Check in the pristine copy of ICU 4.6...

icu46/source/i18n/nortrans.cpp

+/*
+**********************************************************************
+*   Copyright (C) 2001-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*   Date        Name        Description
+*   07/03/01    aliu        Creation.
+**********************************************************************
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_TRANSLITERATION
+
+#include "unicode/normalizer2.h"
+#include "cstring.h"
+#include "nortrans.h"
+
+U_NAMESPACE_BEGIN
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(NormalizationTransliterator)
+
+static inline Transliterator::Token cstrToken(const char *s) {
+    return Transliterator::pointerToken((void *)s);
+}
+
+/**
+ * System registration hook.
+ */
+void NormalizationTransliterator::registerIDs() {
+    // In the Token, the byte after the NUL is the UNormalization2Mode.
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFC"),
+                                     _create, cstrToken("nfc\0\0"));
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFKC"),
+                                     _create, cstrToken("nfkc\0\0"));
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFD"),
+                                     _create, cstrToken("nfc\0\1"));
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-NFKD"),
+                                     _create, cstrToken("nfkc\0\1"));
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-FCD"),
+                                     _create, cstrToken("nfc\0\2"));
+    Transliterator::_registerFactory(UNICODE_STRING_SIMPLE("Any-FCC"),
+                                     _create, cstrToken("nfc\0\3"));
+    Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("NFC"),
+                                            UNICODE_STRING_SIMPLE("NFD"), TRUE);
+    Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("NFKC"),
+                                            UNICODE_STRING_SIMPLE("NFKD"), TRUE);
+    Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("FCC"),
+                                            UNICODE_STRING_SIMPLE("NFD"), FALSE);
+    Transliterator::_registerSpecialInverse(UNICODE_STRING_SIMPLE("FCD"),
+                                            UNICODE_STRING_SIMPLE("FCD"), FALSE);
+}
+
+/**
+ * Factory methods
+ */
+Transliterator* NormalizationTransliterator::_create(const UnicodeString& ID,
+                                                     Token context) {
+    const char *name = (const char *)context.pointer;
+    UNormalization2Mode mode = (UNormalization2Mode)uprv_strchr(name, 0)[1];
+    UErrorCode errorCode = U_ZERO_ERROR;
+    const Normalizer2 *norm2 = Normalizer2::getInstance(NULL, name, mode, errorCode);
+    if(U_SUCCESS(errorCode)) {
+        return new NormalizationTransliterator(ID, *norm2);
+    } else {
+        return NULL;
+    }
+}
+
+/**
+ * Constructs a transliterator.
+ */
+NormalizationTransliterator::NormalizationTransliterator(const UnicodeString& id,
+                                                         const Normalizer2 &norm2) :
+    Transliterator(id, 0), fNorm2(norm2) {}
+
+/**
+ * Destructor.
+ */
+NormalizationTransliterator::~NormalizationTransliterator() {
+}
+
+/**
+ * Copy constructor.
+ */
+NormalizationTransliterator::NormalizationTransliterator(const NormalizationTransliterator& o) :
+    Transliterator(o), fNorm2(o.fNorm2) {}
+
+/**
+ * Transliterator API.
+ */
+Transliterator* NormalizationTransliterator::clone(void) const {
+    return new NormalizationTransliterator(*this);
+}
+
+/**
+ * Implements {@link Transliterator#handleTransliterate}.
+ */
+void NormalizationTransliterator::handleTransliterate(Replaceable& text, UTransPosition& offsets,
+                                                      UBool isIncremental) const {
+    // start and limit of the input range
+    int32_t start = offsets.start;
+    int32_t limit = offsets.limit;
+    if(start >= limit) {
+        return;
+    }
+
+    /*
+     * Normalize as short chunks at a time as possible even in
+     * bulk mode, so that styled text is minimally disrupted.
+     * In incremental mode, a chunk that ends with offsets.limit
+     * must not be normalized.
+     *
+     * If it was known that the input text is not styled, then
+     * a bulk mode normalization could look like this:
+
+    UnicodeString input, normalized;
+    int32_t length = limit - start;
+    _Replaceable_extractBetween(text, start, limit, input.getBuffer(length));
+    input.releaseBuffer(length);
+
+    UErrorCode status = U_ZERO_ERROR;
+    fNorm2.normalize(input, normalized, status);
+
+    text.handleReplaceBetween(start, limit, normalized);
+
+    int32_t delta = normalized.length() - length;
+    offsets.contextLimit += delta;
+    offsets.limit += delta;
+    offsets.start = limit + delta;
+
+     */
+    UErrorCode errorCode = U_ZERO_ERROR;
+    UnicodeString segment;
+    UnicodeString normalized;
+    UChar32 c = text.char32At(start);
+    do {
+        int32_t prev = start;
+        // Skip at least one character so we make progress.
+        // c holds the character at start.
+        segment.remove();
+        do {
+            segment.append(c);
+            start += U16_LENGTH(c);
+        } while(start < limit && !fNorm2.hasBoundaryBefore(c = text.char32At(start)));
+        if(start == limit && isIncremental && !fNorm2.hasBoundaryAfter(c)) {
+            // stop in incremental mode when we reach the input limit
+            // in case there are additional characters that could change the
+            // normalization result
+            start=prev;
+            break;
+        }
+        fNorm2.normalize(segment, normalized, errorCode);
+        if(U_FAILURE(errorCode)) {
+            break;
+        }
+        if(segment != normalized) {
+            // replace the input chunk with its normalized form
+            text.handleReplaceBetween(prev, start, normalized);
+
+            // update all necessary indexes accordingly
+            int32_t delta = normalized.length() - (start - prev);
+            start += delta;
+            limit += delta;
+        }
+    } while(start < limit);
+
+    offsets.start = start;
+    offsets.contextLimit += limit - offsets.limit;
+    offsets.limit = limit;
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_TRANSLITERATION */