/*

  *******************************************************************************

  * Copyright (C) 1996-2005, International Business Machines Corporation and    *

  * others. All Rights Reserved.                                                *

  *******************************************************************************

  */

 #ifndef CANITER_H

 #define CANITER_H

 #include "unicode/utypes.h"

 #if !UCONFIG_NO_NORMALIZATION

 #include "unicode/uobject.h"

 #include "unicode/unistr.h"

 /**

  * \file

  * \brief C++ API: Canonical Iterator

  */

 /** Should permutation skip characters with combining class zero

  *  Should be either TRUE or FALSE. This is a compile time option

  *  @stable ICU 2.4

  */

 #ifndef CANITER_SKIP_ZEROES

 #define CANITER_SKIP_ZEROES TRUE

 #endif

 U_NAMESPACE_BEGIN

 class Hashtable;

 /**

  * This class allows one to iterate through all the strings that are canonically equivalent to a given

  * string. For example, here are some sample results:

 Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

 1: \\u0041\\u030A\\u0064\\u0307\\u0327

  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

 2: \\u0041\\u030A\\u0064\\u0327\\u0307

  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

 3: \\u0041\\u030A\\u1E0B\\u0327

  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

 4: \\u0041\\u030A\\u1E11\\u0307

  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

 5: \\u00C5\\u0064\\u0307\\u0327

  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

 6: \\u00C5\\u0064\\u0327\\u0307

  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

 7: \\u00C5\\u1E0B\\u0327

  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

 8: \\u00C5\\u1E11\\u0307

  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

 9: \\u212B\\u0064\\u0307\\u0327

  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}

 10: \\u212B\\u0064\\u0327\\u0307

  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}

 11: \\u212B\\u1E0B\\u0327

  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}

 12: \\u212B\\u1E11\\u0307

  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}

  *<br>Note: the code is intended for use with small strings, and is not suitable for larger ones,

  * since it has not been optimized for that situation.

  * Note, CanonicalIterator is not intended to be subclassed.

  * @author M. Davis

  * @author C++ port by V. Weinstein

  * @stable ICU 2.4

  */

 class U_COMMON_API CanonicalIterator : public UObject {

 public:

     /**

      * Construct a CanonicalIterator object

      * @param source    string to get results for

      * @param status    Fill-in parameter which receives the status of this operation.

      * @stable ICU 2.4

      */

     CanonicalIterator(const UnicodeString &source, UErrorCode &status);

     /** Destructor

      *  Cleans pieces

      * @stable ICU 2.4

      */

     virtual ~CanonicalIterator();

     /**

      * Gets the NFD form of the current source we are iterating over.

      * @return gets the source: NOTE: it is the NFD form of source

      * @stable ICU 2.4

      */

     UnicodeString getSource();

     /**

      * Resets the iterator so that one can start again from the beginning.

      * @stable ICU 2.4

      */

     void reset();

     /**

      * Get the next canonically equivalent string.

      * <br><b>Warning: The strings are not guaranteed to be in any particular order.</b>

      * @return the next string that is canonically equivalent. A bogus string is returned when

      * the iteration is done.

      * @stable ICU 2.4

      */

     UnicodeString next();

     /**

      * Set a new source for this iterator. Allows object reuse.

      * @param newSource     the source string to iterate against. This allows the same iterator to be used

      *                     while changing the source string, saving object creation.

      * @param status        Fill-in parameter which receives the status of this operation.

      * @stable ICU 2.4

      */

     void setSource(const UnicodeString &newSource, UErrorCode &status);

     /**

      * Dumb recursive implementation of permutation.

      * TODO: optimize

      * @param source     the string to find permutations for

      * @param skipZeros  determine if skip zeros

      * @param result     the results in a set.

      * @param status       Fill-in parameter which receives the status of this operation.

      * @internal

      */

     static void U_EXPORT2 permute(UnicodeString &source, UBool skipZeros, Hashtable *result, UErrorCode &status);

     /**

      * 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:

     // ===================== PRIVATES ==============================

     // private default constructor

     CanonicalIterator();

     /**

      * Copy constructor. Private for now.

      * @internal

      */

     CanonicalIterator(const CanonicalIterator& other);

     /**

      * Assignment operator. Private for now.

      * @internal

      */

     CanonicalIterator& operator=(const CanonicalIterator& other);

     // fields

     UnicodeString source;

     UBool done;

     // 2 dimensional array holds the pieces of the string with

     // their different canonically equivalent representations

     UnicodeString **pieces;

     int32_t pieces_length;

     int32_t *pieces_lengths;

     // current is used in iterating to combine pieces

     int32_t *current;

     int32_t current_length;

     // transient fields

     UnicodeString buffer;

     // we have a segment, in NFD. Find all the strings that are canonically equivalent to it.

     UnicodeString *getEquivalents(const UnicodeString &segment, int32_t &result_len, UErrorCode &status); //private String[] getEquivalents(String segment)

     //Set getEquivalents2(String segment);

     Hashtable *getEquivalents2(const UChar *segment, int32_t segLen, UErrorCode &status);

     //Hashtable *getEquivalents2(const UnicodeString &segment, int32_t segLen, UErrorCode &status);

     /**

      * See if the decomposition of cp2 is at segment starting at segmentPos

      * (with canonical rearrangment!)

      * If so, take the remainder, and return the equivalents

      */

     //Set extract(int comp, String segment, int segmentPos, StringBuffer buffer);

     Hashtable *extract(UChar32 comp, const UChar *segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);

     //Hashtable *extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);

     void cleanPieces();

 };

 U_NAMESPACE_END

 #endif /* #if !UCONFIG_NO_NORMALIZATION */

 #endif