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1 /* GENERATED SOURCE. DO NOT MODIFY. */
2 // © 2016 and later: Unicode, Inc. and others.
3 // License & terms of use: http://www.unicode.org/copyright.html
4 /*
5  *******************************************************************************
6  * Copyright (C) 1996-2014, International Business Machines Corporation and    *
7  * others. All Rights Reserved.                                                *
8  *******************************************************************************
9  */
10 package android.icu.text;
11 
12 import java.util.Iterator;
13 
14 // Android patch: Make UnicodeSetIterator non-final.
15 /**
16  * UnicodeSetIterator iterates over the contents of a UnicodeSet.  It
17  * iterates over either code points or code point ranges.  After all
18  * code points or ranges have been returned, it returns the
19  * multicharacter strings of the UnicodeSet, if any.
20  *
21  * <p>This class is not intended for public subclassing.
22  *
23  * <p>To iterate over code points and multicharacter strings,
24  * use a loop like this:
25  * <pre>
26  * for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.next();) {
27  *   processString(it.getString());
28  * }
29  * </pre>
30  *
31  * <p>To iterate over code point ranges, use a loop like this:
32  * <pre>
33  * for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.nextRange();) {
34  *   if (it.codepoint != UnicodeSetIterator.IS_STRING) {
35  *     processCodepointRange(it.codepoint, it.codepointEnd);
36  *   } else {
37  *     processString(it.getString());
38  *   }
39  * }
40  * </pre>
41  *
42  * <p>To iterate over only the strings, start with <code>new UnicodeSetIterator(set).skipToStrings()</code>.
43  *
44  * <p><b>Warning: </b>For speed, UnicodeSet iteration does not check for concurrent modification.
45  * Do not alter the UnicodeSet while iterating.
46  * @author M. Davis
47  * @see UnicodeSet#ranges()
48  * @see UnicodeSet#strings()
49  * @see UnicodeSet#iterator()
50  */
51 public class UnicodeSetIterator {
52 
53     // Android patch: Make UnicodeSetIterator.IS_STRING non-final.
54     /**
55      * Value of <tt>codepoint</tt> if the iterator points to a string.
56      * If <tt>codepoint == IS_STRING</tt>, then examine
57      * <tt>string</tt> for the current iteration result.
58      */
59     public static int IS_STRING = -1;
60 
61     /**
62      * Current code point, or the special value <tt>IS_STRING</tt>, if
63      * the iterator points to a string.
64      */
65     public int codepoint;
66 
67     /**
68      * When iterating over ranges using <tt>nextRange()</tt>,
69      * <tt>codepointEnd</tt> contains the inclusive end of the
70      * iteration range, if <tt>codepoint != IS_STRING</tt>.  If
71      * iterating over code points using <tt>next()</tt>, or if
72      * <tt>codepoint == IS_STRING</tt>, then the value of
73      * <tt>codepointEnd</tt> is undefined.
74      */
75     public int codepointEnd;
76 
77     /**
78      * If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points
79      * to the current string.  If <tt>codepoint != IS_STRING</tt>, the
80      * value of <tt>string</tt> is undefined.
81      */
82     public String string;
83 
84     /**
85      * Create an iterator over the given set.
86      * @param set set to iterate over
87      */
UnicodeSetIterator(UnicodeSet set)88     public UnicodeSetIterator(UnicodeSet set) {
89         reset(set);
90     }
91 
92     /**
93      * Create an iterator over nothing.  <tt>next()</tt> and
94      * <tt>nextRange()</tt> return false. This is a convenience
95      * constructor allowing the target to be set later.
96      */
UnicodeSetIterator()97     public UnicodeSetIterator() {
98         reset(new UnicodeSet());
99     }
100 
101     /**
102      * Skips over the remaining code points/ranges, if any.
103      * A following call to next() or nextRange() will yield a string, if there is one.
104      * No-op if next() would return false, or if it would yield a string anyway.
105      *
106      * @return this
107      * @see UnicodeSet#strings()
108      */
skipToStrings()109     public UnicodeSetIterator skipToStrings() {
110         // Finish code point/range iteration.
111         range = endRange;
112         endElement = -1;
113         nextElement = 0;
114         return this;
115     }
116 
117     /**
118      * Returns the next element in the set, either a single code point
119      * or a string.  If there are no more elements in the set, return
120      * false.  If <tt>codepoint == IS_STRING</tt>, the value is a
121      * string in the <tt>string</tt> field.  Otherwise the value is a
122      * single code point in the <tt>codepoint</tt> field.
123      *
124      * <p>The order of iteration is all code points in sorted order,
125      * followed by all strings sorted order.  <tt>codepointEnd</tt> is
126      * undefined after calling this method.  <tt>string</tt> is
127      * undefined unless <tt>codepoint == IS_STRING</tt>.  Do not mix
128      * calls to <tt>next()</tt> and <tt>nextRange()</tt> without
129      * calling <tt>reset()</tt> between them.  The results of doing so
130      * are undefined.
131      * <p><b>Warning: </b>For speed, UnicodeSet iteration does not check for concurrent modification.
132      * Do not alter the UnicodeSet while iterating.
133      * @return true if there was another element in the set and this
134      * object contains the element.
135      */
next()136     public boolean next() {
137         if (nextElement <= endElement) {
138             codepoint = codepointEnd = nextElement++;
139             return true;
140         }
141         if (range < endRange) {
142             loadRange(++range);
143             codepoint = codepointEnd = nextElement++;
144             return true;
145         }
146 
147         // stringIterator == null iff there are no string elements remaining
148 
149         if (stringIterator == null) {
150             return false;
151         }
152         codepoint = IS_STRING; // signal that value is actually a string
153         string = stringIterator.next();
154         if (!stringIterator.hasNext()) {
155             stringIterator = null;
156         }
157         return true;
158     }
159 
160     /**
161      * Returns the next element in the set, either a code point range
162      * or a string.  If there are no more elements in the set, return
163      * false.  If <tt>codepoint == IS_STRING</tt>, the value is a
164      * string in the <tt>string</tt> field.  Otherwise the value is a
165      * range of one or more code points from <tt>codepoint</tt> to
166      * <tt>codepointeEnd</tt> inclusive.
167      *
168      * <p>The order of iteration is all code points ranges in sorted
169      * order, followed by all strings sorted order.  Ranges are
170      * disjoint and non-contiguous.  <tt>string</tt> is undefined
171      * unless <tt>codepoint == IS_STRING</tt>.  Do not mix calls to
172      * <tt>next()</tt> and <tt>nextRange()</tt> without calling
173      * <tt>reset()</tt> between them.  The results of doing so are
174      * undefined.
175      *
176      * @return true if there was another element in the set and this
177      * object contains the element.
178      */
nextRange()179     public boolean nextRange() {
180         if (nextElement <= endElement) {
181             codepointEnd = endElement;
182             codepoint = nextElement;
183             nextElement = endElement+1;
184             return true;
185         }
186         if (range < endRange) {
187             loadRange(++range);
188             codepointEnd = endElement;
189             codepoint = nextElement;
190             nextElement = endElement+1;
191             return true;
192         }
193 
194         // stringIterator == null iff there are no string elements remaining
195 
196         if (stringIterator == null) {
197             return false;
198         }
199         codepoint = IS_STRING; // signal that value is actually a string
200         string = stringIterator.next();
201         if (!stringIterator.hasNext()) {
202             stringIterator = null;
203         }
204         return true;
205     }
206 
207     /**
208      * Sets this iterator to visit the elements of the given set and
209      * resets it to the start of that set.  The iterator is valid only
210      * so long as <tt>set</tt> is valid.
211      * @param uset the set to iterate over.
212      */
reset(UnicodeSet uset)213     public void reset(UnicodeSet uset) {
214         set = uset;
215         reset();
216     }
217 
218     /**
219      * Resets this iterator to the start of the set.
220      */
reset()221     public void reset() {
222         endRange = set.getRangeCount() - 1;
223         range = 0;
224         endElement = -1;
225         nextElement = 0;
226         if (endRange >= 0) {
227             loadRange(range);
228         }
229         if (set.hasStrings()) {
230             stringIterator = set.strings.iterator();
231         } else {
232             stringIterator = null;
233         }
234     }
235 
236     /**
237      * Gets the current string from the iterator. Only use after calling next(), not nextRange().
238      */
getString()239     public String getString() {
240         if (codepoint != IS_STRING) {
241             return UTF16.valueOf(codepoint);
242         }
243         return string;
244     }
245 
246     // ======================= PRIVATES ===========================
247 
248     private UnicodeSet set;
249     private int endRange = 0;
250     private int range = 0;
251 
252     /**
253      * @hide original deprecated declaration
254      */
255     private int endElement;
256     /**
257      * @hide original deprecated declaration
258      */
259     private int nextElement;
260 
261     /**
262      * Invariant: stringIterator is null when there are no (more) strings remaining
263      */
264     private Iterator<String> stringIterator = null;
265 
266     /**
267      * @hide original deprecated declaration
268      */
loadRange(int aRange)269     private void loadRange(int aRange) {
270         nextElement = set.getRangeStart(aRange);
271         endElement = set.getRangeEnd(aRange);
272     }
273 }
274