Update ICU to 54.1 step 1

source/i18n/uitercollationiterator.cpp

+/*
+*******************************************************************************
+* Copyright (C) 2012-2014, International Business Machines
+* Corporation and others.  All Rights Reserved.
+*******************************************************************************
+* uitercollationiterator.cpp
+*
+* created on: 2012sep23 (from utf16collationiterator.cpp)
+* created by: Markus W. Scherer
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_COLLATION
+
+#include "unicode/uiter.h"
+#include "charstr.h"
+#include "cmemory.h"
+#include "collation.h"
+#include "collationdata.h"
+#include "collationfcd.h"
+#include "collationiterator.h"
+#include "normalizer2impl.h"
+#include "uassert.h"
+#include "uitercollationiterator.h"
+
+U_NAMESPACE_BEGIN
+
+UIterCollationIterator::~UIterCollationIterator() {}
+
+void
+UIterCollationIterator::resetToOffset(int32_t newOffset) {
+    reset();
+    iter.move(&iter, newOffset, UITER_START);
+}
+
+int32_t
+UIterCollationIterator::getOffset() const {
+    return iter.getIndex(&iter, UITER_CURRENT);
+}
+
+uint32_t
+UIterCollationIterator::handleNextCE32(UChar32 &c, UErrorCode & /*errorCode*/) {
+    c = iter.next(&iter);
+    if(c < 0) {
+        return Collation::FALLBACK_CE32;
+    }
+    return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c);
+}
+
+UChar
+UIterCollationIterator::handleGetTrailSurrogate() {
+    UChar32 trail = iter.next(&iter);
+    if(!U16_IS_TRAIL(trail) && trail >= 0) { iter.previous(&iter); }
+    return (UChar)trail;
+}
+
+UChar32
+UIterCollationIterator::nextCodePoint(UErrorCode & /*errorCode*/) {
+    return uiter_next32(&iter);
+}
+
+UChar32
+UIterCollationIterator::previousCodePoint(UErrorCode & /*errorCode*/) {
+    return uiter_previous32(&iter);
+}
+
+void
+UIterCollationIterator::forwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) {
+    while(num > 0 && (uiter_next32(&iter)) >= 0) {
+        --num;
+    }
+}
+
+void
+UIterCollationIterator::backwardNumCodePoints(int32_t num, UErrorCode & /*errorCode*/) {
+    while(num > 0 && (uiter_previous32(&iter)) >= 0) {
+        --num;
+    }
+}
+
+// FCDUIterCollationIterator ----------------------------------------------- ***
+
+FCDUIterCollationIterator::~FCDUIterCollationIterator() {}
+
+void
+FCDUIterCollationIterator::resetToOffset(int32_t newOffset) {
+    UIterCollationIterator::resetToOffset(newOffset);
+    start = newOffset;
+    state = ITER_CHECK_FWD;
+}
+
+int32_t
+FCDUIterCollationIterator::getOffset() const {
+    if(state <= ITER_CHECK_BWD) {
+        return iter.getIndex(&iter, UITER_CURRENT);
+    } else if(state == ITER_IN_FCD_SEGMENT) {
+        return pos;
+    } else if(pos == 0) {
+        return start;
+    } else {
+        return limit;
+    }
+}
+
+uint32_t
+FCDUIterCollationIterator::handleNextCE32(UChar32 &c, UErrorCode &errorCode) {
+    for(;;) {
+        if(state == ITER_CHECK_FWD) {
+            c = iter.next(&iter);
+            if(c < 0) {
+                return Collation::FALLBACK_CE32;
+            }
+            if(CollationFCD::hasTccc(c)) {
+                if(CollationFCD::maybeTibetanCompositeVowel(c) ||
+                        CollationFCD::hasLccc(iter.current(&iter))) {
+                    iter.previous(&iter);
+                    if(!nextSegment(errorCode)) {
+                        c = U_SENTINEL;
+                        return Collation::FALLBACK_CE32;
+                    }
+                    continue;
+                }
+            }
+            break;
+        } else if(state == ITER_IN_FCD_SEGMENT && pos != limit) {
+            c = iter.next(&iter);
+            ++pos;
+            U_ASSERT(c >= 0);
+            break;
+        } else if(state >= IN_NORM_ITER_AT_LIMIT && pos != normalized.length()) {
+            c = normalized[pos++];
+            break;
+        } else {
+            switchToForward();
+        }
+    }
+    return UTRIE2_GET32_FROM_U16_SINGLE_LEAD(trie, c);
+}
+
+UChar
+FCDUIterCollationIterator::handleGetTrailSurrogate() {
+    if(state <= ITER_IN_FCD_SEGMENT) {
+        UChar32 trail = iter.next(&iter);
+        if(U16_IS_TRAIL(trail)) {
+            if(state == ITER_IN_FCD_SEGMENT) { ++pos; }
+        } else if(trail >= 0) {
+            iter.previous(&iter);
+        }
+        return (UChar)trail;
+    } else {
+        U_ASSERT(pos < normalized.length());
+        UChar trail;
+        if(U16_IS_TRAIL(trail = normalized[pos])) { ++pos; }
+        return trail;
+    }
+}
+
+UChar32
+FCDUIterCollationIterator::nextCodePoint(UErrorCode &errorCode) {
+    UChar32 c;
+    for(;;) {
+        if(state == ITER_CHECK_FWD) {
+            c = iter.next(&iter);
+            if(c < 0) {
+                return c;
+            }
+            if(CollationFCD::hasTccc(c)) {
+                if(CollationFCD::maybeTibetanCompositeVowel(c) ||
+                        CollationFCD::hasLccc(iter.current(&iter))) {
+                    iter.previous(&iter);
+                    if(!nextSegment(errorCode)) {
+                        return U_SENTINEL;
+                    }
+                    continue;
+                }
+            }
+            if(U16_IS_LEAD(c)) {
+                UChar32 trail = iter.next(&iter);
+                if(U16_IS_TRAIL(trail)) {
+                    return U16_GET_SUPPLEMENTARY(c, trail);
+                } else if(trail >= 0) {
+                    iter.previous(&iter);
+                }
+            }
+            return c;
+        } else if(state == ITER_IN_FCD_SEGMENT && pos != limit) {
+            c = uiter_next32(&iter);
+            pos += U16_LENGTH(c);
+            U_ASSERT(c >= 0);
+            return c;
+        } else if(state >= IN_NORM_ITER_AT_LIMIT && pos != normalized.length()) {
+            c = normalized.char32At(pos);
+            pos += U16_LENGTH(c);
+            return c;
+        } else {
+            switchToForward();
+        }
+    }
+}
+
+UChar32
+FCDUIterCollationIterator::previousCodePoint(UErrorCode &errorCode) {
+    UChar32 c;
+    for(;;) {
+        if(state == ITER_CHECK_BWD) {
+            c = iter.previous(&iter);
+            if(c < 0) {
+                start = pos = 0;
+                state = ITER_IN_FCD_SEGMENT;
+                return U_SENTINEL;
+            }
+            if(CollationFCD::hasLccc(c)) {
+                UChar32 prev = U_SENTINEL;
+                if(CollationFCD::maybeTibetanCompositeVowel(c) ||
+                        CollationFCD::hasTccc(prev = iter.previous(&iter))) {
+                    iter.next(&iter);
+                    if(prev >= 0) {
+                        iter.next(&iter);
+                    }
+                    if(!previousSegment(errorCode)) {
+                        return U_SENTINEL;
+                    }
+                    continue;
+                }
+                // hasLccc(trail)=true for all trail surrogates
+                if(U16_IS_TRAIL(c)) {
+                    if(prev < 0) {
+                        prev = iter.previous(&iter);
+                    }
+                    if(U16_IS_LEAD(prev)) {
+                        return U16_GET_SUPPLEMENTARY(prev, c);
+                    }
+                }
+                if(prev >= 0) {
+                    iter.next(&iter);
+                }
+            }
+            return c;
+        } else if(state == ITER_IN_FCD_SEGMENT && pos != start) {
+            c = uiter_previous32(&iter);
+            pos -= U16_LENGTH(c);
+            U_ASSERT(c >= 0);
+            return c;
+        } else if(state >= IN_NORM_ITER_AT_LIMIT && pos != 0) {
+            c = normalized.char32At(pos - 1);
+            pos -= U16_LENGTH(c);
+            return c;
+        } else {
+            switchToBackward();
+        }
+    }
+}
+
+void
+FCDUIterCollationIterator::forwardNumCodePoints(int32_t num, UErrorCode &errorCode) {
+    // Specify the class to avoid a virtual-function indirection.
+    // In Java, we would declare this class final.
+    while(num > 0 && FCDUIterCollationIterator::nextCodePoint(errorCode) >= 0) {
+        --num;
+    }
+}
+
+void
+FCDUIterCollationIterator::backwardNumCodePoints(int32_t num, UErrorCode &errorCode) {
+    // Specify the class to avoid a virtual-function indirection.
+    // In Java, we would declare this class final.
+    while(num > 0 && FCDUIterCollationIterator::previousCodePoint(errorCode) >= 0) {
+        --num;
+    }
+}
+
+void
+FCDUIterCollationIterator::switchToForward() {
+    U_ASSERT(state == ITER_CHECK_BWD ||
+             (state == ITER_IN_FCD_SEGMENT && pos == limit) ||
+             (state >= IN_NORM_ITER_AT_LIMIT && pos == normalized.length()));
+    if(state == ITER_CHECK_BWD) {
+        // Turn around from backward checking.
+        start = pos = iter.getIndex(&iter, UITER_CURRENT);
+        if(pos == limit) {
+            state = ITER_CHECK_FWD;  // Check forward.
+        } else {  // pos < limit
+            state = ITER_IN_FCD_SEGMENT;  // Stay in FCD segment.
+        }
+    } else {
+        // Reached the end of the FCD segment.
+        if(state == ITER_IN_FCD_SEGMENT) {
+            // The input text segment is FCD, extend it forward.
+        } else {
+            // The input text segment needed to be normalized.
+            // Switch to checking forward from it.
+            if(state == IN_NORM_ITER_AT_START) {
+                iter.move(&iter, limit - start, UITER_CURRENT);
+            }
+            start = limit;
+        }
+        state = ITER_CHECK_FWD;
+    }
+}
+
+UBool
+FCDUIterCollationIterator::nextSegment(UErrorCode &errorCode) {
+    if(U_FAILURE(errorCode)) { return FALSE; }
+    U_ASSERT(state == ITER_CHECK_FWD);
+    // The input text [start..(iter index)[ passes the FCD check.
+    pos = iter.getIndex(&iter, UITER_CURRENT);
+    // Collect the characters being checked, in case they need to be normalized.
+    UnicodeString s;
+    uint8_t prevCC = 0;
+    for(;;) {
+        // Fetch the next character and its fcd16 value.
+        UChar32 c = uiter_next32(&iter);
+        if(c < 0) { break; }
+        uint16_t fcd16 = nfcImpl.getFCD16(c);
+        uint8_t leadCC = (uint8_t)(fcd16 >> 8);
+        if(leadCC == 0 && !s.isEmpty()) {
+            // FCD boundary before this character.
+            uiter_previous32(&iter);
+            break;
+        }
+        s.append(c);
+        if(leadCC != 0 && (prevCC > leadCC || CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) {
+            // Fails FCD check. Find the next FCD boundary and normalize.
+            for(;;) {
+                c = uiter_next32(&iter);
+                if(c < 0) { break; }
+                if(nfcImpl.getFCD16(c) <= 0xff) {
+                    uiter_previous32(&iter);
+                    break;
+                }
+                s.append(c);
+            }
+            if(!normalize(s, errorCode)) { return FALSE; }
+            start = pos;
+            limit = pos + s.length();
+            state = IN_NORM_ITER_AT_LIMIT;
+            pos = 0;
+            return TRUE;
+        }
+        prevCC = (uint8_t)fcd16;
+        if(prevCC == 0) {
+            // FCD boundary after the last character.
+            break;
+        }
+    }
+    limit = pos + s.length();
+    U_ASSERT(pos != limit);
+    iter.move(&iter, -s.length(), UITER_CURRENT);
+    state = ITER_IN_FCD_SEGMENT;
+    return TRUE;
+}
+
+void
+FCDUIterCollationIterator::switchToBackward() {
+    U_ASSERT(state == ITER_CHECK_FWD ||
+             (state == ITER_IN_FCD_SEGMENT && pos == start) ||
+             (state >= IN_NORM_ITER_AT_LIMIT && pos == 0));
+    if(state == ITER_CHECK_FWD) {
+        // Turn around from forward checking.
+        limit = pos = iter.getIndex(&iter, UITER_CURRENT);
+        if(pos == start) {
+            state = ITER_CHECK_BWD;  // Check backward.
+        } else {  // pos > start
+            state = ITER_IN_FCD_SEGMENT;  // Stay in FCD segment.
+        }
+    } else {
+        // Reached the start of the FCD segment.
+        if(state == ITER_IN_FCD_SEGMENT) {
+            // The input text segment is FCD, extend it backward.
+        } else {
+            // The input text segment needed to be normalized.
+            // Switch to checking backward from it.
+            if(state == IN_NORM_ITER_AT_LIMIT) {
+                iter.move(&iter, start - limit, UITER_CURRENT);
+            }
+            limit = start;
+        }
+        state = ITER_CHECK_BWD;
+    }
+}
+
+UBool
+FCDUIterCollationIterator::previousSegment(UErrorCode &errorCode) {
+    if(U_FAILURE(errorCode)) { return FALSE; }
+    U_ASSERT(state == ITER_CHECK_BWD);
+    // The input text [(iter index)..limit[ passes the FCD check.
+    pos = iter.getIndex(&iter, UITER_CURRENT);
+    // Collect the characters being checked, in case they need to be normalized.
+    UnicodeString s;
+    uint8_t nextCC = 0;
+    for(;;) {
+        // Fetch the previous character and its fcd16 value.
+        UChar32 c = uiter_previous32(&iter);
+        if(c < 0) { break; }
+        uint16_t fcd16 = nfcImpl.getFCD16(c);
+        uint8_t trailCC = (uint8_t)fcd16;
+        if(trailCC == 0 && !s.isEmpty()) {
+            // FCD boundary after this character.
+            uiter_next32(&iter);
+            break;
+        }
+        s.append(c);
+        if(trailCC != 0 && ((nextCC != 0 && trailCC > nextCC) ||
+                            CollationFCD::isFCD16OfTibetanCompositeVowel(fcd16))) {
+            // Fails FCD check. Find the previous FCD boundary and normalize.
+            while(fcd16 > 0xff) {
+                c = uiter_previous32(&iter);
+                if(c < 0) { break; }
+                fcd16 = nfcImpl.getFCD16(c);
+                if(fcd16 == 0) {
+                    (void)uiter_next32(&iter);
+                    break;
+                }
+                s.append(c);
+            }
+            s.reverse();
+            if(!normalize(s, errorCode)) { return FALSE; }
+            limit = pos;
+            start = pos - s.length();
+            state = IN_NORM_ITER_AT_START;
+            pos = normalized.length();
+            return TRUE;
+        }
+        nextCC = (uint8_t)(fcd16 >> 8);
+        if(nextCC == 0) {
+            // FCD boundary before the following character.
+            break;
+        }
+    }
+    start = pos - s.length();
+    U_ASSERT(pos != start);
+    iter.move(&iter, s.length(), UITER_CURRENT);
+    state = ITER_IN_FCD_SEGMENT;
+    return TRUE;
+}
+
+UBool
+FCDUIterCollationIterator::normalize(const UnicodeString &s, UErrorCode &errorCode) {
+    // NFD without argument checking.
+    U_ASSERT(U_SUCCESS(errorCode));
+    nfcImpl.decompose(s, normalized, errorCode);
+    return U_SUCCESS(errorCode);
+}
+
+U_NAMESPACE_END
+
+#endif  // !UCONFIG_NO_COLLATION