Check in the pristine copy of ICU 4.6...

icu46/source/common/unicode/normalizer2.h

+/*
+*******************************************************************************
+*
+*   Copyright (C) 2009-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  normalizer2.h
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2009nov22
+*   created by: Markus W. Scherer
+*/
+
+#ifndef __NORMALIZER2_H__
+#define __NORMALIZER2_H__
+
+/**
+ * \file
+ * \brief C++ API: New API for Unicode Normalization.
+ */
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_NORMALIZATION
+
+#include "unicode/uniset.h"
+#include "unicode/unistr.h"
+#include "unicode/unorm2.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * Unicode normalization functionality for standard Unicode normalization or
+ * for using custom mapping tables.
+ * All instances of this class are unmodifiable/immutable.
+ * Instances returned by getInstance() are singletons that must not be deleted by the caller.
+ * The Normalizer2 class is not intended for public subclassing.
+ *
+ * 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.
+ *
+ * Not only are the standard compose and decompose modes supplied,
+ * but additional modes are provided as documented in the Mode enum.
+ *
+ * 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.
+ *
+ * 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().
+ *
+ * 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.
+ *
+ * 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).
+ *
+ * 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
+ */
+class U_COMMON_API Normalizer2 : public UObject {
+public:
+    /**
+     * Returns a Normalizer2 instance which uses the specified data file
+     * (packageName/name similar to ucnv_openPackage() and ures_open()/ResourceBundle)
+     * and which composes or decomposes text according to the specified mode.
+     * Returns an unmodifiable singleton instance. Do not delete it.
+     *
+     * Use packageName=NULL for data files that are part of ICU's own data.
+     * Use name="nfc" and UNORM2_COMPOSE/UNORM2_DECOMPOSE for Unicode standard NFC/NFD.
+     * Use name="nfkc" and UNORM2_COMPOSE/UNORM2_DECOMPOSE for Unicode standard NFKC/NFKD.
+     * Use name="nfkc_cf" and UNORM2_COMPOSE for Unicode standard NFKC_CF=NFKC_Casefold.
+     *
+     * @param packageName NULL for ICU built-in data, otherwise application data package name
+     * @param name "nfc" or "nfkc" or "nfkc_cf" or name of custom data file
+     * @param mode normalization mode (compose or decompose etc.)
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return the requested Normalizer2, if successful
+     * @stable ICU 4.4
+     */
+    static const Normalizer2 *
+    getInstance(const char *packageName,
+                const char *name,
+                UNormalization2Mode mode,
+                UErrorCode &errorCode);
+
+    /**
+     * Returns the normalized form of the source string.
+     * @param src source string
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return normalized src
+     * @stable ICU 4.4
+     */
+    UnicodeString
+    normalize(const UnicodeString &src, UErrorCode &errorCode) const {
+        UnicodeString result;
+        normalize(src, result, errorCode);
+        return result;
+    }
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return dest
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    normalize(const UnicodeString &src,
+              UnicodeString &dest,
+              UErrorCode &errorCode) const = 0;
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return first
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    normalizeSecondAndAppend(UnicodeString &first,
+                             const UnicodeString &second,
+                             UErrorCode &errorCode) const = 0;
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return first
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    append(UnicodeString &first,
+           const UnicodeString &second,
+           UErrorCode &errorCode) const = 0;
+
+    /**
+     * Gets the decomposition mapping of c. Equivalent to normalize(UnicodeString(c))
+     * on a UNORM2_DECOMPOSE Normalizer2 instance, but much faster.
+     * This function is independent of the mode of the Normalizer2.
+     * @param c code point
+     * @param decomposition String object which will be set to c's
+     *                      decomposition mapping, if there is one.
+     * @return TRUE if c has a decomposition, otherwise FALSE
+     * @draft ICU 4.6
+     */
+    virtual UBool
+    getDecomposition(UChar32 c, UnicodeString &decomposition) const = 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return TRUE if s is normalized
+     * @stable ICU 4.4
+     */
+    virtual UBool
+    isNormalized(const UnicodeString &s, UErrorCode &errorCode) const = 0;
+
+    /**
+     * Tests if the string is normalized.
+     * For the two COMPOSE modes, the result could be "maybe" in cases that
+     * would take a little more work to resolve definitively.
+     * Use spanQuickCheckYes() and normalizeSecondAndAppend() for a faster
+     * combination of quick check + normalization, to avoid
+     * re-checking the "yes" prefix.
+     * @param s input string
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return UNormalizationCheckResult
+     * @stable ICU 4.4
+     */
+    virtual UNormalizationCheckResult
+    quickCheck(const UnicodeString &s, UErrorCode &errorCode) const = 0;
+
+    /**
+     * Returns the end of the normalized substring of the input string.
+     * In other words, with <code>end=spanQuickCheckYes(s, ec);</code>
+     * the substring <code>UnicodeString(s, 0, end)</code>
+     * will pass the quick check with a "yes" result.
+     *
+     * 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.)
+     *
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return "yes" span end index
+     * @stable ICU 4.4
+     */
+    virtual int32_t
+    spanQuickCheckYes(const UnicodeString &s, UErrorCode &errorCode) const = 0;
+
+    /**
+     * 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
+     */
+    virtual UBool hasBoundaryBefore(UChar32 c) const = 0;
+
+    /**
+     * Tests if the character always has a normalization boundary after it,
+     * regardless of context.
+     * If true, then the character does not normalization-interact with
+     * following characters.
+     * In other words, a string containing this character can be normalized
+     * by processing portions up to this character and after this
+     * character independently.
+     * This is used for iterative normalization. See the class documentation for details.
+     * Note that this operation may be significantly slower than hasBoundaryBefore().
+     * @param c character to test
+     * @return TRUE if c has a normalization boundary after it
+     * @stable ICU 4.4
+     */
+    virtual UBool hasBoundaryAfter(UChar32 c) const = 0;
+
+    /**
+     * Tests if the character is normalization-inert.
+     * If true, then the character does not change, nor normalization-interact with
+     * preceding or following characters.
+     * In other words, a string containing this character can be normalized
+     * by processing portions before this character and after this
+     * character independently.
+     * This is used for iterative normalization. See the class documentation for details.
+     * Note that this operation may be significantly slower than hasBoundaryBefore().
+     * @param c character to test
+     * @return TRUE if c is normalization-inert
+     * @stable ICU 4.4
+     */
+    virtual UBool isInert(UChar32 c) const = 0;
+
+private:
+    // No ICU "poor man's RTTI" for this class nor its subclasses.
+    virtual UClassID getDynamicClassID() const;
+};
+
+/**
+ * Normalization filtered by a UnicodeSet.
+ * Normalizes portions of the text contained in the filter set and leaves
+ * portions not contained in the filter set unchanged.
+ * Filtering is done via UnicodeSet::span(..., USET_SPAN_SIMPLE).
+ * Not-in-the-filter text is treated as "is normalized" and "quick check yes".
+ * This class implements all of (and only) the Normalizer2 API.
+ * An instance of this class is unmodifiable/immutable but is constructed and
+ * must be destructed by the owner.
+ * @stable ICU 4.4
+ */
+class U_COMMON_API FilteredNormalizer2 : public Normalizer2 {
+public:
+    /**
+     * Constructs a filtered normalizer wrapping any Normalizer2 instance
+     * and a filter set.
+     * Both are aliased and must not be modified or deleted while this object
+     * is used.
+     * The filter set should be frozen; otherwise the performance will suffer greatly.
+     * @param n2 wrapped Normalizer2 instance
+     * @param filterSet UnicodeSet which determines the characters to be normalized
+     * @stable ICU 4.4
+     */
+    FilteredNormalizer2(const Normalizer2 &n2, const UnicodeSet &filterSet) :
+            norm2(n2), set(filterSet) {}
+
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return dest
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    normalize(const UnicodeString &src,
+              UnicodeString &dest,
+              UErrorCode &errorCode) const;
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return first
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    normalizeSecondAndAppend(UnicodeString &first,
+                             const UnicodeString &second,
+                             UErrorCode &errorCode) const;
+    /**
+     * 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
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return first
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString &
+    append(UnicodeString &first,
+           const UnicodeString &second,
+           UErrorCode &errorCode) const;
+
+    /**
+     * Gets the decomposition mapping of c. Equivalent to normalize(UnicodeString(c))
+     * on a UNORM2_DECOMPOSE Normalizer2 instance, but much faster.
+     * This function is independent of the mode of the Normalizer2.
+     * @param c code point
+     * @param decomposition String object which will be set to c's
+     *                      decomposition mapping, if there is one.
+     * @return TRUE if c has a decomposition, otherwise FALSE
+     * @draft ICU 4.6
+     */
+    virtual UBool
+    getDecomposition(UChar32 c, UnicodeString &decomposition) const;
+
+    /**
+     * Tests if the string is normalized.
+     * For details see the Normalizer2 base class documentation.
+     * @param s input string
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return TRUE if s is normalized
+     * @stable ICU 4.4
+     */
+    virtual UBool
+    isNormalized(const UnicodeString &s, UErrorCode &errorCode) const;
+    /**
+     * Tests if the string is normalized.
+     * For details see the Normalizer2 base class documentation.
+     * @param s input string
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return UNormalizationCheckResult
+     * @stable ICU 4.4
+     */
+    virtual UNormalizationCheckResult
+    quickCheck(const UnicodeString &s, UErrorCode &errorCode) const;
+    /**
+     * Returns the end of the normalized substring of the input string.
+     * For details see the Normalizer2 base class documentation.
+     * @param s input string
+     * @param errorCode Standard ICU error code. Its input value must
+     *                  pass the U_SUCCESS() test, or else the function returns
+     *                  immediately. Check for U_FAILURE() on output or use with
+     *                  function chaining. (See User Guide for details.)
+     * @return "yes" span end index
+     * @stable ICU 4.4
+     */
+    virtual int32_t
+    spanQuickCheckYes(const UnicodeString &s, UErrorCode &errorCode) const;
+
+    /**
+     * Tests if the character always has a normalization boundary before it,
+     * regardless of context.
+     * For details see the Normalizer2 base class documentation.
+     * @param c character to test
+     * @return TRUE if c has a normalization boundary before it
+     * @stable ICU 4.4
+     */
+    virtual UBool hasBoundaryBefore(UChar32 c) const;
+
+    /**
+     * Tests if the character always has a normalization boundary after it,
+     * regardless of context.
+     * For details see the Normalizer2 base class documentation.
+     * @param c character to test
+     * @return TRUE if c has a normalization boundary after it
+     * @stable ICU 4.4
+     */
+    virtual UBool hasBoundaryAfter(UChar32 c) const;
+
+    /**
+     * Tests if the character is normalization-inert.
+     * For details see the Normalizer2 base class documentation.
+     * @param c character to test
+     * @return TRUE if c is normalization-inert
+     * @stable ICU 4.4
+     */
+    virtual UBool isInert(UChar32 c) const;
+private:
+    UnicodeString &
+    normalize(const UnicodeString &src,
+              UnicodeString &dest,
+              USetSpanCondition spanCondition,
+              UErrorCode &errorCode) const;
+
+    UnicodeString &
+    normalizeSecondAndAppend(UnicodeString &first,
+                             const UnicodeString &second,
+                             UBool doNormalize,
+                             UErrorCode &errorCode) const;
+
+    const Normalizer2 &norm2;
+    const UnicodeSet &set;
+};
+
+U_NAMESPACE_END
+
+#endif  // !UCONFIG_NO_NORMALIZATION
+#endif  // __NORMALIZER2_H__