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| * |
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| |
| /* |
| ******************************************************************************* |
| * Copyright (C) 2009-2014, International Business Machines |
| * Corporation and others. All Rights Reserved. |
| ******************************************************************************* |
| */ |
| |
| package sun.text.normalizer; |
| |
| /** |
| * Unicode normalization functionality for standard Unicode normalization or |
| * for using custom mapping tables. |
| * All instances of this class are unmodifiable/immutable. |
| * The Normalizer2 class is not intended for public subclassing. |
| * <p> |
| * The primary functions are to produce a normalized string and to detect whether |
| * a string is already normalized. |
| * The most commonly used normalization forms are those defined in |
| * http://www.unicode.org/unicode/reports/tr15/ |
| * However, this API supports additional normalization forms for specialized purposes. |
| * For example, NFKC_Casefold is provided via getInstance("nfkc_cf", COMPOSE) |
| * and can be used in implementations of UTS #46. |
| * <p> |
| * Not only are the standard compose and decompose modes supplied, |
| * but additional modes are provided as documented in the Mode enum. |
| * <p> |
| * Some of the functions in this class identify normalization boundaries. |
| * At a normalization boundary, the portions of the string |
| * before it and starting from it do not interact and can be handled independently. |
| * <p> |
| * The spanQuickCheckYes() stops at a normalization boundary. |
| * When the goal is a normalized string, then the text before the boundary |
| * can be copied, and the remainder can be processed with normalizeSecondAndAppend(). |
| * <p> |
| * The hasBoundaryBefore(), hasBoundaryAfter() and isInert() functions test whether |
| * a character is guaranteed to be at a normalization boundary, |
| * regardless of context. |
| * This is used for moving from one normalization boundary to the next |
| * or preceding boundary, and for performing iterative normalization. |
| * <p> |
| * Iterative normalization is useful when only a small portion of a |
| * longer string needs to be processed. |
| * For example, in ICU, iterative normalization is used by the NormalizationTransliterator |
| * (to avoid replacing already-normalized text) and ucol_nextSortKeyPart() |
| * (to process only the substring for which sort key bytes are computed). |
| * <p> |
| * The set of normalization boundaries returned by these functions may not be |
| * complete: There may be more boundaries that could be returned. |
| * Different functions may return different boundaries. |
| * @stable ICU 4.4 |
| * @author Markus W. Scherer |
| */ |
| abstract class Normalizer2 { |
| |
| /** |
| * Returns a Normalizer2 instance for Unicode NFC normalization. |
| * Same as getInstance(null, "nfc", Mode.COMPOSE). |
| * Returns an unmodifiable singleton instance. |
| * @return the requested Normalizer2, if successful |
| * @stable ICU 49 |
| */ |
| public static Normalizer2 getNFCInstance() { |
| return Norm2AllModes.getNFCInstance().comp; |
| } |
| |
| /** |
| * Returns a Normalizer2 instance for Unicode NFD normalization. |
| * Same as getInstance(null, "nfc", Mode.DECOMPOSE). |
| * Returns an unmodifiable singleton instance. |
| * @return the requested Normalizer2, if successful |
| * @stable ICU 49 |
| */ |
| public static Normalizer2 getNFDInstance() { |
| return Norm2AllModes.getNFCInstance().decomp; |
| } |
| |
| /** |
| * Returns a Normalizer2 instance for Unicode NFKC normalization. |
| * Same as getInstance(null, "nfkc", Mode.COMPOSE). |
| * Returns an unmodifiable singleton instance. |
| * @return the requested Normalizer2, if successful |
| * @stable ICU 49 |
| */ |
| public static Normalizer2 getNFKCInstance() { |
| return Norm2AllModes.getNFKCInstance().comp; |
| } |
| |
| /** |
| * Returns a Normalizer2 instance for Unicode NFKD normalization. |
| * Same as getInstance(null, "nfkc", Mode.DECOMPOSE). |
| * Returns an unmodifiable singleton instance. |
| * @return the requested Normalizer2, if successful |
| * @stable ICU 49 |
| */ |
| public static Normalizer2 getNFKDInstance() { |
| return Norm2AllModes.getNFKCInstance().decomp; |
| } |
| |
| /** |
| * Returns the normalized form of the source string. |
| * @param src source string |
| * @return normalized src |
| * @stable ICU 4.4 |
| */ |
| public String normalize(CharSequence src) { |
| if(src instanceof String) { |
| // Fastpath: Do not construct a new String if the src is a String |
| // and is already normalized. |
| int spanLength=spanQuickCheckYes(src); |
| if(spanLength==src.length()) { |
| return (String)src; |
| } |
| if (spanLength != 0) { |
| StringBuilder sb=new StringBuilder(src.length()).append(src, 0, spanLength); |
| return normalizeSecondAndAppend(sb, src.subSequence(spanLength, src.length())).toString(); |
| } |
| } |
| return normalize(src, new StringBuilder(src.length())).toString(); |
| } |
| |
| /** |
| * Writes the normalized form of the source string to the destination string |
| * (replacing its contents) and returns the destination string. |
| * The source and destination strings must be different objects. |
| * @param src source string |
| * @param dest destination string; its contents is replaced with normalized src |
| * @return dest |
| * @stable ICU 4.4 |
| */ |
| public abstract StringBuilder normalize(CharSequence src, StringBuilder dest); |
| |
| /** |
| * Writes the normalized form of the source string to the destination Appendable |
| * and returns the destination Appendable. |
| * The source and destination strings must be different objects. |
| * |
| * <p>Any {@link java.io.IOException} is wrapped into a {@link com.ibm.icu.util.ICUUncheckedIOException}. |
| * |
| * @param src source string |
| * @param dest destination Appendable; gets normalized src appended |
| * @return dest |
| * @stable ICU 4.6 |
| */ |
| public abstract Appendable normalize(CharSequence src, Appendable dest); |
| |
| /** |
| * Appends the normalized form of the second string to the first string |
| * (merging them at the boundary) and returns the first string. |
| * The result is normalized if the first string was normalized. |
| * The first and second strings must be different objects. |
| * @param first string, should be normalized |
| * @param second string, will be normalized |
| * @return first |
| * @stable ICU 4.4 |
| */ |
| public abstract StringBuilder normalizeSecondAndAppend( |
| StringBuilder first, CharSequence second); |
| |
| /** |
| * Appends the second string to the first string |
| * (merging them at the boundary) and returns the first string. |
| * The result is normalized if both the strings were normalized. |
| * The first and second strings must be different objects. |
| * @param first string, should be normalized |
| * @param second string, should be normalized |
| * @return first |
| * @stable ICU 4.4 |
| */ |
| public abstract StringBuilder append(StringBuilder first, CharSequence second); |
| |
| /** |
| * Gets the decomposition mapping of c. |
| * Roughly equivalent to normalizing the String form of c |
| * on a DECOMPOSE Normalizer2 instance, but much faster, and except that this function |
| * returns null if c does not have a decomposition mapping in this instance's data. |
| * This function is independent of the mode of the Normalizer2. |
| * @param c code point |
| * @return c's decomposition mapping, if any; otherwise null |
| * @stable ICU 4.6 |
| */ |
| public abstract String getDecomposition(int c); |
| |
| /** |
| * Gets the combining class of c. |
| * The default implementation returns 0 |
| * but all standard implementations return the Unicode Canonical_Combining_Class value. |
| * @param c code point |
| * @return c's combining class |
| * @stable ICU 49 |
| */ |
| public int getCombiningClass(int c) { return 0; } |
| |
| /** |
| * Tests if the string is normalized. |
| * Internally, in cases where the quickCheck() method would return "maybe" |
| * (which is only possible for the two COMPOSE modes) this method |
| * resolves to "yes" or "no" to provide a definitive result, |
| * at the cost of doing more work in those cases. |
| * @param s input string |
| * @return true if s is normalized |
| * @stable ICU 4.4 |
| */ |
| public abstract boolean isNormalized(CharSequence s); |
| |
| /** |
| * Returns the end of the normalized substring of the input string. |
| * In other words, with <code>end=spanQuickCheckYes(s);</code> |
| * the substring <code>s.subSequence(0, end)</code> |
| * will pass the quick check with a "yes" result. |
| * <p> |
| * The returned end index is usually one or more characters before the |
| * "no" or "maybe" character: The end index is at a normalization boundary. |
| * (See the class documentation for more about normalization boundaries.) |
| * <p> |
| * When the goal is a normalized string and most input strings are expected |
| * to be normalized already, then call this method, |
| * and if it returns a prefix shorter than the input string, |
| * copy that prefix and use normalizeSecondAndAppend() for the remainder. |
| * @param s input string |
| * @return "yes" span end index |
| * @stable ICU 4.4 |
| */ |
| public abstract int spanQuickCheckYes(CharSequence s); |
| |
| /** |
| * Tests if the character always has a normalization boundary before it, |
| * regardless of context. |
| * If true, then the character does not normalization-interact with |
| * preceding characters. |
| * In other words, a string containing this character can be normalized |
| * by processing portions before this character and starting from this |
| * character independently. |
| * This is used for iterative normalization. See the class documentation for details. |
| * @param c character to test |
| * @return true if c has a normalization boundary before it |
| * @stable ICU 4.4 |
| */ |
| public abstract boolean hasBoundaryBefore(int c); |
| |
| /** |
| * Sole constructor. (For invocation by subclass constructors, |
| * typically implicit.) |
| * @internal |
| * deprecated This API is ICU internal only. |
| */ |
| protected Normalizer2() { |
| } |
| } |