaranteed to be meaningful.
+    // We'll first push in the reverse order, i.e.,
+    // t_boundary[0] = numCodePts, and afterwards do a swap.
+    UVector32 t_boundary(numCodePts+1, status);
+
+    int32_t numBreaks = 0;
+    // No segmentation found, set boundary to end of range
+    if ((uint32_t)bestSnlp.elementAti(numCodePts) == kuint32max) {
+        t_boundary.addElement(numCodePts, status);
+        numBreaks++;
+    } else {
+        for (int32_t i = numCodePts; i > 0; i = prev.elementAti(i)) {
+            t_boundary.addElement(i, status);
+            numBreaks++;
+        }
+        U_ASSERT(prev.elementAti(t_boundary.elementAti(numBreaks - 1)) == 0);
+    }
+
+    // Add a break for the start of the dictionary range if there is not one
+    // there already.
+    if (foundBreaks.size() == 0 || foundBreaks.peeki() < rangeStart) {
+        t_boundary.addElement(0, status);
+        numBreaks++;
+    }
+
+    // Now that we're done, convert positions in t_boundary[] (indices in 
+    // the normalized input string) back to indices in the original input UText
+    // while reversing t_boundary and pushing values to foundBreaks.
+    int32_t prevCPPos = -1;
+    int32_t prevUTextPos = -1;
+    for (int32_t i = numBreaks-1; i >= 0; i--) {
+        int32_t cpPos = t_boundary.elementAti(i);
+        U_ASSERT(cpPos > prevCPPos);
+        int32_t utextPos =  inputMap.isValid() ? inputMap->elementAti(cpPos) : cpPos + rangeStart;
+        U_ASSERT(utextPos >= prevUTextPos);
+        if (utextPos > prevUTextPos) {
+            // Boundaries are added to foundBreaks output in ascending order.
+            U_ASSERT(foundBreaks.size() == 0 || foundBreaks.peeki() < utextPos);
+            foundBreaks.push(utextPos, status);
+        } else {
+            // Normalization expanded the input text, the dictionary found a boundary
+            // within the expansion, giving two boundaries with the same index in the
+            // original text. Ignore the second. See ticket #12918.
+            --numBreaks;
+        }
+        prevCPPos = cpPos;
+        prevUTextPos = utextPos;
+    }
+    (void)prevCPPos; // suppress compiler warnings about unused variable
+
+    // inString goes out of scope
+    // inputMap goes out of scope
+    return numBreaks;
+}
+#endif
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_BREAK_ITERATION */
+