/src/icu/source/common/unicode/usetiter.h
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1 | | // © 2016 and later: Unicode, Inc. and others. |
2 | | // License & terms of use: http://www.unicode.org/copyright.html |
3 | | /* |
4 | | ********************************************************************** |
5 | | * Copyright (c) 2002-2014, International Business Machines |
6 | | * Corporation and others. All Rights Reserved. |
7 | | ********************************************************************** |
8 | | */ |
9 | | #ifndef USETITER_H |
10 | | #define USETITER_H |
11 | | |
12 | | #include "unicode/utypes.h" |
13 | | |
14 | | #if U_SHOW_CPLUSPLUS_API |
15 | | |
16 | | #include "unicode/uobject.h" |
17 | | #include "unicode/unistr.h" |
18 | | |
19 | | /** |
20 | | * \file |
21 | | * \brief C++ API: UnicodeSetIterator iterates over the contents of a UnicodeSet. |
22 | | */ |
23 | | |
24 | | U_NAMESPACE_BEGIN |
25 | | |
26 | | class UnicodeSet; |
27 | | class UnicodeString; |
28 | | |
29 | | /** |
30 | | * |
31 | | * UnicodeSetIterator iterates over the contents of a UnicodeSet. It |
32 | | * iterates over either code points or code point ranges. After all |
33 | | * code points or ranges have been returned, it returns the |
34 | | * multicharacter strings of the UnicodeSet, if any. |
35 | | * |
36 | | * This class is not intended for public subclassing. |
37 | | * |
38 | | * <p>To iterate over code points and strings, use a loop like this: |
39 | | * <pre> |
40 | | * UnicodeSetIterator it(set); |
41 | | * while (it.next()) { |
42 | | * processItem(it.getString()); |
43 | | * } |
44 | | * </pre> |
45 | | * <p>Each item in the set is accessed as a string. Set elements |
46 | | * consisting of single code points are returned as strings containing |
47 | | * just the one code point. |
48 | | * |
49 | | * <p>To iterate over code point ranges, instead of individual code points, |
50 | | * use a loop like this: |
51 | | * <pre> |
52 | | * UnicodeSetIterator it(set); |
53 | | * while (it.nextRange()) { |
54 | | * if (it.isString()) { |
55 | | * processString(it.getString()); |
56 | | * } else { |
57 | | * processCodepointRange(it.getCodepoint(), it.getCodepointEnd()); |
58 | | * } |
59 | | * } |
60 | | * </pre> |
61 | | * |
62 | | * To iterate over only the strings, start with <code>skipToStrings()</code>. |
63 | | * |
64 | | * @author M. Davis |
65 | | * @stable ICU 2.4 |
66 | | */ |
67 | | class U_COMMON_API UnicodeSetIterator U_FINAL : public UObject { |
68 | | /** |
69 | | * Value of <tt>codepoint</tt> if the iterator points to a string. |
70 | | * If <tt>codepoint == IS_STRING</tt>, then examine |
71 | | * <tt>string</tt> for the current iteration result. |
72 | | */ |
73 | | enum { IS_STRING = -1 }; |
74 | | |
75 | | /** |
76 | | * Current code point, or the special value <tt>IS_STRING</tt>, if |
77 | | * the iterator points to a string. |
78 | | */ |
79 | | UChar32 codepoint; |
80 | | |
81 | | /** |
82 | | * When iterating over ranges using <tt>nextRange()</tt>, |
83 | | * <tt>codepointEnd</tt> contains the inclusive end of the |
84 | | * iteration range, if <tt>codepoint != IS_STRING</tt>. If |
85 | | * iterating over code points using <tt>next()</tt>, or if |
86 | | * <tt>codepoint == IS_STRING</tt>, then the value of |
87 | | * <tt>codepointEnd</tt> is undefined. |
88 | | */ |
89 | | UChar32 codepointEnd; |
90 | | |
91 | | /** |
92 | | * If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points |
93 | | * to the current string. If <tt>codepoint != IS_STRING</tt>, the |
94 | | * value of <tt>string</tt> is undefined. |
95 | | */ |
96 | | const UnicodeString* string; |
97 | | |
98 | | public: |
99 | | |
100 | | /** |
101 | | * Create an iterator over the given set. The iterator is valid |
102 | | * only so long as <tt>set</tt> is valid. |
103 | | * @param set set to iterate over |
104 | | * @stable ICU 2.4 |
105 | | */ |
106 | | UnicodeSetIterator(const UnicodeSet& set); |
107 | | |
108 | | /** |
109 | | * Create an iterator over nothing. <tt>next()</tt> and |
110 | | * <tt>nextRange()</tt> return false. This is a convenience |
111 | | * constructor allowing the target to be set later. |
112 | | * @stable ICU 2.4 |
113 | | */ |
114 | | UnicodeSetIterator(); |
115 | | |
116 | | /** |
117 | | * Destructor. |
118 | | * @stable ICU 2.4 |
119 | | */ |
120 | | virtual ~UnicodeSetIterator(); |
121 | | |
122 | | /** |
123 | | * Returns true if the current element is a string. If so, the |
124 | | * caller can retrieve it with <tt>getString()</tt>. If this |
125 | | * method returns false, the current element is a code point or |
126 | | * code point range, depending on whether <tt>next()</tt> or |
127 | | * <tt>nextRange()</tt> was called. |
128 | | * Elements of types string and codepoint can both be retrieved |
129 | | * with the function <tt>getString()</tt>. |
130 | | * Elements of type codepoint can also be retrieved with |
131 | | * <tt>getCodepoint()</tt>. |
132 | | * For ranges, <tt>getCodepoint()</tt> returns the starting codepoint |
133 | | * of the range, and <tt>getCodepointEnd()</tt> returns the end |
134 | | * of the range. |
135 | | * @stable ICU 2.4 |
136 | | */ |
137 | | inline UBool isString() const; |
138 | | |
139 | | /** |
140 | | * Returns the current code point, if <tt>isString()</tt> returned |
141 | | * false. Otherwise returns an undefined result. |
142 | | * @stable ICU 2.4 |
143 | | */ |
144 | | inline UChar32 getCodepoint() const; |
145 | | |
146 | | /** |
147 | | * Returns the end of the current code point range, if |
148 | | * <tt>isString()</tt> returned false and <tt>nextRange()</tt> was |
149 | | * called. Otherwise returns an undefined result. |
150 | | * @stable ICU 2.4 |
151 | | */ |
152 | | inline UChar32 getCodepointEnd() const; |
153 | | |
154 | | /** |
155 | | * Returns the current string, if <tt>isString()</tt> returned |
156 | | * true. If the current iteration item is a code point, a UnicodeString |
157 | | * containing that single code point is returned. |
158 | | * |
159 | | * Ownership of the returned string remains with the iterator. |
160 | | * The string is guaranteed to remain valid only until the iterator is |
161 | | * advanced to the next item, or until the iterator is deleted. |
162 | | * |
163 | | * @stable ICU 2.4 |
164 | | */ |
165 | | const UnicodeString& getString(); |
166 | | |
167 | | #ifndef U_HIDE_DRAFT_API |
168 | | /** |
169 | | * Skips over the remaining code points/ranges, if any. |
170 | | * A following call to next() or nextRange() will yield a string, if there is one. |
171 | | * No-op if next() would return false, or if it would yield a string anyway. |
172 | | * |
173 | | * @return *this |
174 | | * @draft ICU 70 |
175 | | * @see UnicodeSet#strings() |
176 | | */ |
177 | 0 | inline UnicodeSetIterator &skipToStrings() { |
178 | 0 | // Finish code point/range iteration. |
179 | 0 | range = endRange; |
180 | 0 | endElement = -1; |
181 | 0 | nextElement = 0; |
182 | 0 | return *this; |
183 | 0 | } |
184 | | #endif // U_HIDE_DRAFT_API |
185 | | |
186 | | /** |
187 | | * Advances the iteration position to the next element in the set, |
188 | | * which can be either a single code point or a string. |
189 | | * If there are no more elements in the set, return false. |
190 | | * |
191 | | * <p> |
192 | | * If <tt>isString() == true</tt>, the value is a |
193 | | * string, otherwise the value is a |
194 | | * single code point. Elements of either type can be retrieved |
195 | | * with the function <tt>getString()</tt>, while elements of |
196 | | * consisting of a single code point can be retrieved with |
197 | | * <tt>getCodepoint()</tt> |
198 | | * |
199 | | * <p>The order of iteration is all code points in sorted order, |
200 | | * followed by all strings sorted order. Do not mix |
201 | | * calls to <tt>next()</tt> and <tt>nextRange()</tt> without |
202 | | * calling <tt>reset()</tt> between them. The results of doing so |
203 | | * are undefined. |
204 | | * |
205 | | * @return true if there was another element in the set. |
206 | | * @stable ICU 2.4 |
207 | | */ |
208 | | UBool next(); |
209 | | |
210 | | /** |
211 | | * Returns the next element in the set, either a code point range |
212 | | * or a string. If there are no more elements in the set, return |
213 | | * false. If <tt>isString() == true</tt>, the value is a |
214 | | * string and can be accessed with <tt>getString()</tt>. Otherwise the value is a |
215 | | * range of one or more code points from <tt>getCodepoint()</tt> to |
216 | | * <tt>getCodepointeEnd()</tt> inclusive. |
217 | | * |
218 | | * <p>The order of iteration is all code points ranges in sorted |
219 | | * order, followed by all strings sorted order. Ranges are |
220 | | * disjoint and non-contiguous. The value returned from <tt>getString()</tt> |
221 | | * is undefined unless <tt>isString() == true</tt>. Do not mix calls to |
222 | | * <tt>next()</tt> and <tt>nextRange()</tt> without calling |
223 | | * <tt>reset()</tt> between them. The results of doing so are |
224 | | * undefined. |
225 | | * |
226 | | * @return true if there was another element in the set. |
227 | | * @stable ICU 2.4 |
228 | | */ |
229 | | UBool nextRange(); |
230 | | |
231 | | /** |
232 | | * Sets this iterator to visit the elements of the given set and |
233 | | * resets it to the start of that set. The iterator is valid only |
234 | | * so long as <tt>set</tt> is valid. |
235 | | * @param set the set to iterate over. |
236 | | * @stable ICU 2.4 |
237 | | */ |
238 | | void reset(const UnicodeSet& set); |
239 | | |
240 | | /** |
241 | | * Resets this iterator to the start of the set. |
242 | | * @stable ICU 2.4 |
243 | | */ |
244 | | void reset(); |
245 | | |
246 | | /** |
247 | | * ICU "poor man's RTTI", returns a UClassID for this class. |
248 | | * |
249 | | * @stable ICU 2.4 |
250 | | */ |
251 | | static UClassID U_EXPORT2 getStaticClassID(); |
252 | | |
253 | | /** |
254 | | * ICU "poor man's RTTI", returns a UClassID for the actual class. |
255 | | * |
256 | | * @stable ICU 2.4 |
257 | | */ |
258 | | virtual UClassID getDynamicClassID() const; |
259 | | |
260 | | // ======================= PRIVATES =========================== |
261 | | |
262 | | private: |
263 | | |
264 | | // endElement and nextElements are really UChar32's, but we keep |
265 | | // them as signed int32_t's so we can do comparisons with |
266 | | // endElement set to -1. Leave them as int32_t's. |
267 | | /** The set |
268 | | */ |
269 | | const UnicodeSet* set; |
270 | | /** End range |
271 | | */ |
272 | | int32_t endRange; |
273 | | /** Range |
274 | | */ |
275 | | int32_t range; |
276 | | /** End element |
277 | | */ |
278 | | int32_t endElement; |
279 | | /** Next element |
280 | | */ |
281 | | int32_t nextElement; |
282 | | /** Next string |
283 | | */ |
284 | | int32_t nextString; |
285 | | /** String count |
286 | | */ |
287 | | int32_t stringCount; |
288 | | |
289 | | /** |
290 | | * Points to the string to use when the caller asks for a |
291 | | * string and the current iteration item is a code point, not a string. |
292 | | */ |
293 | | UnicodeString *cpString; |
294 | | |
295 | | /** Copy constructor. Disallowed. |
296 | | */ |
297 | | UnicodeSetIterator(const UnicodeSetIterator&) = delete; |
298 | | |
299 | | /** Assignment operator. Disallowed. |
300 | | */ |
301 | | UnicodeSetIterator& operator=(const UnicodeSetIterator&) = delete; |
302 | | |
303 | | /** Load range |
304 | | */ |
305 | | void loadRange(int32_t range); |
306 | | }; |
307 | | |
308 | 0 | inline UBool UnicodeSetIterator::isString() const { |
309 | 0 | return codepoint < 0; |
310 | 0 | } |
311 | | |
312 | 0 | inline UChar32 UnicodeSetIterator::getCodepoint() const { |
313 | 0 | return codepoint; |
314 | 0 | } |
315 | | |
316 | 0 | inline UChar32 UnicodeSetIterator::getCodepointEnd() const { |
317 | 0 | return codepointEnd; |
318 | 0 | } |
319 | | |
320 | | |
321 | | U_NAMESPACE_END |
322 | | |
323 | | #endif /* U_SHOW_CPLUSPLUS_API */ |
324 | | |
325 | | #endif |