Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/regex.h

+/*
+**********************************************************************
+*   Copyright (C) 2002-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*   file name:  regex.h
+*   encoding:   US-ASCII
+*   indentation:4
+*
+*   created on: 2002oct22
+*   created by: Andy Heninger
+*
+*   ICU Regular Expressions, API for C++
+*/
+
+#ifndef REGEX_H
+#define REGEX_H
+
+//#define REGEX_DEBUG
+
+/**
+ * \file
+ * \brief  C++ API:  Regular Expressions
+ *
+ * <h2>Regular Expression API</h2>
+ *
+ * <p>The ICU API for processing regular expressions consists of two classes,
+ *  <code>RegexPattern</code> and <code>RegexMatcher</code>.
+ *  <code>RegexPattern</code> objects represent a pre-processed, or compiled
+ *  regular expression.  They are created from a regular expression pattern string,
+ *  and can be used to create <code>RegexMatcher</code> objects for the pattern.</p>
+ *
+ * <p>Class <code>RegexMatcher</code> bundles together a regular expression
+ *  pattern and a target string to which the search pattern will be applied.
+ *  <code>RegexMatcher</code> includes API for doing plain find or search
+ *  operations, for search and replace operations, and for obtaining detailed
+ *  information about bounds of a match. </p>
+ *
+ * <p>Note that by constructing <code>RegexMatcher</code> objects directly from regular
+ * expression pattern strings application code can be simplified and the explicit
+ * need for <code>RegexPattern</code> objects can usually be eliminated.
+ * </p>
+ */
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_REGULAR_EXPRESSIONS
+
+#include "unicode/uobject.h"
+#include "unicode/unistr.h"
+#include "unicode/utext.h"
+#include "unicode/parseerr.h"
+
+#include "unicode/uregex.h"
+
+U_NAMESPACE_BEGIN
+
+
+// Forward Declarations...
+
+class RegexMatcher;
+class RegexPattern;
+class UVector;
+class UVector32;
+class UVector64;
+class UnicodeSet;
+struct REStackFrame;
+struct Regex8BitSet;
+class  RuleBasedBreakIterator;
+class  RegexCImpl;
+
+
+
+
+/**
+ *   RBBIPatternDump   Debug function, displays the compiled form of a pattern.
+ *   @internal
+ */
+#ifdef REGEX_DEBUG
+U_INTERNAL void U_EXPORT2
+    RegexPatternDump(const RegexPattern *pat);
+#else
+    #undef RegexPatternDump
+    #define RegexPatternDump(pat)
+#endif
+
+
+
+/**
+  * Class <code>RegexPattern</code> represents a compiled regular expression.  It includes
+  * factory methods for creating a RegexPattern object from the source (string) form
+  * of a regular expression, methods for creating RegexMatchers that allow the pattern
+  * to be applied to input text, and a few convenience methods for simple common
+  * uses of regular expressions.
+  *
+  * <p>Class RegexPattern is not intended to be subclassed.</p>
+  *
+  * @stable ICU 2.4
+  */
+class U_I18N_API RegexPattern: public UObject {
+public:
+
+    /**
+     * default constructor.  Create a RegexPattern object that refers to no actual
+     *   pattern.  Not normally needed; RegexPattern objects are usually
+     *   created using the factory method <code>compile()</code>.
+     *
+     * @stable ICU 2.4
+     */
+    RegexPattern();
+
+    /**
+     * Copy Constructor.  Create a new RegexPattern object that is equivalent
+     *                    to the source object.
+     * @param source the pattern object to be copied.
+     * @stable ICU 2.4
+     */
+    RegexPattern(const RegexPattern &source);
+
+    /**
+     * Destructor.  Note that a RegexPattern object must persist so long as any
+     *  RegexMatcher objects that were created from the RegexPattern are active.
+     * @stable ICU 2.4
+     */
+    virtual ~RegexPattern();
+
+    /**
+     * Comparison operator.  Two RegexPattern objects are considered equal if they
+     * were constructed from identical source patterns using the same match flag
+     * settings.
+     * @param that a RegexPattern object to compare with "this".
+     * @return TRUE if the objects are equivalent.
+     * @stable ICU 2.4
+     */
+    UBool           operator==(const RegexPattern& that) const;
+
+    /**
+     * Comparison operator.  Two RegexPattern objects are considered equal if they
+     * were constructed from identical source patterns using the same match flag
+     * settings.
+     * @param that a RegexPattern object to compare with "this".
+     * @return TRUE if the objects are different.
+     * @stable ICU 2.4
+     */
+    inline UBool    operator!=(const RegexPattern& that) const {return ! operator ==(that);};
+
+    /**
+     * Assignment operator.  After assignment, this RegexPattern will behave identically
+     *     to the source object.
+     * @stable ICU 2.4
+     */
+    RegexPattern  &operator =(const RegexPattern &source);
+
+    /**
+     * Create an exact copy of this RegexPattern object.  Since RegexPattern is not
+     * intended to be subclasses, <code>clone()</code> and the copy construction are
+     * equivalent operations.
+     * @return the copy of this RegexPattern
+     * @stable ICU 2.4
+     */
+    virtual RegexPattern  *clone() const;
+
+
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object.  These compile methods, rather than the constructors, are the usual
+    * way that RegexPattern objects are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>All pattern match mode flags are set to their default values.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string rather than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled.
+    * @param pe    Receives the position (line and column nubers) of any error
+    *              within the regular expression.)
+    * @param status A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @stable ICU 2.4
+    */
+    static RegexPattern * U_EXPORT2 compile( const UnicodeString &regex,
+        UParseError          &pe,
+        UErrorCode           &status);
+
+
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object.  These compile methods, rather than the constructors, are the usual
+    * way that RegexPattern objects are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>All pattern match mode flags are set to their default values.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string rather than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled. Note, the text referred
+    *              to by this UText must not be deleted during the lifetime of the
+    *              RegexPattern object or any RegexMatcher object created from it.
+    * @param pe    Receives the position (line and column nubers) of any error
+    *              within the regular expression.)
+    * @param status A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @draft ICU 4.6
+    */
+    static RegexPattern * U_EXPORT2 compile( UText *regex,
+        UParseError          &pe,
+        UErrorCode           &status);
+
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object using the specified match mode flags.  These compile methods,
+    * rather than the constructors, are the usual way that RegexPattern objects
+    * are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string instead of than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled.
+    * @param flags The match mode flags to be used.
+    * @param pe    Receives the position (line and column numbers) of any error
+    *              within the regular expression.)
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @stable ICU 2.4
+    */
+    static RegexPattern * U_EXPORT2 compile( const UnicodeString &regex,
+        uint32_t             flags,
+        UParseError          &pe,
+        UErrorCode           &status);
+        
+        
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object using the specified match mode flags.  These compile methods,
+    * rather than the constructors, are the usual way that RegexPattern objects
+    * are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string instead of than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled. Note, the text referred
+    *              to by this UText must not be deleted during the lifetime of the
+    *              RegexPattern object or any RegexMatcher object created from it.
+    * @param flags The match mode flags to be used.
+    * @param pe    Receives the position (line and column numbers) of any error
+    *              within the regular expression.)
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @draft ICU 4.6
+    */
+    static RegexPattern * U_EXPORT2 compile( UText *regex,
+        uint32_t             flags,
+        UParseError          &pe,
+        UErrorCode           &status);
+    
+
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object using the specified match mode flags.  These compile methods,
+    * rather than the constructors, are the usual way that RegexPattern objects
+    * are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string instead of than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled.
+    * @param flags The match mode flags to be used.
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @stable ICU 2.6
+    */
+    static RegexPattern * U_EXPORT2 compile( const UnicodeString &regex,
+        uint32_t             flags,
+        UErrorCode           &status);
+
+
+   /**
+    * Compiles the regular expression in string form into a RegexPattern
+    * object using the specified match mode flags.  These compile methods,
+    * rather than the constructors, are the usual way that RegexPattern objects
+    * are created.
+    *
+    * <p>Note that RegexPattern objects must not be deleted while RegexMatcher
+    * objects created from the pattern are active.  RegexMatchers keep a pointer
+    * back to their pattern, so premature deletion of the pattern is a
+    * catastrophic error.</p>
+    *
+    * <p>Note that it is often more convenient to construct a RegexMatcher directly
+    *    from a pattern string instead of than separately compiling the pattern and
+    *    then creating a RegexMatcher object from the pattern.</p>
+    *
+    * @param regex The regular expression to be compiled. Note, the text referred
+    *              to by this UText must not be deleted during the lifetime of the
+    *              RegexPattern object or any RegexMatcher object created from it.
+    * @param flags The match mode flags to be used.
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return      A regexPattern object for the compiled pattern.
+    *
+    * @draft ICU 4.6
+    */
+    static RegexPattern * U_EXPORT2 compile( UText *regex,
+        uint32_t             flags,
+        UErrorCode           &status);
+    
+
+   /**
+    * Get the match mode flags that were used when compiling this pattern.
+    * @return  the match mode flags
+    * @stable ICU 2.4
+    */
+    virtual uint32_t flags() const;
+
+   /**
+    * Creates a RegexMatcher that will match the given input against this pattern.  The
+    * RegexMatcher can then be used to perform match, find or replace operations
+    * on the input.  Note that a RegexPattern object must not be deleted while
+    * RegexMatchers created from it still exist and might possibly be used again.
+    * <p>
+    * The matcher will retain a reference to the supplied input string, and all regexp
+    * pattern matching operations happen directly on this original string.  It is
+    * critical that the string not be altered or deleted before use by the regular
+    * expression operations is complete.
+    *
+    * @param input    The input string to which the regular expression will be applied.
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return         A RegexMatcher object for this pattern and input.
+    *
+    * @stable ICU 2.4
+    */
+    virtual RegexMatcher *matcher(const UnicodeString &input,
+        UErrorCode          &status) const;
+        
+        
+   /**
+    * Flag to disambiguate RegexPattern::matcher signature
+    * @draft ICU 4.6
+    */
+    enum PatternIsUTextFlag { PATTERN_IS_UTEXT };
+
+   /**
+    * Creates a RegexMatcher that will match the given input against this pattern.  The
+    * RegexMatcher can then be used to perform match, find or replace operations
+    * on the input.  Note that a RegexPattern object must not be deleted while
+    * RegexMatchers created from it still exist and might possibly be used again.
+    * <p>
+    * The matcher will make a shallow clone of the supplied input text, and all regexp
+    * pattern matching operations happen on this clone.  While read-only operations on
+    * the supplied text are permitted, it is critical that the underlying string not be
+    * altered or deleted before use by the regular expression operations is complete.
+    *
+    * @param input    The input text to which the regular expression will be applied.
+    * @param flag     Must be RegexPattern::PATTERN_IS_UTEXT; used to disambiguate
+    *                 method signature.
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return         A RegexMatcher object for this pattern and input.
+    *
+    * @draft ICU 4.6
+    */
+    virtual RegexMatcher *matcher(UText *input,
+        PatternIsUTextFlag      flag, 
+        UErrorCode          &status) const;
+
+private:
+    /**
+     * Cause a compilation error if an application accidently attempts to
+     *   create a matcher with a (UChar *) string as input rather than
+     *   a UnicodeString.  Avoids a dangling reference to a temporary string.
+     * <p>
+     * To efficiently work with UChar *strings, wrap the data in a UnicodeString
+     * using one of the aliasing constructors, such as
+     * <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
+     * or in a UText, using
+     * <code>utext_openUChars(UText *ut, const UChar *text, int64_t textLength, UErrorCode *status);</code>
+     *
+     * @internal
+     */
+    RegexMatcher *matcher(const UChar *input,
+        UErrorCode          &status) const;
+public:
+
+
+   /**
+    * Creates a RegexMatcher that will match against this pattern.  The
+    * RegexMatcher can be used to perform match, find or replace operations.
+    * Note that a RegexPattern object must not be deleted while
+    * RegexMatchers created from it still exist and might possibly be used again.
+    *
+    * @param status   A reference to a UErrorCode to receive any errors.
+    * @return      A RegexMatcher object for this pattern and input.
+    *
+    * @stable ICU 2.6
+    */
+    virtual RegexMatcher *matcher(UErrorCode  &status) const;
+
+
+   /**
+    * Test whether a string matches a regular expression.  This convenience function
+    * both compiles the reguluar expression and applies it in a single operation.
+    * Note that if the same pattern needs to be applied repeatedly, this method will be
+    * less efficient than creating and reusing a RegexMatcher object.
+    *
+    * @param regex The regular expression
+    * @param input The string data to be matched
+    * @param pe Receives the position of any syntax errors within the regular expression
+    * @param status A reference to a UErrorCode to receive any errors.
+    * @return True if the regular expression exactly matches the full input string.
+    *
+    * @stable ICU 2.4
+    */
+    static UBool U_EXPORT2 matches(const UnicodeString   &regex,
+        const UnicodeString   &input,
+              UParseError     &pe,
+              UErrorCode      &status);
+
+
+   /**
+    * Test whether a string matches a regular expression.  This convenience function
+    * both compiles the reguluar expression and applies it in a single operation.
+    * Note that if the same pattern needs to be applied repeatedly, this method will be
+    * less efficient than creating and reusing a RegexMatcher object.
+    *
+    * @param regex The regular expression
+    * @param input The string data to be matched
+    * @param pe Receives the position of any syntax errors within the regular expression
+    * @param status A reference to a UErrorCode to receive any errors.
+    * @return True if the regular expression exactly matches the full input string.
+    *
+    * @draft ICU 4.6
+    */
+    static UBool U_EXPORT2 matches(UText *regex,
+        UText           *input,
+        UParseError     &pe,
+        UErrorCode      &status);
+
+
+   /**
+    * Returns the regular expression from which this pattern was compiled. This method will work
+    * even if the pattern was compiled from a UText.
+    *
+    * Note: If the pattern was originally compiled from a UText, and that UText was modified,
+    * the returned string may no longer reflect the RegexPattern object.
+    * @stable ICU 2.4
+    */
+    virtual UnicodeString pattern() const;
+    
+    
+   /**
+    * Returns the regular expression from which this pattern was compiled. This method will work
+    * even if the pattern was compiled from a UnicodeString.
+    *
+    * Note: This is the original input, not a clone. If the pattern was originally compiled from a
+    * UText, and that UText was modified, the returned UText may no longer reflect the RegexPattern
+    * object.
+    *
+    * @draft ICU 4.6
+    */
+    virtual UText *patternText(UErrorCode      &status) const;
+
+
+    /**
+     * Split a string into fields.  Somewhat like split() from Perl.
+     * The pattern matches identify delimiters that separate the input
+     *  into fields.  The input data between the matches becomes the
+     *  fields themselves.
+     * <p>
+     *  For the best performance on split() operations,
+     *  <code>RegexMatcher::split</code> is perferable to this function
+     *
+     * @param input   The string to be split into fields.  The field delimiters
+     *                match the pattern (in the "this" object)
+     * @param dest    An array of UnicodeStrings to receive the results of the split.
+     *                This is an array of actual UnicodeString objects, not an
+     *                array of pointers to strings.  Local (stack based) arrays can
+     *                work well here.
+     * @param destCapacity  The number of elements in the destination array.
+     *                If the number of fields found is less than destCapacity, the
+     *                extra strings in the destination array are not altered.
+     *                If the number of destination strings is less than the number
+     *                of fields, the trailing part of the input string, including any
+     *                field delimiters, is placed in the last destination string.
+     * @param status  A reference to a UErrorCode to receive any errors.
+     * @return        The number of fields into which the input string was split.
+     * @stable ICU 2.4
+     */
+    virtual int32_t  split(const UnicodeString &input,
+        UnicodeString    dest[],
+        int32_t          destCapacity,
+        UErrorCode       &status) const;
+
+
+    /**
+     * Split a string into fields.  Somewhat like split() from Perl.
+     * The pattern matches identify delimiters that separate the input
+     *  into fields.  The input data between the matches becomes the
+     *  fields themselves.
+     * <p>
+     *  For the best performance on split() operations,
+     *  <code>RegexMatcher::split</code> is perferable to this function
+     *
+     * @param input   The string to be split into fields.  The field delimiters
+     *                match the pattern (in the "this" object)
+     * @param dest    An array of mutable UText structs to receive the results of the split.
+     *                If a field is NULL, a new UText is allocated to contain the results for
+     *                that field. This new UText is not guaranteed to be mutable.
+     * @param destCapacity  The number of elements in the destination array.
+     *                If the number of fields found is less than destCapacity, the
+     *                extra strings in the destination array are not altered.
+     *                If the number of destination strings is less than the number
+     *                of fields, the trailing part of the input string, including any
+     *                field delimiters, is placed in the last destination string.
+     * @param status  A reference to a UErrorCode to receive any errors.
+     * @return        The number of fields into which the input string was split.
+     *
+     * @draft ICU 4.6
+     */
+    virtual int32_t  split(UText *input,
+        UText            *dest[],
+        int32_t          destCapacity,
+        UErrorCode       &status) const;
+
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     *
+     * @stable ICU 2.4
+     */
+    virtual UClassID getDynamicClassID() const;
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     *
+     * @stable ICU 2.4
+     */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+private:
+    //
+    //  Implementation Data
+    //
+    UText          *fPattern;      // The original pattern string.
+    UnicodeString  *fPatternString; // The original pattern UncodeString if relevant
+    uint32_t        fFlags;        // The flags used when compiling the pattern.
+                                   //
+    UVector64       *fCompiledPat; // The compiled pattern p-code.
+    UnicodeString   fLiteralText;  // Any literal string data from the pattern,
+                                   //   after un-escaping, for use during the match.
+
+    UVector         *fSets;        // Any UnicodeSets referenced from the pattern.
+    Regex8BitSet    *fSets8;       //      (and fast sets for latin-1 range.)
+
+
+    UErrorCode      fDeferredStatus; // status if some prior error has left this
+                                   //  RegexPattern in an unusable state.
+
+    int32_t         fMinMatchLen;  // Minimum Match Length.  All matches will have length
+                                   //   >= this value.  For some patterns, this calculated
+                                   //   value may be less than the true shortest
+                                   //   possible match.
+    
+    int32_t         fFrameSize;    // Size of a state stack frame in the
+                                   //   execution engine.
+
+    int32_t         fDataSize;     // The size of the data needed by the pattern that
+                                   //   does not go on the state stack, but has just
+                                   //   a single copy per matcher.
+
+    UVector32       *fGroupMap;    // Map from capture group number to position of
+                                   //   the group's variables in the matcher stack frame.
+
+    int32_t         fMaxCaptureDigits;
+
+    UnicodeSet     **fStaticSets;  // Ptr to static (shared) sets for predefined
+                                   //   regex character classes, e.g. Word.
+
+    Regex8BitSet   *fStaticSets8;  // Ptr to the static (shared) latin-1 only
+                                   //  sets for predefined regex classes.
+
+    int32_t         fStartType;    // Info on how a match must start.
+    int32_t         fInitialStringIdx;     //
+    int32_t         fInitialStringLen;
+    UnicodeSet     *fInitialChars;
+    UChar32         fInitialChar;
+    Regex8BitSet   *fInitialChars8;
+    UBool           fNeedsAltInput;
+
+    friend class RegexCompile;
+    friend class RegexMatcher;
+    friend class RegexCImpl;
+
+    //
+    //  Implementation Methods
+    //
+    void        init();            // Common initialization, for use by constructors.
+    void        zap();             // Common cleanup
+#ifdef REGEX_DEBUG
+    void        dumpOp(int32_t index) const;
+    friend     void U_EXPORT2 RegexPatternDump(const RegexPattern *);
+#endif
+
+};
+
+
+
+/**
+ *  class RegexMatcher bundles together a reular expression pattern and
+ *  input text to which the expression can be applied.  It includes methods
+ *  for testing for matches, and for find and replace operations.
+ *
+ * <p>Class RegexMatcher is not intended to be subclassed.</p>
+ *
+ * @stable ICU 2.4
+ */
+class U_I18N_API RegexMatcher: public UObject {
+public:
+
+    /**
+      * Construct a RegexMatcher for a regular expression.
+      * This is a convenience method that avoids the need to explicitly create
+      * a RegexPattern object.  Note that if several RegexMatchers need to be
+      * created for the same expression, it will be more efficient to
+      * separately create and cache a RegexPattern object, and use
+      * its matcher() method to create the RegexMatcher objects.
+      *
+      *  @param regexp The Regular Expression to be compiled.
+      *  @param flags  Regular expression options, such as case insensitive matching.
+      *                @see UREGEX_CASE_INSENSITIVE
+      *  @param status Any errors are reported by setting this UErrorCode variable.
+      *  @stable ICU 2.6
+      */
+    RegexMatcher(const UnicodeString &regexp, uint32_t flags, UErrorCode &status);
+
+    /**
+      * Construct a RegexMatcher for a regular expression.
+      * This is a convenience method that avoids the need to explicitly create
+      * a RegexPattern object.  Note that if several RegexMatchers need to be
+      * created for the same expression, it will be more efficient to
+      * separately create and cache a RegexPattern object, and use
+      * its matcher() method to create the RegexMatcher objects.
+      *
+      *  @param regexp The regular expression to be compiled.
+      *  @param flags  Regular expression options, such as case insensitive matching.
+      *                @see UREGEX_CASE_INSENSITIVE
+      *  @param status Any errors are reported by setting this UErrorCode variable.
+      *
+      *  @draft ICU 4.6
+      */
+    RegexMatcher(UText *regexp, uint32_t flags, UErrorCode &status);
+    
+    /**
+      * Construct a RegexMatcher for a regular expression.
+      * This is a convenience method that avoids the need to explicitly create
+      * a RegexPattern object.  Note that if several RegexMatchers need to be
+      * created for the same expression, it will be more efficient to
+      * separately create and cache a RegexPattern object, and use
+      * its matcher() method to create the RegexMatcher objects.
+      * <p>
+      * The matcher will retain a reference to the supplied input string, and all regexp
+      * pattern matching operations happen directly on the original string.  It is
+      * critical that the string not be altered or deleted before use by the regular
+      * expression operations is complete.
+      *
+      *  @param regexp The Regular Expression to be compiled.
+      *  @param input  The string to match.  The matcher retains a reference to the
+      *                caller's string; mo copy is made.
+      *  @param flags  Regular expression options, such as case insensitive matching.
+      *                @see UREGEX_CASE_INSENSITIVE
+      *  @param status Any errors are reported by setting this UErrorCode variable.
+      *  @stable ICU 2.6
+      */
+    RegexMatcher(const UnicodeString &regexp, const UnicodeString &input,
+        uint32_t flags, UErrorCode &status);
+
+    /**
+      * Construct a RegexMatcher for a regular expression.
+      * This is a convenience method that avoids the need to explicitly create
+      * a RegexPattern object.  Note that if several RegexMatchers need to be
+      * created for the same expression, it will be more efficient to
+      * separately create and cache a RegexPattern object, and use
+      * its matcher() method to create the RegexMatcher objects.
+      * <p>
+      * The matcher will make a shallow clone of the supplied input text, and all regexp
+      * pattern matching operations happen on this clone.  While read-only operations on
+      * the supplied text are permitted, it is critical that the underlying string not be
+      * altered or deleted before use by the regular expression operations is complete.
+      *
+      *  @param regexp The Regular Expression to be compiled.
+      *  @param input  The string to match.  The matcher retains a shallow clone of the text.
+      *  @param flags  Regular expression options, such as case insensitive matching.
+      *                @see UREGEX_CASE_INSENSITIVE
+      *  @param status Any errors are reported by setting this UErrorCode variable.
+      *
+      *  @draft ICU 4.6
+      */
+    RegexMatcher(UText *regexp, UText *input,
+        uint32_t flags, UErrorCode &status);
+
+private:
+    /**
+     * Cause a compilation error if an application accidently attempts to
+     *   create a matcher with a (UChar *) string as input rather than
+     *   a UnicodeString.    Avoids a dangling reference to a temporary string.
+     * <p>
+     * To efficiently work with UChar *strings, wrap the data in a UnicodeString
+     * using one of the aliasing constructors, such as
+     * <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
+     * or in a UText, using
+     * <code>utext_openUChars(UText *ut, const UChar *text, int64_t textLength, UErrorCode *status);</code>
+     *
+     * @internal
+     */
+    RegexMatcher(const UnicodeString &regexp, const UChar *input,
+        uint32_t flags, UErrorCode &status);
+public:
+
+
+   /**
+    *   Destructor.
+    *
+    *  @stable ICU 2.4
+    */
+    virtual ~RegexMatcher();
+
+
+   /**
+    *   Attempts to match the entire input region against the pattern.
+    *    @param   status     A reference to a UErrorCode to receive any errors.
+    *    @return TRUE if there is a match
+    *    @stable ICU 2.4
+    */
+    virtual UBool matches(UErrorCode &status);
+
+
+   /**
+    *   Resets the matcher, then attempts to match the input beginning 
+    *   at the specified startIndex, and extending to the end of the input.
+    *   The input region is reset to include the entire input string.
+    *   A successful match must extend to the end of the input.
+    *    @param   startIndex The input string (native) index at which to begin matching.
+    *    @param   status     A reference to a UErrorCode to receive any errors.
+    *    @return TRUE if there is a match
+    *    @stable ICU 2.8
+    */
+    virtual UBool matches(int64_t startIndex, UErrorCode &status);
+
+
+   /**
+    *   Attempts to match the input string, starting from the beginning of the region,
+    *   against the pattern.  Like the matches() method, this function 
+    *   always starts at the beginning of the input region;
+    *   unlike that function, it does not require that the entire region be matched.
+    *
+    *   <p>If the match succeeds then more information can be obtained via the <code>start()</code>,
+    *     <code>end()</code>, and <code>group()</code> functions.</p>
+    *
+    *    @param   status     A reference to a UErrorCode to receive any errors.
+    *    @return  TRUE if there is a match at the start of the input string.
+    *    @stable ICU 2.4
+    */
+    virtual UBool lookingAt(UErrorCode &status);
+
+
+  /**
+    *   Attempts to match the input string, starting from the specified index, against the pattern.
+    *   The match may be of any length, and is not required to extend to the end
+    *   of the input string.  Contrast with match().
+    *
+    *   <p>If the match succeeds then more information can be obtained via the <code>start()</code>,
+    *     <code>end()</code>, and <code>group()</code> functions.</p>
+    *
+    *    @param   startIndex The input string (native) index at which to begin matching.
+    *    @param   status     A reference to a UErrorCode to receive any errors.
+    *    @return  TRUE if there is a match.
+    *    @stable ICU 2.8
+    */
+    virtual UBool lookingAt(int64_t startIndex, UErrorCode &status);
+
+
+   /**
+    *  Find the next pattern match in the input string.
+    *  The find begins searching the input at the location following the end of
+    *  the previous match, or at the start of the string if there is no previous match.
+    *  If a match is found, <code>start(), end()</code> and <code>group()</code>
+    *  will provide more information regarding the match.
+    *  <p>Note that if the input string is changed by the application,
+    *     use find(startPos, status) instead of find(), because the saved starting
+    *     position may not be valid with the altered input string.</p>
+    *  @return  TRUE if a match is found.
+    *  @stable ICU 2.4
+    */
+    virtual UBool find();
+
+
+   /**
+    *   Resets this RegexMatcher and then attempts to find the next substring of the
+    *   input string that matches the pattern, starting at the specified index.
+    *
+    *   @param   start     The (native) index in the input string to begin the search.
+    *   @param   status    A reference to a UErrorCode to receive any errors.
+    *   @return  TRUE if a match is found.
+    *   @stable ICU 2.4
+    */
+    virtual UBool find(int64_t start, UErrorCode &status);
+
+
+   /**
+    *   Returns a string containing the text matched by the previous match.
+    *   If the pattern can match an empty string, an empty string may be returned.
+    *   @param   status      A reference to a UErrorCode to receive any errors.
+    *                        Possible errors are  U_REGEX_INVALID_STATE if no match
+    *                        has been attempted or the last match failed.
+    *   @return  a string containing the matched input text.
+    *   @stable ICU 2.4
+    */
+    virtual UnicodeString group(UErrorCode &status) const;
+
+
+   /**
+    *    Returns a string containing the text captured by the given group
+    *    during the previous match operation.  Group(0) is the entire match.
+    *
+    *    @param groupNum the capture group number
+    *    @param   status     A reference to a UErrorCode to receive any errors.
+    *                        Possible errors are  U_REGEX_INVALID_STATE if no match
+    *                        has been attempted or the last match failed and
+    *                        U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number.
+    *    @return the captured text
+    *    @stable ICU 2.4
+    */
+    virtual UnicodeString group(int32_t groupNum, UErrorCode &status) const;
+
+
+   /**
+    *   Returns the number of capturing groups in this matcher's pattern.
+    *   @return the number of capture groups
+    *   @stable ICU 2.4
+    */
+    virtual int32_t groupCount() const;
+
+
+   /**
+    *   Returns a shallow clone of the entire live input string with the UText current native index
+    *   set to the beginning of the requested group.
+    *   Note that copying the entire input string may cause significant performance and memory issues.
+    *   @param   dest        The UText into which the input should be copied, or NULL to create a new UText
+    *   @param   group_len   A reference to receive the length of the desired capture group
+    *   @param   status      A reference to a UErrorCode to receive any errors.
+    *                        Possible errors are  U_REGEX_INVALID_STATE if no match
+    *                        has been attempted or the last match failed and
+    *                        U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number.
+    *   @return dest if non-NULL, a shallow copy of the input text otherwise
+    *
+    *   @draft ICU 4.6
+    */
+    virtual UText *group(UText *dest, int64_t &group_len, UErrorCode &status) const; 
+
+   /**
+    * @draft ICU 4.6
+    */
+    virtual UText *group(int32_t groupNum, UText *dest, int64_t &group_len, UErrorCode &status) const;
+
+   /**
+    *   Returns a string containing the text captured by the given group
+    *   during the previous match operation.  Group(0) is the entire match.
+    *
+    *   @param   groupNum    the capture group number
+    *   @param   dest        A mutable UText in which the matching text is placed.
+    *                        If NULL, a new UText will be created (which may not be mutable).
+    *   @param   status      A reference to a UErrorCode to receive any errors.
+    *                        Possible errors are  U_REGEX_INVALID_STATE if no match
+    *                        has been attempted or the last match failed.
+    *   @return  A string containing the matched input text. If a pre-allocated UText
+    *            was provided, it will always be used and returned.
+    *
+    *   @internal ICU 4.4 technology preview
+    */
+    virtual UText *group(int32_t groupNum, UText *dest, UErrorCode &status) const;
+
+
+   /**
+    *   Returns the index in the input string of the start of the text matched
+    *   during the previous match operation.
+    *    @param   status      a reference to a UErrorCode to receive any errors.
+    *    @return              The (native) position in the input string of the start of the last match.
+    *    @stable ICU 2.4
+    */
+    virtual int32_t start(UErrorCode &status) const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+    virtual int64_t start64(UErrorCode &status) const;
+
+
+   /**
+    *   Returns the index in the input string of the start of the text matched by the
+    *    specified capture group during the previous match operation.  Return -1 if
+    *    the capture group exists in the pattern, but was not part of the last match.
+    *
+    *    @param  group       the capture group number
+    *    @param  status      A reference to a UErrorCode to receive any errors.  Possible
+    *                        errors are  U_REGEX_INVALID_STATE if no match has been
+    *                        attempted or the last match failed, and
+    *                        U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number
+    *    @return the (native) start position of substring matched by the specified group.
+    *    @stable ICU 2.4
+    */
+    virtual int32_t start(int32_t group, UErrorCode &status) const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+    virtual int64_t start64(int32_t group, UErrorCode &status) const;
+
+
+   /**
+    *    Returns the index in the input string of the first character following the
+    *    text matched during the previous match operation.
+    *   @param   status      A reference to a UErrorCode to receive any errors.  Possible
+    *                        errors are  U_REGEX_INVALID_STATE if no match has been
+    *                        attempted or the last match failed.
+    *    @return the index of the last character matched, plus one.
+    *                        The index value returned is a native index, corresponding to
+    *                        code units for the underlying encoding type, for example,
+    *                        a byte index for UTF8.
+    *   @stable ICU 2.4
+    */
+    virtual int32_t end(UErrorCode &status) const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+    virtual int64_t end64(UErrorCode &status) const;
+
+
+   /**
+    *    Returns the index in the input string of the character following the
+    *    text matched by the specified capture group during the previous match operation.
+    *    @param group  the capture group number
+    *    @param   status      A reference to a UErrorCode to receive any errors.  Possible
+    *                        errors are  U_REGEX_INVALID_STATE if no match has been
+    *                        attempted or the last match failed and
+    *                        U_INDEX_OUTOFBOUNDS_ERROR for a bad capture group number
+    *    @return  the index of the first character following the text
+    *              captured by the specifed group during the previous match operation.
+    *              Return -1 if the capture group exists in the pattern but was not part of the match.
+    *              The index value returned is a native index, corresponding to
+    *              code units for the underlying encoding type, for example,
+    *              a byte index for UTF8.
+    *    @stable ICU 2.4
+    */
+    virtual int32_t end(int32_t group, UErrorCode &status) const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+    virtual int64_t end64(int32_t group, UErrorCode &status) const;
+
+
+   /**
+    *   Resets this matcher.  The effect is to remove any memory of previous matches,
+    *       and to cause subsequent find() operations to begin at the beginning of
+    *       the input string.
+    *
+    *   @return this RegexMatcher.
+    *   @stable ICU 2.4
+    */
+    virtual RegexMatcher &reset();
+
+
+   /**
+    *   Resets this matcher, and set the current input position.
+    *   The effect is to remove any memory of previous matches,
+    *       and to cause subsequent find() operations to begin at
+    *       the specified (native) position in the input string.
+    * <p>
+    *   The matcher's region is reset to its default, which is the entire
+    *   input string.
+    * <p>
+    *   An alternative to this function is to set a match region
+    *   beginning at the desired index.
+    *
+    *   @return this RegexMatcher.
+    *   @stable ICU 2.8
+    */
+    virtual RegexMatcher &reset(int64_t index, UErrorCode &status);
+
+
+   /**
+    *   Resets this matcher with a new input string.  This allows instances of RegexMatcher
+    *     to be reused, which is more efficient than creating a new RegexMatcher for
+    *     each input string to be processed.
+    *   @param input The new string on which subsequent pattern matches will operate.
+    *                The matcher retains a reference to the callers string, and operates
+    *                directly on that.  Ownership of the string remains with the caller.
+    *                Because no copy of the string is made, it is essential that the
+    *                caller not delete the string until after regexp operations on it
+    *                are done.
+    *                Note that while a reset on the matcher with an input string that is then
+    *                modified across/during matcher operations may be supported currently for UnicodeString,
+    *                this was not originally intended behavior, and support for this is not guaranteed
+    *                in upcoming versions of ICU.
+    *   @return this RegexMatcher.
+    *   @stable ICU 2.4
+    */
+    virtual RegexMatcher &reset(const UnicodeString &input);
+
+
+   /**
+    *   Resets this matcher with a new input string.  This allows instances of RegexMatcher
+    *     to be reused, which is more efficient than creating a new RegexMatcher for
+    *     each input string to be processed.
+    *   @param input The new string on which subsequent pattern matches will operate.
+    *                The matcher makes a shallow clone of the given text; ownership of the
+    *                original string remains with the caller. Because no deep copy of the
+    *                text is made, it is essential that the caller not modify the string
+    *                until after regexp operations on it are done.
+    *   @return this RegexMatcher.
+    *
+    *   @draft ICU 4.6
+    */
+    virtual RegexMatcher &reset(UText *input);
+
+private:
+    /**
+     * Cause a compilation error if an application accidently attempts to
+     *   reset a matcher with a (UChar *) string as input rather than
+     *   a UnicodeString.    Avoids a dangling reference to a temporary string.
+     * <p>
+     * To efficiently work with UChar *strings, wrap the data in a UnicodeString
+     * using one of the aliasing constructors, such as
+     * <code>UnicodeString(UBool isTerminated, const UChar *text, int32_t textLength);</code>
+     * or in a UText, using
+     * <code>utext_openUChars(UText *ut, const UChar *text, int64_t textLength, UErrorCode *status);</code>
+     *
+     * @internal
+     */
+    RegexMatcher &reset(const UChar *input);
+public:
+
+   /**
+    *   Returns the input string being matched.  Ownership of the string belongs to
+    *   the matcher; it should not be altered or deleted. This method will work even if the input
+    *   was originally supplied as a UText.
+    *   @return the input string
+    *   @stable ICU 2.4
+    */
+    virtual const UnicodeString &input() const;
+    
+   /**
+    *   Returns the input string being matched.  This is the live input text; it should not be
+    *   altered or deleted. This method will work even if the input was originally supplied as
+    *   a UnicodeString.
+    *   @return the input text
+    *
+    *   @draft ICU 4.6
+    */
+    virtual UText *inputText() const;
+    
+   /**
+    *   Returns the input string being matched, either by copying it into the provided
+    *   UText parameter or by returning a shallow clone of the live input. Note that copying
+    *   the entire input may cause significant performance and memory issues.
+    *   @param dest The UText into which the input should be copied, or NULL to create a new UText
+    *   @return dest if non-NULL, a shallow copy of the input text otherwise
+    *
+    *   @draft ICU 4.6
+    */
+    virtual UText *getInput(UText *dest, UErrorCode &status) const;
+    
+
+   /** Sets the limits of this matcher's region.
+     * The region is the part of the input string that will be searched to find a match.
+     * Invoking this method resets the matcher, and then sets the region to start
+     * at the index specified by the start parameter and end at the index specified
+     * by the end parameter.
+     *
+     * Depending on the transparency and anchoring being used (see useTransparentBounds
+     * and useAnchoringBounds), certain constructs such as anchors may behave differently
+     * at or around the boundaries of the region
+     *
+     * The function will fail if start is greater than limit, or if either index
+     *  is less than zero or greater than the length of the string being matched.
+     *
+     * @param start  The (native) index to begin searches at.
+     * @param limit  The index to end searches at (exclusive).
+     * @param status A reference to a UErrorCode to receive any errors.
+     * @stable ICU 4.0
+     */
+     virtual RegexMatcher &region(int64_t start, int64_t limit, UErrorCode &status);
+
+   /** 
+     * Identical to region(start, limit, status) but also allows a start position without
+     *  resetting the region state.
+     * @param startIndex  The (native) index within the region bounds at which to begin searches.
+     * @param status A reference to a UErrorCode to receive any errors.
+     *                If startIndex is not within the specified region bounds, 
+     *                U_INDEX_OUTOFBOUNDS_ERROR is returned.
+     * @draft ICU 4.6
+     */
+     virtual RegexMatcher &region(int64_t regionStart, int64_t regionLimit, int64_t startIndex, UErrorCode &status);
+
+   /**
+     * Reports the start index of this matcher's region. The searches this matcher
+     * conducts are limited to finding matches within regionStart (inclusive) and
+     * regionEnd (exclusive).
+     *
+     * @return The starting (native) index of this matcher's region.
+     * @stable ICU 4.0
+     */
+     virtual int32_t regionStart() const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+     virtual int64_t regionStart64() const;
+
+
+    /**
+      * Reports the end (limit) index (exclusive) of this matcher's region. The searches
+      * this matcher conducts are limited to finding matches within regionStart
+      * (inclusive) and regionEnd (exclusive).
+      *
+      * @return The ending point (native) of this matcher's region.
+      * @stable ICU 4.0
+      */
+      virtual int32_t regionEnd() const;
+
+   /**
+    *   @draft ICU 4.6
+    */
+      virtual int64_t regionEnd64() const;
+
+    /**
+      * Queries the transparency of region bounds for this matcher.
+      * See useTransparentBounds for a description of transparent and opaque bounds.
+      * By default, a matcher uses opaque region boundaries.
+      *
+      * @return TRUE if this matcher is using opaque bounds, false if it is not.
+      * @stable ICU 4.0
+      */
+      virtual UBool hasTransparentBounds() const;
+
+    /**
+      * Sets the transparency of region bounds for this matcher.
+      * Invoking this function with an argument of true will set this matcher to use transparent bounds.
+      * If the boolean argument is false, then opaque bounds will be used.
+      *
+      * Using transparent bounds, the boundaries of this matcher's region are transparent
+      * to lookahead, lookbehind, and boundary matching constructs. Those constructs can
+      * see text beyond the boundaries of the region while checking for a match.
+      *
+      * With opaque bounds, no text outside of the matcher's region is visible to lookahead,
+      * lookbehind, and boundary matching constructs.
+      *
+      * By default, a matcher uses opaque bounds.
+      *
+      * @param   b TRUE for transparent bounds; FALSE for opaque bounds
+      * @return  This Matcher;
+      * @stable ICU 4.0
+      **/
+      virtual RegexMatcher &useTransparentBounds(UBool b);
+
+     
+    /**
+      * Return true if this matcher is using anchoring bounds.
+      * By default, matchers use anchoring region boounds.
+      *
+      * @return TRUE if this matcher is using anchoring bounds.
+      * @stable ICU 4.0
+      */    
+      virtual UBool hasAnchoringBounds() const;
+
+
+    /**
+      * Set whether this matcher is using Anchoring Bounds for its region.
+      * With anchoring bounds, pattern anchors such as ^ and $ will match at the start
+      * and end of the region.  Without Anchoring Bounds, anchors will only match at
+      * the positions they would in the complete text.
+      *
+      * Anchoring Bounds are the default for regions.
+      *
+      * @param b TRUE if to enable anchoring bounds; FALSE to disable them.
+      * @return  This Matcher
+      * @stable ICU 4.0
+      */
+      virtual RegexMatcher &useAnchoringBounds(UBool b);
+
+
+    /**
+      * Return TRUE if the most recent matching operation touched the
+      *  end of the text being processed.  In this case, additional input text could
+      *  change the results of that match.
+      *
+      *  hitEnd() is defined for both successful and unsuccessful matches.
+      *  In either case hitEnd() will return TRUE if if the end of the text was
+      *  reached at any point during the matching process.
+      *
+      *  @return  TRUE if the most recent match hit the end of input
+      *  @stable ICU 4.0
+      */
+      virtual UBool hitEnd() const;
+
+    /**
+      * Return TRUE the most recent match succeeded and additional input could cause
+      * it to fail. If this method returns false and a match was found, then more input
+      * might change the match but the match won't be lost. If a match was not found,
+      * then requireEnd has no meaning.
+      *
+      * @return TRUE if more input could cause the most recent match to no longer match.
+      * @stable ICU 4.0
+      */
+      virtual UBool requireEnd() const;
+
+
+   /**
+    *    Returns the pattern that is interpreted by this matcher.
+    *    @return  the RegexPattern for this RegexMatcher
+    *    @stable ICU 2.4
+    */
+    virtual const RegexPattern &pattern() const;
+
+
+   /**
+    *    Replaces every substring of the input that matches the pattern
+    *    with the given replacement string.  This is a convenience function that
+    *    provides a complete find-and-replace-all operation.
+    *
+    *    This method first resets this matcher. It then scans the input string
+    *    looking for matches of the pattern. Input that is not part of any
+    *    match is left unchanged; each match is replaced in the result by the
+    *    replacement string. The replacement string may contain references to
+    *    capture groups.
+    *
+    *    @param   replacement a string containing the replacement text.
+    *    @param   status      a reference to a UErrorCode to receive any errors.
+    *    @return              a string containing the results of the find and replace.
+    *    @stable ICU 2.4
+    */
+    virtual UnicodeString replaceAll(const UnicodeString &replacement, UErrorCode &status);
+
+
+   /**
+    *    Replaces every substring of the input that matches the pattern
+    *    with the given replacement string.  This is a convenience function that
+    *    provides a complete find-and-replace-all operation.
+    *
+    *    This method first resets this matcher. It then scans the input string
+    *    looking for matches of the pattern. Input that is not part of any
+    *    match is left unchanged; each match is replaced in the result by the
+    *    replacement string. The replacement string may contain references to
+    *    capture groups.
+    *
+    *    @param   replacement a string containing the replacement text.
+    *    @param   dest        a mutable UText in which the results are placed.
+    *                          If NULL, a new UText will be created (which may not be mutable).
+    *    @param   status      a reference to a UErrorCode to receive any errors.
+    *    @return              a string containing the results of the find and replace.
+    *                          If a pre-allocated UText was provided, it will always be used and returned.
+    *
+    *    @draft ICU 4.6
+    */
+    virtual UText *replaceAll(UText *replacement, UText *dest, UErrorCode &status);
+    
+
+   /**
+    * Replaces the first substring of the input that matches
+    * the pattern with the replacement string.   This is a convenience
+    * function that provides a complete find-and-replace operation.
+    *
+    * <p>This function first resets this RegexMatcher. It then scans the input string
+    * looking for a match of the pattern. Input that is not part
+    * of the match is appended directly to the result string; the match is replaced
+    * in the result by the replacement string. The replacement string may contain
+    * references to captured groups.</p>
+    *
+    * <p>The state of the matcher (the position at which a subsequent find()
+    *    would begin) after completing a replaceFirst() is not specified.  The
+    *    RegexMatcher should be reset before doing additional find() operations.</p>
+    *
+    *    @param   replacement a string containing the replacement text.
+    *    @param   status      a reference to a UErrorCode to receive any errors.
+    *    @return              a string containing the results of the find and replace.
+    *    @stable ICU 2.4
+    */
+    virtual UnicodeString replaceFirst(const UnicodeString &replacement, UErrorCode &status);
+    
+
+   /**
+    * Replaces the first substring of the input that matches
+    * the pattern with the replacement string.   This is a convenience
+    * function that provides a complete find-and-replace operation.
+    *
+    * <p>This function first resets this RegexMatcher. It then scans the input string
+    * looking for a match of the pattern. Input that is not part
+    * of the match is appended directly to the result string; the match is replaced
+    * in the result by the replacement string. The replacement string may contain
+    * references to captured groups.</p>
+    *
+    * <p>The state of the matcher (the position at which a subsequent find()
+    *    would begin) after completing a replaceFirst() is not specified.  The
+    *    RegexMatcher should be reset before doing additional find() operations.</p>
+    *
+    *    @param   replacement a string containing the replacement text.
+    *    @param   dest        a mutable UText in which the results are placed.
+    *                          If NULL, a new UText will be created (which may not be mutable).
+    *    @param   status      a reference to a UErrorCode to receive any errors.
+    *    @return              a string containing the results of the find and replace.
+    *                          If a pre-allocated UText was provided, it will always be used and returned.
+    *
+    *    @draft ICU 4.6
+    */
+    virtual UText *replaceFirst(UText *replacement, UText *dest, UErrorCode &status);
+    
+    
+   /**
+    *   Implements a replace operation intended to be used as part of an
+    *   incremental find-and-replace.
+    *
+    *   <p>The input string, starting from the end of the previous replacement and ending at
+    *   the start of the current match, is appended to the destination string.  Then the
+    *   replacement string is appended to the output string,
+    *   including handling any substitutions of captured text.</p>
+    *
+    *   <p>For simple, prepackaged, non-incremental find-and-replace
+    *   operations, see replaceFirst() or replaceAll().</p>
+    *
+    *   @param   dest        A UnicodeString to which the results of the find-and-replace are appended.
+    *   @param   replacement A UnicodeString that provides the text to be substituted for
+    *                        the input text that matched the regexp pattern.  The replacement
+    *                        text may contain references to captured text from the
+    *                        input.
+    *   @param   status      A reference to a UErrorCode to receive any errors.  Possible
+    *                        errors are  U_REGEX_INVALID_STATE if no match has been
+    *                        attempted or the last match failed, and U_INDEX_OUTOFBOUNDS_ERROR
+    *                        if the replacement text specifies a capture group that
+    *                        does not exist in the pattern.
+    *
+    *   @return  this  RegexMatcher
+    *   @stable ICU 2.4
+    *
+    */
+    virtual RegexMatcher &appendReplacement(UnicodeString &dest,
+        const UnicodeString &replacement, UErrorCode &status);
+    
+    
+   /**
+    *   Implements a replace operation intended to be used as part of an
+    *   incremental find-and-replace.
+    *
+    *   <p>The input string, starting from the end of the previous replacement and ending at
+    *   the start of the current match, is appended to the destination string.  Then the
+    *   replacement string is appended to the output string,
+    *   including handling any substitutions of captured text.</p>
+    *
+    *   <p>For simple, prepackaged, non-incremental find-and-replace
+    *   operations, see replaceFirst() or replaceAll().</p>
+    *
+    *   @param   dest        A mutable UText to which the results of the find-and-replace are appended.
+    *                         Must not be NULL.
+    *   @param   replacement A UText that provides the text to be substituted for
+    *                        the input text that matched the regexp pattern.  The replacement
+    *                        text may contain references to captured text from the input.
+    *   @param   status      A reference to a UErrorCode to receive any errors.  Possible
+    *                        errors are  U_REGEX_INVALID_STATE if no match has been
+    *                        attempted or the last match failed, and U_INDEX_OUTOFBOUNDS_ERROR
+    *                        if the replacement text specifies a capture group that
+    *                        does not exist in the pattern.
+    *
+    *   @return  this  RegexMatcher
+    *
+    *   @draft ICU 4.6
+    */
+    virtual RegexMatcher &appendReplacement(UText *dest,
+        UText *replacement, UErrorCode &status);
+
+
+   /**
+    * As the final step in a find-and-replace operation, append the remainder
+    * of the input string, starting at the position following the last appendReplacement(),
+    * to the destination string. <code>appendTail()</code> is intended to be invoked after one
+    * or more invocations of the <code>RegexMatcher::appendReplacement()</code>.
+    *
+    *  @param dest A UnicodeString to which the results of the find-and-replace are appended.
+    *  @return  the destination string.
+    *  @stable ICU 2.4
+    */
+    virtual UnicodeString &appendTail(UnicodeString &dest);
+
+
+   /**
+    * As the final step in a find-and-replace operation, append the remainder
+    * of the input string, starting at the position following the last appendReplacement(),
+    * to the destination string. <code>appendTail()</code> is intended to be invoked after one
+    * or more invocations of the <code>RegexMatcher::appendReplacement()</code>.
+    *
+    *  @param dest A mutable UText to which the results of the find-and-replace are appended.
+    *               Must not be NULL.
+    *  @return  the destination string.
+    *
+    *  @draft ICU 4.6
+    */
+    virtual UText *appendTail(UText *dest, UErrorCode &status);
+
+
+    /**
+     * Split a string into fields.  Somewhat like split() from Perl.
+     * The pattern matches identify delimiters that separate the input
+     *  into fields.  The input data between the matches becomes the
+     *  fields themselves.
+     *
+     * @param input   The string to be split into fields.  The field delimiters
+     *                match the pattern (in the "this" object).  This matcher
+     *                will be reset to this input string.
+     * @param dest    An array of UnicodeStrings to receive the results of the split.
+     *                This is an array of actual UnicodeString objects, not an
+     *                array of pointers to strings.  Local (stack based) arrays can
+     *                work well here.
+     * @param destCapacity  The number of elements in the destination array.
+     *                If the number of fields found is less than destCapacity, the
+     *                extra strings in the destination array are not altered.
+     *                If the number of destination strings is less than the number
+     *                of fields, the trailing part of the input string, including any
+     *                field delimiters, is placed in the last destination string.
+     * @param status  A reference to a UErrorCode to receive any errors.
+     * @return        The number of fields into which the input string was split.
+     * @stable ICU 2.6
+     */
+    virtual int32_t  split(const UnicodeString &input,
+        UnicodeString    dest[],
+        int32_t          destCapacity,
+        UErrorCode       &status);
+
+
+    /**
+     * Split a string into fields.  Somewhat like split() from Perl.
+     * The pattern matches identify delimiters that separate the input
+     *  into fields.  The input data between the matches becomes the
+     *  fields themselves.
+     *
+     * @param input   The string to be split into fields.  The field delimiters
+     *                match the pattern (in the "this" object).  This matcher
+     *                will be reset to this input string.
+     * @param dest    An array of mutable UText structs to receive the results of the split.
+     *                If a field is NULL, a new UText is allocated to contain the results for
+     *                that field. This new UText is not guaranteed to be mutable.
+     * @param destCapacity  The number of elements in the destination array.
+     *                If the number of fields found is less than destCapacity, the
+     *                extra strings in the destination array are not altered.
+     *                If the number of destination strings is less than the number
+     *                of fields, the trailing part of the input string, including any
+     *                field delimiters, is placed in the last destination string.
+     * @param status  A reference to a UErrorCode to receive any errors.
+     * @return        The number of fields into which the input string was split.
+     *
+     * @draft ICU 4.6
+     */
+    virtual int32_t  split(UText *input,
+        UText           *dest[],
+        int32_t          destCapacity,
+        UErrorCode       &status);
+    
+  /**
+    *   Set a processing time limit for match operations with this Matcher.
+    *  
+    *   Some patterns, when matching certain strings, can run in exponential time.
+    *   For practical purposes, the match operation may appear to be in an
+    *   infinite loop.
+    *   When a limit is set a match operation will fail with an error if the
+    *   limit is exceeded.
+    *   <p>
+    *   The units of the limit are steps of the match engine.
+    *   Correspondence with actual processor time will depend on the speed
+    *   of the processor and the details of the specific pattern, but will
+    *   typically be on the order of milliseconds.
+    *   <p>
+    *   By default, the matching time is not limited.
+    *   <p>
+    *
+    *   @param   limit       The limit value, or 0 for no limit.
+    *   @param   status      A reference to a UErrorCode to receive any errors.
+    *   @stable ICU 4.0
+    */
+    virtual void setTimeLimit(int32_t limit, UErrorCode &status);
+
+  /**
+    * Get the time limit, if any, for match operations made with this Matcher.
+    *
+    *   @return the maximum allowed time for a match, in units of processing steps.
+    *   @stable ICU 4.0
+    */
+    virtual int32_t getTimeLimit() const;
+
+  /**
+    *  Set the amount of heap storage avaliable for use by the match backtracking stack.
+    *  The matcher is also reset, discarding any results from previous matches.
+    *  <p>
+    *  ICU uses a backtracking regular expression engine, with the backtrack stack
+    *  maintained on the heap.  This function sets the limit to the amount of memory
+    *  that can be used  for this purpose.  A backtracking stack overflow will
+    *  result in an error from the match operation that caused it.
+    *  <p>
+    *  A limit is desirable because a malicious or poorly designed pattern can use
+    *  excessive memory, potentially crashing the process.  A limit is enabled
+    *  by default.
+    *  <p>
+    *  @param limit  The maximum size, in bytes, of the matching backtrack stack.
+    *                A value of zero means no limit.
+    *                The limit must be greater or equal to zero.
+    *
+    *  @param status   A reference to a UErrorCode to receive any errors.
+    *
+    *  @stable ICU 4.0
+    */
+    virtual void setStackLimit(int32_t  limit, UErrorCode &status);
+    
+  /**
+    *  Get the size of the heap storage available for use by the back tracking stack.
+    *
+    *  @return  the maximum backtracking stack size, in bytes, or zero if the
+    *           stack size is unlimited.
+    *  @stable ICU 4.0
+    */
+    virtual int32_t  getStackLimit() const;
+
+
+  /**
+    * Set a callback function for use with this Matcher.
+    * During matching operations the function will be called periodically,
+    * giving the application the opportunity to terminate a long-running
+    * match.
+    *
+    *    @param   callback    A pointer to the user-supplied callback function.
+    *    @param   context     User context pointer.  The value supplied at the
+    *                         time the callback function is set will be saved
+    *                         and passed to the callback each time that it is called.
+    *    @param   status      A reference to a UErrorCode to receive any errors.
+    *  @stable ICU 4.0
+    */
+    virtual void setMatchCallback(URegexMatchCallback     *callback,
+                                  const void              *context,
+                                  UErrorCode              &status);
+
+
+  /**
+    *  Get the callback function for this URegularExpression.
+    *
+    *    @param   callback    Out paramater, receives a pointer to the user-supplied 
+    *                         callback function.
+    *    @param   context     Out parameter, receives the user context pointer that
+    *                         was set when uregex_setMatchCallback() was called.
+    *    @param   status      A reference to a UErrorCode to receive any errors.
+    *    @stable ICU 4.0
+    */
+    virtual void getMatchCallback(URegexMatchCallback     *&callback,
+                                  const void              *&context,
+                                  UErrorCode              &status);
+
+
+  /**
+    * Set a progress callback function for use with find operations on this Matcher.
+    * During find operations, the callback will be invoked after each return from a
+    * match attempt, giving the application the opportunity to terminate a long-running
+    * find operation.
+    *
+    *    @param   callback    A pointer to the user-supplied callback function.
+    *    @param   context     User context pointer.  The value supplied at the
+    *                         time the callback function is set will be saved
+    *                         and passed to the callback each time that it is called.
+    *    @param   status      A reference to a UErrorCode to receive any errors.
+    *    @draft ICU 4.6
+    */
+    virtual void setFindProgressCallback(URegexFindProgressCallback      *callback,
+                                              const void                              *context,
+                                              UErrorCode                              &status);
+
+
+  /**
+    *  Get the find progress callback function for this URegularExpression.
+    *
+    *    @param   callback    Out paramater, receives a pointer to the user-supplied 
+    *                         callback function.
+    *    @param   context     Out parameter, receives the user context pointer that
+    *                         was set when uregex_setFindProgressCallback() was called.
+    *    @param   status      A reference to a UErrorCode to receive any errors.
+    *    @draft ICU 4.6
+    */
+    virtual void getFindProgressCallback(URegexFindProgressCallback      *&callback,
+                                              const void                      *&context,
+                                              UErrorCode                      &status);
+
+
+   /**
+     *   setTrace   Debug function, enable/disable tracing of the matching engine.
+     *              For internal ICU development use only.  DO NO USE!!!!
+     *   @internal
+     */
+    void setTrace(UBool state);
+
+
+    /**
+    * ICU "poor man's RTTI", returns a UClassID for this class.
+    *
+    * @stable ICU 2.2
+    */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     *
+     * @stable ICU 2.2
+     */
+    virtual UClassID getDynamicClassID() const;
+
+private:
+    // Constructors and other object boilerplate are private.
+    // Instances of RegexMatcher can not be assigned, copied, cloned, etc.
+    RegexMatcher();                  // default constructor not implemented
+    RegexMatcher(const RegexPattern *pat);
+    RegexMatcher(const RegexMatcher &other);
+    RegexMatcher &operator =(const RegexMatcher &rhs);
+    void init(UErrorCode &status);                      // Common initialization
+    void init2(UText *t, UErrorCode &e);  // Common initialization, part 2.
+
+    friend class RegexPattern;
+    friend class RegexCImpl;
+public:
+    /** @internal  */
+    void resetPreserveRegion();  // Reset matcher state, but preserve any region.
+private:
+
+    //
+    //  MatchAt   This is the internal interface to the match engine itself.
+    //            Match status comes back in matcher member variables.
+    //
+    void                 MatchAt(int64_t startIdx, UBool toEnd, UErrorCode &status);
+    inline void          backTrack(int64_t &inputIdx, int32_t &patIdx);
+    UBool                isWordBoundary(int64_t pos);         // perform Perl-like  \b test
+    UBool                isUWordBoundary(int64_t pos);        // perform RBBI based \b test
+    REStackFrame        *resetStack();
+    inline REStackFrame *StateSave(REStackFrame *fp, int64_t savePatIdx, UErrorCode &status);
+    void                 IncrementTime(UErrorCode &status);
+    UBool                ReportFindProgress(int64_t matchIndex, UErrorCode &status);
+    
+    int64_t              appendGroup(int32_t groupNum, UText *dest, UErrorCode &status) const;
+    
+    UBool                findUsingChunk();
+    void                 MatchChunkAt(int32_t startIdx, UBool toEnd, UErrorCode &status);
+    UBool                isChunkWordBoundary(int32_t pos);
+
+    const RegexPattern  *fPattern;
+    RegexPattern        *fPatternOwned;    // Non-NULL if this matcher owns the pattern, and
+                                           //   should delete it when through.
+
+    const UnicodeString *fInput;           // The string being matched. Only used for input()
+    UText               *fInputText;       // The text being matched. Is never NULL.
+    UText               *fAltInputText;    // A shallow copy of the text being matched.
+                                           //   Only created if the pattern contains backreferences.
+    int64_t              fInputLength;     // Full length of the input text.
+    int32_t              fFrameSize;       // The size of a frame in the backtrack stack.
+    
+    int64_t              fRegionStart;     // Start of the input region, default = 0.
+    int64_t              fRegionLimit;     // End of input region, default to input.length.
+    
+    int64_t              fAnchorStart;     // Region bounds for anchoring operations (^ or $).
+    int64_t              fAnchorLimit;     //   See useAnchoringBounds
+    
+    int64_t              fLookStart;       // Region bounds for look-ahead/behind and
+    int64_t              fLookLimit;       //   and other boundary tests.  See
+                                           //   useTransparentBounds
+
+    int64_t              fActiveStart;     // Currently active bounds for matching.
+    int64_t              fActiveLimit;     //   Usually is the same as region, but
+                                           //   is changed to fLookStart/Limit when
+                                           //   entering look around regions.
+
+    UBool                fTransparentBounds;  // True if using transparent bounds.
+    UBool                fAnchoringBounds; // True if using anchoring bounds.
+
+    UBool                fMatch;           // True if the last attempted match was successful.
+    int64_t              fMatchStart;      // Position of the start of the most recent match
+    int64_t              fMatchEnd;        // First position after the end of the most recent match
+                                           //   Zero if no previous match, even when a region
+                                           //   is active.
+    int64_t              fLastMatchEnd;    // First position after the end of the previous match,
+                                           //   or -1 if there was no previous match.
+    int64_t              fAppendPosition;  // First position after the end of the previous
+                                           //   appendReplacement().  As described by the
+                                           //   JavaDoc for Java Matcher, where it is called 
+                                           //   "append position"
+    UBool                fHitEnd;          // True if the last match touched the end of input.
+    UBool                fRequireEnd;      // True if the last match required end-of-input
+                                           //    (matched $ or Z)
+
+    UVector64           *fStack;
+    REStackFrame        *fFrame;           // After finding a match, the last active stack frame,
+                                           //   which will contain the capture group results.
+                                           //   NOT valid while match engine is running.
+
+    int64_t             *fData;            // Data area for use by the compiled pattern.
+    int64_t             fSmallData[8];     //   Use this for data if it's enough.
+
+    int32_t             fTimeLimit;        // Max time (in arbitrary steps) to let the
+                                           //   match engine run.  Zero for unlimited.
+    
+    int32_t             fTime;             // Match time, accumulates while matching.
+    int32_t             fTickCounter;      // Low bits counter for time.  Counts down StateSaves.
+                                           //   Kept separately from fTime to keep as much
+                                           //   code as possible out of the inline
+                                           //   StateSave function.
+
+    int32_t             fStackLimit;       // Maximum memory size to use for the backtrack
+                                           //   stack, in bytes.  Zero for unlimited.
+
+    URegexMatchCallback *fCallbackFn;       // Pointer to match progress callback funct.
+                                           //   NULL if there is no callback.
+    const void         *fCallbackContext;  // User Context ptr for callback function.
+
+    URegexFindProgressCallback  *fFindProgressCallbackFn;  // Pointer to match progress callback funct.
+                                                           //   NULL if there is no callback.
+    const void         *fFindProgressCallbackContext;      // User Context ptr for callback function.
+
+
+    UBool               fInputUniStrMaybeMutable;  // Set when fInputText wraps a UnicodeString that may be mutable - compatibility.
+
+    UBool               fTraceDebug;       // Set true for debug tracing of match engine.
+
+    UErrorCode          fDeferredStatus;   // Save error state that cannot be immediately
+                                           //   reported, or that permanently disables this matcher.
+
+    RuleBasedBreakIterator  *fWordBreakItr;
+
+
+};
+
+U_NAMESPACE_END
+#endif  // UCONFIG_NO_REGULAR_EXPRESSIONS
+#endif