text: /*
   *******************************************************************************
   * Copyright (C) 1996-2010, 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;
  class Normalizer2;
  class Normalizer2Impl;
  
  /**
   * 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;
  
      const Normalizer2 &nfd;
      const Normalizer2Impl &nfcImpl;
  
      // 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(Hashtable *fillinResult, 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(Hashtable *fillinResult, 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
  