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      1 /*
      2  *******************************************************************************
      3  * Copyright (C) 1996-2006, International Business Machines Corporation and    *
      4  * others. All Rights Reserved.                                                *
      5  *******************************************************************************
      6  */
      7 
      8 #ifndef CANITER_H
      9 #define CANITER_H
     10 
     11 #include "unicode/utypes.h"
     12 
     13 #if !UCONFIG_NO_NORMALIZATION
     14 
     15 #include "unicode/uobject.h"
     16 #include "unicode/unistr.h"
     17 
     18 /**
     19  * \file
     20  * \brief C++ API: Canonical Iterator
     21  */
     22 
     23 /** Should permutation skip characters with combining class zero
     24  *  Should be either TRUE or FALSE. This is a compile time option
     25  *  @stable ICU 2.4
     26  */
     27 #ifndef CANITER_SKIP_ZEROES
     28 #define CANITER_SKIP_ZEROES TRUE
     29 #endif
     30 
     31 U_NAMESPACE_BEGIN
     32 
     33 class Hashtable;
     34 
     35 /**
     36  * This class allows one to iterate through all the strings that are canonically equivalent to a given
     37  * string. For example, here are some sample results:
     38 Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
     39 1: \\u0041\\u030A\\u0064\\u0307\\u0327
     40  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
     41 2: \\u0041\\u030A\\u0064\\u0327\\u0307
     42  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
     43 3: \\u0041\\u030A\\u1E0B\\u0327
     44  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
     45 4: \\u0041\\u030A\\u1E11\\u0307
     46  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
     47 5: \\u00C5\\u0064\\u0307\\u0327
     48  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
     49 6: \\u00C5\\u0064\\u0327\\u0307
     50  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
     51 7: \\u00C5\\u1E0B\\u0327
     52  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
     53 8: \\u00C5\\u1E11\\u0307
     54  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
     55 9: \\u212B\\u0064\\u0307\\u0327
     56  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
     57 10: \\u212B\\u0064\\u0327\\u0307
     58  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
     59 11: \\u212B\\u1E0B\\u0327
     60  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
     61 12: \\u212B\\u1E11\\u0307
     62  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
     63  *<br>Note: the code is intended for use with small strings, and is not suitable for larger ones,
     64  * since it has not been optimized for that situation.
     65  * Note, CanonicalIterator is not intended to be subclassed.
     66  * @author M. Davis
     67  * @author C++ port by V. Weinstein
     68  * @stable ICU 2.4
     69  */
     70 class U_COMMON_API CanonicalIterator : public UObject {
     71 public:
     72     /**
     73      * Construct a CanonicalIterator object
     74      * @param source    string to get results for
     75      * @param status    Fill-in parameter which receives the status of this operation.
     76      * @stable ICU 2.4
     77      */
     78     CanonicalIterator(const UnicodeString &source, UErrorCode &status);
     79 
     80     /** Destructor
     81      *  Cleans pieces
     82      * @stable ICU 2.4
     83      */
     84     virtual ~CanonicalIterator();
     85 
     86     /**
     87      * Gets the NFD form of the current source we are iterating over.
     88      * @return gets the source: NOTE: it is the NFD form of source
     89      * @stable ICU 2.4
     90      */
     91     UnicodeString getSource();
     92 
     93     /**
     94      * Resets the iterator so that one can start again from the beginning.
     95      * @stable ICU 2.4
     96      */
     97     void reset();
     98 
     99     /**
    100      * Get the next canonically equivalent string.
    101      * <br><b>Warning: The strings are not guaranteed to be in any particular order.</b>
    102      * @return the next string that is canonically equivalent. A bogus string is returned when
    103      * the iteration is done.
    104      * @stable ICU 2.4
    105      */
    106     UnicodeString next();
    107 
    108     /**
    109      * Set a new source for this iterator. Allows object reuse.
    110      * @param newSource     the source string to iterate against. This allows the same iterator to be used
    111      *                     while changing the source string, saving object creation.
    112      * @param status        Fill-in parameter which receives the status of this operation.
    113      * @stable ICU 2.4
    114      */
    115     void setSource(const UnicodeString &newSource, UErrorCode &status);
    116 
    117     /**
    118      * Dumb recursive implementation of permutation.
    119      * TODO: optimize
    120      * @param source     the string to find permutations for
    121      * @param skipZeros  determine if skip zeros
    122      * @param result     the results in a set.
    123      * @param status       Fill-in parameter which receives the status of this operation.
    124      * @internal
    125      */
    126     static void U_EXPORT2 permute(UnicodeString &source, UBool skipZeros, Hashtable *result, UErrorCode &status);
    127 
    128     /**
    129      * ICU "poor man's RTTI", returns a UClassID for this class.
    130      *
    131      * @stable ICU 2.2
    132      */
    133     static UClassID U_EXPORT2 getStaticClassID();
    134 
    135     /**
    136      * ICU "poor man's RTTI", returns a UClassID for the actual class.
    137      *
    138      * @stable ICU 2.2
    139      */
    140     virtual UClassID getDynamicClassID() const;
    141 
    142 private:
    143     // ===================== PRIVATES ==============================
    144     // private default constructor
    145     CanonicalIterator();
    146 
    147 
    148     /**
    149      * Copy constructor. Private for now.
    150      * @internal
    151      */
    152     CanonicalIterator(const CanonicalIterator& other);
    153 
    154     /**
    155      * Assignment operator. Private for now.
    156      * @internal
    157      */
    158     CanonicalIterator& operator=(const CanonicalIterator& other);
    159 
    160     // fields
    161     UnicodeString source;
    162     UBool done;
    163 
    164     // 2 dimensional array holds the pieces of the string with
    165     // their different canonically equivalent representations
    166     UnicodeString **pieces;
    167     int32_t pieces_length;
    168     int32_t *pieces_lengths;
    169 
    170     // current is used in iterating to combine pieces
    171     int32_t *current;
    172     int32_t current_length;
    173 
    174     // transient fields
    175     UnicodeString buffer;
    176 
    177     // we have a segment, in NFD. Find all the strings that are canonically equivalent to it.
    178     UnicodeString *getEquivalents(const UnicodeString &segment, int32_t &result_len, UErrorCode &status); //private String[] getEquivalents(String segment)
    179 
    180     //Set getEquivalents2(String segment);
    181     Hashtable *getEquivalents2(Hashtable *fillinResult, const UChar *segment, int32_t segLen, UErrorCode &status);
    182     //Hashtable *getEquivalents2(const UnicodeString &segment, int32_t segLen, UErrorCode &status);
    183 
    184     /**
    185      * See if the decomposition of cp2 is at segment starting at segmentPos
    186      * (with canonical rearrangment!)
    187      * If so, take the remainder, and return the equivalents
    188      */
    189     //Set extract(int comp, String segment, int segmentPos, StringBuffer buffer);
    190     Hashtable *extract(Hashtable *fillinResult, UChar32 comp, const UChar *segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);
    191     //Hashtable *extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);
    192 
    193     void cleanPieces();
    194 
    195 };
    196 
    197 U_NAMESPACE_END
    198 
    199 #endif /* #if !UCONFIG_NO_NORMALIZATION */
    200 
    201 #endif
    202