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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) 1996-2016, International Business Machines Corporation and
6  * others. All Rights Reserved.
7  *******************************************************************************
8  */
9 package com.ibm.icu.text;
10 
11 import java.io.IOException;
12 import java.text.ParsePosition;
13 import java.util.ArrayList;
14 import java.util.Arrays;
15 import java.util.Collection;
16 import java.util.Collections;
17 import java.util.Iterator;
18 import java.util.NoSuchElementException;
19 import java.util.SortedSet;
20 import java.util.TreeSet;
21 
22 import com.ibm.icu.impl.BMPSet;
23 import com.ibm.icu.impl.CharacterPropertiesImpl;
24 import com.ibm.icu.impl.PatternProps;
25 import com.ibm.icu.impl.RuleCharacterIterator;
26 import com.ibm.icu.impl.SortedSetRelation;
27 import com.ibm.icu.impl.StringRange;
28 import com.ibm.icu.impl.UCaseProps;
29 import com.ibm.icu.impl.UCharacterProperty;
30 import com.ibm.icu.impl.UPropertyAliases;
31 import com.ibm.icu.impl.UnicodeSetStringSpan;
32 import com.ibm.icu.impl.Utility;
33 import com.ibm.icu.lang.CharSequences;
34 import com.ibm.icu.lang.CharacterProperties;
35 import com.ibm.icu.lang.UCharacter;
36 import com.ibm.icu.lang.UProperty;
37 import com.ibm.icu.lang.UScript;
38 import com.ibm.icu.util.Freezable;
39 import com.ibm.icu.util.ICUUncheckedIOException;
40 import com.ibm.icu.util.OutputInt;
41 import com.ibm.icu.util.ULocale;
42 import com.ibm.icu.util.VersionInfo;
43 
44 /**
45  * A mutable set of Unicode characters and multicharacter strings.
46  * Objects of this class represent <em>character classes</em> used
47  * in regular expressions. A character specifies a subset of Unicode
48  * code points.  Legal code points are U+0000 to U+10FFFF, inclusive.
49  *
50  * Note: method freeze() will not only make the set immutable, but
51  * also makes important methods much higher performance:
52  * contains(c), containsNone(...), span(...), spanBack(...) etc.
53  * After the object is frozen, any subsequent call that wants to change
54  * the object will throw UnsupportedOperationException.
55  *
56  * <p>The UnicodeSet class is not designed to be subclassed.
57  *
58  * <p><code>UnicodeSet</code> supports two APIs. The first is the
59  * <em>operand</em> API that allows the caller to modify the value of
60  * a <code>UnicodeSet</code> object. It conforms to Java 2's
61  * <code>java.util.Set</code> interface, although
62  * <code>UnicodeSet</code> does not actually implement that
63  * interface. All methods of <code>Set</code> are supported, with the
64  * modification that they take a character range or single character
65  * instead of an <code>Object</code>, and they take a
66  * <code>UnicodeSet</code> instead of a <code>Collection</code>.  The
67  * operand API may be thought of in terms of boolean logic: a boolean
68  * OR is implemented by <code>add</code>, a boolean AND is implemented
69  * by <code>retain</code>, a boolean XOR is implemented by
70  * <code>complement</code> taking an argument, and a boolean NOT is
71  * implemented by <code>complement</code> with no argument.  In terms
72  * of traditional set theory function names, <code>add</code> is a
73  * union, <code>retain</code> is an intersection, <code>remove</code>
74  * is an asymmetric difference, and <code>complement</code> with no
75  * argument is a set complement with respect to the superset range
76  * <code>MIN_VALUE-MAX_VALUE</code>
77  *
78  * <p>The second API is the
79  * <code>applyPattern()</code>/<code>toPattern()</code> API from the
80  * <code>java.text.Format</code>-derived classes.  Unlike the
81  * methods that add characters, add categories, and control the logic
82  * of the set, the method <code>applyPattern()</code> sets all
83  * attributes of a <code>UnicodeSet</code> at once, based on a
84  * string pattern.
85  *
86  * <p><b>Pattern syntax</b></p>
87  *
88  * Patterns are accepted by the constructors and the
89  * <code>applyPattern()</code> methods and returned by the
90  * <code>toPattern()</code> method.  These patterns follow a syntax
91  * similar to that employed by version 8 regular expression character
92  * classes.  Here are some simple examples:
93  *
94  * <blockquote>
95  *   <table>
96  *     <tr style="vertical-align: top">
97  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[]</code></td>
98  *       <td style="vertical-align: top;">No characters</td>
99  *     </tr><tr style="vertical-align: top">
100  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[a]</code></td>
101  *       <td style="vertical-align: top;">The character 'a'</td>
102  *     </tr><tr style="vertical-align: top">
103  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[ae]</code></td>
104  *       <td style="vertical-align: top;">The characters 'a' and 'e'</td>
105  *     </tr>
106  *     <tr>
107  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[a-e]</code></td>
108  *       <td style="vertical-align: top;">The characters 'a' through 'e' inclusive, in Unicode code
109  *       point order</td>
110  *     </tr>
111  *     <tr>
112  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[\\u4E01]</code></td>
113  *       <td style="vertical-align: top;">The character U+4E01</td>
114  *     </tr>
115  *     <tr>
116  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[a{ab}{ac}]</code></td>
117  *       <td style="vertical-align: top;">The character 'a' and the multicharacter strings &quot;ab&quot; and
118  *       &quot;ac&quot;</td>
119  *     </tr>
120  *     <tr>
121  *       <td style="white-space: nowrap; vertical-align: top; horizontal-align: left;"><code>[\p{Lu}]</code></td>
122  *       <td style="vertical-align: top;">All characters in the general category Uppercase Letter</td>
123  *     </tr>
124  *   </table>
125  * </blockquote>
126  *
127  * Any character may be preceded by a backslash in order to remove any special
128  * meaning.  White space characters, as defined by the Unicode Pattern_White_Space property, are
129  * ignored, unless they are escaped.
130  *
131  * <p>Property patterns specify a set of characters having a certain
132  * property as defined by the Unicode standard.  Both the POSIX-like
133  * "[:Lu:]" and the Perl-like syntax "\p{Lu}" are recognized.  For a
134  * complete list of supported property patterns, see the User's Guide
135  * for UnicodeSet at
136  * <a href="https://unicode-org.github.io/icu/userguide/strings/unicodeset">
137  * https://unicode-org.github.io/icu/userguide/strings/unicodeset</a>.
138  * Actual determination of property data is defined by the underlying
139  * Unicode database as implemented by UCharacter.
140  *
141  * <p>Patterns specify individual characters, ranges of characters, and
142  * Unicode property sets.  When elements are concatenated, they
143  * specify their union.  To complement a set, place a '^' immediately
144  * after the opening '['.  Property patterns are inverted by modifying
145  * their delimiters; "[:^foo]" and "\P{foo}".  In any other location,
146  * '^' has no special meaning.
147  *
148  * <p>Since ICU 70, "[^...]", "[:^foo]", "\P{foo}", and "[:binaryProperty=No:]"
149  * perform a “code point complement” (all code points minus the original set),
150  * removing all multicharacter strings,
151  * equivalent to .{@link #complement()}.{@link #removeAllStrings()} .
152  * The {@link #complement()} API function continues to perform a
153  * symmetric difference with all code points and thus retains all multicharacter strings.
154  *
155  * <p>Ranges are indicated by placing two a '-' between two
156  * characters, as in "a-z".  This specifies the range of all
157  * characters from the left to the right, in Unicode order.  If the
158  * left character is greater than or equal to the
159  * right character it is a syntax error.  If a '-' occurs as the first
160  * character after the opening '[' or '[^', or if it occurs as the
161  * last character before the closing ']', then it is taken as a
162  * literal.  Thus "[a\\-b]", "[-ab]", and "[ab-]" all indicate the same
163  * set of three characters, 'a', 'b', and '-'.
164  *
165  * <p>Sets may be intersected using the '&amp;' operator or the asymmetric
166  * set difference may be taken using the '-' operator, for example,
167  * "[[:L:]&amp;[\\u0000-\\u0FFF]]" indicates the set of all Unicode letters
168  * with values less than 4096.  Operators ('&amp;' and '|') have equal
169  * precedence and bind left-to-right.  Thus
170  * "[[:L:]-[a-z]-[\\u0100-\\u01FF]]" is equivalent to
171  * "[[[:L:]-[a-z]]-[\\u0100-\\u01FF]]".  This only really matters for
172  * difference; intersection is commutative.
173  *
174  * <table>
175  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[a]</code><td>The set containing 'a'
176  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[a-z]</code><td>The set containing 'a'
177  * through 'z' and all letters in between, in Unicode order
178  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[^a-z]</code><td>The set containing
179  * all characters but 'a' through 'z',
180  * that is, U+0000 through 'a'-1 and 'z'+1 through U+10FFFF
181  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[[<em>pat1</em>][<em>pat2</em>]]</code>
182  * <td>The union of sets specified by <em>pat1</em> and <em>pat2</em>
183  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[[<em>pat1</em>]&amp;[<em>pat2</em>]]</code>
184  * <td>The intersection of sets specified by <em>pat1</em> and <em>pat2</em>
185  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[[<em>pat1</em>]-[<em>pat2</em>]]</code>
186  * <td>The asymmetric difference of sets specified by <em>pat1</em> and
187  * <em>pat2</em>
188  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[:Lu:] or \p{Lu}</code>
189  * <td>The set of characters having the specified
190  * Unicode property; in
191  * this case, Unicode uppercase letters
192  * <tr style="vertical-align: top;"><td style="white-space: nowrap;"><code>[:^Lu:] or \P{Lu}</code>
193  * <td>The set of characters <em>not</em> having the given
194  * Unicode property
195  * </table>
196  *
197  * <p><b>Formal syntax</b></p>
198  *
199  * <blockquote>
200  *   <table>
201  *     <tr style="vertical-align: top">
202  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>pattern :=&nbsp; </code></td>
203  *       <td style="vertical-align: top;"><code>('[' '^'? item* ']') |
204  *       property</code></td>
205  *     </tr>
206  *     <tr style="vertical-align: top">
207  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>item :=&nbsp; </code></td>
208  *       <td style="vertical-align: top;"><code>char | (char '-' char) | pattern-expr<br>
209  *       </code></td>
210  *     </tr>
211  *     <tr style="vertical-align: top">
212  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>pattern-expr :=&nbsp; </code></td>
213  *       <td style="vertical-align: top;"><code>pattern | pattern-expr pattern |
214  *       pattern-expr op pattern<br>
215  *       </code></td>
216  *     </tr>
217  *     <tr style="vertical-align: top">
218  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>op :=&nbsp; </code></td>
219  *       <td style="vertical-align: top;"><code>'&amp;' | '-'<br>
220  *       </code></td>
221  *     </tr>
222  *     <tr style="vertical-align: top">
223  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>special :=&nbsp; </code></td>
224  *       <td style="vertical-align: top;"><code>'[' | ']' | '-'<br>
225  *       </code></td>
226  *     </tr>
227  *     <tr style="vertical-align: top">
228  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>char :=&nbsp; </code></td>
229  *       <td style="vertical-align: top;"><em>any character that is not</em><code> special<br>
230  *       | ('\\' </code><em>any character</em><code>)<br>
231  *       | ('&#92;u' hex hex hex hex)<br>
232  *       </code></td>
233  *     </tr>
234  *     <tr style="vertical-align: top">
235  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>hex :=&nbsp; </code></td>
236  *       <td style="vertical-align: top;"><code>'0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' |<br>
237  *       &nbsp;&nbsp;&nbsp;&nbsp;'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'a' | 'b' | 'c' | 'd' | 'e' | 'f'</code></td>
238  *     </tr>
239  *     <tr>
240  *       <td style="white-space: nowrap; vertical-align: top;" align="right"><code>property :=&nbsp; </code></td>
241  *       <td style="vertical-align: top;"><em>a Unicode property set pattern</em></td>
242  *     </tr>
243  *   </table>
244  *   <br>
245  *   <table border="1">
246  *     <tr>
247  *       <td>Legend: <table>
248  *         <tr>
249  *           <td style="white-space: nowrap; vertical-align: top;"><code>a := b</code></td>
250  *           <td style="width: 20; vertical-align: top;">&nbsp; </td>
251  *           <td style="vertical-align: top;"><code>a</code> may be replaced by <code>b</code> </td>
252  *         </tr>
253  *         <tr>
254  *           <td style="white-space: nowrap; vertical-align: top;"><code>a?</code></td>
255  *           <td style="vertical-align: top;"></td>
256  *           <td style="vertical-align: top;">zero or one instance of <code>a</code><br>
257  *           </td>
258  *         </tr>
259  *         <tr>
260  *           <td style="white-space: nowrap; vertical-align: top;"><code>a*</code></td>
261  *           <td style="vertical-align: top;"></td>
262  *           <td style="vertical-align: top;">one or more instances of <code>a</code><br>
263  *           </td>
264  *         </tr>
265  *         <tr>
266  *           <td style="white-space: nowrap; vertical-align: top;"><code>a | b</code></td>
267  *           <td style="vertical-align: top;"></td>
268  *           <td style="vertical-align: top;">either <code>a</code> or <code>b</code><br>
269  *           </td>
270  *         </tr>
271  *         <tr>
272  *           <td style="white-space: nowrap; vertical-align: top;"><code>'a'</code></td>
273  *           <td style="vertical-align: top;"></td>
274  *           <td style="vertical-align: top;">the literal string between the quotes </td>
275  *         </tr>
276  *       </table>
277  *       </td>
278  *     </tr>
279  *   </table>
280  * </blockquote>
281  * <p>To iterate over contents of UnicodeSet, the following are available:
282  * <ul><li>{@link #ranges()} to iterate through the ranges</li>
283  * <li>{@link #strings()} to iterate through the strings</li>
284  * <li>{@link #iterator()} to iterate through the entire contents in a single loop.
285  * That method is, however, not particularly efficient, since it "boxes" each code point into a String.
286  * </ul>
287  * All of the above can be used in <b>for</b> loops.
288  * The {@link com.ibm.icu.text.UnicodeSetIterator UnicodeSetIterator} can also be used, but not in <b>for</b> loops.
289  * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
290  *
291  * @author Alan Liu
292  * @stable ICU 2.0
293  * @see UnicodeSetIterator
294  * @see UnicodeSetSpanner
295  */
296 public class UnicodeSet extends UnicodeFilter implements Iterable<String>, Comparable<UnicodeSet>, Freezable<UnicodeSet> {
297     private static final SortedSet<String> EMPTY_STRINGS =
298             Collections.unmodifiableSortedSet(new TreeSet<String>());
299 
300     /**
301      * Constant for the empty set.
302      * @stable ICU 4.8
303      */
304     public static final UnicodeSet EMPTY = new UnicodeSet().freeze();
305     /**
306      * Constant for the set of all code points. (Since UnicodeSets can include strings, does not include everything that a UnicodeSet can.)
307      * @stable ICU 4.8
308      */
309     public static final UnicodeSet ALL_CODE_POINTS = new UnicodeSet(0, 0x10FFFF).freeze();
310 
311     private static XSymbolTable XSYMBOL_TABLE = null; // for overriding the the function processing
312 
313     private static final int LOW = 0x000000; // LOW <= all valid values. ZERO for codepoints
314     private static final int HIGH = 0x110000; // HIGH > all valid values. 10000 for code units.
315     // 110000 for codepoints
316 
317     /**
318      * Enough for sets with few ranges.
319      * For example, White_Space has 10 ranges, list length 21.
320      */
321     private static final int INITIAL_CAPACITY = 25;
322 
323     /** Max list [0, 1, 2, ..., max code point, HIGH] */
324     private static final int MAX_LENGTH = HIGH + 1;
325 
326     /**
327      * Minimum value that can be stored in a UnicodeSet.
328      * @stable ICU 2.0
329      */
330     public static final int MIN_VALUE = LOW;
331 
332     /**
333      * Maximum value that can be stored in a UnicodeSet.
334      * @stable ICU 2.0
335      */
336     public static final int MAX_VALUE = HIGH - 1;
337 
338     private int len;      // length used; list may be longer to minimize reallocs
339     private int[] list;   // MUST be terminated with HIGH
340     private int[] rangeList; // internal buffer
341     private int[] buffer; // internal buffer
342 
343     // is not private so that UnicodeSetIterator can get access
344     SortedSet<String> strings = EMPTY_STRINGS;
345 
346     /**
347      * The pattern representation of this set.  This may not be the
348      * most economical pattern.  It is the pattern supplied to
349      * applyPattern(), with variables substituted and whitespace
350      * removed.  For sets constructed without applyPattern(), or
351      * modified using the non-pattern API, this string will be null,
352      * indicating that toPattern() must generate a pattern
353      * representation from the inversion list.
354      */
355     private String pat = null;
356 
357     // Special property set IDs
358     private static final String ANY_ID   = "ANY";   // [\u0000-\U0010FFFF]
359     private static final String ASCII_ID = "ASCII"; // [\u0000-\u007F]
360     private static final String ASSIGNED = "Assigned"; // [:^Cn:]
361 
362     private volatile BMPSet bmpSet; // The set is frozen if bmpSet or stringSpan is not null.
363     private volatile UnicodeSetStringSpan stringSpan;
364     //----------------------------------------------------------------
365     // Public API
366     //----------------------------------------------------------------
367 
368     /**
369      * Constructs an empty set.
370      * @stable ICU 2.0
371      */
UnicodeSet()372     public UnicodeSet() {
373         list = new int[INITIAL_CAPACITY];
374         list[0] = HIGH;
375         len = 1;
376     }
377 
378     /**
379      * Constructs a copy of an existing set.
380      * @stable ICU 2.0
381      */
UnicodeSet(UnicodeSet other)382     public UnicodeSet(UnicodeSet other) {
383         set(other);
384     }
385 
386     /**
387      * Constructs a set containing the given range. If <code>end &gt;
388      * start</code> then an empty set is created.
389      *
390      * @param start first character, inclusive, of range
391      * @param end last character, inclusive, of range
392      * @stable ICU 2.0
393      */
UnicodeSet(int start, int end)394     public UnicodeSet(int start, int end) {
395         this();
396         add(start, end);
397     }
398 
399     /**
400      * Quickly constructs a set from a set of ranges &lt;s0, e0, s1, e1, s2, e2, ..., sn, en&gt;.
401      * There must be an even number of integers, and they must be all greater than zero,
402      * all less than or equal to Character.MAX_CODE_POINT.
403      * In each pair (..., si, ei, ...) it must be true that si &lt;= ei
404      * Between adjacent pairs (...ei, sj...), it must be true that ei+1 &lt; sj
405      * @param pairs pairs of character representing ranges
406      * @stable ICU 4.4
407      */
UnicodeSet(int... pairs)408     public UnicodeSet(int... pairs) {
409         if ((pairs.length & 1) != 0) {
410             throw new IllegalArgumentException("Must have even number of integers");
411         }
412         list = new int[pairs.length + 1]; // don't allocate extra space, because it is likely that this is a fixed set.
413         len = list.length;
414         int last = -1; // used to ensure that the results are monotonically increasing.
415         int i = 0;
416         while (i < pairs.length) {
417             int start = pairs[i];
418             if (last >= start) {
419                 throw new IllegalArgumentException("Must be monotonically increasing.");
420             }
421             list[i++] = start;
422             int limit = pairs[i] + 1;
423             if (start >= limit) {
424                 throw new IllegalArgumentException("Must be monotonically increasing.");
425             }
426             list[i++] = last = limit;
427         }
428         list[i] = HIGH; // terminate
429     }
430 
431     /**
432      * Constructs a set from the given pattern.  See the class description
433      * for the syntax of the pattern language.  Whitespace is ignored.
434      * @param pattern a string specifying what characters are in the set
435      * @exception java.lang.IllegalArgumentException if the pattern contains
436      * a syntax error.
437      * @stable ICU 2.0
438      */
UnicodeSet(String pattern)439     public UnicodeSet(String pattern) {
440         this();
441         applyPattern(pattern, null, null, IGNORE_SPACE);
442     }
443 
444     /**
445      * Constructs a set from the given pattern.  See the class description
446      * for the syntax of the pattern language.
447      * @param pattern a string specifying what characters are in the set
448      * @param ignoreWhitespace if true, ignore Unicode Pattern_White_Space characters
449      * @exception java.lang.IllegalArgumentException if the pattern contains
450      * a syntax error.
451      * @stable ICU 2.0
452      */
UnicodeSet(String pattern, boolean ignoreWhitespace)453     public UnicodeSet(String pattern, boolean ignoreWhitespace) {
454         this();
455         applyPattern(pattern, null, null, ignoreWhitespace ? IGNORE_SPACE : 0);
456     }
457 
458     /**
459      * Constructs a set from the given pattern.  See the class description
460      * for the syntax of the pattern language.
461      * @param pattern a string specifying what characters are in the set
462      * @param options a bitmask indicating which options to apply.
463      * Valid options are {@link #IGNORE_SPACE} and
464      * at most one of {@link #CASE_INSENSITIVE}, {@link #ADD_CASE_MAPPINGS},
465      * {@link #SIMPLE_CASE_INSENSITIVE}. These case options are mutually exclusive.
466      * @exception java.lang.IllegalArgumentException if the pattern contains
467      * a syntax error.
468      * @stable ICU 3.8
469      */
UnicodeSet(String pattern, int options)470     public UnicodeSet(String pattern, int options) {
471         this();
472         applyPattern(pattern, null, null, options);
473     }
474 
475     /**
476      * Constructs a set from the given pattern.  See the class description
477      * for the syntax of the pattern language.
478      * @param pattern a string specifying what characters are in the set
479      * @param pos on input, the position in pattern at which to start parsing.
480      * On output, the position after the last character parsed.
481      * @param symbols a symbol table mapping variables to char[] arrays
482      * and chars to UnicodeSets
483      * @exception java.lang.IllegalArgumentException if the pattern
484      * contains a syntax error.
485      * @stable ICU 2.0
486      */
UnicodeSet(String pattern, ParsePosition pos, SymbolTable symbols)487     public UnicodeSet(String pattern, ParsePosition pos, SymbolTable symbols) {
488         this();
489         applyPattern(pattern, pos, symbols, IGNORE_SPACE);
490     }
491 
492     /**
493      * Constructs a set from the given pattern.  See the class description
494      * for the syntax of the pattern language.
495      * @param pattern a string specifying what characters are in the set
496      * @param pos on input, the position in pattern at which to start parsing.
497      * On output, the position after the last character parsed.
498      * @param symbols a symbol table mapping variables to char[] arrays
499      * and chars to UnicodeSets
500      * @param options a bitmask indicating which options to apply.
501      * Valid options are {@link #IGNORE_SPACE} and
502      * at most one of {@link #CASE_INSENSITIVE}, {@link #ADD_CASE_MAPPINGS},
503      * {@link #SIMPLE_CASE_INSENSITIVE}. These case options are mutually exclusive.
504      * @exception java.lang.IllegalArgumentException if the pattern
505      * contains a syntax error.
506      * @stable ICU 3.2
507      */
UnicodeSet(String pattern, ParsePosition pos, SymbolTable symbols, int options)508     public UnicodeSet(String pattern, ParsePosition pos, SymbolTable symbols, int options) {
509         this();
510         applyPattern(pattern, pos, symbols, options);
511     }
512 
513 
514     /**
515      * Return a new set that is equivalent to this one.
516      * @stable ICU 2.0
517      */
518     @Override
clone()519     public Object clone() {
520         if (isFrozen()) {
521             return this;
522         }
523         return new UnicodeSet(this);
524     }
525 
526     /**
527      * Make this object represent the range <code>start - end</code>.
528      * If <code>start &gt; end</code> then this object is set to an empty range.
529      *
530      * @param start first character in the set, inclusive
531      * @param end last character in the set, inclusive
532      * @stable ICU 2.0
533      */
set(int start, int end)534     public UnicodeSet set(int start, int end) {
535         checkFrozen();
536         clear();
537         complement(start, end);
538         return this;
539     }
540 
541     /**
542      * Make this object represent the same set as <code>other</code>.
543      * @param other a <code>UnicodeSet</code> whose value will be
544      * copied to this object
545      * @stable ICU 2.0
546      */
set(UnicodeSet other)547     public UnicodeSet set(UnicodeSet other) {
548         checkFrozen();
549         list = Arrays.copyOf(other.list, other.len);
550         len = other.len;
551         pat = other.pat;
552         if (other.hasStrings()) {
553             strings = new TreeSet<>(other.strings);
554         } else {
555             strings = EMPTY_STRINGS;
556         }
557         return this;
558     }
559 
560     /**
561      * Modifies this set to represent the set specified by the given pattern.
562      * See the class description for the syntax of the pattern language.
563      * Whitespace is ignored.
564      * @param pattern a string specifying what characters are in the set
565      * @exception java.lang.IllegalArgumentException if the pattern
566      * contains a syntax error.
567      * @stable ICU 2.0
568      */
applyPattern(String pattern)569     public final UnicodeSet applyPattern(String pattern) {
570         checkFrozen();
571         return applyPattern(pattern, null, null, IGNORE_SPACE);
572     }
573 
574     /**
575      * Modifies this set to represent the set specified by the given pattern,
576      * optionally ignoring whitespace.
577      * See the class description for the syntax of the pattern language.
578      * @param pattern a string specifying what characters are in the set
579      * @param ignoreWhitespace if true then Unicode Pattern_White_Space characters are ignored
580      * @exception java.lang.IllegalArgumentException if the pattern
581      * contains a syntax error.
582      * @stable ICU 2.0
583      */
applyPattern(String pattern, boolean ignoreWhitespace)584     public UnicodeSet applyPattern(String pattern, boolean ignoreWhitespace) {
585         checkFrozen();
586         return applyPattern(pattern, null, null, ignoreWhitespace ? IGNORE_SPACE : 0);
587     }
588 
589     /**
590      * Modifies this set to represent the set specified by the given pattern,
591      * optionally ignoring whitespace.
592      * See the class description for the syntax of the pattern language.
593      * @param pattern a string specifying what characters are in the set
594      * @param options a bitmask indicating which options to apply.
595      * Valid options are {@link #IGNORE_SPACE} and
596      * at most one of {@link #CASE_INSENSITIVE}, {@link #ADD_CASE_MAPPINGS},
597      * {@link #SIMPLE_CASE_INSENSITIVE}. These case options are mutually exclusive.
598      * @exception java.lang.IllegalArgumentException if the pattern
599      * contains a syntax error.
600      * @stable ICU 3.8
601      */
applyPattern(String pattern, int options)602     public UnicodeSet applyPattern(String pattern, int options) {
603         checkFrozen();
604         return applyPattern(pattern, null, null, options);
605     }
606 
607     /**
608      * Return true if the given position, in the given pattern, appears
609      * to be the start of a UnicodeSet pattern.
610      * @stable ICU 2.0
611      */
resemblesPattern(String pattern, int pos)612     public static boolean resemblesPattern(String pattern, int pos) {
613         return ((pos+1) < pattern.length() &&
614                 pattern.charAt(pos) == '[') ||
615                 resemblesPropertyPattern(pattern, pos);
616     }
617 
618     /**
619      * TODO: create Appendable version of UTF16.append(buf, c),
620      * maybe in new class Appendables?
621      * @throws IOException
622      */
appendCodePoint(Appendable app, int c)623     private static void appendCodePoint(Appendable app, int c) {
624         assert 0 <= c && c <= 0x10ffff;
625         try {
626             if (c <= 0xffff) {
627                 app.append((char) c);
628             } else {
629                 app.append(UTF16.getLeadSurrogate(c)).append(UTF16.getTrailSurrogate(c));
630             }
631         } catch (IOException e) {
632             throw new ICUUncheckedIOException(e);
633         }
634     }
635 
636     /**
637      * TODO: create class Appendables?
638      * @throws IOException
639      */
append(Appendable app, CharSequence s)640     private static void append(Appendable app, CharSequence s) {
641         try {
642             app.append(s);
643         } catch (IOException e) {
644             throw new ICUUncheckedIOException(e);
645         }
646     }
647 
648     /**
649      * Append the <code>toPattern()</code> representation of a
650      * string to the given <code>Appendable</code>.
651      */
_appendToPat(T buf, String s, boolean escapeUnprintable)652     private static <T extends Appendable> T _appendToPat(T buf, String s, boolean escapeUnprintable) {
653         int cp;
654         for (int i = 0; i < s.length(); i += Character.charCount(cp)) {
655             cp = s.codePointAt(i);
656             _appendToPat(buf, cp, escapeUnprintable);
657         }
658         return buf;
659     }
660 
661     /**
662      * Append the <code>toPattern()</code> representation of a
663      * character to the given <code>Appendable</code>.
664      */
_appendToPat(T buf, int c, boolean escapeUnprintable)665     private static <T extends Appendable> T _appendToPat(T buf, int c, boolean escapeUnprintable) {
666         try {
667             if (escapeUnprintable ? Utility.isUnprintable(c) : Utility.shouldAlwaysBeEscaped(c)) {
668                 // Use hex escape notation (<backslash>uxxxx or <backslash>Uxxxxxxxx) for anything
669                 // unprintable
670                 return Utility.escape(buf, c);
671             }
672             // Okay to let ':' pass through
673             switch (c) {
674             case '[': // SET_OPEN:
675             case ']': // SET_CLOSE:
676             case '-': // HYPHEN:
677             case '^': // COMPLEMENT:
678             case '&': // INTERSECTION:
679             case '\\': //BACKSLASH:
680             case '{':
681             case '}':
682             case '$':
683             case ':':
684                 buf.append('\\');
685                 break;
686             default:
687                 // Escape whitespace
688                 if (PatternProps.isWhiteSpace(c)) {
689                     buf.append('\\');
690                 }
691                 break;
692             }
693             appendCodePoint(buf, c);
694             return buf;
695         } catch (IOException e) {
696             throw new ICUUncheckedIOException(e);
697         }
698     }
699 
_appendToPat( T result, int start, int end, boolean escapeUnprintable)700     private static <T extends Appendable> T _appendToPat(
701             T result, int start, int end, boolean escapeUnprintable) {
702         _appendToPat(result, start, escapeUnprintable);
703         if (start != end) {
704             if ((start+1) != end ||
705                     // Avoid writing what looks like a lead+trail surrogate pair.
706                     start == 0xdbff) {
707                 try {
708                     result.append('-');
709                 } catch (IOException e) {
710                     throw new ICUUncheckedIOException(e);
711                 }
712             }
713             _appendToPat(result, end, escapeUnprintable);
714         }
715         return result;
716     }
717 
718     /**
719      * Returns a string representation of this set.  If the result of
720      * calling this function is passed to a UnicodeSet constructor, it
721      * will produce another set that is equal to this one.
722      * @stable ICU 2.0
723      */
724     @Override
toPattern(boolean escapeUnprintable)725     public String toPattern(boolean escapeUnprintable) {
726         if (pat != null && !escapeUnprintable) {
727             return pat;
728         }
729         StringBuilder result = new StringBuilder();
730         return _toPattern(result, escapeUnprintable).toString();
731     }
732 
733     /**
734      * Append a string representation of this set to result.  This will be
735      * a cleaned version of the string passed to applyPattern(), if there
736      * is one.  Otherwise it will be generated.
737      */
_toPattern(T result, boolean escapeUnprintable)738     private <T extends Appendable> T _toPattern(T result,
739             boolean escapeUnprintable) {
740         if (pat == null) {
741             return appendNewPattern(result, escapeUnprintable, true);
742         }
743         try {
744             if (!escapeUnprintable) {
745                 // TODO: The C++ version does not have this shortcut, and instead
746                 // always cleans up the pattern string,
747                 // which also escapes Utility.shouldAlwaysBeEscaped(c).
748                 // We should sync these implementations.
749                 result.append(pat);
750                 return result;
751             }
752             boolean oddNumberOfBackslashes = false;
753             for (int i=0; i<pat.length(); ) {
754                 int c = pat.codePointAt(i);
755                 i += Character.charCount(c);
756                 if (Utility.isUnprintable(c)) {
757                     // If the unprintable character is preceded by an odd
758                     // number of backslashes, then it has been escaped
759                     // and we omit the last backslash.
760                     Utility.escape(result, c);
761                     oddNumberOfBackslashes = false;
762                 } else if (!oddNumberOfBackslashes && c == '\\') {
763                     // Temporarily withhold an odd-numbered backslash.
764                     oddNumberOfBackslashes = true;
765                 } else {
766                     if (oddNumberOfBackslashes) {
767                         result.append('\\');
768                     }
769                     appendCodePoint(result, c);
770                     oddNumberOfBackslashes = false;
771                 }
772             }
773             if (oddNumberOfBackslashes) {
774                 result.append('\\');
775             }
776             return result;
777         } catch (IOException e) {
778             throw new ICUUncheckedIOException(e);
779         }
780     }
781 
782     /**
783      * Generate and append a string representation of this set to result.
784      * This does not use this.pat, the cleaned up copy of the string
785      * passed to applyPattern().
786      *
787      * @param result the buffer into which to generate the pattern
788      * @param escapeUnprintable escape unprintable characters if true
789      * @stable ICU 2.0
790      */
_generatePattern(StringBuffer result, boolean escapeUnprintable)791     public StringBuffer _generatePattern(StringBuffer result, boolean escapeUnprintable) {
792         return _generatePattern(result, escapeUnprintable, true);
793     }
794 
795     /**
796      * Generate and append a string representation of this set to result.
797      * This does not use this.pat, the cleaned up copy of the string
798      * passed to applyPattern().
799      *
800      * @param result the buffer into which to generate the pattern
801      * @param escapeUnprintable escape unprintable characters if true
802      * @param includeStrings if false, doesn't include the strings.
803      * @stable ICU 3.8
804      */
_generatePattern(StringBuffer result, boolean escapeUnprintable, boolean includeStrings)805     public StringBuffer _generatePattern(StringBuffer result,
806             boolean escapeUnprintable, boolean includeStrings) {
807         return appendNewPattern(result, escapeUnprintable, includeStrings);
808     }
809 
810     // Implementation of public _generatePattern().
811     // Allows other callers to use a StringBuilder while the existing API is stuck with StringBuffer.
appendNewPattern( T result, boolean escapeUnprintable, boolean includeStrings)812     private <T extends Appendable> T appendNewPattern(
813             T result, boolean escapeUnprintable, boolean includeStrings) {
814         try {
815             result.append('[');
816 
817             int i = 0;
818             int limit = len & ~1;  // = 2 * getRangeCount()
819 
820             // If the set contains at least 2 intervals and includes both
821             // MIN_VALUE and MAX_VALUE, then the inverse representation will
822             // be more economical.
823             //     if (getRangeCount() >= 2 &&
824             //             getRangeStart(0) == MIN_VALUE &&
825             //             getRangeEnd(last) == MAX_VALUE)
826             // Invariant: list[len-1] == HIGH == MAX_VALUE + 1
827             // If limit == len then len is even and the last range ends with MAX_VALUE.
828             //
829             // *But* do not write the inverse (complement) if there are strings.
830             // Since ICU 70, the '^' performs a code point complement which removes all strings.
831             if (len >= 4 && list[0] == 0 && limit == len && !hasStrings()) {
832                 // Emit the inverse
833                 result.append('^');
834                 // Offsetting the inversion list index by one lets us
835                 // iterate over the ranges of the set complement.
836                 i = 1;
837                 --limit;
838             }
839 
840             // Emit the ranges as pairs.
841             while (i < limit) {
842                 int start = list[i];  // getRangeStart()
843                 int end = list[i + 1] - 1;  // getRangeEnd() = range limit minus one
844                 if (!(0xd800 <= end && end <= 0xdbff)) {
845                     _appendToPat(result, start, end, escapeUnprintable);
846                     i += 2;
847                 } else {
848                     // The range ends with a lead surrogate.
849                     // Avoid writing what looks like a lead+trail surrogate pair.
850                     // 1. Postpone ranges that start with a lead surrogate code point.
851                     int firstLead = i;
852                     while ((i += 2) < limit && list[i] <= 0xdbff) {}
853                     int firstAfterLead = i;
854                     // 2. Write following ranges that start with a trail surrogate code point.
855                     while (i < limit && (start = list[i]) <= 0xdfff) {
856                         _appendToPat(result, start, list[i + 1] - 1, escapeUnprintable);
857                         i += 2;
858                     }
859                     // 3. Now write the postponed ranges.
860                     for (int j = firstLead; j < firstAfterLead; j += 2) {
861                         _appendToPat(result, list[j], list[j + 1] - 1, escapeUnprintable);
862                     }
863                 }
864             }
865 
866             if (includeStrings && hasStrings()) {
867                 for (String s : strings) {
868                     result.append('{');
869                     _appendToPat(result, s, escapeUnprintable);
870                     result.append('}');
871                 }
872             }
873             result.append(']');
874             return result;
875         } catch (IOException e) {
876             throw new ICUUncheckedIOException(e);
877         }
878     }
879 
880     /**
881      * Returns the number of elements in this set (its cardinality)
882      * Note than the elements of a set may include both individual
883      * codepoints and strings.
884      *
885      * @return the number of elements in this set (its cardinality).
886      * @stable ICU 2.0
887      */
size()888     public int size() {
889         int n = 0;
890         int count = getRangeCount();
891         for (int i = 0; i < count; ++i) {
892             n += getRangeEnd(i) - getRangeStart(i) + 1;
893         }
894         return n + strings.size();
895     }
896 
897     /**
898      * Returns <tt>true</tt> if this set contains no elements.
899      *
900      * @return <tt>true</tt> if this set contains no elements.
901      * @stable ICU 2.0
902      */
isEmpty()903     public boolean isEmpty() {
904         return len == 1 && !hasStrings();
905     }
906 
907     /**
908      * @return true if this set contains multi-character strings or the empty string.
909      * @stable ICU 70
910      */
hasStrings()911     public boolean hasStrings() {
912         return !strings.isEmpty();
913     }
914 
915     /**
916      * Implementation of UnicodeMatcher API.  Returns <tt>true</tt> if
917      * this set contains any character whose low byte is the given
918      * value.  This is used by <tt>RuleBasedTransliterator</tt> for
919      * indexing.
920      * @stable ICU 2.0
921      */
922     @Override
matchesIndexValue(int v)923     public boolean matchesIndexValue(int v) {
924         /* The index value v, in the range [0,255], is contained in this set if
925          * it is contained in any pair of this set.  Pairs either have the high
926          * bytes equal, or unequal.  If the high bytes are equal, then we have
927          * aaxx..aayy, where aa is the high byte.  Then v is contained if xx <=
928          * v <= yy.  If the high bytes are unequal we have aaxx..bbyy, bb>aa.
929          * Then v is contained if xx <= v || v <= yy.  (This is identical to the
930          * time zone month containment logic.)
931          */
932         for (int i=0; i<getRangeCount(); ++i) {
933             int low = getRangeStart(i);
934             int high = getRangeEnd(i);
935             if ((low & ~0xFF) == (high & ~0xFF)) {
936                 if ((low & 0xFF) <= v && v <= (high & 0xFF)) {
937                     return true;
938                 }
939             } else if ((low & 0xFF) <= v || v <= (high & 0xFF)) {
940                 return true;
941             }
942         }
943         if (hasStrings()) {
944             for (String s : strings) {
945                 if (s.isEmpty()) {
946                     continue;  // skip the empty string
947                 }
948                 int c = UTF16.charAt(s, 0);
949                 if ((c & 0xFF) == v) {
950                     return true;
951                 }
952             }
953         }
954         return false;
955     }
956 
957     /**
958      * Implementation of UnicodeMatcher.matches().  Always matches the
959      * longest possible multichar string.
960      * @stable ICU 2.0
961      */
962     @Override
matches(Replaceable text, int[] offset, int limit, boolean incremental)963     public int matches(Replaceable text,
964             int[] offset,
965             int limit,
966             boolean incremental) {
967 
968         if (offset[0] == limit) {
969             if (contains(UnicodeMatcher.ETHER)) {
970                 return incremental ? U_PARTIAL_MATCH : U_MATCH;
971             } else {
972                 return U_MISMATCH;
973             }
974         } else {
975             if (hasStrings()) { // try strings first
976 
977                 // might separate forward and backward loops later
978                 // for now they are combined
979 
980                 // TODO Improve efficiency of this, at least in the forward
981                 // direction, if not in both.  In the forward direction we
982                 // can assume the strings are sorted.
983 
984                 boolean forward = offset[0] < limit;
985 
986                 // firstChar is the leftmost char to match in the
987                 // forward direction or the rightmost char to match in
988                 // the reverse direction.
989                 char firstChar = text.charAt(offset[0]);
990 
991                 // If there are multiple strings that can match we
992                 // return the longest match.
993                 int highWaterLength = 0;
994 
995                 for (String trial : strings) {
996                     if (trial.isEmpty()) {
997                         continue;  // skip the empty string
998                     }
999 
1000                     char c = trial.charAt(forward ? 0 : trial.length() - 1);
1001 
1002                     // Strings are sorted, so we can optimize in the
1003                     // forward direction.
1004                     if (forward && c > firstChar) break;
1005                     if (c != firstChar) continue;
1006 
1007                     int length = matchRest(text, offset[0], limit, trial);
1008 
1009                     if (incremental) {
1010                         int maxLen = forward ? limit-offset[0] : offset[0]-limit;
1011                         if (length == maxLen) {
1012                             // We have successfully matched but only up to limit.
1013                             return U_PARTIAL_MATCH;
1014                         }
1015                     }
1016 
1017                     if (length == trial.length()) {
1018                         // We have successfully matched the whole string.
1019                         if (length > highWaterLength) {
1020                             highWaterLength = length;
1021                         }
1022                         // In the forward direction we know strings
1023                         // are sorted so we can bail early.
1024                         if (forward && length < highWaterLength) {
1025                             break;
1026                         }
1027                         continue;
1028                     }
1029                 }
1030 
1031                 // We've checked all strings without a partial match.
1032                 // If we have full matches, return the longest one.
1033                 if (highWaterLength != 0) {
1034                     offset[0] += forward ? highWaterLength : -highWaterLength;
1035                     return U_MATCH;
1036                 }
1037             }
1038             return super.matches(text, offset, limit, incremental);
1039         }
1040     }
1041 
1042     /**
1043      * Returns the longest match for s in text at the given position.
1044      * If limit > start then match forward from start+1 to limit
1045      * matching all characters except s.charAt(0).  If limit < start,
1046      * go backward starting from start-1 matching all characters
1047      * except s.charAt(s.length()-1).  This method assumes that the
1048      * first character, text.charAt(start), matches s, so it does not
1049      * check it.
1050      * @param text the text to match
1051      * @param start the first character to match.  In the forward
1052      * direction, text.charAt(start) is matched against s.charAt(0).
1053      * In the reverse direction, it is matched against
1054      * s.charAt(s.length()-1).
1055      * @param limit the limit offset for matching, either last+1 in
1056      * the forward direction, or last-1 in the reverse direction,
1057      * where last is the index of the last character to match.
1058      * @return If part of s matches up to the limit, return |limit -
1059      * start|.  If all of s matches before reaching the limit, return
1060      * s.length().  If there is a mismatch between s and text, return
1061      * 0
1062      */
matchRest(Replaceable text, int start, int limit, String s)1063     private static int matchRest (Replaceable text, int start, int limit, String s) {
1064         int maxLen;
1065         int slen = s.length();
1066         if (start < limit) {
1067             maxLen = limit - start;
1068             if (maxLen > slen) maxLen = slen;
1069             for (int i = 1; i < maxLen; ++i) {
1070                 if (text.charAt(start + i) != s.charAt(i)) return 0;
1071             }
1072         } else {
1073             maxLen = start - limit;
1074             if (maxLen > slen) maxLen = slen;
1075             --slen; // <=> slen = s.length() - 1;
1076             for (int i = 1; i < maxLen; ++i) {
1077                 if (text.charAt(start - i) != s.charAt(slen - i)) return 0;
1078             }
1079         }
1080         return maxLen;
1081     }
1082 
1083     /**
1084      * Tests whether the text matches at the offset. If so, returns the end of the longest substring that it matches. If not, returns -1.
1085      * @internal
1086      * @deprecated This API is ICU internal only.
1087      */
1088     @Deprecated
matchesAt(CharSequence text, int offset)1089     public int matchesAt(CharSequence text, int offset) {
1090         int lastLen = -1;
1091         strings:
1092             if (hasStrings()) {
1093                 char firstChar = text.charAt(offset);
1094                 String trial = null;
1095                 // find the first string starting with firstChar
1096                 Iterator<String> it = strings.iterator();
1097                 while (it.hasNext()) {
1098                     trial = it.next();
1099                     char firstStringChar = trial.charAt(0);
1100                     if (firstStringChar < firstChar) continue;
1101                     if (firstStringChar > firstChar) break strings;
1102                 }
1103 
1104                 // now keep checking string until we get the longest one
1105                 for (;;) {
1106                     int tempLen = matchesAt(text, offset, trial);
1107                     if (lastLen > tempLen) break strings;
1108                     lastLen = tempLen;
1109                     if (!it.hasNext()) break;
1110                     trial = it.next();
1111                 }
1112             }
1113 
1114         if (lastLen < 2) {
1115             int cp = UTF16.charAt(text, offset);
1116             if (contains(cp)) lastLen = UTF16.getCharCount(cp);
1117         }
1118 
1119         return offset+lastLen;
1120     }
1121 
1122     /**
1123      * Does one string contain another, starting at a specific offset?
1124      * @param text text to match
1125      * @param offsetInText offset within that text
1126      * @param substring substring to match at offset in text
1127      * @return -1 if match fails, otherwise other.length()
1128      */
1129     // Note: This method was moved from CollectionUtilities
matchesAt(CharSequence text, int offsetInText, CharSequence substring)1130     private static int matchesAt(CharSequence text, int offsetInText, CharSequence substring) {
1131         int len = substring.length();
1132         int textLength = text.length();
1133         if (textLength + offsetInText > len) {
1134             return -1;
1135         }
1136         int i = 0;
1137         for (int j = offsetInText; i < len; ++i, ++j) {
1138             char pc = substring.charAt(i);
1139             char tc = text.charAt(j);
1140             if (pc != tc) return -1;
1141         }
1142         return i;
1143     }
1144 
1145     /**
1146      * Implementation of UnicodeMatcher API.  Union the set of all
1147      * characters that may be matched by this object into the given
1148      * set.
1149      * @param toUnionTo the set into which to union the source characters
1150      * @stable ICU 2.2
1151      */
1152     @Override
addMatchSetTo(UnicodeSet toUnionTo)1153     public void addMatchSetTo(UnicodeSet toUnionTo) {
1154         toUnionTo.addAll(this);
1155     }
1156 
1157     /**
1158      * Returns the index of the given character within this set, where
1159      * the set is ordered by ascending code point.  If the character
1160      * is not in this set, return -1.  The inverse of this method is
1161      * <code>charAt()</code>.
1162      * @return an index from 0..size()-1, or -1
1163      * @stable ICU 2.0
1164      */
indexOf(int c)1165     public int indexOf(int c) {
1166         if (c < MIN_VALUE || c > MAX_VALUE) {
1167             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(c, 6));
1168         }
1169         int i = 0;
1170         int n = 0;
1171         for (;;) {
1172             int start = list[i++];
1173             if (c < start) {
1174                 return -1;
1175             }
1176             int limit = list[i++];
1177             if (c < limit) {
1178                 return n + c - start;
1179             }
1180             n += limit - start;
1181         }
1182     }
1183 
1184     /**
1185      * Returns the character at the given index within this set, where
1186      * the set is ordered by ascending code point.  If the index is
1187      * out of range, return -1.  The inverse of this method is
1188      * <code>indexOf()</code>.
1189      * @param index an index from 0..size()-1
1190      * @return the character at the given index, or -1.
1191      * @stable ICU 2.0
1192      */
charAt(int index)1193     public int charAt(int index) {
1194         if (index >= 0) {
1195             // len2 is the largest even integer <= len, that is, it is len
1196             // for even values and len-1 for odd values.  With odd values
1197             // the last entry is UNICODESET_HIGH.
1198             int len2 = len & ~1;
1199             for (int i=0; i < len2;) {
1200                 int start = list[i++];
1201                 int count = list[i++] - start;
1202                 if (index < count) {
1203                     return start + index;
1204                 }
1205                 index -= count;
1206             }
1207         }
1208         return -1;
1209     }
1210 
1211     /**
1212      * Adds the specified range to this set if it is not already
1213      * present.  If this set already contains the specified range,
1214      * the call leaves this set unchanged.  If <code>start &gt; end</code>
1215      * then an empty range is added, leaving the set unchanged.
1216      *
1217      * @param start first character, inclusive, of range to be added
1218      * to this set.
1219      * @param end last character, inclusive, of range to be added
1220      * to this set.
1221      * @stable ICU 2.0
1222      */
add(int start, int end)1223     public UnicodeSet add(int start, int end) {
1224         checkFrozen();
1225         return add_unchecked(start, end);
1226     }
1227 
1228     /**
1229      * Adds all characters in range (uses preferred naming convention).
1230      * @param start The index of where to start on adding all characters.
1231      * @param end The index of where to end on adding all characters.
1232      * @return a reference to this object
1233      * @stable ICU 4.4
1234      */
addAll(int start, int end)1235     public UnicodeSet addAll(int start, int end) {
1236         checkFrozen();
1237         return add_unchecked(start, end);
1238     }
1239 
1240     // for internal use, after checkFrozen has been called
add_unchecked(int start, int end)1241     private UnicodeSet add_unchecked(int start, int end) {
1242         if (start < MIN_VALUE || start > MAX_VALUE) {
1243             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
1244         }
1245         if (end < MIN_VALUE || end > MAX_VALUE) {
1246             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
1247         }
1248         if (start < end) {
1249             int limit = end + 1;
1250             // Fast path for adding a new range after the last one.
1251             // Odd list length: [..., lastStart, lastLimit, HIGH]
1252             if ((len & 1) != 0) {
1253                 // If the list is empty, set lastLimit low enough to not be adjacent to 0.
1254                 int lastLimit = len == 1 ? -2 : list[len - 2];
1255                 if (lastLimit <= start) {
1256                     checkFrozen();
1257                     if (lastLimit == start) {
1258                         // Extend the last range.
1259                         list[len - 2] = limit;
1260                         if (limit == HIGH) {
1261                             --len;
1262                         }
1263                     } else {
1264                         list[len - 1] = start;
1265                         if (limit < HIGH) {
1266                             ensureCapacity(len + 2);
1267                             list[len++] = limit;
1268                             list[len++] = HIGH;
1269                         } else {  // limit == HIGH
1270                             ensureCapacity(len + 1);
1271                             list[len++] = HIGH;
1272                         }
1273                     }
1274                     pat = null;
1275                     return this;
1276                 }
1277             }
1278             // This is slow. Could be much faster using findCodePoint(start)
1279             // and modifying the list, dealing with adjacent & overlapping ranges.
1280             add(range(start, end), 2, 0);
1281         } else if (start == end) {
1282             add(start);
1283         }
1284         return this;
1285     }
1286 
1287     //    /**
1288     //     * Format out the inversion list as a string, for debugging.  Uncomment when
1289     //     * needed.
1290     //     */
1291     //    public final String dump() {
1292     //        StringBuffer buf = new StringBuffer("[");
1293     //        for (int i=0; i<len; ++i) {
1294     //            if (i != 0) buf.append(", ");
1295     //            int c = list[i];
1296     //            //if (c <= 0x7F && c != '\n' && c != '\r' && c != '\t' && c != ' ') {
1297     //            //    buf.append((char) c);
1298     //            //} else {
1299     //                buf.append("U+").append(Utility.hex(c, (c<0x10000)?4:6));
1300     //            //}
1301     //        }
1302     //        buf.append("]");
1303     //        return buf.toString();
1304     //    }
1305 
1306     /**
1307      * Adds the specified character to this set if it is not already
1308      * present.  If this set already contains the specified character,
1309      * the call leaves this set unchanged.
1310      * @stable ICU 2.0
1311      */
add(int c)1312     public final UnicodeSet add(int c) {
1313         checkFrozen();
1314         return add_unchecked(c);
1315     }
1316 
1317     // for internal use only, after checkFrozen has been called
add_unchecked(int c)1318     private final UnicodeSet add_unchecked(int c) {
1319         if (c < MIN_VALUE || c > MAX_VALUE) {
1320             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(c, 6));
1321         }
1322 
1323         // find smallest i such that c < list[i]
1324         // if odd, then it is IN the set
1325         // if even, then it is OUT of the set
1326         int i = findCodePoint(c);
1327 
1328         // already in set?
1329         if ((i & 1) != 0) return this;
1330 
1331         // HIGH is 0x110000
1332         // assert(list[len-1] == HIGH);
1333 
1334         // empty = [HIGH]
1335         // [start_0, limit_0, start_1, limit_1, HIGH]
1336 
1337         // [..., start_k-1, limit_k-1, start_k, limit_k, ..., HIGH]
1338         //                             ^
1339         //                             list[i]
1340 
1341         // i == 0 means c is before the first range
1342         // TODO: Is the "list[i]-1" a typo? Even if you pass MAX_VALUE into
1343         //      add_unchecked, the maximum value that "c" will be compared to
1344         //      is "MAX_VALUE-1" meaning that "if (c == MAX_VALUE)" will
1345         //      never be reached according to this logic.
1346         if (c == list[i]-1) {
1347             // c is before start of next range
1348             list[i] = c;
1349             // if we touched the HIGH mark, then add a new one
1350             if (c == MAX_VALUE) {
1351                 ensureCapacity(len+1);
1352                 list[len++] = HIGH;
1353             }
1354             if (i > 0 && c == list[i-1]) {
1355                 // collapse adjacent ranges
1356 
1357                 // [..., start_k-1, c, c, limit_k, ..., HIGH]
1358                 //                     ^
1359                 //                     list[i]
1360                 System.arraycopy(list, i+1, list, i-1, len-i-1);
1361                 len -= 2;
1362             }
1363         }
1364 
1365         else if (i > 0 && c == list[i-1]) {
1366             // c is after end of prior range
1367             list[i-1]++;
1368             // no need to check for collapse here
1369         }
1370 
1371         else {
1372             // At this point we know the new char is not adjacent to
1373             // any existing ranges, and it is not 10FFFF.
1374 
1375 
1376             // [..., start_k-1, limit_k-1, start_k, limit_k, ..., HIGH]
1377             //                             ^
1378             //                             list[i]
1379 
1380             // [..., start_k-1, limit_k-1, c, c+1, start_k, limit_k, ..., HIGH]
1381             //                             ^
1382             //                             list[i]
1383 
1384             // Don't use ensureCapacity() to save on copying.
1385             // NOTE: This has no measurable impact on performance,
1386             // but it might help in some usage patterns.
1387             if (len+2 > list.length) {
1388                 int[] temp = new int[nextCapacity(len + 2)];
1389                 if (i != 0) System.arraycopy(list, 0, temp, 0, i);
1390                 System.arraycopy(list, i, temp, i+2, len-i);
1391                 list = temp;
1392             } else {
1393                 System.arraycopy(list, i, list, i+2, len-i);
1394             }
1395 
1396             list[i] = c;
1397             list[i+1] = c+1;
1398             len += 2;
1399         }
1400 
1401         pat = null;
1402         return this;
1403     }
1404 
1405     /**
1406      * Adds the specified multicharacter to this set if it is not already
1407      * present.  If this set already contains the multicharacter,
1408      * the call leaves this set unchanged.
1409      * Thus "ch" =&gt; {"ch"}
1410      *
1411      * @param s the source string
1412      * @return this object, for chaining
1413      * @stable ICU 2.0
1414      */
add(CharSequence s)1415     public final UnicodeSet add(CharSequence s) {
1416         checkFrozen();
1417         int cp = getSingleCP(s);
1418         if (cp < 0) {
1419             String str = s.toString();
1420             if (!strings.contains(str)) {
1421                 addString(str);
1422                 pat = null;
1423             }
1424         } else {
1425             add_unchecked(cp, cp);
1426         }
1427         return this;
1428     }
1429 
addString(CharSequence s)1430     private void addString(CharSequence s) {
1431         if (strings == EMPTY_STRINGS) {
1432             strings = new TreeSet<>();
1433         }
1434         strings.add(s.toString());
1435     }
1436 
1437     /**
1438      * Utility for getting code point from single code point CharSequence.
1439      * See the public UTF16.getSingleCodePoint() (which returns -1 for null rather than throwing NPE).
1440      *
1441      * @return a code point IF the string consists of a single one.
1442      * otherwise returns -1.
1443      * @param s to test
1444      */
getSingleCP(CharSequence s)1445     private static int getSingleCP(CharSequence s) {
1446         if (s.length() == 1) return s.charAt(0);
1447         if (s.length() == 2) {
1448             int cp = Character.codePointAt(s, 0);
1449             if (cp > 0xFFFF) { // is surrogate pair
1450                 return cp;
1451             }
1452         }
1453         return -1;
1454     }
1455 
1456     /**
1457      * Adds each of the characters in this string to the set. Thus "ch" =&gt; {"c", "h"}
1458      * If this set already any particular character, it has no effect on that character.
1459      * @param s the source string
1460      * @return this object, for chaining
1461      * @stable ICU 2.0
1462      */
addAll(CharSequence s)1463     public final UnicodeSet addAll(CharSequence s) {
1464         checkFrozen();
1465         int cp;
1466         for (int i = 0; i < s.length(); i += UTF16.getCharCount(cp)) {
1467             cp = UTF16.charAt(s, i);
1468             add_unchecked(cp, cp);
1469         }
1470         return this;
1471     }
1472 
1473     /**
1474      * Retains EACH of the characters in this string. Note: "ch" == {"c", "h"}
1475      * If this set already any particular character, it has no effect on that character.
1476      * @param s the source string
1477      * @return this object, for chaining
1478      * @stable ICU 2.0
1479      */
retainAll(CharSequence s)1480     public final UnicodeSet retainAll(CharSequence s) {
1481         return retainAll(fromAll(s));
1482     }
1483 
1484     /**
1485      * Complement EACH of the characters in this string. Note: "ch" == {"c", "h"}
1486      * If this set already any particular character, it has no effect on that character.
1487      * @param s the source string
1488      * @return this object, for chaining
1489      * @stable ICU 2.0
1490      */
complementAll(CharSequence s)1491     public final UnicodeSet complementAll(CharSequence s) {
1492         return complementAll(fromAll(s));
1493     }
1494 
1495     /**
1496      * Remove EACH of the characters in this string. Note: "ch" == {"c", "h"}
1497      * If this set already any particular character, it has no effect on that character.
1498      * @param s the source string
1499      * @return this object, for chaining
1500      * @stable ICU 2.0
1501      */
removeAll(CharSequence s)1502     public final UnicodeSet removeAll(CharSequence s) {
1503         return removeAll(fromAll(s));
1504     }
1505 
1506     /**
1507      * Remove all strings from this UnicodeSet
1508      * @return this object, for chaining
1509      * @stable ICU 4.2
1510      */
removeAllStrings()1511     public final UnicodeSet removeAllStrings() {
1512         checkFrozen();
1513         if (hasStrings()) {
1514             strings.clear();
1515             pat = null;
1516         }
1517         return this;
1518     }
1519 
1520     /**
1521      * Makes a set from a multicharacter string. Thus "ch" =&gt; {"ch"}
1522      *
1523      * @param s the source string
1524      * @return a newly created set containing the given string
1525      * @stable ICU 2.0
1526      */
from(CharSequence s)1527     public static UnicodeSet from(CharSequence s) {
1528         return new UnicodeSet().add(s);
1529     }
1530 
1531 
1532     /**
1533      * Makes a set from each of the characters in the string. Thus "ch" =&gt; {"c", "h"}
1534      * @param s the source string
1535      * @return a newly created set containing the given characters
1536      * @stable ICU 2.0
1537      */
fromAll(CharSequence s)1538     public static UnicodeSet fromAll(CharSequence s) {
1539         return new UnicodeSet().addAll(s);
1540     }
1541 
1542 
1543     /**
1544      * Retain only the elements in this set that are contained in the
1545      * specified range.  If <code>start &gt; end</code> then an empty range is
1546      * retained, leaving the set empty.
1547      *
1548      * @param start first character, inclusive, of range
1549      * @param end last character, inclusive, of range
1550      * @stable ICU 2.0
1551      */
retain(int start, int end)1552     public UnicodeSet retain(int start, int end) {
1553         checkFrozen();
1554         if (start < MIN_VALUE || start > MAX_VALUE) {
1555             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
1556         }
1557         if (end < MIN_VALUE || end > MAX_VALUE) {
1558             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
1559         }
1560         if (start <= end) {
1561             retain(range(start, end), 2, 0);
1562         } else {
1563             clear();
1564         }
1565         return this;
1566     }
1567 
1568     /**
1569      * Retain the specified character from this set if it is present.
1570      * Upon return this set will be empty if it did not contain c, or
1571      * will only contain c if it did contain c.
1572      * @param c the character to be retained
1573      * @return this object, for chaining
1574      * @stable ICU 2.0
1575      */
retain(int c)1576     public final UnicodeSet retain(int c) {
1577         return retain(c, c);
1578     }
1579 
1580     /**
1581      * Retain the specified string in this set if it is present.
1582      * Upon return this set will be empty if it did not contain s, or
1583      * will only contain s if it did contain s.
1584      * @param cs the string to be retained
1585      * @return this object, for chaining
1586      * @stable ICU 2.0
1587      */
retain(CharSequence cs)1588     public final UnicodeSet retain(CharSequence cs) {
1589         int cp = getSingleCP(cs);
1590         if (cp < 0) {
1591             checkFrozen();
1592             String s = cs.toString();
1593             boolean isIn = strings.contains(s);
1594             // Check for getRangeCount() first to avoid somewhat-expensive size()
1595             // when there are single code points.
1596             if (isIn && getRangeCount() == 0 && size() == 1) {
1597                 return this;
1598             }
1599             clear();
1600             if (isIn) {
1601                 addString(s);
1602             }
1603             pat = null;
1604         } else {
1605             retain(cp, cp);
1606         }
1607         return this;
1608     }
1609 
1610     /**
1611      * Removes the specified range from this set if it is present.
1612      * The set will not contain the specified range once the call
1613      * returns.  If <code>start &gt; end</code> then an empty range is
1614      * removed, leaving the set unchanged.
1615      *
1616      * @param start first character, inclusive, of range to be removed
1617      * from this set.
1618      * @param end last character, inclusive, of range to be removed
1619      * from this set.
1620      * @stable ICU 2.0
1621      */
remove(int start, int end)1622     public UnicodeSet remove(int start, int end) {
1623         checkFrozen();
1624         if (start < MIN_VALUE || start > MAX_VALUE) {
1625             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
1626         }
1627         if (end < MIN_VALUE || end > MAX_VALUE) {
1628             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
1629         }
1630         if (start <= end) {
1631             retain(range(start, end), 2, 2);
1632         }
1633         return this;
1634     }
1635 
1636     /**
1637      * Removes the specified character from this set if it is present.
1638      * The set will not contain the specified character once the call
1639      * returns.
1640      * @param c the character to be removed
1641      * @return this object, for chaining
1642      * @stable ICU 2.0
1643      */
remove(int c)1644     public final UnicodeSet remove(int c) {
1645         return remove(c, c);
1646     }
1647 
1648     /**
1649      * Removes the specified string from this set if it is present.
1650      * The set will not contain the specified string once the call
1651      * returns.
1652      * @param s the string to be removed
1653      * @return this object, for chaining
1654      * @stable ICU 2.0
1655      */
remove(CharSequence s)1656     public final UnicodeSet remove(CharSequence s) {
1657         int cp = getSingleCP(s);
1658         if (cp < 0) {
1659             checkFrozen();
1660             String str = s.toString();
1661             if (strings.contains(str)) {
1662                 strings.remove(str);
1663                 pat = null;
1664             }
1665         } else {
1666             remove(cp, cp);
1667         }
1668         return this;
1669     }
1670 
1671     /**
1672      * Complements the specified range in this set.  Any character in
1673      * the range will be removed if it is in this set, or will be
1674      * added if it is not in this set.  If <code>start &gt; end</code>
1675      * then an empty range is complemented, leaving the set unchanged.
1676      *
1677      * @param start first character, inclusive, of range
1678      * @param end last character, inclusive, of range
1679      * @stable ICU 2.0
1680      */
complement(int start, int end)1681     public UnicodeSet complement(int start, int end) {
1682         checkFrozen();
1683         if (start < MIN_VALUE || start > MAX_VALUE) {
1684             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
1685         }
1686         if (end < MIN_VALUE || end > MAX_VALUE) {
1687             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
1688         }
1689         if (start <= end) {
1690             xor(range(start, end), 2, 0);
1691         }
1692         pat = null;
1693         return this;
1694     }
1695 
1696     /**
1697      * Complements the specified character in this set.  The character
1698      * will be removed if it is in this set, or will be added if it is
1699      * not in this set.
1700      * @stable ICU 2.0
1701      */
complement(int c)1702     public final UnicodeSet complement(int c) {
1703         return complement(c, c);
1704     }
1705 
1706     /**
1707      * This is equivalent to
1708      * <code>complement(MIN_VALUE, MAX_VALUE)</code>.
1709      *
1710      * <p><strong>Note:</strong> This performs a symmetric difference with all code points
1711      * <em>and thus retains all multicharacter strings</em>.
1712      * In order to achieve a “code point complement” (all code points minus this set),
1713      * the easiest is to .{@link #complement()}.{@link #removeAllStrings()} .
1714      *
1715      * @stable ICU 2.0
1716      */
complement()1717     public UnicodeSet complement() {
1718         checkFrozen();
1719         if (list[0] == LOW) {
1720             System.arraycopy(list, 1, list, 0, len-1);
1721             --len;
1722         } else {
1723             ensureCapacity(len+1);
1724             System.arraycopy(list, 0, list, 1, len);
1725             list[0] = LOW;
1726             ++len;
1727         }
1728         pat = null;
1729         return this;
1730     }
1731 
1732     /**
1733      * Complement the specified string in this set.
1734      * The set will not contain the specified string once the call
1735      * returns.
1736      *
1737      * @param s the string to complement
1738      * @return this object, for chaining
1739      * @stable ICU 2.0
1740      */
complement(CharSequence s)1741     public final UnicodeSet complement(CharSequence s) {
1742         checkFrozen();
1743         int cp = getSingleCP(s);
1744         if (cp < 0) {
1745             String s2 = s.toString();
1746             if (strings.contains(s2)) {
1747                 strings.remove(s2);
1748             } else {
1749                 addString(s2);
1750             }
1751             pat = null;
1752         } else {
1753             complement(cp, cp);
1754         }
1755         return this;
1756     }
1757 
1758     /**
1759      * Returns true if this set contains the given character.
1760      * @param c character to be checked for containment
1761      * @return true if the test condition is met
1762      * @stable ICU 2.0
1763      */
1764     @Override
contains(int c)1765     public boolean contains(int c) {
1766         if (c < MIN_VALUE || c > MAX_VALUE) {
1767             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(c, 6));
1768         }
1769         if (bmpSet != null) {
1770             return bmpSet.contains(c);
1771         }
1772         if (stringSpan != null) {
1773             return stringSpan.contains(c);
1774         }
1775 
1776         /*
1777         // Set i to the index of the start item greater than ch
1778         // We know we will terminate without length test!
1779         int i = -1;
1780         while (true) {
1781             if (c < list[++i]) break;
1782         }
1783          */
1784 
1785         int i = findCodePoint(c);
1786 
1787         return ((i & 1) != 0); // return true if odd
1788     }
1789 
1790     /**
1791      * Returns the smallest value i such that c < list[i].  Caller
1792      * must ensure that c is a legal value or this method will enter
1793      * an infinite loop.  This method performs a binary search.
1794      * @param c a character in the range MIN_VALUE..MAX_VALUE
1795      * inclusive
1796      * @return the smallest integer i in the range 0..len-1,
1797      * inclusive, such that c < list[i]
1798      */
findCodePoint(int c)1799     private final int findCodePoint(int c) {
1800         /* Examples:
1801                                            findCodePoint(c)
1802            set              list[]         c=0 1 3 4 7 8
1803            ===              ==============   ===========
1804            []               [110000]         0 0 0 0 0 0
1805            [\u0000-\u0003]  [0, 4, 110000]   1 1 1 2 2 2
1806            [\u0004-\u0007]  [4, 8, 110000]   0 0 0 1 1 2
1807            [:all:]          [0, 110000]      1 1 1 1 1 1
1808          */
1809 
1810         // Return the smallest i such that c < list[i].  Assume
1811         // list[len - 1] == HIGH and that c is legal (0..HIGH-1).
1812         if (c < list[0]) return 0;
1813         // High runner test.  c is often after the last range, so an
1814         // initial check for this condition pays off.
1815         if (len >= 2 && c >= list[len-2]) return len-1;
1816         int lo = 0;
1817         int hi = len - 1;
1818         // invariant: c >= list[lo]
1819         // invariant: c < list[hi]
1820         for (;;) {
1821             int i = (lo + hi) >>> 1;
1822         if (i == lo) return hi;
1823         if (c < list[i]) {
1824             hi = i;
1825         } else {
1826             lo = i;
1827         }
1828         }
1829     }
1830 
1831     //    //----------------------------------------------------------------
1832     //    // Unrolled binary search
1833     //    //----------------------------------------------------------------
1834     //
1835     //    private int validLen = -1; // validated value of len
1836     //    private int topOfLow;
1837     //    private int topOfHigh;
1838     //    private int power;
1839     //    private int deltaStart;
1840     //
1841     //    private void validate() {
1842     //        if (len <= 1) {
1843     //            throw new IllegalArgumentException("list.len==" + len + "; must be >1");
1844     //        }
1845     //
1846     //        // find greatest power of 2 less than or equal to len
1847     //        for (power = exp2.length-1; power > 0 && exp2[power] > len; power--) {}
1848     //
1849     //        // assert(exp2[power] <= len);
1850     //
1851     //        // determine the starting points
1852     //        topOfLow = exp2[power] - 1;
1853     //        topOfHigh = len - 1;
1854     //        deltaStart = exp2[power-1];
1855     //        validLen = len;
1856     //    }
1857     //
1858     //    private static final int exp2[] = {
1859     //        0x1, 0x2, 0x4, 0x8,
1860     //        0x10, 0x20, 0x40, 0x80,
1861     //        0x100, 0x200, 0x400, 0x800,
1862     //        0x1000, 0x2000, 0x4000, 0x8000,
1863     //        0x10000, 0x20000, 0x40000, 0x80000,
1864     //        0x100000, 0x200000, 0x400000, 0x800000,
1865     //        0x1000000, 0x2000000, 0x4000000, 0x8000000,
1866     //        0x10000000, 0x20000000 // , 0x40000000 // no unsigned int in Java
1867     //    };
1868     //
1869     //    /**
1870     //     * Unrolled lowest index GT.
1871     //     */
1872     //    private final int leastIndexGT(int searchValue) {
1873     //
1874     //        if (len != validLen) {
1875     //            if (len == 1) return 0;
1876     //            validate();
1877     //        }
1878     //        int temp;
1879     //
1880     //        // set up initial range to search. Each subrange is a power of two in length
1881     //        int high = searchValue < list[topOfLow] ? topOfLow : topOfHigh;
1882     //
1883     //        // Completely unrolled binary search, folhighing "Programming Pearls"
1884     //        // Each case deliberately falls through to the next
1885     //        // Logically, list[-1] < all_search_values && list[count] > all_search_values
1886     //        // although the values -1 and count are never actually touched.
1887     //
1888     //        // The bounds at each point are low & high,
1889     //        // where low == high - delta*2
1890     //        // so high - delta is the midpoint
1891     //
1892     //        // The invariant AFTER each line is that list[low] < searchValue <= list[high]
1893     //
1894     //        switch (power) {
1895     //        //case 31: if (searchValue < list[temp = high-0x40000000]) high = temp; // no unsigned int in Java
1896     //        case 30: if (searchValue < list[temp = high-0x20000000]) high = temp;
1897     //        case 29: if (searchValue < list[temp = high-0x10000000]) high = temp;
1898     //
1899     //        case 28: if (searchValue < list[temp = high- 0x8000000]) high = temp;
1900     //        case 27: if (searchValue < list[temp = high- 0x4000000]) high = temp;
1901     //        case 26: if (searchValue < list[temp = high- 0x2000000]) high = temp;
1902     //        case 25: if (searchValue < list[temp = high- 0x1000000]) high = temp;
1903     //
1904     //        case 24: if (searchValue < list[temp = high-  0x800000]) high = temp;
1905     //        case 23: if (searchValue < list[temp = high-  0x400000]) high = temp;
1906     //        case 22: if (searchValue < list[temp = high-  0x200000]) high = temp;
1907     //        case 21: if (searchValue < list[temp = high-  0x100000]) high = temp;
1908     //
1909     //        case 20: if (searchValue < list[temp = high-   0x80000]) high = temp;
1910     //        case 19: if (searchValue < list[temp = high-   0x40000]) high = temp;
1911     //        case 18: if (searchValue < list[temp = high-   0x20000]) high = temp;
1912     //        case 17: if (searchValue < list[temp = high-   0x10000]) high = temp;
1913     //
1914     //        case 16: if (searchValue < list[temp = high-    0x8000]) high = temp;
1915     //        case 15: if (searchValue < list[temp = high-    0x4000]) high = temp;
1916     //        case 14: if (searchValue < list[temp = high-    0x2000]) high = temp;
1917     //        case 13: if (searchValue < list[temp = high-    0x1000]) high = temp;
1918     //
1919     //        case 12: if (searchValue < list[temp = high-     0x800]) high = temp;
1920     //        case 11: if (searchValue < list[temp = high-     0x400]) high = temp;
1921     //        case 10: if (searchValue < list[temp = high-     0x200]) high = temp;
1922     //        case  9: if (searchValue < list[temp = high-     0x100]) high = temp;
1923     //
1924     //        case  8: if (searchValue < list[temp = high-      0x80]) high = temp;
1925     //        case  7: if (searchValue < list[temp = high-      0x40]) high = temp;
1926     //        case  6: if (searchValue < list[temp = high-      0x20]) high = temp;
1927     //        case  5: if (searchValue < list[temp = high-      0x10]) high = temp;
1928     //
1929     //        case  4: if (searchValue < list[temp = high-       0x8]) high = temp;
1930     //        case  3: if (searchValue < list[temp = high-       0x4]) high = temp;
1931     //        case  2: if (searchValue < list[temp = high-       0x2]) high = temp;
1932     //        case  1: if (searchValue < list[temp = high-       0x1]) high = temp;
1933     //        }
1934     //
1935     //        return high;
1936     //    }
1937     //
1938     //    // For debugging only
1939     //    public int len() {
1940     //        return len;
1941     //    }
1942     //
1943     //    //----------------------------------------------------------------
1944     //    //----------------------------------------------------------------
1945 
1946     /**
1947      * Returns true if this set contains every character
1948      * of the given range.
1949      * @param start first character, inclusive, of the range
1950      * @param end last character, inclusive, of the range
1951      * @return true if the test condition is met
1952      * @stable ICU 2.0
1953      */
contains(int start, int end)1954     public boolean contains(int start, int end) {
1955         if (start < MIN_VALUE || start > MAX_VALUE) {
1956             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
1957         }
1958         if (end < MIN_VALUE || end > MAX_VALUE) {
1959             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
1960         }
1961         //int i = -1;
1962         //while (true) {
1963         //    if (start < list[++i]) break;
1964         //}
1965         int i = findCodePoint(start);
1966         return ((i & 1) != 0 && end < list[i]);
1967     }
1968 
1969     /**
1970      * Returns <tt>true</tt> if this set contains the given
1971      * multicharacter string.
1972      * @param s string to be checked for containment
1973      * @return <tt>true</tt> if this set contains the specified string
1974      * @stable ICU 2.0
1975      */
contains(CharSequence s)1976     public final boolean contains(CharSequence s) {
1977 
1978         int cp = getSingleCP(s);
1979         if (cp < 0) {
1980             return strings.contains(s.toString());
1981         } else {
1982             return contains(cp);
1983         }
1984     }
1985 
1986     /**
1987      * Returns true if this set contains all the characters and strings
1988      * of the given set.
1989      * @param b set to be checked for containment
1990      * @return true if the test condition is met
1991      * @stable ICU 2.0
1992      */
containsAll(UnicodeSet b)1993     public boolean containsAll(UnicodeSet b) {
1994         // The specified set is a subset if all of its pairs are contained in
1995         // this set. This implementation accesses the lists directly for speed.
1996         // TODO: this could be faster if size() were cached. But that would affect building speed
1997         // so it needs investigation.
1998         int[] listB = b.list;
1999         boolean needA = true;
2000         boolean needB = true;
2001         int aPtr = 0;
2002         int bPtr = 0;
2003         int aLen = len - 1;
2004         int bLen = b.len - 1;
2005         int startA = 0, startB = 0, limitA = 0, limitB = 0;
2006         while (true) {
2007             // double iterations are such a pain...
2008             if (needA) {
2009                 if (aPtr >= aLen) {
2010                     // ran out of A. If B is also exhausted, then break;
2011                     if (needB && bPtr >= bLen) {
2012                         break;
2013                     }
2014                     return false;
2015                 }
2016                 startA = list[aPtr++];
2017                 limitA = list[aPtr++];
2018             }
2019             if (needB) {
2020                 if (bPtr >= bLen) {
2021                     // ran out of B. Since we got this far, we have an A and we are ok so far
2022                     break;
2023                 }
2024                 startB = listB[bPtr++];
2025                 limitB = listB[bPtr++];
2026             }
2027             // if B doesn't overlap and is greater than A, get new A
2028             if (startB >= limitA) {
2029                 needA = true;
2030                 needB = false;
2031                 continue;
2032             }
2033             // if B is wholy contained in A, then get a new B
2034             if (startB >= startA && limitB <= limitA) {
2035                 needA = false;
2036                 needB = true;
2037                 continue;
2038             }
2039             // all other combinations mean we fail
2040             return false;
2041         }
2042 
2043         if (!strings.containsAll(b.strings)) return false;
2044         return true;
2045     }
2046 
2047     //    /**
2048     //     * Returns true if this set contains all the characters and strings
2049     //     * of the given set.
2050     //     * @param c set to be checked for containment
2051     //     * @return true if the test condition is met
2052     //     * @stable ICU 2.0
2053     //     */
2054     //    public boolean containsAllOld(UnicodeSet c) {
2055     //        // The specified set is a subset if all of its pairs are contained in
2056     //        // this set.  It's possible to code this more efficiently in terms of
2057     //        // direct manipulation of the inversion lists if the need arises.
2058     //        int n = c.getRangeCount();
2059     //        for (int i=0; i<n; ++i) {
2060     //            if (!contains(c.getRangeStart(i), c.getRangeEnd(i))) {
2061     //                return false;
2062     //            }
2063     //        }
2064     //        if (!strings.containsAll(c.strings)) return false;
2065     //        return true;
2066     //    }
2067 
2068     /**
2069      * Returns true if there is a partition of the string such that this set contains each of the partitioned strings.
2070      * For example, for the Unicode set [a{bc}{cd}]<br>
2071      * containsAll is true for each of: "a", "bc", ""cdbca"<br>
2072      * containsAll is false for each of: "acb", "bcda", "bcx"<br>
2073      * @param s string containing characters to be checked for containment
2074      * @return true if the test condition is met
2075      * @stable ICU 2.0
2076      */
containsAll(String s)2077     public boolean containsAll(String s) {
2078         int cp;
2079         for (int i = 0; i < s.length(); i += UTF16.getCharCount(cp)) {
2080             cp = UTF16.charAt(s, i);
2081             if (!contains(cp))  {
2082                 if (!hasStrings()) {
2083                     return false;
2084                 }
2085                 return containsAll(s, 0);
2086             }
2087         }
2088         return true;
2089     }
2090 
2091     /**
2092      * Recursive routine called if we fail to find a match in containsAll, and there are strings
2093      * @param s source string
2094      * @param i point to match to the end on
2095      * @return true if ok
2096      */
containsAll(String s, int i)2097     private boolean containsAll(String s, int i) {
2098         if (i >= s.length()) {
2099             return true;
2100         }
2101         int  cp= UTF16.charAt(s, i);
2102         if (contains(cp) && containsAll(s, i+UTF16.getCharCount(cp))) {
2103             return true;
2104         }
2105         for (String setStr : strings) {
2106             if (!setStr.isEmpty() &&  // skip the empty string
2107                     s.startsWith(setStr, i) &&  containsAll(s, i+setStr.length())) {
2108                 return true;
2109             }
2110         }
2111         return false;
2112 
2113     }
2114 
2115     /**
2116      * Get the Regex equivalent for this UnicodeSet
2117      * @return regex pattern equivalent to this UnicodeSet
2118      * @internal
2119      * @deprecated This API is ICU internal only.
2120      */
2121     @Deprecated
getRegexEquivalent()2122     public String getRegexEquivalent() {
2123         if (!hasStrings()) {
2124             return toString();
2125         }
2126         StringBuilder result = new StringBuilder("(?:");
2127         appendNewPattern(result, true, false);
2128         for (String s : strings) {
2129             result.append('|');
2130             _appendToPat(result, s, true);
2131         }
2132         return result.append(")").toString();
2133     }
2134 
2135     /**
2136      * Returns true if this set contains none of the characters
2137      * of the given range.
2138      * @param start first character, inclusive, of the range
2139      * @param end last character, inclusive, of the range
2140      * @return true if the test condition is met
2141      * @stable ICU 2.0
2142      */
containsNone(int start, int end)2143     public boolean containsNone(int start, int end) {
2144         if (start < MIN_VALUE || start > MAX_VALUE) {
2145             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(start, 6));
2146         }
2147         if (end < MIN_VALUE || end > MAX_VALUE) {
2148             throw new IllegalArgumentException("Invalid code point U+" + Utility.hex(end, 6));
2149         }
2150         int i = -1;
2151         while (true) {
2152             if (start < list[++i]) break;
2153         }
2154         return ((i & 1) == 0 && end < list[i]);
2155     }
2156 
2157     /**
2158      * Returns true if none of the characters or strings in this UnicodeSet appears in the string.
2159      * For example, for the Unicode set [a{bc}{cd}]<br>
2160      * containsNone is true for: "xy", "cb"<br>
2161      * containsNone is false for: "a", "bc", "bcd"<br>
2162      * @param b set to be checked for containment
2163      * @return true if the test condition is met
2164      * @stable ICU 2.0
2165      */
containsNone(UnicodeSet b)2166     public boolean containsNone(UnicodeSet b) {
2167         // The specified set is a subset if some of its pairs overlap with some of this set's pairs.
2168         // This implementation accesses the lists directly for speed.
2169         int[] listB = b.list;
2170         boolean needA = true;
2171         boolean needB = true;
2172         int aPtr = 0;
2173         int bPtr = 0;
2174         int aLen = len - 1;
2175         int bLen = b.len - 1;
2176         int startA = 0, startB = 0, limitA = 0, limitB = 0;
2177         while (true) {
2178             // double iterations are such a pain...
2179             if (needA) {
2180                 if (aPtr >= aLen) {
2181                     // ran out of A: break so we test strings
2182                     break;
2183                 }
2184                 startA = list[aPtr++];
2185                 limitA = list[aPtr++];
2186             }
2187             if (needB) {
2188                 if (bPtr >= bLen) {
2189                     // ran out of B: break so we test strings
2190                     break;
2191                 }
2192                 startB = listB[bPtr++];
2193                 limitB = listB[bPtr++];
2194             }
2195             // if B is higher than any part of A, get new A
2196             if (startB >= limitA) {
2197                 needA = true;
2198                 needB = false;
2199                 continue;
2200             }
2201             // if A is higher than any part of B, get new B
2202             if (startA >= limitB) {
2203                 needA = false;
2204                 needB = true;
2205                 continue;
2206             }
2207             // all other combinations mean we fail
2208             return false;
2209         }
2210 
2211         if (!SortedSetRelation.hasRelation(strings, SortedSetRelation.DISJOINT, b.strings)) return false;
2212         return true;
2213     }
2214 
2215     //    /**
2216     //     * Returns true if none of the characters or strings in this UnicodeSet appears in the string.
2217     //     * For example, for the Unicode set [a{bc}{cd}]<br>
2218     //     * containsNone is true for: "xy", "cb"<br>
2219     //     * containsNone is false for: "a", "bc", "bcd"<br>
2220     //     * @param c set to be checked for containment
2221     //     * @return true if the test condition is met
2222     //     * @stable ICU 2.0
2223     //     */
2224     //    public boolean containsNoneOld(UnicodeSet c) {
2225     //        // The specified set is a subset if all of its pairs are contained in
2226     //        // this set.  It's possible to code this more efficiently in terms of
2227     //        // direct manipulation of the inversion lists if the need arises.
2228     //        int n = c.getRangeCount();
2229     //        for (int i=0; i<n; ++i) {
2230     //            if (!containsNone(c.getRangeStart(i), c.getRangeEnd(i))) {
2231     //                return false;
2232     //            }
2233     //        }
2234     //        if (!SortedSetRelation.hasRelation(strings, SortedSetRelation.DISJOINT, c.strings)) return false;
2235     //        return true;
2236     //    }
2237 
2238     /**
2239      * Returns true if this set contains none of the characters
2240      * of the given string.
2241      * @param s string containing characters to be checked for containment
2242      * @return true if the test condition is met
2243      * @stable ICU 2.0
2244      */
containsNone(CharSequence s)2245     public boolean containsNone(CharSequence s) {
2246         return span(s, SpanCondition.NOT_CONTAINED) == s.length();
2247     }
2248 
2249     /**
2250      * Returns true if this set contains one or more of the characters
2251      * in the given range.
2252      * @param start first character, inclusive, of the range
2253      * @param end last character, inclusive, of the range
2254      * @return true if the condition is met
2255      * @stable ICU 2.0
2256      */
containsSome(int start, int end)2257     public final boolean containsSome(int start, int end) {
2258         return !containsNone(start, end);
2259     }
2260 
2261     /**
2262      * Returns true if this set contains one or more of the characters
2263      * and strings of the given set.
2264      * @param s set to be checked for containment
2265      * @return true if the condition is met
2266      * @stable ICU 2.0
2267      */
containsSome(UnicodeSet s)2268     public final boolean containsSome(UnicodeSet s) {
2269         return !containsNone(s);
2270     }
2271 
2272     /**
2273      * Returns true if this set contains one or more of the characters
2274      * of the given string.
2275      * @param s string containing characters to be checked for containment
2276      * @return true if the condition is met
2277      * @stable ICU 2.0
2278      */
containsSome(CharSequence s)2279     public final boolean containsSome(CharSequence s) {
2280         return !containsNone(s);
2281     }
2282 
2283 
2284     /**
2285      * Adds all of the elements in the specified set to this set if
2286      * they're not already present.  This operation effectively
2287      * modifies this set so that its value is the <i>union</i> of the two
2288      * sets.  The behavior of this operation is unspecified if the specified
2289      * collection is modified while the operation is in progress.
2290      *
2291      * @param c set whose elements are to be added to this set.
2292      * @stable ICU 2.0
2293      */
addAll(UnicodeSet c)2294     public UnicodeSet addAll(UnicodeSet c) {
2295         checkFrozen();
2296         add(c.list, c.len, 0);
2297         if (c.hasStrings()) {
2298             if (strings == EMPTY_STRINGS) {
2299                 strings = new TreeSet<>(c.strings);
2300             } else {
2301                 strings.addAll(c.strings);
2302             }
2303         }
2304         return this;
2305     }
2306 
2307     /**
2308      * Retains only the elements in this set that are contained in the
2309      * specified set.  In other words, removes from this set all of
2310      * its elements that are not contained in the specified set.  This
2311      * operation effectively modifies this set so that its value is
2312      * the <i>intersection</i> of the two sets.
2313      *
2314      * @param c set that defines which elements this set will retain.
2315      * @stable ICU 2.0
2316      */
retainAll(UnicodeSet c)2317     public UnicodeSet retainAll(UnicodeSet c) {
2318         checkFrozen();
2319         retain(c.list, c.len, 0);
2320         if (hasStrings()) {
2321             if (!c.hasStrings()) {
2322                 strings.clear();
2323             } else {
2324                 strings.retainAll(c.strings);
2325             }
2326         }
2327         return this;
2328     }
2329 
2330     /**
2331      * Removes from this set all of its elements that are contained in the
2332      * specified set.  This operation effectively modifies this
2333      * set so that its value is the <i>asymmetric set difference</i> of
2334      * the two sets.
2335      *
2336      * @param c set that defines which elements will be removed from
2337      *          this set.
2338      * @stable ICU 2.0
2339      */
removeAll(UnicodeSet c)2340     public UnicodeSet removeAll(UnicodeSet c) {
2341         checkFrozen();
2342         retain(c.list, c.len, 2);
2343         if (hasStrings() && c.hasStrings()) {
2344             strings.removeAll(c.strings);
2345         }
2346         return this;
2347     }
2348 
2349     /**
2350      * Complements in this set all elements contained in the specified
2351      * set.  Any character in the other set will be removed if it is
2352      * in this set, or will be added if it is not in this set.
2353      *
2354      * @param c set that defines which elements will be complemented from
2355      *          this set.
2356      * @stable ICU 2.0
2357      */
complementAll(UnicodeSet c)2358     public UnicodeSet complementAll(UnicodeSet c) {
2359         checkFrozen();
2360         xor(c.list, c.len, 0);
2361         if (c.hasStrings()) {
2362             if (strings == EMPTY_STRINGS) {
2363                 strings = new TreeSet<>(c.strings);
2364             } else {
2365                 SortedSetRelation.doOperation(strings, SortedSetRelation.COMPLEMENTALL, c.strings);
2366             }
2367         }
2368         return this;
2369     }
2370 
2371     /**
2372      * Removes all of the elements from this set.  This set will be
2373      * empty after this call returns.
2374      * @stable ICU 2.0
2375      */
clear()2376     public UnicodeSet clear() {
2377         checkFrozen();
2378         list[0] = HIGH;
2379         len = 1;
2380         pat = null;
2381         if (hasStrings()) {
2382             strings.clear();
2383         }
2384         return this;
2385     }
2386 
2387     /**
2388      * Iteration method that returns the number of ranges contained in
2389      * this set.
2390      * @see #getRangeStart
2391      * @see #getRangeEnd
2392      * @stable ICU 2.0
2393      */
getRangeCount()2394     public int getRangeCount() {
2395         return len/2;
2396     }
2397 
2398     /**
2399      * Iteration method that returns the first character in the
2400      * specified range of this set.
2401      * @exception ArrayIndexOutOfBoundsException if index is outside
2402      * the range <code>0..getRangeCount()-1</code>
2403      * @see #getRangeCount
2404      * @see #getRangeEnd
2405      * @stable ICU 2.0
2406      */
getRangeStart(int index)2407     public int getRangeStart(int index) {
2408         return list[index*2];
2409     }
2410 
2411     /**
2412      * Iteration method that returns the last character in the
2413      * specified range of this set.
2414      * @exception ArrayIndexOutOfBoundsException if index is outside
2415      * the range <code>0..getRangeCount()-1</code>
2416      * @see #getRangeStart
2417      * @see #getRangeEnd
2418      * @stable ICU 2.0
2419      */
getRangeEnd(int index)2420     public int getRangeEnd(int index) {
2421         return (list[index*2 + 1] - 1);
2422     }
2423 
2424     /**
2425      * Reallocate this objects internal structures to take up the least
2426      * possible space, without changing this object's value.
2427      * @stable ICU 2.0
2428      */
compact()2429     public UnicodeSet compact() {
2430         checkFrozen();
2431         if ((len + 7) < list.length) {
2432             // If we have more than a little unused capacity, shrink it to len.
2433             list = Arrays.copyOf(list, len);
2434         }
2435         rangeList = null;
2436         buffer = null;
2437         if (strings != EMPTY_STRINGS && strings.isEmpty()) {
2438             strings = EMPTY_STRINGS;
2439         }
2440         return this;
2441     }
2442 
2443     /**
2444      * Compares the specified object with this set for equality.  Returns
2445      * <tt>true</tt> if the specified object is also a set, the two sets
2446      * have the same size, and every member of the specified set is
2447      * contained in this set (or equivalently, every member of this set is
2448      * contained in the specified set).
2449      *
2450      * @param o Object to be compared for equality with this set.
2451      * @return <tt>true</tt> if the specified Object is equal to this set.
2452      * @stable ICU 2.0
2453      */
2454     @Override
equals(Object o)2455     public boolean equals(Object o) {
2456         if (o == null) {
2457             return false;
2458         }
2459         if (this == o) {
2460             return true;
2461         }
2462         try {
2463             UnicodeSet that = (UnicodeSet) o;
2464             if (len != that.len) return false;
2465             for (int i = 0; i < len; ++i) {
2466                 if (list[i] != that.list[i]) return false;
2467             }
2468             if (!strings.equals(that.strings)) return false;
2469         } catch (Exception e) {
2470             return false;
2471         }
2472         return true;
2473     }
2474 
2475     /**
2476      * Returns the hash code value for this set.
2477      *
2478      * @return the hash code value for this set.
2479      * @see java.lang.Object#hashCode()
2480      * @stable ICU 2.0
2481      */
2482     @Override
hashCode()2483     public int hashCode() {
2484         int result = len;
2485         for (int i = 0; i < len; ++i) {
2486             result *= 1000003;
2487             result += list[i];
2488         }
2489         return result;
2490     }
2491 
2492     /**
2493      * Return a programmer-readable string representation of this object.
2494      * @stable ICU 2.0
2495      */
2496     @Override
toString()2497     public String toString() {
2498         return toPattern(true);
2499     }
2500 
2501     //----------------------------------------------------------------
2502     // Implementation: Pattern parsing
2503     //----------------------------------------------------------------
2504 
2505     /**
2506      * Parses the given pattern, starting at the given position.  The character
2507      * at pattern.charAt(pos.getIndex()) must be '[', or the parse fails.
2508      * Parsing continues until the corresponding closing ']'.  If a syntax error
2509      * is encountered between the opening and closing brace, the parse fails.
2510      * Upon return from a successful parse, the ParsePosition is updated to
2511      * point to the character following the closing ']', and an inversion
2512      * list for the parsed pattern is returned.  This method
2513      * calls itself recursively to parse embedded subpatterns.
2514      *
2515      * @param pattern the string containing the pattern to be parsed.  The
2516      * portion of the string from pos.getIndex(), which must be a '[', to the
2517      * corresponding closing ']', is parsed.
2518      * @param pos upon entry, the position at which to being parsing.  The
2519      * character at pattern.charAt(pos.getIndex()) must be a '['.  Upon return
2520      * from a successful parse, pos.getIndex() is either the character after the
2521      * closing ']' of the parsed pattern, or pattern.length() if the closing ']'
2522      * is the last character of the pattern string.
2523      * @return an inversion list for the parsed substring
2524      * of <code>pattern</code>
2525      * @exception java.lang.IllegalArgumentException if the parse fails.
2526      * @internal
2527      * @deprecated This API is ICU internal only.
2528      */
2529     @Deprecated
applyPattern(String pattern, ParsePosition pos, SymbolTable symbols, int options)2530     public UnicodeSet applyPattern(String pattern,
2531             ParsePosition pos,
2532             SymbolTable symbols,
2533             int options) {
2534 
2535         // Need to build the pattern in a temporary string because
2536         // _applyPattern calls add() etc., which set pat to empty.
2537         boolean parsePositionWasNull = pos == null;
2538         if (parsePositionWasNull) {
2539             pos = new ParsePosition(0);
2540         }
2541 
2542         StringBuilder rebuiltPat = new StringBuilder();
2543         RuleCharacterIterator chars =
2544                 new RuleCharacterIterator(pattern, symbols, pos);
2545         applyPattern(chars, symbols, rebuiltPat, options, 0);
2546         if (chars.inVariable()) {
2547             syntaxError(chars, "Extra chars in variable value");
2548         }
2549         pat = rebuiltPat.toString();
2550         if (parsePositionWasNull) {
2551             int i = pos.getIndex();
2552 
2553             // Skip over trailing whitespace
2554             if ((options & IGNORE_SPACE) != 0) {
2555                 i = PatternProps.skipWhiteSpace(pattern, i);
2556             }
2557 
2558             if (i != pattern.length()) {
2559                 throw new IllegalArgumentException("Parse of \"" + pattern +
2560                         "\" failed at " + i);
2561             }
2562         }
2563         return this;
2564     }
2565 
2566     // Add constants to make the applyPattern() code easier to follow.
2567 
2568     private static final int LAST0_START = 0,
2569             LAST1_RANGE = 1,
2570             LAST2_SET = 2;
2571 
2572     private static final int MODE0_NONE = 0,
2573             MODE1_INBRACKET = 1,
2574             MODE2_OUTBRACKET = 2;
2575 
2576     private static final int SETMODE0_NONE = 0,
2577             SETMODE1_UNICODESET = 1,
2578             SETMODE2_PROPERTYPAT = 2,
2579             SETMODE3_PREPARSED = 3;
2580 
2581     private static final int MAX_DEPTH = 100;
2582 
2583     /**
2584      * Parse the pattern from the given RuleCharacterIterator.  The
2585      * iterator is advanced over the parsed pattern.
2586      * @param chars iterator over the pattern characters.  Upon return
2587      * it will be advanced to the first character after the parsed
2588      * pattern, or the end of the iteration if all characters are
2589      * parsed.
2590      * @param symbols symbol table to use to parse and dereference
2591      * variables, or null if none.
2592      * @param rebuiltPat the pattern that was parsed, rebuilt or
2593      * copied from the input pattern, as appropriate.
2594      * @param options a bit mask.
2595      * Valid options are {@link #IGNORE_SPACE} and
2596      * at most one of {@link #CASE_INSENSITIVE}, {@link #ADD_CASE_MAPPINGS},
2597      * {@link #SIMPLE_CASE_INSENSITIVE}. These case options are mutually exclusive.
2598      */
applyPattern(RuleCharacterIterator chars, SymbolTable symbols, Appendable rebuiltPat, int options, int depth)2599     private void applyPattern(RuleCharacterIterator chars, SymbolTable symbols,
2600             Appendable rebuiltPat, int options, int depth) {
2601         if (depth > MAX_DEPTH) {
2602             syntaxError(chars, "Pattern nested too deeply");
2603         }
2604 
2605         // Syntax characters: [ ] ^ - & { }
2606 
2607         // Recognized special forms for chars, sets: c-c s-s s&s
2608 
2609         int opts = RuleCharacterIterator.PARSE_VARIABLES |
2610                 RuleCharacterIterator.PARSE_ESCAPES;
2611         if ((options & IGNORE_SPACE) != 0) {
2612             opts |= RuleCharacterIterator.SKIP_WHITESPACE;
2613         }
2614 
2615         StringBuilder patBuf = new StringBuilder(), buf = null;
2616         boolean usePat = false;
2617         UnicodeSet scratch = null;
2618         RuleCharacterIterator.Position backup = null;
2619 
2620         // mode: 0=before [, 1=between [...], 2=after ]
2621         // lastItem: 0=none, 1=char, 2=set
2622         int lastItem = LAST0_START, lastChar = 0, mode = MODE0_NONE;
2623         char op = 0;
2624 
2625         boolean invert = false;
2626 
2627         clear();
2628         String lastString = null;
2629 
2630         while (mode != MODE2_OUTBRACKET && !chars.atEnd()) {
2631             //Eclipse stated the following is "dead code"
2632             /*
2633             if (false) {
2634                 // Debugging assertion
2635                 if (!((lastItem == 0 && op == 0) ||
2636                         (lastItem == 1 && (op == 0 || op == '-')) ||
2637                         (lastItem == 2 && (op == 0 || op == '-' || op == '&')))) {
2638                     throw new IllegalArgumentException();
2639                 }
2640             }*/
2641 
2642             int c = 0;
2643             boolean literal = false;
2644             UnicodeSet nested = null;
2645 
2646             // -------- Check for property pattern
2647 
2648             // setMode: 0=none, 1=unicodeset, 2=propertypat, 3=preparsed
2649             int setMode = SETMODE0_NONE;
2650             if (resemblesPropertyPattern(chars, opts)) {
2651                 setMode = SETMODE2_PROPERTYPAT;
2652             }
2653 
2654             // -------- Parse '[' of opening delimiter OR nested set.
2655             // If there is a nested set, use `setMode' to define how
2656             // the set should be parsed.  If the '[' is part of the
2657             // opening delimiter for this pattern, parse special
2658             // strings "[", "[^", "[-", and "[^-".  Check for stand-in
2659             // characters representing a nested set in the symbol
2660             // table.
2661 
2662             else {
2663                 // Prepare to backup if necessary
2664                 backup = chars.getPos(backup);
2665                 c = chars.next(opts);
2666                 literal = chars.isEscaped();
2667 
2668                 if (c == '[' && !literal) {
2669                     if (mode == MODE1_INBRACKET) {
2670                         chars.setPos(backup); // backup
2671                         setMode = SETMODE1_UNICODESET;
2672                     } else {
2673                         // Handle opening '[' delimiter
2674                         mode = MODE1_INBRACKET;
2675                         patBuf.append('[');
2676                         backup = chars.getPos(backup); // prepare to backup
2677                         c = chars.next(opts);
2678                         literal = chars.isEscaped();
2679                         if (c == '^' && !literal) {
2680                             invert = true;
2681                             patBuf.append('^');
2682                             backup = chars.getPos(backup); // prepare to backup
2683                             c = chars.next(opts);
2684                             literal = chars.isEscaped();
2685                         }
2686                         // Fall through to handle special leading '-';
2687                         // otherwise restart loop for nested [], \p{}, etc.
2688                         if (c == '-') {
2689                             literal = true;
2690                             // Fall through to handle literal '-' below
2691                         } else {
2692                             chars.setPos(backup); // backup
2693                             continue;
2694                         }
2695                     }
2696                 } else if (symbols != null) {
2697                     UnicodeMatcher m = symbols.lookupMatcher(c); // may be null
2698                     if (m != null) {
2699                         try {
2700                             nested = (UnicodeSet) m;
2701                             setMode = SETMODE3_PREPARSED;
2702                         } catch (ClassCastException e) {
2703                             syntaxError(chars, "Syntax error");
2704                         }
2705                     }
2706                 }
2707             }
2708 
2709             // -------- Handle a nested set.  This either is inline in
2710             // the pattern or represented by a stand-in that has
2711             // previously been parsed and was looked up in the symbol
2712             // table.
2713 
2714             if (setMode != SETMODE0_NONE) {
2715                 if (lastItem == LAST1_RANGE) {
2716                     if (op != 0) {
2717                         syntaxError(chars, "Char expected after operator");
2718                     }
2719                     add_unchecked(lastChar, lastChar);
2720                     _appendToPat(patBuf, lastChar, false);
2721                     lastItem = LAST0_START;
2722                     op = 0;
2723                 }
2724 
2725                 if (op == '-' || op == '&') {
2726                     patBuf.append(op);
2727                 }
2728 
2729                 if (nested == null) {
2730                     if (scratch == null) scratch = new UnicodeSet();
2731                     nested = scratch;
2732                 }
2733                 switch (setMode) {
2734                 case SETMODE1_UNICODESET:
2735                     nested.applyPattern(chars, symbols, patBuf, options, depth + 1);
2736                     break;
2737                 case SETMODE2_PROPERTYPAT:
2738                     chars.skipIgnored(opts);
2739                     nested.applyPropertyPattern(chars, patBuf, symbols);
2740                     break;
2741                 case SETMODE3_PREPARSED: // `nested' already parsed
2742                     nested._toPattern(patBuf, false);
2743                     break;
2744                 }
2745 
2746                 usePat = true;
2747 
2748                 if (mode == MODE0_NONE) {
2749                     // Entire pattern is a category; leave parse loop
2750                     set(nested);
2751                     mode = MODE2_OUTBRACKET;
2752                     break;
2753                 }
2754 
2755                 switch (op) {
2756                 case '-':
2757                     removeAll(nested);
2758                     break;
2759                 case '&':
2760                     retainAll(nested);
2761                     break;
2762                 case 0:
2763                     addAll(nested);
2764                     break;
2765                 }
2766 
2767                 op = 0;
2768                 lastItem = LAST2_SET;
2769 
2770                 continue;
2771             }
2772 
2773             if (mode == MODE0_NONE) {
2774                 syntaxError(chars, "Missing '['");
2775             }
2776 
2777             // -------- Parse special (syntax) characters.  If the
2778             // current character is not special, or if it is escaped,
2779             // then fall through and handle it below.
2780 
2781             if (!literal) {
2782                 switch (c) {
2783                 case ']':
2784                     if (lastItem == LAST1_RANGE) {
2785                         add_unchecked(lastChar, lastChar);
2786                         _appendToPat(patBuf, lastChar, false);
2787                     }
2788                     // Treat final trailing '-' as a literal
2789                     if (op == '-') {
2790                         add_unchecked(op, op);
2791                         patBuf.append(op);
2792                     } else if (op == '&') {
2793                         syntaxError(chars, "Trailing '&'");
2794                     }
2795                     patBuf.append(']');
2796                     mode = MODE2_OUTBRACKET;
2797                     continue;
2798                 case '-':
2799                     if (op == 0) {
2800                         if (lastItem != LAST0_START) {
2801                             op = (char) c;
2802                             continue;
2803                         } else if (lastString != null) {
2804                             op = (char) c;
2805                             continue;
2806                         } else {
2807                             // Treat final trailing '-' as a literal
2808                             add_unchecked(c, c);
2809                             c = chars.next(opts);
2810                             literal = chars.isEscaped();
2811                             if (c == ']' && !literal) {
2812                                 patBuf.append("-]");
2813                                 mode = MODE2_OUTBRACKET;
2814                                 continue;
2815                             }
2816                         }
2817                     }
2818                     syntaxError(chars, "'-' not after char, string, or set");
2819                     break;
2820                 case '&':
2821                     if (lastItem == LAST2_SET && op == 0) {
2822                         op = (char) c;
2823                         continue;
2824                     }
2825                     syntaxError(chars, "'&' not after set");
2826                     break;
2827                 case '^':
2828                     syntaxError(chars, "'^' not after '['");
2829                     break;
2830                 case '{':
2831                     if (op != 0 && op != '-') {
2832                         syntaxError(chars, "Missing operand after operator");
2833                     }
2834                     if (lastItem == LAST1_RANGE) {
2835                         add_unchecked(lastChar, lastChar);
2836                         _appendToPat(patBuf, lastChar, false);
2837                     }
2838                     lastItem = LAST0_START;
2839                     if (buf == null) {
2840                         buf = new StringBuilder();
2841                     } else {
2842                         buf.setLength(0);
2843                     }
2844                     boolean ok = false;
2845                     while (!chars.atEnd()) {
2846                         c = chars.next(opts);
2847                         literal = chars.isEscaped();
2848                         if (c == '}' && !literal) {
2849                             ok = true;
2850                             break;
2851                         }
2852                         appendCodePoint(buf, c);
2853                     }
2854                     if (!ok) {
2855                         syntaxError(chars, "Invalid multicharacter string");
2856                     }
2857                     // We have new string. Add it to set and continue;
2858                     // we don't need to drop through to the further
2859                     // processing
2860                     String curString = buf.toString();
2861                     if (op == '-') {
2862                         int lastSingle = CharSequences.getSingleCodePoint(lastString == null ? "" : lastString);
2863                         int curSingle = CharSequences.getSingleCodePoint(curString);
2864                         if (lastSingle != Integer.MAX_VALUE && curSingle != Integer.MAX_VALUE) {
2865                             add(lastSingle,curSingle);
2866                         } else {
2867                             if (strings == EMPTY_STRINGS) {
2868                                 strings = new TreeSet<>();
2869                             }
2870                             try {
2871                                 StringRange.expand(lastString, curString, true, strings);
2872                             } catch (Exception e) {
2873                                 syntaxError(chars, e.getMessage());
2874                             }
2875                         }
2876                         lastString = null;
2877                         op = 0;
2878                     } else {
2879                         add(curString);
2880                         lastString = curString;
2881                     }
2882                     patBuf.append('{');
2883                     _appendToPat(patBuf, curString, false);
2884                     patBuf.append('}');
2885                     continue;
2886                 case SymbolTable.SYMBOL_REF:
2887                     //         symbols  nosymbols
2888                     // [a-$]   error    error (ambiguous)
2889                     // [a$]    anchor   anchor
2890                     // [a-$x]  var "x"* literal '$'
2891                     // [a-$.]  error    literal '$'
2892                     // *We won't get here in the case of var "x"
2893                     backup = chars.getPos(backup);
2894                     c = chars.next(opts);
2895                     literal = chars.isEscaped();
2896                     boolean anchor = (c == ']' && !literal);
2897                     if (symbols == null && !anchor) {
2898                         c = SymbolTable.SYMBOL_REF;
2899                         chars.setPos(backup);
2900                         break; // literal '$'
2901                     }
2902                     if (anchor && op == 0) {
2903                         if (lastItem == LAST1_RANGE) {
2904                             add_unchecked(lastChar, lastChar);
2905                             _appendToPat(patBuf, lastChar, false);
2906                         }
2907                         add_unchecked(UnicodeMatcher.ETHER);
2908                         usePat = true;
2909                         patBuf.append(SymbolTable.SYMBOL_REF).append(']');
2910                         mode = MODE2_OUTBRACKET;
2911                         continue;
2912                     }
2913                     syntaxError(chars, "Unquoted '$'");
2914                     break;
2915                 default:
2916                     break;
2917                 }
2918             }
2919 
2920             // -------- Parse literal characters.  This includes both
2921             // escaped chars ("\u4E01") and non-syntax characters
2922             // ("a").
2923 
2924             switch (lastItem) {
2925             case LAST0_START:
2926                 if (op == '-' && lastString != null) {
2927                     syntaxError(chars, "Invalid range");
2928                 }
2929                 lastItem = LAST1_RANGE;
2930                 lastChar = c;
2931                 lastString = null;
2932                 break;
2933             case LAST1_RANGE:
2934                 if (op == '-') {
2935                     if (lastString != null) {
2936                         syntaxError(chars, "Invalid range");
2937                     }
2938                     if (lastChar >= c) {
2939                         // Don't allow redundant (a-a) or empty (b-a) ranges;
2940                         // these are most likely typos.
2941                         syntaxError(chars, "Invalid range");
2942                     }
2943                     add_unchecked(lastChar, c);
2944                     _appendToPat(patBuf, lastChar, false);
2945                     patBuf.append(op);
2946                     _appendToPat(patBuf, c, false);
2947                     lastItem = LAST0_START;
2948                     op = 0;
2949                 } else {
2950                     add_unchecked(lastChar, lastChar);
2951                     _appendToPat(patBuf, lastChar, false);
2952                     lastChar = c;
2953                 }
2954                 break;
2955             case LAST2_SET:
2956                 if (op != 0) {
2957                     syntaxError(chars, "Set expected after operator");
2958                 }
2959                 lastChar = c;
2960                 lastItem = LAST1_RANGE;
2961                 break;
2962             }
2963         }
2964 
2965         if (mode != MODE2_OUTBRACKET) {
2966             syntaxError(chars, "Missing ']'");
2967         }
2968 
2969         chars.skipIgnored(opts);
2970 
2971         /**
2972          * Handle global flags (invert, case insensitivity).  If this
2973          * pattern should be compiled case-insensitive, then we need
2974          * to close over case BEFORE COMPLEMENTING.  This makes
2975          * patterns like /[^abc]/i work.
2976          */
2977         if ((options & CASE_MASK) != 0) {
2978             closeOver(options);
2979         }
2980         if (invert) {
2981             complement().removeAllStrings();  // code point complement
2982         }
2983 
2984         // Use the rebuilt pattern (pat) only if necessary.  Prefer the
2985         // generated pattern.
2986         if (usePat) {
2987             append(rebuiltPat, patBuf.toString());
2988         } else {
2989             appendNewPattern(rebuiltPat, false, true);
2990         }
2991     }
2992 
syntaxError(RuleCharacterIterator chars, String msg)2993     private static void syntaxError(RuleCharacterIterator chars, String msg) {
2994         throw new IllegalArgumentException("Error: " + msg + " at \"" +
2995                 Utility.escape(chars.toString()) +
2996                 '"');
2997     }
2998 
2999     /**
3000      * Add the contents of the UnicodeSet (as strings) into a collection.
3001      * @param target collection to add into
3002      * @stable ICU 4.4
3003      */
addAllTo(T target)3004     public <T extends Collection<String>> T addAllTo(T target) {
3005         return addAllTo(this, target);
3006     }
3007 
3008 
3009     /**
3010      * Add the contents of the UnicodeSet (as strings) into a collection.
3011      * @param target collection to add into
3012      * @stable ICU 4.4
3013      */
addAllTo(String[] target)3014     public String[] addAllTo(String[] target) {
3015         return addAllTo(this, target);
3016     }
3017 
3018     /**
3019      * Add the contents of the UnicodeSet (as strings) into an array.
3020      * @stable ICU 4.4
3021      */
toArray(UnicodeSet set)3022     public static String[] toArray(UnicodeSet set) {
3023         return addAllTo(set, new String[set.size()]);
3024     }
3025 
3026     /**
3027      * Add the contents of the collection (as strings) into this UnicodeSet.
3028      * The collection must not contain null.
3029      * @param source the collection to add
3030      * @return a reference to this object
3031      * @stable ICU 4.4
3032      */
add(Iterable<?> source)3033     public UnicodeSet add(Iterable<?> source) {
3034         return addAll(source);
3035     }
3036 
3037     /**
3038      * Add a collection (as strings) into this UnicodeSet.
3039      * Uses standard naming convention.
3040      * @param source collection to add into
3041      * @return a reference to this object
3042      * @stable ICU 4.4
3043      */
addAll(Iterable<?> source)3044     public UnicodeSet addAll(Iterable<?> source) {
3045         checkFrozen();
3046         for (Object o : source) {
3047             add(o.toString());
3048         }
3049         return this;
3050     }
3051 
3052     //----------------------------------------------------------------
3053     // Implementation: Utility methods
3054     //----------------------------------------------------------------
3055 
nextCapacity(int minCapacity)3056     private int nextCapacity(int minCapacity) {
3057         // Grow exponentially to reduce the frequency of allocations.
3058         if (minCapacity < INITIAL_CAPACITY) {
3059             return minCapacity + INITIAL_CAPACITY;
3060         } else if (minCapacity <= 2500) {
3061             return 5 * minCapacity;
3062         } else {
3063             int newCapacity = 2 * minCapacity;
3064             if (newCapacity > MAX_LENGTH) {
3065                 newCapacity = MAX_LENGTH;
3066             }
3067             return newCapacity;
3068         }
3069     }
3070 
ensureCapacity(int newLen)3071     private void ensureCapacity(int newLen) {
3072         if (newLen > MAX_LENGTH) {
3073             newLen = MAX_LENGTH;
3074         }
3075         if (newLen <= list.length) return;
3076         int newCapacity = nextCapacity(newLen);
3077         int[] temp = new int[newCapacity];
3078         // Copy only the actual contents.
3079         System.arraycopy(list, 0, temp, 0, len);
3080         list = temp;
3081     }
3082 
ensureBufferCapacity(int newLen)3083     private void ensureBufferCapacity(int newLen) {
3084         if (newLen > MAX_LENGTH) {
3085             newLen = MAX_LENGTH;
3086         }
3087         if (buffer != null && newLen <= buffer.length) return;
3088         int newCapacity = nextCapacity(newLen);
3089         buffer = new int[newCapacity];
3090         // The buffer has no contents to be copied.
3091         // It is always filled from scratch after this call.
3092     }
3093 
3094     /**
3095      * Assumes start <= end.
3096      */
range(int start, int end)3097     private int[] range(int start, int end) {
3098         if (rangeList == null) {
3099             rangeList = new int[] { start, end+1, HIGH };
3100         } else {
3101             rangeList[0] = start;
3102             rangeList[1] = end+1;
3103         }
3104         return rangeList;
3105     }
3106 
3107     //----------------------------------------------------------------
3108     // Implementation: Fundamental operations
3109     //----------------------------------------------------------------
3110 
3111     // polarity = 0, 3 is normal: x xor y
3112     // polarity = 1, 2: x xor ~y == x === y
3113 
xor(int[] other, int otherLen, int polarity)3114     private UnicodeSet xor(int[] other, int otherLen, int polarity) {
3115         ensureBufferCapacity(len + otherLen);
3116         int i = 0, j = 0, k = 0;
3117         int a = list[i++];
3118         int b;
3119         // TODO: Based on the call hierarchy, polarity of 1 or 2 is never used
3120         //      so the following if statement will not be called.
3121         ///CLOVER:OFF
3122         if (polarity == 1 || polarity == 2) {
3123             b = LOW;
3124             if (other[j] == LOW) { // skip base if already LOW
3125                 ++j;
3126                 b = other[j];
3127             }
3128             ///CLOVER:ON
3129         } else {
3130             b = other[j++];
3131         }
3132         // simplest of all the routines
3133         // sort the values, discarding identicals!
3134         while (true) {
3135             if (a < b) {
3136                 buffer[k++] = a;
3137                 a = list[i++];
3138             } else if (b < a) {
3139                 buffer[k++] = b;
3140                 b = other[j++];
3141             } else if (a != HIGH) { // at this point, a == b
3142                 // discard both values!
3143                 a = list[i++];
3144                 b = other[j++];
3145             } else { // DONE!
3146                 buffer[k++] = HIGH;
3147                 len = k;
3148                 break;
3149             }
3150         }
3151         // swap list and buffer
3152         int[] temp = list;
3153         list = buffer;
3154         buffer = temp;
3155         pat = null;
3156         return this;
3157     }
3158 
3159     // polarity = 0 is normal: x union y
3160     // polarity = 2: x union ~y
3161     // polarity = 1: ~x union y
3162     // polarity = 3: ~x union ~y
3163 
add(int[] other, int otherLen, int polarity)3164     private UnicodeSet add(int[] other, int otherLen, int polarity) {
3165         ensureBufferCapacity(len + otherLen);
3166         int i = 0, j = 0, k = 0;
3167         int a = list[i++];
3168         int b = other[j++];
3169         // change from xor is that we have to check overlapping pairs
3170         // polarity bit 1 means a is second, bit 2 means b is.
3171         main:
3172             while (true) {
3173                 switch (polarity) {
3174                 case 0: // both first; take lower if unequal
3175                     if (a < b) { // take a
3176                         // Back up over overlapping ranges in buffer[]
3177                         if (k > 0 && a <= buffer[k-1]) {
3178                             // Pick latter end value in buffer[] vs. list[]
3179                             a = max(list[i], buffer[--k]);
3180                         } else {
3181                             // No overlap
3182                             buffer[k++] = a;
3183                             a = list[i];
3184                         }
3185                         i++; // Common if/else code factored out
3186                         polarity ^= 1;
3187                     } else if (b < a) { // take b
3188                         if (k > 0 && b <= buffer[k-1]) {
3189                             b = max(other[j], buffer[--k]);
3190                         } else {
3191                             buffer[k++] = b;
3192                             b = other[j];
3193                         }
3194                         j++;
3195                         polarity ^= 2;
3196                     } else { // a == b, take a, drop b
3197                         if (a == HIGH) break main;
3198                         // This is symmetrical; it doesn't matter if
3199                         // we backtrack with a or b. - liu
3200                         if (k > 0 && a <= buffer[k-1]) {
3201                             a = max(list[i], buffer[--k]);
3202                         } else {
3203                             // No overlap
3204                             buffer[k++] = a;
3205                             a = list[i];
3206                         }
3207                         i++;
3208                         polarity ^= 1;
3209                         b = other[j++]; polarity ^= 2;
3210                     }
3211                     break;
3212                 case 3: // both second; take higher if unequal, and drop other
3213                     if (b <= a) { // take a
3214                         if (a == HIGH) break main;
3215                         buffer[k++] = a;
3216                     } else { // take b
3217                         if (b == HIGH) break main;
3218                         buffer[k++] = b;
3219                     }
3220                     a = list[i++]; polarity ^= 1;   // factored common code
3221                     b = other[j++]; polarity ^= 2;
3222                     break;
3223                 case 1: // a second, b first; if b < a, overlap
3224                     if (a < b) { // no overlap, take a
3225                         buffer[k++] = a; a = list[i++]; polarity ^= 1;
3226                     } else if (b < a) { // OVERLAP, drop b
3227                         b = other[j++]; polarity ^= 2;
3228                     } else { // a == b, drop both!
3229                         if (a == HIGH) break main;
3230                         a = list[i++]; polarity ^= 1;
3231                         b = other[j++]; polarity ^= 2;
3232                     }
3233                     break;
3234                 case 2: // a first, b second; if a < b, overlap
3235                     if (b < a) { // no overlap, take b
3236                         buffer[k++] = b; b = other[j++]; polarity ^= 2;
3237                     } else  if (a < b) { // OVERLAP, drop a
3238                         a = list[i++]; polarity ^= 1;
3239                     } else { // a == b, drop both!
3240                         if (a == HIGH) break main;
3241                         a = list[i++]; polarity ^= 1;
3242                         b = other[j++]; polarity ^= 2;
3243                     }
3244                     break;
3245                 }
3246             }
3247         buffer[k++] = HIGH;    // terminate
3248         len = k;
3249         // swap list and buffer
3250         int[] temp = list;
3251         list = buffer;
3252         buffer = temp;
3253         pat = null;
3254         return this;
3255     }
3256 
3257     // polarity = 0 is normal: x intersect y
3258     // polarity = 2: x intersect ~y == set-minus
3259     // polarity = 1: ~x intersect y
3260     // polarity = 3: ~x intersect ~y
3261 
retain(int[] other, int otherLen, int polarity)3262     private UnicodeSet retain(int[] other, int otherLen, int polarity) {
3263         ensureBufferCapacity(len + otherLen);
3264         int i = 0, j = 0, k = 0;
3265         int a = list[i++];
3266         int b = other[j++];
3267         // change from xor is that we have to check overlapping pairs
3268         // polarity bit 1 means a is second, bit 2 means b is.
3269         main:
3270             while (true) {
3271                 switch (polarity) {
3272                 case 0: // both first; drop the smaller
3273                     if (a < b) { // drop a
3274                         a = list[i++]; polarity ^= 1;
3275                     } else if (b < a) { // drop b
3276                         b = other[j++]; polarity ^= 2;
3277                     } else { // a == b, take one, drop other
3278                         if (a == HIGH) break main;
3279                         buffer[k++] = a; a = list[i++]; polarity ^= 1;
3280                         b = other[j++]; polarity ^= 2;
3281                     }
3282                     break;
3283                 case 3: // both second; take lower if unequal
3284                     if (a < b) { // take a
3285                         buffer[k++] = a; a = list[i++]; polarity ^= 1;
3286                     } else if (b < a) { // take b
3287                         buffer[k++] = b; b = other[j++]; polarity ^= 2;
3288                     } else { // a == b, take one, drop other
3289                         if (a == HIGH) break main;
3290                         buffer[k++] = a; a = list[i++]; polarity ^= 1;
3291                         b = other[j++]; polarity ^= 2;
3292                     }
3293                     break;
3294                 case 1: // a second, b first;
3295                     if (a < b) { // NO OVERLAP, drop a
3296                         a = list[i++]; polarity ^= 1;
3297                     } else if (b < a) { // OVERLAP, take b
3298                         buffer[k++] = b; b = other[j++]; polarity ^= 2;
3299                     } else { // a == b, drop both!
3300                         if (a == HIGH) break main;
3301                         a = list[i++]; polarity ^= 1;
3302                         b = other[j++]; polarity ^= 2;
3303                     }
3304                     break;
3305                 case 2: // a first, b second; if a < b, overlap
3306                     if (b < a) { // no overlap, drop b
3307                         b = other[j++]; polarity ^= 2;
3308                     } else  if (a < b) { // OVERLAP, take a
3309                         buffer[k++] = a; a = list[i++]; polarity ^= 1;
3310                     } else { // a == b, drop both!
3311                         if (a == HIGH) break main;
3312                         a = list[i++]; polarity ^= 1;
3313                         b = other[j++]; polarity ^= 2;
3314                     }
3315                     break;
3316                 }
3317             }
3318         buffer[k++] = HIGH;    // terminate
3319         len = k;
3320         // swap list and buffer
3321         int[] temp = list;
3322         list = buffer;
3323         buffer = temp;
3324         pat = null;
3325         return this;
3326     }
3327 
max(int a, int b)3328     private static final int max(int a, int b) {
3329         return (a > b) ? a : b;
3330     }
3331 
3332     //----------------------------------------------------------------
3333     // Generic filter-based scanning code
3334     //----------------------------------------------------------------
3335 
3336     private static interface Filter {
contains(int codePoint)3337         boolean contains(int codePoint);
3338     }
3339 
3340     private static final class NumericValueFilter implements Filter {
3341         double value;
NumericValueFilter(double value)3342         NumericValueFilter(double value) { this.value = value; }
3343         @Override
contains(int ch)3344         public boolean contains(int ch) {
3345             return UCharacter.getUnicodeNumericValue(ch) == value;
3346         }
3347     }
3348 
3349     private static final class GeneralCategoryMaskFilter implements Filter {
3350         int mask;
GeneralCategoryMaskFilter(int mask)3351         GeneralCategoryMaskFilter(int mask) { this.mask = mask; }
3352         @Override
contains(int ch)3353         public boolean contains(int ch) {
3354             return ((1 << UCharacter.getType(ch)) & mask) != 0;
3355         }
3356     }
3357 
3358     private static final class IntPropertyFilter implements Filter {
3359         int prop;
3360         int value;
IntPropertyFilter(int prop, int value)3361         IntPropertyFilter(int prop, int value) {
3362             this.prop = prop;
3363             this.value = value;
3364         }
3365         @Override
contains(int ch)3366         public boolean contains(int ch) {
3367             return UCharacter.getIntPropertyValue(ch, prop) == value;
3368         }
3369     }
3370 
3371     private static final class ScriptExtensionsFilter implements Filter {
3372         int script;
ScriptExtensionsFilter(int script)3373         ScriptExtensionsFilter(int script) { this.script = script; }
3374         @Override
contains(int c)3375         public boolean contains(int c) {
3376             return UScript.hasScript(c, script);
3377         }
3378     }
3379 
3380     private static final class IdentifierTypeFilter implements Filter {
3381         int idType;
IdentifierTypeFilter(int idType)3382         IdentifierTypeFilter(int idType) { this.idType = idType; }
3383         @Override
contains(int c)3384         public boolean contains(int c) {
3385             return UCharacterProperty.INSTANCE.hasIDType(c, idType);
3386         }
3387     }
3388 
3389     // VersionInfo for unassigned characters
3390     private static final VersionInfo NO_VERSION = VersionInfo.getInstance(0, 0, 0, 0);
3391 
3392     private static final class VersionFilter implements Filter {
3393         VersionInfo version;
VersionFilter(VersionInfo version)3394         VersionFilter(VersionInfo version) { this.version = version; }
3395         @Override
contains(int ch)3396         public boolean contains(int ch) {
3397             VersionInfo v = UCharacter.getAge(ch);
3398             // Reference comparison ok; VersionInfo caches and reuses
3399             // unique objects.
3400             return !Utility.sameObjects(v, NO_VERSION) &&
3401                     v.compareTo(version) <= 0;
3402         }
3403     }
3404 
3405     /**
3406      * Generic filter-based scanning code for UCD property UnicodeSets.
3407      */
applyFilter(Filter filter, UnicodeSet inclusions)3408     private void applyFilter(Filter filter, UnicodeSet inclusions) {
3409         // Logically, walk through all Unicode characters, noting the start
3410         // and end of each range for which filter.contain(c) is
3411         // true.  Add each range to a set.
3412         //
3413         // To improve performance, use an inclusions set which
3414         // encodes information about character ranges that are known
3415         // to have identical properties.
3416         // inclusions contains the first characters of
3417         // same-value ranges for the given property.
3418 
3419         clear();
3420 
3421         int startHasProperty = -1;
3422         int limitRange = inclusions.getRangeCount();
3423 
3424         for (int j=0; j<limitRange; ++j) {
3425             // get current range
3426             int start = inclusions.getRangeStart(j);
3427             int end = inclusions.getRangeEnd(j);
3428 
3429             // for all the code points in the range, process
3430             for (int ch = start; ch <= end; ++ch) {
3431                 // only add to the unicodeset on inflection points --
3432                 // where the hasProperty value changes to false
3433                 if (filter.contains(ch)) {
3434                     if (startHasProperty < 0) {
3435                         startHasProperty = ch;
3436                     }
3437                 } else if (startHasProperty >= 0) {
3438                     add_unchecked(startHasProperty, ch-1);
3439                     startHasProperty = -1;
3440                 }
3441             }
3442         }
3443         if (startHasProperty >= 0) {
3444             add_unchecked(startHasProperty, 0x10FFFF);
3445         }
3446     }
3447 
3448     /**
3449      * Remove leading and trailing Pattern_White_Space and compress
3450      * internal Pattern_White_Space to a single space character.
3451      */
mungeCharName(String source)3452     private static String mungeCharName(String source) {
3453         source = PatternProps.trimWhiteSpace(source);
3454         StringBuilder buf = null;
3455         for (int i=0; i<source.length(); ++i) {
3456             char ch = source.charAt(i);
3457             if (PatternProps.isWhiteSpace(ch)) {
3458                 if (buf == null) {
3459                     buf = new StringBuilder().append(source, 0, i);
3460                 } else if (buf.charAt(buf.length() - 1) == ' ') {
3461                     continue;
3462                 }
3463                 ch = ' '; // convert to ' '
3464             }
3465             if (buf != null) {
3466                 buf.append(ch);
3467             }
3468         }
3469         return buf == null ? source : buf.toString();
3470     }
3471 
3472     //----------------------------------------------------------------
3473     // Property set API
3474     //----------------------------------------------------------------
3475 
3476     /**
3477      * Modifies this set to contain those code points which have the
3478      * given value for the given binary or enumerated property, as
3479      * returned by UCharacter.getIntPropertyValue.  Prior contents of
3480      * this set are lost.
3481      *
3482      * @param prop a property in the range
3483      * UProperty.BIN_START..UProperty.BIN_LIMIT-1 or
3484      * UProperty.INT_START..UProperty.INT_LIMIT-1 or.
3485      * UProperty.MASK_START..UProperty.MASK_LIMIT-1.
3486      *
3487      * @param value a value in the range
3488      * UCharacter.getIntPropertyMinValue(prop)..
3489      * UCharacter.getIntPropertyMaxValue(prop), with one exception.
3490      * If prop is UProperty.GENERAL_CATEGORY_MASK, then value should not be
3491      * a UCharacter.getType() result, but rather a mask value produced
3492      * by logically ORing (1 &lt;&lt; UCharacter.getType()) values together.
3493      * This allows grouped categories such as [:L:] to be represented.
3494      *
3495      * @return a reference to this set
3496      *
3497      * @stable ICU 2.4
3498      */
applyIntPropertyValue(int prop, int value)3499     public UnicodeSet applyIntPropertyValue(int prop, int value) {
3500         // All of the following include checkFrozen() before modifying this set.
3501         if (prop == UProperty.GENERAL_CATEGORY_MASK) {
3502             UnicodeSet inclusions = CharacterPropertiesImpl.getInclusionsForProperty(prop);
3503             applyFilter(new GeneralCategoryMaskFilter(value), inclusions);
3504         } else if (prop == UProperty.SCRIPT_EXTENSIONS) {
3505             UnicodeSet inclusions = CharacterPropertiesImpl.getInclusionsForProperty(prop);
3506             applyFilter(new ScriptExtensionsFilter(value), inclusions);
3507         } else if (prop == UProperty.IDENTIFIER_TYPE) {
3508             UnicodeSet inclusions = CharacterPropertiesImpl.getInclusionsForProperty(prop);
3509             applyFilter(new IdentifierTypeFilter(value), inclusions);
3510         } else if (0 <= prop && prop < UProperty.BINARY_LIMIT) {
3511             if (value == 0 || value == 1) {
3512                 set(CharacterProperties.getBinaryPropertySet(prop));
3513                 if (value == 0) {
3514                     complement().removeAllStrings();  // code point complement
3515                 }
3516             } else {
3517                 clear();
3518             }
3519         } else if (UProperty.INT_START <= prop && prop < UProperty.INT_LIMIT) {
3520             UnicodeSet inclusions = CharacterPropertiesImpl.getInclusionsForProperty(prop);
3521             applyFilter(new IntPropertyFilter(prop, value), inclusions);
3522         } else {
3523             throw new IllegalArgumentException("unsupported property " + prop);
3524         }
3525         return this;
3526     }
3527 
3528 
3529 
3530     /**
3531      * Modifies this set to contain those code points which have the
3532      * given value for the given property.  Prior contents of this
3533      * set are lost.
3534      *
3535      * @param propertyAlias a property alias, either short or long.
3536      * The name is matched loosely.  See PropertyAliases.txt for names
3537      * and a description of loose matching.  If the value string is
3538      * empty, then this string is interpreted as either a
3539      * General_Category value alias, a Script value alias, a binary
3540      * property alias, or a special ID.  Special IDs are matched
3541      * loosely and correspond to the following sets:
3542      *
3543      * "ANY" = [\\u0000-\\U0010FFFF],
3544      * "ASCII" = [\\u0000-\\u007F].
3545      *
3546      * @param valueAlias a value alias, either short or long.  The
3547      * name is matched loosely.  See PropertyValueAliases.txt for
3548      * names and a description of loose matching.  In addition to
3549      * aliases listed, numeric values and canonical combining classes
3550      * may be expressed numerically, e.g., ("nv", "0.5") or ("ccc",
3551      * "220").  The value string may also be empty.
3552      *
3553      * @return a reference to this set
3554      *
3555      * @stable ICU 2.4
3556      */
applyPropertyAlias(String propertyAlias, String valueAlias)3557     public UnicodeSet applyPropertyAlias(String propertyAlias, String valueAlias) {
3558         return applyPropertyAlias(propertyAlias, valueAlias, null);
3559     }
3560 
3561     /**
3562      * Modifies this set to contain those code points which have the
3563      * given value for the given property.  Prior contents of this
3564      * set are lost.
3565      * @param propertyAlias A string of the property alias.
3566      * @param valueAlias A string of the value alias.
3567      * @param symbols if not null, then symbols are first called to see if a property
3568      * is available. If true, then everything else is skipped.
3569      * @return this set
3570      * @stable ICU 3.2
3571      */
applyPropertyAlias(String propertyAlias, String valueAlias, SymbolTable symbols)3572     public UnicodeSet applyPropertyAlias(String propertyAlias,
3573             String valueAlias, SymbolTable symbols) {
3574         checkFrozen();
3575         int p;
3576         int v;
3577         boolean invert = false;
3578 
3579         if (symbols != null
3580                 && (symbols instanceof XSymbolTable)
3581                 && ((XSymbolTable)symbols).applyPropertyAlias(propertyAlias, valueAlias, this)) {
3582             return this;
3583         }
3584 
3585         if (XSYMBOL_TABLE != null) {
3586             if (XSYMBOL_TABLE.applyPropertyAlias(propertyAlias, valueAlias, this)) {
3587                 return this;
3588             }
3589         }
3590 
3591         if (valueAlias.length() > 0) {
3592             p = UCharacter.getPropertyEnum(propertyAlias);
3593 
3594             // Treat gc as gcm
3595             if (p == UProperty.GENERAL_CATEGORY) {
3596                 p = UProperty.GENERAL_CATEGORY_MASK;
3597             }
3598 
3599             if ((p >= UProperty.BINARY_START && p < UProperty.BINARY_LIMIT) ||
3600                     (p >= UProperty.INT_START && p < UProperty.INT_LIMIT) ||
3601                     (p >= UProperty.MASK_START && p < UProperty.MASK_LIMIT)) {
3602                 try {
3603                     v = UCharacter.getPropertyValueEnum(p, valueAlias);
3604                 } catch (IllegalArgumentException e) {
3605                     // Handle numeric CCC
3606                     if (p == UProperty.CANONICAL_COMBINING_CLASS ||
3607                             p == UProperty.LEAD_CANONICAL_COMBINING_CLASS ||
3608                             p == UProperty.TRAIL_CANONICAL_COMBINING_CLASS) {
3609                         v = Integer.parseInt(PatternProps.trimWhiteSpace(valueAlias));
3610                         // Anything between 0 and 255 is valid even if unused.
3611                         if (v < 0 || v > 255) throw e;
3612                     } else {
3613                         throw e;
3614                     }
3615                 }
3616             }
3617 
3618             else {
3619                 switch (p) {
3620                 case UProperty.NUMERIC_VALUE:
3621                 {
3622                     double value = Double.parseDouble(PatternProps.trimWhiteSpace(valueAlias));
3623                     applyFilter(new NumericValueFilter(value),
3624                             CharacterPropertiesImpl.getInclusionsForProperty(p));
3625                     return this;
3626                 }
3627                 case UProperty.NAME:
3628                 {
3629                     // Must munge name, since
3630                     // UCharacter.charFromName() does not do
3631                     // 'loose' matching.
3632                     String buf = mungeCharName(valueAlias);
3633                     int ch = UCharacter.getCharFromExtendedName(buf);
3634                     if (ch == -1) {
3635                         throw new IllegalArgumentException("Invalid character name");
3636                     }
3637                     clear();
3638                     add_unchecked(ch);
3639                     return this;
3640                 }
3641                 case UProperty.UNICODE_1_NAME:
3642                     // ICU 49 deprecates the Unicode_1_Name property APIs.
3643                     throw new IllegalArgumentException("Unicode_1_Name (na1) not supported");
3644                 case UProperty.AGE:
3645                 {
3646                     // Must munge name, since
3647                     // VersionInfo.getInstance() does not do
3648                     // 'loose' matching.
3649                     VersionInfo version = VersionInfo.getInstance(mungeCharName(valueAlias));
3650                     applyFilter(new VersionFilter(version),
3651                             CharacterPropertiesImpl.getInclusionsForProperty(p));
3652                     return this;
3653                 }
3654                 case UProperty.SCRIPT_EXTENSIONS:
3655                     v = UCharacter.getPropertyValueEnum(UProperty.SCRIPT, valueAlias);
3656                     // fall through to calling applyIntPropertyValue()
3657                     break;
3658                 case UProperty.IDENTIFIER_TYPE:
3659                     v = UCharacter.getPropertyValueEnum(p, valueAlias);
3660                     // fall through to calling applyIntPropertyValue()
3661                     break;
3662                 default:
3663                     // p is a non-binary, non-enumerated property that we
3664                     // don't support (yet).
3665                     throw new IllegalArgumentException("Unsupported property");
3666                 }
3667             }
3668         }
3669 
3670         else {
3671             // valueAlias is empty.  Interpret as General Category, Script,
3672             // Binary property, or ANY or ASCII.  Upon success, p and v will
3673             // be set.
3674             UPropertyAliases pnames = UPropertyAliases.INSTANCE;
3675             p = UProperty.GENERAL_CATEGORY_MASK;
3676             v = pnames.getPropertyValueEnum(p, propertyAlias);
3677             if (v == UProperty.UNDEFINED) {
3678                 p = UProperty.SCRIPT;
3679                 v = pnames.getPropertyValueEnum(p, propertyAlias);
3680                 if (v == UProperty.UNDEFINED) {
3681                     p = pnames.getPropertyEnum(propertyAlias);
3682                     if (p == UProperty.UNDEFINED) {
3683                         p = -1;
3684                     }
3685                     if (p >= UProperty.BINARY_START && p < UProperty.BINARY_LIMIT) {
3686                         v = 1;
3687                     } else if (p == -1) {
3688                         if (0 == UPropertyAliases.compare(ANY_ID, propertyAlias)) {
3689                             set(MIN_VALUE, MAX_VALUE);
3690                             return this;
3691                         } else if (0 == UPropertyAliases.compare(ASCII_ID, propertyAlias)) {
3692                             set(0, 0x7F);
3693                             return this;
3694                         } else if (0 == UPropertyAliases.compare(ASSIGNED, propertyAlias)) {
3695                             // [:Assigned:]=[:^Cn:]
3696                             p = UProperty.GENERAL_CATEGORY_MASK;
3697                             v = (1<<UCharacter.UNASSIGNED);
3698                             invert = true;
3699                         } else {
3700                             // Property name was never matched.
3701                             throw new IllegalArgumentException("Invalid property alias: " + propertyAlias + "=" + valueAlias);
3702                         }
3703                     } else {
3704                         // Valid property name, but it isn't binary, so the value
3705                         // must be supplied.
3706                         throw new IllegalArgumentException("Missing property value");
3707                     }
3708                 }
3709             }
3710         }
3711 
3712         applyIntPropertyValue(p, v);
3713         if(invert) {
3714             complement().removeAllStrings();  // code point complement
3715         }
3716 
3717         return this;
3718     }
3719 
3720     //----------------------------------------------------------------
3721     // Property set patterns
3722     //----------------------------------------------------------------
3723 
3724     /**
3725      * Return true if the given position, in the given pattern, appears
3726      * to be the start of a property set pattern.
3727      */
resemblesPropertyPattern(String pattern, int pos)3728     private static boolean resemblesPropertyPattern(String pattern, int pos) {
3729         // Patterns are at least 5 characters long
3730         if ((pos+5) > pattern.length()) {
3731             return false;
3732         }
3733 
3734         // Look for an opening [:, [:^, \p, or \P
3735         return pattern.regionMatches(pos, "[:", 0, 2) ||
3736                 pattern.regionMatches(true, pos, "\\p", 0, 2) ||
3737                 pattern.regionMatches(pos, "\\N", 0, 2);
3738     }
3739 
3740     /**
3741      * Return true if the given iterator appears to point at a
3742      * property pattern.  Regardless of the result, return with the
3743      * iterator unchanged.
3744      * @param chars iterator over the pattern characters.  Upon return
3745      * it will be unchanged.
3746      * @param iterOpts RuleCharacterIterator options
3747      */
resemblesPropertyPattern(RuleCharacterIterator chars, int iterOpts)3748     private static boolean resemblesPropertyPattern(RuleCharacterIterator chars,
3749             int iterOpts) {
3750         boolean result = false;
3751         iterOpts &= ~RuleCharacterIterator.PARSE_ESCAPES;
3752         RuleCharacterIterator.Position pos = chars.getPos(null);
3753         int c = chars.next(iterOpts);
3754         if (c == '[' || c == '\\') {
3755             int d = chars.next(iterOpts & ~RuleCharacterIterator.SKIP_WHITESPACE);
3756             result = (c == '[') ? (d == ':') :
3757                 (d == 'N' || d == 'p' || d == 'P');
3758         }
3759         chars.setPos(pos);
3760         return result;
3761     }
3762 
3763     /**
3764      * Parse the given property pattern at the given parse position.
3765      * @param symbols TODO
3766      */
applyPropertyPattern(String pattern, ParsePosition ppos, SymbolTable symbols)3767     private UnicodeSet applyPropertyPattern(String pattern, ParsePosition ppos, SymbolTable symbols) {
3768         int pos = ppos.getIndex();
3769 
3770         // On entry, ppos should point to one of the following locations:
3771 
3772         // Minimum length is 5 characters, e.g. \p{L}
3773         if ((pos+5) > pattern.length()) {
3774             return null;
3775         }
3776 
3777         boolean posix = false; // true for [:pat:], false for \p{pat} \P{pat} \N{pat}
3778         boolean isName = false; // true for \N{pat}, o/w false
3779         boolean invert = false;
3780 
3781         // Look for an opening [:, [:^, \p, or \P
3782         if (pattern.regionMatches(pos, "[:", 0, 2)) {
3783             posix = true;
3784             pos = PatternProps.skipWhiteSpace(pattern, (pos+2));
3785             if (pos < pattern.length() && pattern.charAt(pos) == '^') {
3786                 ++pos;
3787                 invert = true;
3788             }
3789         } else if (pattern.regionMatches(true, pos, "\\p", 0, 2) ||
3790                 pattern.regionMatches(pos, "\\N", 0, 2)) {
3791             char c = pattern.charAt(pos+1);
3792             invert = (c == 'P');
3793             isName = (c == 'N');
3794             pos = PatternProps.skipWhiteSpace(pattern, (pos+2));
3795             if (pos == pattern.length() || pattern.charAt(pos++) != '{') {
3796                 // Syntax error; "\p" or "\P" not followed by "{"
3797                 return null;
3798             }
3799         } else {
3800             // Open delimiter not seen
3801             return null;
3802         }
3803 
3804         // Look for the matching close delimiter, either :] or }
3805         int close = pattern.indexOf(posix ? ":]" : "}", pos);
3806         if (close < 0) {
3807             // Syntax error; close delimiter missing
3808             return null;
3809         }
3810 
3811         // Look for an '=' sign.  If this is present, we will parse a
3812         // medium \p{gc=Cf} or long \p{GeneralCategory=Format}
3813         // pattern.
3814         int equals = pattern.indexOf('=', pos);
3815         String propName, valueName;
3816         if (equals >= 0 && equals < close && !isName) {
3817             // Equals seen; parse medium/long pattern
3818             propName = pattern.substring(pos, equals);
3819             valueName = pattern.substring(equals+1, close);
3820         }
3821 
3822         else {
3823             // Handle case where no '=' is seen, and \N{}
3824             propName = pattern.substring(pos, close);
3825             valueName = "";
3826 
3827             // Handle \N{name}
3828             if (isName) {
3829                 // This is a little inefficient since it means we have to
3830                 // parse "na" back to UProperty.NAME even though we already
3831                 // know it's UProperty.NAME.  If we refactor the API to
3832                 // support args of (int, String) then we can remove
3833                 // "na" and make this a little more efficient.
3834                 valueName = propName;
3835                 propName = "na";
3836             }
3837         }
3838 
3839         applyPropertyAlias(propName, valueName, symbols);
3840 
3841         if (invert) {
3842             complement().removeAllStrings();  // code point complement
3843         }
3844 
3845         // Move to the limit position after the close delimiter
3846         ppos.setIndex(close + (posix ? 2 : 1));
3847 
3848         return this;
3849     }
3850 
3851     /**
3852      * Parse a property pattern.
3853      * @param chars iterator over the pattern characters.  Upon return
3854      * it will be advanced to the first character after the parsed
3855      * pattern, or the end of the iteration if all characters are
3856      * parsed.
3857      * @param rebuiltPat the pattern that was parsed, rebuilt or
3858      * copied from the input pattern, as appropriate.
3859      * @param symbols TODO
3860      */
applyPropertyPattern(RuleCharacterIterator chars, Appendable rebuiltPat, SymbolTable symbols)3861     private void applyPropertyPattern(RuleCharacterIterator chars,
3862             Appendable rebuiltPat, SymbolTable symbols) {
3863         String patStr = chars.getCurrentBuffer();
3864         int start = chars.getCurrentBufferPos();
3865         ParsePosition pos = new ParsePosition(start);
3866         applyPropertyPattern(patStr, pos, symbols);
3867         int length = pos.getIndex() - start;
3868         if (length == 0) {
3869             syntaxError(chars, "Invalid property pattern");
3870         }
3871         chars.jumpahead(length);
3872         append(rebuiltPat, patStr.substring(start, pos.getIndex()));
3873     }
3874 
3875     //----------------------------------------------------------------
3876     // Case folding API
3877     //----------------------------------------------------------------
3878 
3879     /**
3880      * Bitmask for constructor and applyPattern() indicating that
3881      * white space should be ignored.  If set, ignore Unicode Pattern_White_Space characters,
3882      * unless they are quoted or escaped.  This may be ORed together
3883      * with other selectors.
3884      * @stable ICU 3.8
3885      */
3886     public static final int IGNORE_SPACE = 1;
3887 
3888     /**
3889      * Alias for {@link #CASE_INSENSITIVE}.
3890      *
3891      * @deprecated ICU 73 Use {@link #CASE_INSENSITIVE} instead.
3892      */
3893     @Deprecated
3894     public static final int CASE = 2;
3895 
3896     /**
3897      * Enable case insensitive matching.  E.g., "[ab]" with this flag
3898      * will match 'a', 'A', 'b', and 'B'.  "[^ab]" with this flag will
3899      * match all except 'a', 'A', 'b', and 'B'. This performs a full
3900      * closure over case mappings, e.g. 'ſ' (U+017F long s) for 's'.
3901      *
3902      * <p>This value is an options bit set value for some
3903      * constructors, applyPattern(), and closeOver().
3904      * It can be ORed together with other, unrelated options.
3905      *
3906      * <p>The resulting set is a superset of the input for the code points but
3907      * not for the strings.
3908      * It performs a case mapping closure of the code points and adds
3909      * full case folding strings for the code points, and reduces strings of
3910      * the original set to their full case folding equivalents.
3911      *
3912      * <p>This is designed for case-insensitive matches, for example
3913      * in regular expressions. The full code point case closure allows checking of
3914      * an input character directly against the closure set.
3915      * Strings are matched by comparing the case-folded form from the closure
3916      * set with an incremental case folding of the string in question.
3917      *
3918      * <p>The closure set will also contain single code points if the original
3919      * set contained case-equivalent strings (like U+00DF for "ss" or "Ss" etc.).
3920      * This is not necessary (that is, redundant) for the above matching method
3921      * but results in the same closure sets regardless of whether the original
3922      * set contained the code point or a string.
3923      *
3924      * @stable ICU 3.4
3925      */
3926     public static final int CASE_INSENSITIVE = 2;
3927 
3928     /**
3929      * Adds all case mappings for each element in the set.
3930      * This adds the full lower-, title-, and uppercase mappings as well as the full case folding
3931      * of each existing element in the set.
3932      *
3933      * <p>This value is an options bit set value for some
3934      * constructors, applyPattern(), and closeOver().
3935      * It can be ORed together with other, unrelated options.
3936      *
3937      * <p>Unlike the “case insensitive” options, this does not perform a closure.
3938      * For example, it does not add 'ſ' (U+017F long s) for 's',
3939      * 'K' (U+212A Kelvin sign) for 'k', or replace set strings by their case-folded versions.
3940      *
3941      * @stable ICU 3.4
3942      */
3943     public static final int ADD_CASE_MAPPINGS = 4;
3944 
3945     /**
3946      * Enable case insensitive matching.
3947      * Same as {@link #CASE_INSENSITIVE} but using only Simple_Case_Folding (scf) mappings,
3948      * which map each code point to one code point,
3949      * not full Case_Folding (cf) mappings, which map some code points to multiple code points.
3950      *
3951      * <p>This is designed for case-insensitive matches, for example in certain
3952      * regular expression implementations where only Simple_Case_Folding mappings are used,
3953      * such as in ECMAScript (JavaScript) regular expressions.
3954      *
3955      * <p>This value is an options bit set value for some
3956      * constructors, applyPattern(), and closeOver().
3957      * It can be ORed together with other, unrelated options.
3958      *
3959      * @stable ICU 73
3960      */
3961     public static final int SIMPLE_CASE_INSENSITIVE = 6;
3962 
3963     private static final int CASE_MASK = CASE_INSENSITIVE | ADD_CASE_MAPPINGS;
3964 
3965     //  add the result of a full case mapping to the set
3966     //  use str as a temporary string to avoid constructing one
addCaseMapping(UnicodeSet set, int result, StringBuilder full)3967     private static final void addCaseMapping(UnicodeSet set, int result, StringBuilder full) {
3968         if(result >= 0) {
3969             if(result > UCaseProps.MAX_STRING_LENGTH) {
3970                 // add a single-code point case mapping
3971                 set.add(result);
3972             } else {
3973                 // add a string case mapping from full with length result
3974                 set.add(full.toString());
3975                 full.setLength(0);
3976             }
3977         }
3978         // result < 0: the code point mapped to itself, no need to add it
3979         // see UCaseProps
3980     }
3981 
3982     /** For case closure on a large set, look only at code points with relevant properties. */
maybeOnlyCaseSensitive(UnicodeSet src)3983     UnicodeSet maybeOnlyCaseSensitive(UnicodeSet src) {
3984         if (src.size() < 30) {
3985             return src;
3986         }
3987         // Return the intersection of the src code points with Case_Sensitive ones.
3988         UnicodeSet sensitive = CharacterProperties.getBinaryPropertySet(UProperty.CASE_SENSITIVE);
3989         // Start by cloning the "smaller" set. Try not to copy the strings, if there are any in src.
3990         if (src.hasStrings() || src.getRangeCount() > sensitive.getRangeCount()) {
3991             return sensitive.cloneAsThawed().retainAll(src);
3992         } else {
3993             return ((UnicodeSet) src.clone()).retainAll(sensitive);
3994         }
3995     }
3996 
3997     // Per-character scf = Simple_Case_Folding of a string.
3998     // (Normally when we case-fold a string we use full case foldings.)
scfString(CharSequence s, StringBuilder scf)3999     private static final boolean scfString(CharSequence s, StringBuilder scf) {
4000         int length = s.length();
4001         // Loop while not needing modification.
4002         for (int i = 0; i < length;) {
4003             int c = Character.codePointAt(s, i);
4004             int scfChar = UCharacter.foldCase(c, UCharacter.FOLD_CASE_DEFAULT);
4005             if (scfChar != c) {
4006                 // Copy the characters before c.
4007                 scf.setLength(0);
4008                 scf.append(s, 0, i);
4009                 // Loop over the rest of the string and keep case-folding.
4010                 for (;;) {
4011                     scf.appendCodePoint(scfChar);
4012                     i += Character.charCount(c);
4013                     if (i == length) {
4014                         return true;
4015                     }
4016                     c = Character.codePointAt(s, i);
4017                     scfChar = UCharacter.foldCase(c, UCharacter.FOLD_CASE_DEFAULT);
4018                 }
4019             }
4020             i += Character.charCount(c);
4021         }
4022         return false;
4023     }
4024 
4025     /**
4026      * Close this set over the given attribute.  For the attribute
4027      * {@link #CASE_INSENSITIVE}, the result is to modify this set so that:
4028      *
4029      * <ol>
4030      * <li>For each character or string 'a' in this set, all strings
4031      * 'b' such that foldCase(a) == foldCase(b) are added to this set.
4032      * (For most 'a' that are single characters, 'b' will have
4033      * b.length() == 1.)
4034      *
4035      * <li>For each string 'e' in the resulting set, if e !=
4036      * foldCase(e), 'e' will be removed.
4037      * </ol>
4038      *
4039      * <p>Example: [aq\u00DF{Bc}{bC}{Fi}] =&gt; [aAqQ\u00DF\uFB01{ss}{bc}{fi}]
4040      *
4041      * <p>(Here foldCase(x) refers to the operation
4042      * UCharacter.foldCase(x, true), and a == b actually denotes
4043      * a.equals(b), not pointer comparison.)
4044      *
4045      * @param attribute bitmask for attributes to close over.
4046      * Valid options:
4047      * At most one of {@link #CASE_INSENSITIVE}, {@link #ADD_CASE_MAPPINGS},
4048      * {@link #SIMPLE_CASE_INSENSITIVE}. These case options are mutually exclusive.
4049      * Unrelated options bits are ignored.
4050      * @return a reference to this set.
4051      * @stable ICU 3.8
4052      */
closeOver(int attribute)4053     public UnicodeSet closeOver(int attribute) {
4054         checkFrozen();
4055         switch (attribute & CASE_MASK) {
4056         case 0:
4057             break;
4058         case CASE_INSENSITIVE:
4059             closeOverCaseInsensitive(/* simple= */ false);
4060             break;
4061         case ADD_CASE_MAPPINGS:
4062             closeOverAddCaseMappings();
4063             break;
4064         case SIMPLE_CASE_INSENSITIVE:
4065             closeOverCaseInsensitive(/* simple= */ true);
4066             break;
4067         default:
4068             // bad option (unreachable)
4069             break;
4070         }
4071         return this;
4072     }
4073 
closeOverCaseInsensitive(boolean simple)4074     private void closeOverCaseInsensitive(boolean simple) {
4075         UCaseProps csp = UCaseProps.INSTANCE;
4076         // Start with input set to guarantee inclusion.
4077         UnicodeSet foldSet = new UnicodeSet(this);
4078 
4079         // Full case mappings closure:
4080         // Remove strings because the strings will actually be reduced (folded);
4081         // therefore, start with no strings and add only those needed.
4082         // Do this before processing code points, because they may add strings.
4083         if (!simple && foldSet.hasStrings()) {
4084             foldSet.strings.clear();
4085         }
4086 
4087         UnicodeSet codePoints = maybeOnlyCaseSensitive(this);
4088 
4089         // Iterate over the ranges of single code points. Nested loop for each code point.
4090         int n = codePoints.getRangeCount();
4091         for (int i=0; i<n; ++i) {
4092             int start = codePoints.getRangeStart(i);
4093             int end   = codePoints.getRangeEnd(i);
4094 
4095             if (simple) {
4096                 for (int cp=start; cp<=end; ++cp) {
4097                     csp.addSimpleCaseClosure(cp, foldSet);
4098                 }
4099             } else {
4100                 for (int cp=start; cp<=end; ++cp) {
4101                     csp.addCaseClosure(cp, foldSet);
4102                 }
4103             }
4104         }
4105         if (hasStrings()) {
4106             StringBuilder sb = simple ? new StringBuilder() : null;
4107             for (String s : strings) {
4108                 if (simple) {
4109                     if (scfString(s, sb)) {
4110                         foldSet.remove(s).add(sb);
4111                     }
4112                 } else {
4113                     String str = UCharacter.foldCase(s, 0);
4114                     if(!csp.addStringCaseClosure(str, foldSet)) {
4115                         foldSet.add(str); // does not map to code points: add the folded string itself
4116                     }
4117                 }
4118             }
4119         }
4120         set(foldSet);
4121     }
4122 
closeOverAddCaseMappings()4123     private void closeOverAddCaseMappings() {
4124         UCaseProps csp = UCaseProps.INSTANCE;
4125         // Start with input set to guarantee inclusion.
4126         UnicodeSet foldSet = new UnicodeSet(this);
4127 
4128         UnicodeSet codePoints = maybeOnlyCaseSensitive(this);
4129 
4130         // Iterate over the ranges of single code points. Nested loop for each code point.
4131         int n = codePoints.getRangeCount();
4132         int result;
4133         StringBuilder full = new StringBuilder();
4134 
4135         for (int i=0; i<n; ++i) {
4136             int start = codePoints.getRangeStart(i);
4137             int end   = codePoints.getRangeEnd(i);
4138 
4139             // add case mappings
4140             // (does not add long s for regular s, or Kelvin for k, for example)
4141             for (int cp=start; cp<=end; ++cp) {
4142                 result = csp.toFullLower(cp, null, full, UCaseProps.LOC_ROOT);
4143                 addCaseMapping(foldSet, result, full);
4144 
4145                 result = csp.toFullTitle(cp, null, full, UCaseProps.LOC_ROOT);
4146                 addCaseMapping(foldSet, result, full);
4147 
4148                 result = csp.toFullUpper(cp, null, full, UCaseProps.LOC_ROOT);
4149                 addCaseMapping(foldSet, result, full);
4150 
4151                 result = csp.toFullFolding(cp, full, 0);
4152                 addCaseMapping(foldSet, result, full);
4153             }
4154         }
4155         if (hasStrings()) {
4156             ULocale root = ULocale.ROOT;
4157             BreakIterator bi = BreakIterator.getWordInstance(root);
4158             for (String str : strings) {
4159                 // TODO: call lower-level functions
4160                 foldSet.add(UCharacter.toLowerCase(root, str));
4161                 foldSet.add(UCharacter.toTitleCase(root, str, bi));
4162                 foldSet.add(UCharacter.toUpperCase(root, str));
4163                 foldSet.add(UCharacter.foldCase(str, 0));
4164             }
4165         }
4166         set(foldSet);
4167     }
4168 
4169     /**
4170      * Internal class for customizing UnicodeSet parsing of properties.
4171      * TODO: extend to allow customizing of codepoint ranges
4172      * @draft ICU3.8 (retain)
4173      * @author medavis
4174      */
4175     abstract public static class XSymbolTable implements SymbolTable {
4176         /**
4177          * Default constructor
4178          * @draft ICU3.8 (retain)
4179          */
XSymbolTable()4180         public XSymbolTable(){}
4181         /**
4182          * Supplies default implementation for SymbolTable (no action).
4183          * @draft ICU3.8 (retain)
4184          */
4185         @Override
lookupMatcher(int i)4186         public UnicodeMatcher lookupMatcher(int i) {
4187             return null;
4188         }
4189 
4190         /**
4191          * Override the interpretation of the sequence [:propertyName=propertyValue:] (and its negated and Perl-style
4192          * variant). The propertyName and propertyValue may be existing Unicode aliases, or may not be.
4193          * <p>
4194          * This routine will be called whenever the parsing of a UnicodeSet pattern finds such a
4195          * propertyName+propertyValue combination.
4196          *
4197          * @param propertyName
4198          *            the name of the property
4199          * @param propertyValue
4200          *            the name of the property value
4201          * @param result UnicodeSet value to change
4202          *            a set to which the characters having the propertyName+propertyValue are to be added.
4203          * @return returns true if the propertyName+propertyValue combination is to be overridden, and the characters
4204          *         with that property have been added to the UnicodeSet, and returns false if the
4205          *         propertyName+propertyValue combination is not recognized (in which case result is unaltered).
4206          * @draft ICU3.8 (retain)
4207          */
applyPropertyAlias(String propertyName, String propertyValue, UnicodeSet result)4208         public boolean applyPropertyAlias(String propertyName, String propertyValue, UnicodeSet result) {
4209             return false;
4210         }
4211         /**
4212          * Supplies default implementation for SymbolTable (no action).
4213          * @draft ICU3.8 (retain)
4214          */
4215         @Override
lookup(String s)4216         public char[] lookup(String s) {
4217             return null;
4218         }
4219         /**
4220          * Supplies default implementation for SymbolTable (no action).
4221          * @draft ICU3.8 (retain)
4222          */
4223         @Override
parseReference(String text, ParsePosition pos, int limit)4224         public String parseReference(String text, ParsePosition pos, int limit) {
4225             return null;
4226         }
4227     }
4228 
4229     /**
4230      * Is this frozen, according to the Freezable interface?
4231      *
4232      * @return value
4233      * @stable ICU 3.8
4234      */
4235     @Override
isFrozen()4236     public boolean isFrozen() {
4237         return (bmpSet != null || stringSpan != null);
4238     }
4239 
4240     /**
4241      * Freeze this class, according to the Freezable interface.
4242      *
4243      * @return this
4244      * @stable ICU 4.4
4245      */
4246     @Override
freeze()4247     public UnicodeSet freeze() {
4248         if (!isFrozen()) {
4249             compact();
4250 
4251             // Optimize contains() and span() and similar functions.
4252             if (hasStrings()) {
4253                 stringSpan = new UnicodeSetStringSpan(this, new ArrayList<>(strings), UnicodeSetStringSpan.ALL);
4254             }
4255             if (stringSpan == null || !stringSpan.needsStringSpanUTF16()) {
4256                 // Optimize for code point spans.
4257                 // There are no strings, or
4258                 // all strings are irrelevant for span() etc. because
4259                 // all of each string's code points are contained in this set.
4260                 // However, fully contained strings are relevant for spanAndCount(),
4261                 // so we create both objects.
4262                 bmpSet = new BMPSet(list, len);
4263             }
4264         }
4265         return this;
4266     }
4267 
4268     /**
4269      * Span a string using this UnicodeSet.
4270      * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
4271      * @param s The string to be spanned
4272      * @param spanCondition The span condition
4273      * @return the length of the span
4274      * @stable ICU 4.4
4275      */
span(CharSequence s, SpanCondition spanCondition)4276     public int span(CharSequence s, SpanCondition spanCondition) {
4277         return span(s, 0, spanCondition);
4278     }
4279 
4280     /**
4281      * Span a string using this UnicodeSet.
4282      *   If the start index is less than 0, span will start from 0.
4283      *   If the start index is greater than the string length, span returns the string length.
4284      * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
4285      * @param s The string to be spanned
4286      * @param start The start index that the span begins
4287      * @param spanCondition The span condition
4288      * @return the string index which ends the span (i.e. exclusive)
4289      * @stable ICU 4.4
4290      */
span(CharSequence s, int start, SpanCondition spanCondition)4291     public int span(CharSequence s, int start, SpanCondition spanCondition) {
4292         int end = s.length();
4293         if (start < 0) {
4294             start = 0;
4295         } else if (start >= end) {
4296             return end;
4297         }
4298         if (bmpSet != null) {
4299             // Frozen set without strings, or no string is relevant for span().
4300             return bmpSet.span(s, start, spanCondition, null);
4301         }
4302         if (stringSpan != null) {
4303             return stringSpan.span(s, start, spanCondition);
4304         } else if (hasStrings()) {
4305             int which = spanCondition == SpanCondition.NOT_CONTAINED ? UnicodeSetStringSpan.FWD_UTF16_NOT_CONTAINED
4306                     : UnicodeSetStringSpan.FWD_UTF16_CONTAINED;
4307             UnicodeSetStringSpan strSpan = new UnicodeSetStringSpan(this, new ArrayList<>(strings), which);
4308             if (strSpan.needsStringSpanUTF16()) {
4309                 return strSpan.span(s, start, spanCondition);
4310             }
4311         }
4312 
4313         return spanCodePointsAndCount(s, start, spanCondition, null);
4314     }
4315 
4316     /**
4317      * Same as span() but also counts the smallest number of set elements on any path across the span.
4318      * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
4319      * @param outCount An output-only object (must not be null) for returning the count.
4320      * @return the limit (exclusive end) of the span
4321      * @internal
4322      * @deprecated This API is ICU internal only.
4323      */
4324     @Deprecated
spanAndCount(CharSequence s, int start, SpanCondition spanCondition, OutputInt outCount)4325     public int spanAndCount(CharSequence s, int start, SpanCondition spanCondition, OutputInt outCount) {
4326         if (outCount == null) {
4327             throw new IllegalArgumentException("outCount must not be null");
4328         }
4329         int end = s.length();
4330         if (start < 0) {
4331             start = 0;
4332         } else if (start >= end) {
4333             return end;
4334         }
4335         if (stringSpan != null) {
4336             // We might also have bmpSet != null,
4337             // but fully-contained strings are relevant for counting elements.
4338             return stringSpan.spanAndCount(s, start, spanCondition, outCount);
4339         } else if (bmpSet != null) {
4340             return bmpSet.span(s, start, spanCondition, outCount);
4341         } else if (hasStrings()) {
4342             int which = spanCondition == SpanCondition.NOT_CONTAINED ? UnicodeSetStringSpan.FWD_UTF16_NOT_CONTAINED
4343                     : UnicodeSetStringSpan.FWD_UTF16_CONTAINED;
4344             which |= UnicodeSetStringSpan.WITH_COUNT;
4345             UnicodeSetStringSpan strSpan = new UnicodeSetStringSpan(this, new ArrayList<>(strings), which);
4346             return strSpan.spanAndCount(s, start, spanCondition, outCount);
4347         }
4348 
4349         return spanCodePointsAndCount(s, start, spanCondition, outCount);
4350     }
4351 
spanCodePointsAndCount(CharSequence s, int start, SpanCondition spanCondition, OutputInt outCount)4352     private int spanCodePointsAndCount(CharSequence s, int start,
4353             SpanCondition spanCondition, OutputInt outCount) {
4354         // Pin to 0/1 values.
4355         boolean spanContained = (spanCondition != SpanCondition.NOT_CONTAINED);
4356 
4357         int c;
4358         int next = start;
4359         int length = s.length();
4360         int count = 0;
4361         do {
4362             c = Character.codePointAt(s, next);
4363             if (spanContained != contains(c)) {
4364                 break;
4365             }
4366             ++count;
4367             next += Character.charCount(c);
4368         } while (next < length);
4369         if (outCount != null) { outCount.value = count; }
4370         return next;
4371     }
4372 
4373     /**
4374      * Span a string backwards (from the end) using this UnicodeSet.
4375      * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
4376      * @param s The string to be spanned
4377      * @param spanCondition The span condition
4378      * @return The string index which starts the span (i.e. inclusive).
4379      * @stable ICU 4.4
4380      */
spanBack(CharSequence s, SpanCondition spanCondition)4381     public int spanBack(CharSequence s, SpanCondition spanCondition) {
4382         return spanBack(s, s.length(), spanCondition);
4383     }
4384 
4385     /**
4386      * Span a string backwards (from the fromIndex) using this UnicodeSet.
4387      * If the fromIndex is less than 0, spanBack will return 0.
4388      * If fromIndex is greater than the string length, spanBack will start from the string length.
4389      * <p>To replace, count elements, or delete spans, see {@link com.ibm.icu.text.UnicodeSetSpanner UnicodeSetSpanner}.
4390      * @param s The string to be spanned
4391      * @param fromIndex The index of the char (exclusive) that the string should be spanned backwards
4392      * @param spanCondition The span condition
4393      * @return The string index which starts the span (i.e. inclusive).
4394      * @stable ICU 4.4
4395      */
spanBack(CharSequence s, int fromIndex, SpanCondition spanCondition)4396     public int spanBack(CharSequence s, int fromIndex, SpanCondition spanCondition) {
4397         if (fromIndex <= 0) {
4398             return 0;
4399         }
4400         if (fromIndex > s.length()) {
4401             fromIndex = s.length();
4402         }
4403         if (bmpSet != null) {
4404             // Frozen set without strings, or no string is relevant for spanBack().
4405             return bmpSet.spanBack(s, fromIndex, spanCondition);
4406         }
4407         if (stringSpan != null) {
4408             return stringSpan.spanBack(s, fromIndex, spanCondition);
4409         } else if (hasStrings()) {
4410             int which = (spanCondition == SpanCondition.NOT_CONTAINED)
4411                     ? UnicodeSetStringSpan.BACK_UTF16_NOT_CONTAINED
4412                             : UnicodeSetStringSpan.BACK_UTF16_CONTAINED;
4413             UnicodeSetStringSpan strSpan = new UnicodeSetStringSpan(this, new ArrayList<>(strings), which);
4414             if (strSpan.needsStringSpanUTF16()) {
4415                 return strSpan.spanBack(s, fromIndex, spanCondition);
4416             }
4417         }
4418 
4419         // Pin to 0/1 values.
4420         boolean spanContained = (spanCondition != SpanCondition.NOT_CONTAINED);
4421 
4422         int c;
4423         int prev = fromIndex;
4424         do {
4425             c = Character.codePointBefore(s, prev);
4426             if (spanContained != contains(c)) {
4427                 break;
4428             }
4429             prev -= Character.charCount(c);
4430         } while (prev > 0);
4431         return prev;
4432     }
4433 
4434     /**
4435      * Clone a thawed version of this class, according to the Freezable interface.
4436      * @return the clone, not frozen
4437      * @stable ICU 4.4
4438      */
4439     @Override
cloneAsThawed()4440     public UnicodeSet cloneAsThawed() {
4441         UnicodeSet result = new UnicodeSet(this);
4442         assert !result.isFrozen();
4443         return result;
4444     }
4445 
4446     // internal function
checkFrozen()4447     private void checkFrozen() {
4448         if (isFrozen()) {
4449             throw new UnsupportedOperationException("Attempt to modify frozen object");
4450         }
4451     }
4452 
4453     // ************************
4454     // Additional methods for integration with Generics and Collections
4455     // ************************
4456 
4457     /**
4458      * A struct-like class used for iteration through ranges, for faster iteration than by String.
4459      * Read about the restrictions on usage in {@link UnicodeSet#ranges()}.
4460      *
4461      * @stable ICU 54
4462      */
4463     public static class EntryRange {
4464         /**
4465          * The starting code point of the range.
4466          *
4467          * @stable ICU 54
4468          */
4469         public int codepoint;
4470         /**
4471          * The ending code point of the range
4472          *
4473          * @stable ICU 54
4474          */
4475         public int codepointEnd;
4476 
EntryRange()4477         EntryRange() {
4478         }
4479 
4480         /**
4481          * {@inheritDoc}
4482          *
4483          * @stable ICU 54
4484          */
4485         @Override
toString()4486         public String toString() {
4487             StringBuilder b = new StringBuilder();
4488             return (
4489                     codepoint == codepointEnd ? _appendToPat(b, codepoint, false)
4490                             : _appendToPat(_appendToPat(b, codepoint, false).append('-'), codepointEnd, false))
4491                             .toString();
4492         }
4493     }
4494 
4495     /**
4496      * Provide for faster iteration than by String. Returns an Iterable/Iterator over ranges of code points.
4497      * The UnicodeSet must not be altered during the iteration.
4498      * The EntryRange instance is the same each time; the contents are just reset.
4499      *
4500      * <p><b>Warning: </b>To iterate over the full contents, you have to also iterate over the strings.
4501      *
4502      * <p><b>Warning: </b>For speed, UnicodeSet iteration does not check for concurrent modification.
4503      * Do not alter the UnicodeSet while iterating.
4504      *
4505      * <pre>
4506      * // Sample code
4507      * for (EntryRange range : us1.ranges()) {
4508      *     // do something with code points between range.codepoint and range.codepointEnd;
4509      * }
4510      * for (String s : us1.strings()) {
4511      *     // do something with each string;
4512      * }
4513      * </pre>
4514      *
4515      * @stable ICU 54
4516      */
ranges()4517     public Iterable<EntryRange> ranges() {
4518         return new EntryRangeIterable();
4519     }
4520 
4521     private class EntryRangeIterable implements Iterable<EntryRange> {
4522         @Override
iterator()4523         public Iterator<EntryRange> iterator() {
4524             return new EntryRangeIterator();
4525         }
4526     }
4527 
4528     private class EntryRangeIterator implements Iterator<EntryRange> {
4529         int pos;
4530         EntryRange result = new EntryRange();
4531 
4532         @Override
hasNext()4533         public boolean hasNext() {
4534             return pos < len-1;
4535         }
4536         @Override
next()4537         public EntryRange next() {
4538             if (pos < len-1) {
4539                 result.codepoint = list[pos++];
4540                 result.codepointEnd = list[pos++]-1;
4541             } else {
4542                 throw new NoSuchElementException();
4543             }
4544             return result;
4545         }
4546         @Override
remove()4547         public void remove() {
4548             throw new UnsupportedOperationException();
4549         }
4550     }
4551 
4552 
4553     /**
4554      * Returns a string iterator. Uses the same order of iteration as {@link UnicodeSetIterator}.
4555      * <p><b>Warning: </b>For speed, UnicodeSet iteration does not check for concurrent modification.
4556      * Do not alter the UnicodeSet while iterating.
4557      * @see java.util.Set#iterator()
4558      * @stable ICU 4.4
4559      */
4560     @Override
iterator()4561     public Iterator<String> iterator() {
4562         return new UnicodeSetIterator2(this);
4563     }
4564 
4565     // Cover for string iteration.
4566     private static class UnicodeSetIterator2 implements Iterator<String> {
4567         // Invariants:
4568         // sourceList != null then sourceList[item] is a valid character
4569         // sourceList == null then delegates to stringIterator
4570         private int[] sourceList;
4571         private int len;
4572         private int item;
4573         private int current;
4574         private int limit;
4575         private SortedSet<String> sourceStrings;
4576         private Iterator<String> stringIterator;
4577         private char[] buffer;
4578 
UnicodeSetIterator2(UnicodeSet source)4579         UnicodeSetIterator2(UnicodeSet source) {
4580             // set according to invariants
4581             len = source.len - 1;
4582             if (len > 0) {
4583                 sourceStrings = source.strings;
4584                 sourceList = source.list;
4585                 current = sourceList[item++];
4586                 limit = sourceList[item++];
4587             } else {
4588                 stringIterator = source.strings.iterator();
4589                 sourceList = null;
4590             }
4591         }
4592 
4593         /* (non-Javadoc)
4594          * @see java.util.Iterator#hasNext()
4595          */
4596         @Override
hasNext()4597         public boolean hasNext() {
4598             return sourceList != null || stringIterator.hasNext();
4599         }
4600 
4601         /* (non-Javadoc)
4602          * @see java.util.Iterator#next()
4603          */
4604         @Override
next()4605         public String next() {
4606             if (sourceList == null) {
4607                 return stringIterator.next();
4608             }
4609             int codepoint = current++;
4610             // we have the codepoint we need, but we may need to adjust the state
4611             if (current >= limit) {
4612                 if (item >= len) {
4613                     stringIterator = sourceStrings.iterator();
4614                     sourceList = null;
4615                 } else {
4616                     current = sourceList[item++];
4617                     limit = sourceList[item++];
4618                 }
4619             }
4620             // Now return. Single code point is easy
4621             if (codepoint <= 0xFFFF) {
4622                 return String.valueOf((char)codepoint);
4623             }
4624             // But Java lacks a valueOfCodePoint, so we handle ourselves for speed
4625             // allocate a buffer the first time, to make conversion faster.
4626             if (buffer == null) {
4627                 buffer = new char[2];
4628             }
4629             // compute ourselves, to save tests and calls
4630             int offset = codepoint - Character.MIN_SUPPLEMENTARY_CODE_POINT;
4631             buffer[0] = (char)((offset >>> 10) + Character.MIN_HIGH_SURROGATE);
4632             buffer[1] = (char)((offset & 0x3ff) + Character.MIN_LOW_SURROGATE);
4633             return String.valueOf(buffer);
4634         }
4635 
4636         /* (non-Javadoc)
4637          * @see java.util.Iterator#remove()
4638          */
4639         @Override
remove()4640         public void remove() {
4641             throw new UnsupportedOperationException();
4642         }
4643     }
4644 
4645     /**
4646      * @see #containsAll(com.ibm.icu.text.UnicodeSet)
4647      * @stable ICU 4.4
4648      */
containsAll(Iterable<T> collection)4649     public <T extends CharSequence> boolean containsAll(Iterable<T> collection) {
4650         for (T o : collection) {
4651             if (!contains(o)) {
4652                 return false;
4653             }
4654         }
4655         return true;
4656     }
4657 
4658     /**
4659      * @see #containsNone(com.ibm.icu.text.UnicodeSet)
4660      * @stable ICU 4.4
4661      */
containsNone(Iterable<T> collection)4662     public <T extends CharSequence> boolean containsNone(Iterable<T> collection) {
4663         for (T o : collection) {
4664             if (contains(o)) {
4665                 return false;
4666             }
4667         }
4668         return true;
4669     }
4670 
4671     /**
4672      * @see #containsAll(com.ibm.icu.text.UnicodeSet)
4673      * @stable ICU 4.4
4674      */
containsSome(Iterable<T> collection)4675     public final <T extends CharSequence> boolean containsSome(Iterable<T> collection) {
4676         return !containsNone(collection);
4677     }
4678 
4679     /**
4680      * @see #addAll(com.ibm.icu.text.UnicodeSet)
4681      * @stable ICU 4.4
4682      */
4683     @SuppressWarnings("unchecked")  // See ticket #11395, this is safe.
addAll(T... collection)4684     public <T extends CharSequence> UnicodeSet addAll(T... collection) {
4685         checkFrozen();
4686         for (T str : collection) {
4687             add(str);
4688         }
4689         return this;
4690     }
4691 
4692 
4693     /**
4694      * @see #removeAll(com.ibm.icu.text.UnicodeSet)
4695      * @stable ICU 4.4
4696      */
removeAll(Iterable<T> collection)4697     public <T extends CharSequence> UnicodeSet removeAll(Iterable<T> collection) {
4698         checkFrozen();
4699         for (T o : collection) {
4700             remove(o);
4701         }
4702         return this;
4703     }
4704 
4705     /**
4706      * @see #retainAll(com.ibm.icu.text.UnicodeSet)
4707      * @stable ICU 4.4
4708      */
retainAll(Iterable<T> collection)4709     public <T extends CharSequence> UnicodeSet retainAll(Iterable<T> collection) {
4710         checkFrozen();
4711         // TODO optimize
4712         UnicodeSet toRetain = new UnicodeSet();
4713         toRetain.addAll(collection);
4714         retainAll(toRetain);
4715         return this;
4716     }
4717 
4718     /**
4719      * Comparison style enums used by {@link UnicodeSet#compareTo(UnicodeSet, ComparisonStyle)}.
4720      * @stable ICU 4.4
4721      */
4722     public enum ComparisonStyle {
4723         /**
4724          * @stable ICU 4.4
4725          */
4726         SHORTER_FIRST,
4727         /**
4728          * @stable ICU 4.4
4729          */
4730         LEXICOGRAPHIC,
4731         /**
4732          * @stable ICU 4.4
4733          */
4734         LONGER_FIRST
4735     }
4736 
4737     /**
4738      * Compares UnicodeSets, where shorter come first, and otherwise lexicographically
4739      * (according to the comparison of the first characters that differ).
4740      * @see java.lang.Comparable#compareTo(java.lang.Object)
4741      * @stable ICU 4.4
4742      */
4743     @Override
compareTo(UnicodeSet o)4744     public int compareTo(UnicodeSet o) {
4745         return compareTo(o, ComparisonStyle.SHORTER_FIRST);
4746     }
4747     /**
4748      * Compares UnicodeSets, in three different ways.
4749      * @see java.lang.Comparable#compareTo(java.lang.Object)
4750      * @stable ICU 4.4
4751      */
compareTo(UnicodeSet o, ComparisonStyle style)4752     public int compareTo(UnicodeSet o, ComparisonStyle style) {
4753         if (style != ComparisonStyle.LEXICOGRAPHIC) {
4754             int diff = size() - o.size();
4755             if (diff != 0) {
4756                 return (diff < 0) == (style == ComparisonStyle.SHORTER_FIRST) ? -1 : 1;
4757             }
4758         }
4759         int result;
4760         for (int i = 0; ; ++i) {
4761             if (0 != (result = list[i] - o.list[i])) {
4762                 // if either list ran out, compare to the last string
4763                 if (list[i] == HIGH) {
4764                     if (!hasStrings()) return 1;
4765                     String item = strings.first();
4766                     return compare(item, o.list[i]);
4767                 }
4768                 if (o.list[i] == HIGH) {
4769                     if (!o.hasStrings()) return -1;
4770                     String item = o.strings.first();
4771                     int compareResult = compare(item, list[i]);
4772                     return compareResult > 0 ? -1 : compareResult < 0 ? 1 : 0; // Reverse the order.
4773                 }
4774                 // otherwise return the result if even index, or the reversal if not
4775                 return (i & 1) == 0 ? result : -result;
4776             }
4777             if (list[i] == HIGH) {
4778                 break;
4779             }
4780         }
4781         return compare(strings, o.strings);
4782     }
4783 
4784     /**
4785      * @stable ICU 4.4
4786      */
compareTo(Iterable<String> other)4787     public int compareTo(Iterable<String> other) {
4788         return compare(this, other);
4789     }
4790 
4791     /**
4792      * Utility to compare a string to a code point.
4793      * Same results as turning the code point into a string (with the [ugly] new StringBuilder().appendCodePoint(codepoint).toString())
4794      * and comparing, but much faster (no object creation).
4795      * Actually, there is one difference; a null compares as less.
4796      * Note that this (=String) order is UTF-16 order -- <i>not</i> code point order.
4797      * @stable ICU 4.4
4798      */
4799 
compare(CharSequence string, int codePoint)4800     public static int compare(CharSequence string, int codePoint) {
4801         return CharSequences.compare(string, codePoint);
4802     }
4803 
4804     /**
4805      * Utility to compare a string to a code point.
4806      * Same results as turning the code point into a string and comparing, but much faster (no object creation).
4807      * Actually, there is one difference; a null compares as less.
4808      * Note that this (=String) order is UTF-16 order -- <i>not</i> code point order.
4809      * @stable ICU 4.4
4810      */
compare(int codePoint, CharSequence string)4811     public static int compare(int codePoint, CharSequence string) {
4812         return -CharSequences.compare(string, codePoint);
4813     }
4814 
4815 
4816     /**
4817      * Utility to compare two iterables. Warning: the ordering in iterables is important. For Collections that are ordered,
4818      * like Lists, that is expected. However, Sets in Java violate Leibniz's law when it comes to iteration.
4819      * That means that sets can't be compared directly with this method, unless they are TreeSets without
4820      * (or with the same) comparator. Unfortunately, it is impossible to reliably detect in Java whether subclass of
4821      * Collection satisfies the right criteria, so it is left to the user to avoid those circumstances.
4822      * @stable ICU 4.4
4823      */
compare(Iterable<T> collection1, Iterable<T> collection2)4824     public static <T extends Comparable<T>> int compare(Iterable<T> collection1, Iterable<T> collection2) {
4825         return compare(collection1.iterator(), collection2.iterator());
4826     }
4827 
4828     /**
4829      * Utility to compare two iterators. Warning: the ordering in iterables is important. For Collections that are ordered,
4830      * like Lists, that is expected. However, Sets in Java violate Leibniz's law when it comes to iteration.
4831      * That means that sets can't be compared directly with this method, unless they are TreeSets without
4832      * (or with the same) comparator. Unfortunately, it is impossible to reliably detect in Java whether subclass of
4833      * Collection satisfies the right criteria, so it is left to the user to avoid those circumstances.
4834      * @internal
4835      * @deprecated This API is ICU internal only.
4836      */
4837     @Deprecated
compare(Iterator<T> first, Iterator<T> other)4838     public static <T extends Comparable<T>> int compare(Iterator<T> first, Iterator<T> other) {
4839         while (true) {
4840             if (!first.hasNext()) {
4841                 return other.hasNext() ? -1 : 0;
4842             } else if (!other.hasNext()) {
4843                 return 1;
4844             }
4845             T item1 = first.next();
4846             T item2 = other.next();
4847             int result = item1.compareTo(item2);
4848             if (result != 0) {
4849                 return result;
4850             }
4851         }
4852     }
4853 
4854 
4855     /**
4856      * Utility to compare two collections, optionally by size, and then lexicographically.
4857      * @stable ICU 4.4
4858      */
compare(Collection<T> collection1, Collection<T> collection2, ComparisonStyle style)4859     public static <T extends Comparable<T>> int compare(Collection<T> collection1, Collection<T> collection2, ComparisonStyle style) {
4860         if (style != ComparisonStyle.LEXICOGRAPHIC) {
4861             int diff = collection1.size() - collection2.size();
4862             if (diff != 0) {
4863                 return (diff < 0) == (style == ComparisonStyle.SHORTER_FIRST) ? -1 : 1;
4864             }
4865         }
4866         return compare(collection1, collection2);
4867     }
4868 
4869     /**
4870      * Utility for adding the contents of an iterable to a collection.
4871      * @stable ICU 4.4
4872      */
addAllTo(Iterable<T> source, U target)4873     public static <T, U extends Collection<T>> U addAllTo(Iterable<T> source, U target) {
4874         for (T item : source) {
4875             target.add(item);
4876         }
4877         return target;
4878     }
4879 
4880     /**
4881      * Utility for adding the contents of an iterable to a collection.
4882      * @stable ICU 4.4
4883      */
addAllTo(Iterable<T> source, T[] target)4884     public static <T> T[] addAllTo(Iterable<T> source, T[] target) {
4885         int i = 0;
4886         for (T item : source) {
4887             target[i++] = item;
4888         }
4889         return target;
4890     }
4891 
4892     /**
4893      * For iterating through the strings in the set. Example:
4894      * <pre>
4895      * for (String key : myUnicodeSet.strings()) {
4896      *   doSomethingWith(key);
4897      * }
4898      * </pre>
4899      * @stable ICU 4.4
4900      */
strings()4901     public Collection<String> strings() {
4902         if (hasStrings()) {
4903             return Collections.unmodifiableSortedSet(strings);
4904         } else {
4905             return EMPTY_STRINGS;
4906         }
4907     }
4908 
4909     /**
4910      * Return the value of the first code point, if the string is exactly one code point. Otherwise return Integer.MAX_VALUE.
4911      * @internal
4912      * @deprecated This API is ICU internal only.
4913      */
4914     @Deprecated
getSingleCodePoint(CharSequence s)4915     public static int getSingleCodePoint(CharSequence s) {
4916         return CharSequences.getSingleCodePoint(s);
4917     }
4918 
4919     /**
4920      * Simplify the ranges in a Unicode set by merging any ranges that are only separated by characters in the dontCare set.
4921      * For example, the ranges: \\u2E80-\\u2E99\\u2E9B-\\u2EF3\\u2F00-\\u2FD5\\u2FF0-\\u2FFB\\u3000-\\u303E change to \\u2E80-\\u303E
4922      * if the dontCare set includes unassigned characters (for a particular version of Unicode).
4923      * @param dontCare Set with the don't-care characters for spanning
4924      * @return the input set, modified
4925      * @internal
4926      * @deprecated This API is ICU internal only.
4927      */
4928     @Deprecated
addBridges(UnicodeSet dontCare)4929     public UnicodeSet addBridges(UnicodeSet dontCare) {
4930         UnicodeSet notInInput = new UnicodeSet(this).complement().removeAllStrings();
4931         for (UnicodeSetIterator it = new UnicodeSetIterator(notInInput); it.nextRange();) {
4932             if (it.codepoint != 0 && it.codepointEnd != 0x10FFFF &&
4933                     dontCare.contains(it.codepoint, it.codepointEnd)) {
4934                 add(it.codepoint,it.codepointEnd);
4935             }
4936         }
4937         return this;
4938     }
4939 
4940     /**
4941      * Find the first index at or after fromIndex where the UnicodeSet matches at that index.
4942      * If findNot is true, then reverse the sense of the match: find the first place where the UnicodeSet doesn't match.
4943      * If there is no match, length is returned.
4944      * @internal
4945      * @deprecated This API is ICU internal only. Use span instead.
4946      */
4947     @Deprecated
findIn(CharSequence value, int fromIndex, boolean findNot)4948     public int findIn(CharSequence value, int fromIndex, boolean findNot) {
4949         //TODO add strings, optimize, using ICU4C algorithms
4950         int cp;
4951         for (; fromIndex < value.length(); fromIndex += UTF16.getCharCount(cp)) {
4952             cp = UTF16.charAt(value, fromIndex);
4953             if (contains(cp) != findNot) {
4954                 break;
4955             }
4956         }
4957         return fromIndex;
4958     }
4959 
4960     /**
4961      * Find the last index before fromIndex where the UnicodeSet matches at that index.
4962      * If findNot is true, then reverse the sense of the match: find the last place where the UnicodeSet doesn't match.
4963      * If there is no match, -1 is returned.
4964      * BEFORE index is not in the UnicodeSet.
4965      * @internal
4966      * @deprecated This API is ICU internal only. Use spanBack instead.
4967      */
4968     @Deprecated
findLastIn(CharSequence value, int fromIndex, boolean findNot)4969     public int findLastIn(CharSequence value, int fromIndex, boolean findNot) {
4970         //TODO add strings, optimize, using ICU4C algorithms
4971         int cp;
4972         fromIndex -= 1;
4973         for (; fromIndex >= 0; fromIndex -= UTF16.getCharCount(cp)) {
4974             cp = UTF16.charAt(value, fromIndex);
4975             if (contains(cp) != findNot) {
4976                 break;
4977             }
4978         }
4979         return fromIndex < 0 ? -1 : fromIndex;
4980     }
4981 
4982     /**
4983      * Strips code points from source. If matches is true, script all that match <i>this</i>. If matches is false, then strip all that <i>don't</i> match.
4984      * @param source The source of the CharSequence to strip from.
4985      * @param matches A boolean to either strip all that matches or don't match with the current UnicodeSet object.
4986      * @return The string after it has been stripped.
4987      * @internal
4988      * @deprecated This API is ICU internal only. Use replaceFrom.
4989      */
4990     @Deprecated
stripFrom(CharSequence source, boolean matches)4991     public String stripFrom(CharSequence source, boolean matches) {
4992         StringBuilder result = new StringBuilder();
4993         for (int pos = 0; pos < source.length();) {
4994             int inside = findIn(source, pos, !matches);
4995             result.append(source.subSequence(pos, inside));
4996             pos = findIn(source, inside, matches); // get next start
4997         }
4998         return result.toString();
4999     }
5000 
5001     /**
5002      * Argument values for whether span() and similar functions continue while the current character is contained vs.
5003      * not contained in the set.
5004      * <p>
5005      * The functionality is straightforward for sets with only single code points, without strings (which is the common
5006      * case):
5007      * <ul>
5008      * <li>CONTAINED and SIMPLE work the same.
5009      * <li>CONTAINED and SIMPLE are inverses of NOT_CONTAINED.
5010      * <li>span() and spanBack() partition any string the
5011      * same way when alternating between span(NOT_CONTAINED) and span(either "contained" condition).
5012      * <li>Using a
5013      * complemented (inverted) set and the opposite span conditions yields the same results.
5014      * </ul>
5015      * When a set contains multi-code point strings, then these statements may not be true, depending on the strings in
5016      * the set (for example, whether they overlap with each other) and the string that is processed. For a set with
5017      * strings:
5018      * <ul>
5019      * <li>The complement of the set contains the opposite set of code points, but the same set of strings.
5020      * Therefore, complementing both the set and the span conditions may yield different results.
5021      * <li>When starting spans
5022      * at different positions in a string (span(s, ...) vs. span(s+1, ...)) the ends of the spans may be different
5023      * because a set string may start before the later position.
5024      * <li>span(SIMPLE) may be shorter than
5025      * span(CONTAINED) because it will not recursively try all possible paths. For example, with a set which
5026      * contains the three strings "xy", "xya" and "ax", span("xyax", CONTAINED) will return 4 but span("xyax",
5027      * SIMPLE) will return 3. span(SIMPLE) will never be longer than span(CONTAINED).
5028      * <li>With either "contained" condition, span() and spanBack() may partition a string in different ways. For example,
5029      * with a set which contains the two strings "ab" and "ba", and when processing the string "aba", span() will yield
5030      * contained/not-contained boundaries of { 0, 2, 3 } while spanBack() will yield boundaries of { 0, 1, 3 }.
5031      * </ul>
5032      * Note: If it is important to get the same boundaries whether iterating forward or backward through a string, then
5033      * either only span() should be used and the boundaries cached for backward operation, or an ICU BreakIterator could
5034      * be used.
5035      * <p>
5036      * Note: Unpaired surrogates are treated like surrogate code points. Similarly, set strings match only on code point
5037      * boundaries, never in the middle of a surrogate pair.
5038      *
5039      * @stable ICU 4.4
5040      */
5041     public enum SpanCondition {
5042         /**
5043          * Continues a span() while there is no set element at the current position.
5044          * Increments by one code point at a time.
5045          * Stops before the first set element (character or string).
5046          * (For code points only, this is like while contains(current)==false).
5047          * <p>
5048          * When span() returns, the substring between where it started and the position it returned consists only of
5049          * characters that are not in the set, and none of its strings overlap with the span.
5050          *
5051          * @stable ICU 4.4
5052          */
5053         NOT_CONTAINED,
5054 
5055         /**
5056          * Spans the longest substring that is a concatenation of set elements (characters or strings).
5057          * (For characters only, this is like while contains(current)==true).
5058          * <p>
5059          * When span() returns, the substring between where it started and the position it returned consists only of set
5060          * elements (characters or strings) that are in the set.
5061          * <p>
5062          * If a set contains strings, then the span will be the longest substring for which there
5063          * exists at least one non-overlapping concatenation of set elements (characters or strings).
5064          * This is equivalent to a POSIX regular expression for <code>(OR of each set element)*</code>.
5065          * (Java/ICU/Perl regex stops at the first match of an OR.)
5066          *
5067          * @stable ICU 4.4
5068          */
5069         CONTAINED,
5070 
5071         /**
5072          * Continues a span() while there is a set element at the current position.
5073          * Increments by the longest matching element at each position.
5074          * (For characters only, this is like while contains(current)==true).
5075          * <p>
5076          * When span() returns, the substring between where it started and the position it returned consists only of set
5077          * elements (characters or strings) that are in the set.
5078          * <p>
5079          * If a set only contains single characters, then this is the same as CONTAINED.
5080          * <p>
5081          * If a set contains strings, then the span will be the longest substring with a match at each position with the
5082          * longest single set element (character or string).
5083          * <p>
5084          * Use this span condition together with other longest-match algorithms, such as ICU converters
5085          * (ucnv_getUnicodeSet()).
5086          *
5087          * @stable ICU 4.4
5088          */
5089         SIMPLE,
5090 
5091         /**
5092          * One more than the last span condition.
5093          *
5094          * @stable ICU 4.4
5095          */
5096         CONDITION_COUNT
5097     }
5098 
5099     /**
5100      * Get the default symbol table. Null means ordinary processing. For internal use only.
5101      * @return the symbol table
5102      * @internal
5103      * @deprecated This API is ICU internal only.
5104      */
5105     @Deprecated
getDefaultXSymbolTable()5106     public static XSymbolTable getDefaultXSymbolTable() {
5107         return XSYMBOL_TABLE;
5108     }
5109 
5110     /**
5111      * Set the default symbol table. Null means ordinary processing. For internal use only. Will affect all subsequent parsing
5112      * of UnicodeSets.
5113      * <p>
5114      * WARNING: If this function is used with a UnicodeProperty, and the
5115      * Unassigned characters (gc=Cn) are different than in ICU, you MUST call
5116      * {@code UnicodeProperty.ResetCacheProperties} afterwards. If you then call {@code UnicodeSet.setDefaultXSymbolTable}
5117      * with null to clear the value, you MUST also call {@code UnicodeProperty.ResetCacheProperties}.
5118      *
5119      * @param xSymbolTable the new default symbol table.
5120      * @internal
5121      * @deprecated This API is ICU internal only.
5122      */
5123     @Deprecated
setDefaultXSymbolTable(XSymbolTable xSymbolTable)5124     public static void setDefaultXSymbolTable(XSymbolTable xSymbolTable) {
5125         // If the properties override inclusions, these have to be regenerated.
5126         // TODO: Check if the Unicode Tools or Unicode Utilities really need this.
5127         CharacterPropertiesImpl.clear();
5128         XSYMBOL_TABLE = xSymbolTable;
5129     }
5130 }
5131 //eof
5132