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