xref: /aosp_15_r20/external/icu/libicu/cts_headers/unicode/caniter.h (revision 0e209d3975ff4a8c132096b14b0e9364a753506e)
1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4  *******************************************************************************
5  * Copyright (C) 1996-2014, International Business Machines Corporation and
6  * others. All Rights Reserved.
7  *******************************************************************************
8  */
9 
10 #ifndef CANITER_H
11 #define CANITER_H
12 
13 #include "unicode/utypes.h"
14 
15 #if U_SHOW_CPLUSPLUS_API
16 
17 #if !UCONFIG_NO_NORMALIZATION
18 
19 #include "unicode/uobject.h"
20 #include "unicode/unistr.h"
21 
22 /**
23  * \file
24  * \brief C++ API: Canonical Iterator
25  */
26 
27 /** Should permutation skip characters with combining class zero
28  *  Should be either true or false. This is a compile time option
29  *  @stable ICU 2.4
30  */
31 #ifndef CANITER_SKIP_ZEROES
32 #define CANITER_SKIP_ZEROES true
33 #endif
34 
35 U_NAMESPACE_BEGIN
36 
37 class Hashtable;
38 class Normalizer2;
39 class Normalizer2Impl;
40 
41 /**
42  * This class allows one to iterate through all the strings that are canonically equivalent to a given
43  * string. For example, here are some sample results:
44 Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
45 1: \\u0041\\u030A\\u0064\\u0307\\u0327
46  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
47 2: \\u0041\\u030A\\u0064\\u0327\\u0307
48  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
49 3: \\u0041\\u030A\\u1E0B\\u0327
50  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
51 4: \\u0041\\u030A\\u1E11\\u0307
52  = {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
53 5: \\u00C5\\u0064\\u0307\\u0327
54  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
55 6: \\u00C5\\u0064\\u0327\\u0307
56  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
57 7: \\u00C5\\u1E0B\\u0327
58  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
59 8: \\u00C5\\u1E11\\u0307
60  = {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
61 9: \\u212B\\u0064\\u0307\\u0327
62  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
63 10: \\u212B\\u0064\\u0327\\u0307
64  = {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
65 11: \\u212B\\u1E0B\\u0327
66  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
67 12: \\u212B\\u1E11\\u0307
68  = {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
69  *<br>Note: the code is intended for use with small strings, and is not suitable for larger ones,
70  * since it has not been optimized for that situation.
71  * Note, CanonicalIterator is not intended to be subclassed.
72  * @author M. Davis
73  * @author C++ port by V. Weinstein
74  * @stable ICU 2.4
75  */
76 class U_COMMON_API CanonicalIterator final : public UObject {
77 public:
78     /**
79      * Construct a CanonicalIterator object
80      * @param source    string to get results for
81      * @param status    Fill-in parameter which receives the status of this operation.
82      * @stable ICU 2.4
83      */
84     CanonicalIterator(const UnicodeString &source, UErrorCode &status);
85 
86     /** Destructor
87      *  Cleans pieces
88      * @stable ICU 2.4
89      */
90     virtual ~CanonicalIterator();
91 
92     /**
93      * Gets the NFD form of the current source we are iterating over.
94      * @return gets the source: NOTE: it is the NFD form of source
95      * @stable ICU 2.4
96      */
97     UnicodeString getSource();
98 
99     /**
100      * Resets the iterator so that one can start again from the beginning.
101      * @stable ICU 2.4
102      */
103     void reset();
104 
105     /**
106      * Get the next canonically equivalent string.
107      * <br><b>Warning: The strings are not guaranteed to be in any particular order.</b>
108      * @return the next string that is canonically equivalent. A bogus string is returned when
109      * the iteration is done.
110      * @stable ICU 2.4
111      */
112     UnicodeString next();
113 
114     /**
115      * Set a new source for this iterator. Allows object reuse.
116      * @param newSource     the source string to iterate against. This allows the same iterator to be used
117      *                     while changing the source string, saving object creation.
118      * @param status        Fill-in parameter which receives the status of this operation.
119      * @stable ICU 2.4
120      */
121     void setSource(const UnicodeString &newSource, UErrorCode &status);
122 
123 #ifndef U_HIDE_INTERNAL_API
124     /**
125      * Dumb recursive implementation of permutation.
126      * TODO: optimize
127      * @param source     the string to find permutations for
128      * @param skipZeros  determine if skip zeros
129      * @param result     the results in a set.
130      * @param status       Fill-in parameter which receives the status of this operation.
131      * @param depth     depth of the call.
132      * @internal
133      */
134     static void U_EXPORT2 permute(UnicodeString &source, UBool skipZeros, Hashtable *result, UErrorCode &status, int32_t depth=0);
135 #endif  /* U_HIDE_INTERNAL_API */
136 
137     /**
138      * ICU "poor man's RTTI", returns a UClassID for this class.
139      *
140      * @stable ICU 2.2
141      */
142     static UClassID U_EXPORT2 getStaticClassID();
143 
144     /**
145      * ICU "poor man's RTTI", returns a UClassID for the actual class.
146      *
147      * @stable ICU 2.2
148      */
149     virtual UClassID getDynamicClassID() const override;
150 
151 private:
152     // ===================== PRIVATES ==============================
153     // private default constructor
154     CanonicalIterator() = delete;
155 
156 
157     /**
158      * Copy constructor. Private for now.
159      * @internal (private)
160      */
161     CanonicalIterator(const CanonicalIterator& other) = delete;
162 
163     /**
164      * Assignment operator. Private for now.
165      * @internal (private)
166      */
167     CanonicalIterator& operator=(const CanonicalIterator& other) = delete;
168 
169     // fields
170     UnicodeString source;
171     UBool done;
172 
173     // 2 dimensional array holds the pieces of the string with
174     // their different canonically equivalent representations
175     UnicodeString **pieces;
176     int32_t pieces_length;
177     int32_t *pieces_lengths;
178 
179     // current is used in iterating to combine pieces
180     int32_t *current;
181     int32_t current_length;
182 
183     // transient fields
184     UnicodeString buffer;
185 
186     const Normalizer2 *nfd;
187     const Normalizer2Impl *nfcImpl;
188 
189     // we have a segment, in NFD. Find all the strings that are canonically equivalent to it.
190     UnicodeString *getEquivalents(const UnicodeString &segment, int32_t &result_len, UErrorCode &status); //private String[] getEquivalents(String segment)
191 
192     //Set getEquivalents2(String segment);
193     Hashtable *getEquivalents2(Hashtable *fillinResult, const char16_t *segment, int32_t segLen, UErrorCode &status);
194     //Hashtable *getEquivalents2(const UnicodeString &segment, int32_t segLen, UErrorCode &status);
195 
196     /**
197      * See if the decomposition of cp2 is at segment starting at segmentPos
198      * (with canonical rearrangement!)
199      * If so, take the remainder, and return the equivalents
200      */
201     //Set extract(int comp, String segment, int segmentPos, StringBuffer buffer);
202     Hashtable *extract(Hashtable *fillinResult, UChar32 comp, const char16_t *segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);
203     //Hashtable *extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);
204 
205     void cleanPieces();
206 
207 };
208 
209 U_NAMESPACE_END
210 
211 #endif /* #if !UCONFIG_NO_NORMALIZATION */
212 
213 #endif /* U_SHOW_CPLUSPLUS_API */
214 
215 #endif
216