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    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
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   17    * You should have received a copy of the GNU General Public License version
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   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
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   25   
   26   package java.util.regex;
   27   
   28   import java.security.AccessController;
   29   import java.security.PrivilegedAction;
   30   import java.text.CharacterIterator;
   31   import java.text.Normalizer;
   32   import java.util.Locale;
   33   import java.util.Map;
   34   import java.util.ArrayList;
   35   import java.util.HashMap;
   36   import java.util.Arrays;
   37   
   38   
   39   /**
   40    * A compiled representation of a regular expression.
   41    *
   42    * <p> A regular expression, specified as a string, must first be compiled into
   43    * an instance of this class.  The resulting pattern can then be used to create
   44    * a {@link Matcher} object that can match arbitrary {@link
   45    * java.lang.CharSequence </code>character sequences<code>} against the regular
   46    * expression.  All of the state involved in performing a match resides in the
   47    * matcher, so many matchers can share the same pattern.
   48    *
   49    * <p> A typical invocation sequence is thus
   50    *
   51    * <blockquote><pre>
   52    * Pattern p = Pattern.{@link #compile compile}("a*b");
   53    * Matcher m = p.{@link #matcher matcher}("aaaaab");
   54    * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
   55    *
   56    * <p> A {@link #matches matches} method is defined by this class as a
   57    * convenience for when a regular expression is used just once.  This method
   58    * compiles an expression and matches an input sequence against it in a single
   59    * invocation.  The statement
   60    *
   61    * <blockquote><pre>
   62    * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
   63    *
   64    * is equivalent to the three statements above, though for repeated matches it
   65    * is less efficient since it does not allow the compiled pattern to be reused.
   66    *
   67    * <p> Instances of this class are immutable and are safe for use by multiple
   68    * concurrent threads.  Instances of the {@link Matcher} class are not safe for
   69    * such use.
   70    *
   71    *
   72    * <a name="sum">
   73    * <h4> Summary of regular-expression constructs </h4>
   74    *
   75    * <table border="0" cellpadding="1" cellspacing="0"
   76    *  summary="Regular expression constructs, and what they match">
   77    *
   78    * <tr align="left">
   79    * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th>
   80    * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
   81    * </tr>
   82    *
   83    * <tr><th>&nbsp;</th></tr>
   84    * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
   85    *
   86    * <tr><td valign="top" headers="construct characters"><i>x</i></td>
   87    *     <td headers="matches">The character <i>x</i></td></tr>
   88    * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
   89    *     <td headers="matches">The backslash character</td></tr>
   90    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
   91    *     <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
   92    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
   93    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
   94    *     <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
   95    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
   96    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
   97    *     <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
   98    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>m</i>&nbsp;<tt>&lt;=</tt>&nbsp;3,
   99    *         0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
  100    * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
  101    *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hh</i></td></tr>
  102    * <tr><td valign="top" headers="construct characters"><tt>&#92;u</tt><i>hhhh</i></td>
  103    *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hhhh</i></td></tr>
  104    * <tr><td valign="top" headers="construct characters"><tt>&#92;x</tt><i>{h...h}</i></td>
  105    *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>h...h</i>
  106    *         ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
  107    *         &nbsp;&lt;=&nbsp;<tt>0x</tt><i>h...h</i>&nbsp;&lt;=&nbsp
  108    *          {@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
  109    * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
  110    *     <td headers="matches">The tab character (<tt>'&#92;u0009'</tt>)</td></tr>
  111    * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
  112    *     <td headers="matches">The newline (line feed) character (<tt>'&#92;u000A'</tt>)</td></tr>
  113    * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
  114    *     <td headers="matches">The carriage-return character (<tt>'&#92;u000D'</tt>)</td></tr>
  115    * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
  116    *     <td headers="matches">The form-feed character (<tt>'&#92;u000C'</tt>)</td></tr>
  117    * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
  118    *     <td headers="matches">The alert (bell) character (<tt>'&#92;u0007'</tt>)</td></tr>
  119    * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
  120    *     <td headers="matches">The escape character (<tt>'&#92;u001B'</tt>)</td></tr>
  121    * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
  122    *     <td headers="matches">The control character corresponding to <i>x</i></td></tr>
  123    *
  124    * <tr><th>&nbsp;</th></tr>
  125    * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
  126    *
  127    * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td>
  128    *     <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr>
  129    * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td>
  130    *     <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr>
  131    * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td>
  132    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>
  133    *         or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr>
  134    * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td>
  135    *     <td headers="matches"><tt>a</tt> through <tt>d</tt>,
  136    *      or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr>
  137    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td>
  138    *     <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr>
  139    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td>
  140    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
  141    *         except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr>
  142    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td>
  143    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
  144    *          and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr>
  145    * <tr><th>&nbsp;</th></tr>
  146    *
  147    * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
  148    *
  149    * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
  150    *     <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
  151    * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
  152    *     <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
  153    * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
  154    *     <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
  155    * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
  156    *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
  157    * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
  158    *     <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
  159    * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
  160    *     <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
  161    * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
  162    *     <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
  163    *
  164    * <tr><th>&nbsp;</th></tr>
  165    * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr>
  166    *
  167    * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td>
  168    *     <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr>
  169    * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td>
  170    *     <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr>
  171    * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td>
  172    *     <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
  173    * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td>
  174    *     <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr>
  175    * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td>
  176    *     <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr>
  177    * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td>
  178    *     <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr>
  179    * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td>
  180    *     <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr>
  181    *     <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt>
  182    *          <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> -->
  183    * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td>
  184    *     <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr>
  185    * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td>
  186    *     <td headers="matches">A printable character: <tt>[\p{Graph}\x20]</tt></td></tr>
  187    * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td>
  188    *     <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr>
  189    * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td>
  190    *     <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</tt></td></tr>
  191    * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td>
  192    *     <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr>
  193    * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td>
  194    *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
  195    *
  196    * <tr><th>&nbsp;</th></tr>
  197    * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
  198    *
  199    * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
  200    *     <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
  201    * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
  202    *     <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
  203    * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
  204    *     <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
  205    * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
  206    *     <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
  207    *
  208    * <tr><th>&nbsp;</th></tr>
  209    * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
  210    * * <tr><td valign="top" headers="construct unicode"><tt>\p{IsLatin}</tt></td>
  211    *     <td headers="matches">A Latin&nbsp;script character (<a href="#usc">script</a>)</td></tr>
  212    * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td>
  213    *     <td headers="matches">A character in the Greek&nbsp;block (<a href="#ubc">block</a>)</td></tr>
  214    * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td>
  215    *     <td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
  216    * <tr><td valign="top" headers="construct unicode"><tt>\p{IsAlphabetic}</tt></td>
  217    *     <td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
  218    * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td>
  219    *     <td headers="matches">A currency symbol</td></tr>
  220    * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td>
  221    *     <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
  222    * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]]&nbsp;</tt></td>
  223    *     <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
  224    *
  225    * <tr><th>&nbsp;</th></tr>
  226    * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
  227    *
  228    * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
  229    *     <td headers="matches">The beginning of a line</td></tr>
  230    * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
  231    *     <td headers="matches">The end of a line</td></tr>
  232    * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
  233    *     <td headers="matches">A word boundary</td></tr>
  234    * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
  235    *     <td headers="matches">A non-word boundary</td></tr>
  236    * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
  237    *     <td headers="matches">The beginning of the input</td></tr>
  238    * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
  239    *     <td headers="matches">The end of the previous match</td></tr>
  240    * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
  241    *     <td headers="matches">The end of the input but for the final
  242    *         <a href="#lt">terminator</a>, if&nbsp;any</td></tr>
  243    * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
  244    *     <td headers="matches">The end of the input</td></tr>
  245    *
  246    * <tr><th>&nbsp;</th></tr>
  247    * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
  248    *
  249    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
  250    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  251    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
  252    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  253    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
  254    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  255    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
  256    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  257    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
  258    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  259    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
  260    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  261    *
  262    * <tr><th>&nbsp;</th></tr>
  263    * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
  264    *
  265    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
  266    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  267    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
  268    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  269    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
  270    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  271    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
  272    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  273    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
  274    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  275    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
  276    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  277    *
  278    * <tr><th>&nbsp;</th></tr>
  279    * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
  280    *
  281    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
  282    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  283    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
  284    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  285    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
  286    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  287    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
  288    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  289    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
  290    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  291    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
  292    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  293    *
  294    * <tr><th>&nbsp;</th></tr>
  295    * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
  296    *
  297    * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
  298    *     <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
  299    * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
  300    *     <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
  301    * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
  302    *     <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
  303    *
  304    * <tr><th>&nbsp;</th></tr>
  305    * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
  306    *
  307    * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
  308    *     <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
  309    *     <a href="#cg">capturing group</a> matched</td></tr>
  310    *
  311    * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i>&lt;<i>name</i>&gt;</td>
  312    *     <td valign="bottom" headers="matches">Whatever the
  313    *     <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
  314    *
  315    * <tr><th>&nbsp;</th></tr>
  316    * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
  317    *
  318    * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
  319    *     <td headers="matches">Nothing, but quotes the following character</td></tr>
  320    * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
  321    *     <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
  322    * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
  323    *     <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
  324    *     <!-- Metachars: !$()*+.<>?[\]^{|} -->
  325    *
  326    * <tr><th>&nbsp;</th></tr>
  327    * <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
  328    *
  329    * <tr><td valign="top" headers="construct special"><tt>(?&lt;<a href="#groupname">name</a>&gt;</tt><i>X</i><tt>)</tt></td>
  330    *     <td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
  331    * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
  332    *     <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
  333    * <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU)&nbsp;</tt></td>
  334    *     <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
  335    * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
  336    * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
  337    * on - off</td></tr>
  338    * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt>&nbsp;&nbsp;</td>
  339    *     <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
  340    *         given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
  341    * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
  342    * <a href="#COMMENTS">x</a> on - off</td></tr>
  343    * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
  344    *     <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
  345    * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
  346    *     <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
  347    * <tr><td valign="top" headers="construct special"><tt>(?&lt;=</tt><i>X</i><tt>)</tt></td>
  348    *     <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
  349    * <tr><td valign="top" headers="construct special"><tt>(?&lt;!</tt><i>X</i><tt>)</tt></td>
  350    *     <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
  351    * <tr><td valign="top" headers="construct special"><tt>(?&gt;</tt><i>X</i><tt>)</tt></td>
  352    *     <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
  353    *
  354    * </table>
  355    *
  356    * <hr>
  357    *
  358    *
  359    * <a name="bs">
  360    * <h4> Backslashes, escapes, and quoting </h4>
  361    *
  362    * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
  363    * constructs, as defined in the table above, as well as to quote characters
  364    * that otherwise would be interpreted as unescaped constructs.  Thus the
  365    * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
  366    * left brace.
  367    *
  368    * <p> It is an error to use a backslash prior to any alphabetic character that
  369    * does not denote an escaped construct; these are reserved for future
  370    * extensions to the regular-expression language.  A backslash may be used
  371    * prior to a non-alphabetic character regardless of whether that character is
  372    * part of an unescaped construct.
  373    *
  374    * <p> Backslashes within string literals in Java source code are interpreted
  375    * as required by
  376    * <cite>The Java&trade; Language Specification</cite>
  377    * as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
  378    * It is therefore necessary to double backslashes in string
  379    * literals that represent regular expressions to protect them from
  380    * interpretation by the Java bytecode compiler.  The string literal
  381    * <tt>"&#92;b"</tt>, for example, matches a single backspace character when
  382    * interpreted as a regular expression, while <tt>"&#92;&#92;b"</tt> matches a
  383    * word boundary.  The string literal <tt>"&#92;(hello&#92;)"</tt> is illegal
  384    * and leads to a compile-time error; in order to match the string
  385    * <tt>(hello)</tt> the string literal <tt>"&#92;&#92;(hello&#92;&#92;)"</tt>
  386    * must be used.
  387    *
  388    * <a name="cc">
  389    * <h4> Character Classes </h4>
  390    *
  391    *    <p> Character classes may appear within other character classes, and
  392    *    may be composed by the union operator (implicit) and the intersection
  393    *    operator (<tt>&amp;&amp;</tt>).
  394    *    The union operator denotes a class that contains every character that is
  395    *    in at least one of its operand classes.  The intersection operator
  396    *    denotes a class that contains every character that is in both of its
  397    *    operand classes.
  398    *
  399    *    <p> The precedence of character-class operators is as follows, from
  400    *    highest to lowest:
  401    *
  402    *    <blockquote><table border="0" cellpadding="1" cellspacing="0"
  403    *                 summary="Precedence of character class operators.">
  404    *      <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
  405    *        <td>Literal escape&nbsp;&nbsp;&nbsp;&nbsp;</td>
  406    *        <td><tt>\x</tt></td></tr>
  407    *     <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
  408    *        <td>Grouping</td>
  409    *        <td><tt>[...]</tt></td></tr>
  410    *     <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
  411    *        <td>Range</td>
  412    *        <td><tt>a-z</tt></td></tr>
  413    *      <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
  414    *        <td>Union</td>
  415    *        <td><tt>[a-e][i-u]</tt></td></tr>
  416    *      <tr><th>5&nbsp;&nbsp;&nbsp;&nbsp;</th>
  417    *        <td>Intersection</td>
  418    *        <td><tt>[a-z&&[aeiou]]</tt></td></tr>
  419    *    </table></blockquote>
  420    *
  421    *    <p> Note that a different set of metacharacters are in effect inside
  422    *    a character class than outside a character class. For instance, the
  423    *    regular expression <tt>.</tt> loses its special meaning inside a
  424    *    character class, while the expression <tt>-</tt> becomes a range
  425    *    forming metacharacter.
  426    *
  427    * <a name="lt">
  428    * <h4> Line terminators </h4>
  429    *
  430    * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
  431    * the end of a line of the input character sequence.  The following are
  432    * recognized as line terminators:
  433    *
  434    * <ul>
  435    *
  436    *   <li> A newline (line feed) character&nbsp;(<tt>'\n'</tt>),
  437    *
  438    *   <li> A carriage-return character followed immediately by a newline
  439    *   character&nbsp;(<tt>"\r\n"</tt>),
  440    *
  441    *   <li> A standalone carriage-return character&nbsp;(<tt>'\r'</tt>),
  442    *
  443    *   <li> A next-line character&nbsp;(<tt>'&#92;u0085'</tt>),
  444    *
  445    *   <li> A line-separator character&nbsp;(<tt>'&#92;u2028'</tt>), or
  446    *
  447    *   <li> A paragraph-separator character&nbsp;(<tt>'&#92;u2029</tt>).
  448    *
  449    * </ul>
  450    * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
  451    * recognized are newline characters.
  452    *
  453    * <p> The regular expression <tt>.</tt> matches any character except a line
  454    * terminator unless the {@link #DOTALL} flag is specified.
  455    *
  456    * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
  457    * line terminators and only match at the beginning and the end, respectively,
  458    * of the entire input sequence. If {@link #MULTILINE} mode is activated then
  459    * <tt>^</tt> matches at the beginning of input and after any line terminator
  460    * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
  461    * matches just before a line terminator or the end of the input sequence.
  462    *
  463    * <a name="cg">
  464    * <h4> Groups and capturing </h4>
  465    *
  466    * <a name="gnumber">
  467    * <h5> Group number </h5>
  468    * <p> Capturing groups are numbered by counting their opening parentheses from
  469    * left to right.  In the expression <tt>((A)(B(C)))</tt>, for example, there
  470    * are four such groups: </p>
  471    *
  472    * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
  473    * <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
  474    *     <td><tt>((A)(B(C)))</tt></td></tr>
  475    * <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
  476    *     <td><tt>(A)</tt></td></tr>
  477    * <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
  478    *     <td><tt>(B(C))</tt></td></tr>
  479    * <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
  480    *     <td><tt>(C)</tt></td></tr>
  481    * </table></blockquote>
  482    *
  483    * <p> Group zero always stands for the entire expression.
  484    *
  485    * <p> Capturing groups are so named because, during a match, each subsequence
  486    * of the input sequence that matches such a group is saved.  The captured
  487    * subsequence may be used later in the expression, via a back reference, and
  488    * may also be retrieved from the matcher once the match operation is complete.
  489    *
  490    * <a name="groupname">
  491    * <h5> Group name </h5>
  492    * <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
  493    * and then be back-referenced later by the "name". Group names are composed of
  494    * the following characters. The first character must be a <tt>letter</tt>.
  495    *
  496    * <ul>
  497    *   <li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
  498    *        (<tt>'&#92;u0041'</tt>&nbsp;through&nbsp;<tt>'&#92;u005a'</tt>),
  499    *   <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
  500    *        (<tt>'&#92;u0061'</tt>&nbsp;through&nbsp;<tt>'&#92;u007a'</tt>),
  501    *   <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
  502    *        (<tt>'&#92;u0030'</tt>&nbsp;through&nbsp;<tt>'&#92;u0039'</tt>),
  503    * </ul>
  504    *
  505    * <p> A <tt>named-capturing group</tt> is still numbered as described in
  506    * <a href="#gnumber">Group number</a>.
  507    *
  508    * <p> The captured input associated with a group is always the subsequence
  509    * that the group most recently matched.  If a group is evaluated a second time
  510    * because of quantification then its previously-captured value, if any, will
  511    * be retained if the second evaluation fails.  Matching the string
  512    * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
  513    * group two set to <tt>"b"</tt>.  All captured input is discarded at the
  514    * beginning of each match.
  515    *
  516    * <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
  517    * that do not capture text and do not count towards the group total, or
  518    * <i>named-capturing</i> group.
  519    *
  520    * <h4> Unicode support </h4>
  521    *
  522    * <p> This class is in conformance with Level 1 of <a
  523    * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
  524    * Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
  525    * Canonical Equivalents.
  526    * <p>
  527    * <b>Unicode escape sequences</b> such as <tt>&#92;u2014</tt> in Java source code
  528    * are processed as described in section 3.3 of
  529    * <cite>The Java&trade; Language Specification</cite>.
  530    * Such escape sequences are also implemented directly by the regular-expression
  531    * parser so that Unicode escapes can be used in expressions that are read from
  532    * files or from the keyboard.  Thus the strings <tt>"&#92;u2014"</tt> and
  533    * <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which
  534    * matches the character with hexadecimal value <tt>0x2014</tt>.
  535    * <p>
  536    * A Unicode character can also be represented in a regular-expression by
  537    * using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct
  538    * <tt>&#92;x{...}</tt>, for example a supplementary character U+2011F
  539    * can be specified as <tt>&#92;x{2011F}</tt>, instead of two consecutive
  540    * Unicode escape sequences of the surrogate pair
  541    * <tt>&#92;uD840</tt><tt>&#92;uDD1F</tt>.
  542    * <p>
  543    * Unicode scripts, blocks, categories and binary properties are written with
  544    * the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl.
  545    * <tt>\p{</tt><i>prop</i><tt>}</tt> matches if
  546    * the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt>
  547    * does not match if the input has that property.
  548    * <p>
  549    * Scripts, blocks, categories and binary properties can be used both inside
  550    * and outside of a character class.
  551    * <a name="usc">
  552    * <p>
  553    * <b>Scripts</b> are specified either with the prefix {@code Is}, as in
  554    * {@code IsHiragana}, or by using  the {@code script} keyword (or its short
  555    * form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}.
  556    * <p>
  557    * The script names supported by <code>Pattern</code> are the valid script names
  558    * accepted and defined by
  559    * {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
  560    * <a name="ubc">
  561    * <p>
  562    * <b>Blocks</b> are specified with the prefix {@code In}, as in
  563    * {@code InMongolian}, or by using the keyword {@code block} (or its short
  564    * form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
  565    * <p>
  566    * The block names supported by <code>Pattern</code> are the valid block names
  567    * accepted and defined by
  568    * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
  569    * <p>
  570    * <a name="ucc">
  571    * <b>Categories</b> may be specified with the optional prefix {@code Is}:
  572    * Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
  573    * letters. Same as scripts and blocks, categories can also be specified
  574    * by using the keyword {@code general_category} (or its short form
  575    * {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
  576    * <p>
  577    * The supported categories are those of
  578    * <a href="http://www.unicode.org/unicode/standard/standard.html">
  579    * <i>The Unicode Standard</i></a> in the version specified by the
  580    * {@link java.lang.Character Character} class. The category names are those
  581    * defined in the Standard, both normative and informative.
  582    * <p>
  583    * <a name="ubpc">
  584    * <b>Binary properties</b> are specified with the prefix {@code Is}, as in
  585    * {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code>
  586    * are
  587    * <ul>
  588    *   <li> Alphabetic
  589    *   <li> Ideographic
  590    *   <li> Letter
  591    *   <li> Lowercase
  592    *   <li> Uppercase
  593    *   <li> Titlecase
  594    *   <li> Punctuation
  595    *   <Li> Control
  596    *   <li> White_Space
  597    *   <li> Digit
  598    *   <li> Hex_Digit
  599    *   <li> Noncharacter_Code_Point
  600    *   <li> Assigned
  601    * </ul>
  602   
  603   
  604    * <p>
  605    * <b>Predefined Character classes</b> and <b>POSIX character classes</b> are in
  606    * conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
  607    * of <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Regular Expression
  608    * </i></a>, when {@link #UNICODE_CHARACTER_CLASS} flag is specified.
  609    * <p>
  610    * <table border="0" cellpadding="1" cellspacing="0"
  611    *  summary="predefined and posix character classes in Unicode mode">
  612    * <tr align="left">
  613    * <th bgcolor="#CCCCFF" align="left" id="classes">Classes</th>
  614    * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
  615    *</tr>
  616    * <tr><td><tt>\p{Lower}</tt></td>
  617    *     <td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr>
  618    * <tr><td><tt>\p{Upper}</tt></td>
  619    *     <td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr>
  620    * <tr><td><tt>\p{ASCII}</tt></td>
  621    *     <td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
  622    * <tr><td><tt>\p{Alpha}</tt></td>
  623    *     <td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr>
  624    * <tr><td><tt>\p{Digit}</tt></td>
  625    *     <td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr>
  626    * <tr><td><tt>\p{Alnum}</tt></td>
  627    *     <td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr>
  628    * <tr><td><tt>\p{Punct}</tt></td>
  629    *     <td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr>
  630    * <tr><td><tt>\p{Graph}</tt></td>
  631    *     <td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr>
  632    * <tr><td><tt>\p{Print}</tt></td>
  633    *     <td>A printable character: <tt>[\p{Graph}\p{Blank}&&[^\p{Cntrl}]]</tt></td></tr>
  634    * <tr><td><tt>\p{Blank}</tt></td>
  635    *     <td>A space or a tab: <tt>[\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]</tt></td></tr>
  636    * <tr><td><tt>\p{Cntrl}</tt></td>
  637    *     <td>A control character: <tt>\p{gc=Cc}</tt></td></tr>
  638    * <tr><td><tt>\p{XDigit}</tt></td>
  639    *     <td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr>
  640    * <tr><td><tt>\p{Space}</tt></td>
  641    *     <td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr>
  642    * <tr><td><tt>\d</tt></td>
  643    *     <td>A digit: <tt>\p{IsDigit}</tt></td></tr>
  644    * <tr><td><tt>\D</tt></td>
  645    *     <td>A non-digit: <tt>[^\d]</tt></td></tr>
  646    * <tr><td><tt>\s</tt></td>
  647    *     <td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr>
  648    * <tr><td><tt>\S</tt></td>
  649    *     <td>A non-whitespace character: <tt>[^\s]</tt></td></tr>
  650    * <tr><td><tt>\w</tt></td>
  651    *     <td>A word character: <tt>[\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}]</tt></td></tr>
  652    * <tr><td><tt>\W</tt></td>
  653    *     <td>A non-word character: <tt>[^\w]</tt></td></tr>
  654    * </table>
  655    * <p>
  656    * <a name="jcc">
  657    * Categories that behave like the java.lang.Character
  658    * boolean is<i>methodname</i> methods (except for the deprecated ones) are
  659    * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
  660    * the specified property has the name <tt>java<i>methodname</i></tt>.
  661    *
  662    * <h4> Comparison to Perl 5 </h4>
  663    *
  664    * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
  665    * with ordered alternation as occurs in Perl 5.
  666    *
  667    * <p> Perl constructs not supported by this class: </p>
  668    *
  669    * <ul>
  670    *    <li><p> Predefined character classes (Unicode character)
  671    *    <p><tt>\h&nbsp;&nbsp;&nbsp;&nbsp;</tt>A horizontal whitespace
  672    *    <p><tt>\H&nbsp;&nbsp;&nbsp;&nbsp;</tt>A non horizontal whitespace
  673    *    <p><tt>\v&nbsp;&nbsp;&nbsp;&nbsp;</tt>A vertical whitespace
  674    *    <p><tt>\V&nbsp;&nbsp;&nbsp;&nbsp;</tt>A non vertical whitespace
  675    *    <p><tt>\R&nbsp;&nbsp;&nbsp;&nbsp;</tt>Any Unicode linebreak sequence
  676    *    <tt>\u005cu000D\u005cu000A|[\u005cu000A\u005cu000B\u005cu000C\u005cu000D\u005cu0085\u005cu2028\u005cu2029]</tt>
  677    *    <p><tt>\X&nbsp;&nbsp;&nbsp;&nbsp;</tt>Match Unicode
  678    *    <a href="http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
  679    *    <i>extended grapheme cluster</i></a>
  680    *    </p></li>
  681    *
  682    *    <li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for
  683    *    the <i>n</i><sup>th</sup><a href="#cg">capturing group</a> and
  684    *    <tt>\g{</tt><i>name</i><tt>}</tt> for
  685    *    <a href="#groupname">named-capturing group</a>.
  686    *    </p></li>
  687    *
  688    *    <li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt>
  689    *    for a Unicode character by its name.
  690    *    </p></li>
  691    *
  692    *    <li><p> The conditional constructs
  693    *    <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and
  694    *    <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
  695    *    </p></li>
  696    *
  697    *    <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
  698    *    and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
  699    *
  700    *    <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
  701    *
  702    *    <li><p> The preprocessing operations <tt>\l</tt> <tt>&#92;u</tt>,
  703    *    <tt>\L</tt>, and <tt>\U</tt>.  </p></li>
  704    *
  705    * </ul>
  706    *
  707    * <p> Constructs supported by this class but not by Perl: </p>
  708    *
  709    * <ul>
  710    *
  711    *    <li><p> Character-class union and intersection as described
  712    *    <a href="#cc">above</a>.</p></li>
  713    *
  714    * </ul>
  715    *
  716    * <p> Notable differences from Perl: </p>
  717    *
  718    * <ul>
  719    *
  720    *    <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
  721    *    as back references; a backslash-escaped number greater than <tt>9</tt> is
  722    *    treated as a back reference if at least that many subexpressions exist,
  723    *    otherwise it is interpreted, if possible, as an octal escape.  In this
  724    *    class octal escapes must always begin with a zero. In this class,
  725    *    <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
  726    *    references, and a larger number is accepted as a back reference if at
  727    *    least that many subexpressions exist at that point in the regular
  728    *    expression, otherwise the parser will drop digits until the number is
  729    *    smaller or equal to the existing number of groups or it is one digit.
  730    *    </p></li>
  731    *
  732    *    <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
  733    *    where the last match left off.  This functionality is provided implicitly
  734    *    by the {@link Matcher} class: Repeated invocations of the {@link
  735    *    Matcher#find find} method will resume where the last match left off,
  736    *    unless the matcher is reset.  </p></li>
  737    *
  738    *    <li><p> In Perl, embedded flags at the top level of an expression affect
  739    *    the whole expression.  In this class, embedded flags always take effect
  740    *    at the point at which they appear, whether they are at the top level or
  741    *    within a group; in the latter case, flags are restored at the end of the
  742    *    group just as in Perl.  </p></li>
  743    *
  744    * </ul>
  745    *
  746    *
  747    * <p> For a more precise description of the behavior of regular expression
  748    * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
  749    * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
  750    * O'Reilly and Associates, 2006.</a>
  751    * </p>
  752    *
  753    * @see java.lang.String#split(String, int)
  754    * @see java.lang.String#split(String)
  755    *
  756    * @author      Mike McCloskey
  757    * @author      Mark Reinhold
  758    * @author      JSR-51 Expert Group
  759    * @since       1.4
  760    * @spec        JSR-51
  761    */
  762   
  763   public final class Pattern
  764       implements java.io.Serializable
  765   {
  766   
  767       /**
  768        * Regular expression modifier values.  Instead of being passed as
  769        * arguments, they can also be passed as inline modifiers.
  770        * For example, the following statements have the same effect.
  771        * <pre>
  772        * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
  773        * RegExp r2 = RegExp.compile("(?im)abc", 0);
  774        * </pre>
  775        *
  776        * The flags are duplicated so that the familiar Perl match flag
  777        * names are available.
  778        */
  779   
  780       /**
  781        * Enables Unix lines mode.
  782        *
  783        * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
  784        * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
  785        *
  786        * <p> Unix lines mode can also be enabled via the embedded flag
  787        * expression&nbsp;<tt>(?d)</tt>.
  788        */
  789       public static final int UNIX_LINES = 0x01;
  790   
  791       /**
  792        * Enables case-insensitive matching.
  793        *
  794        * <p> By default, case-insensitive matching assumes that only characters
  795        * in the US-ASCII charset are being matched.  Unicode-aware
  796        * case-insensitive matching can be enabled by specifying the {@link
  797        * #UNICODE_CASE} flag in conjunction with this flag.
  798        *
  799        * <p> Case-insensitive matching can also be enabled via the embedded flag
  800        * expression&nbsp;<tt>(?i)</tt>.
  801        *
  802        * <p> Specifying this flag may impose a slight performance penalty.  </p>
  803        */
  804       public static final int CASE_INSENSITIVE = 0x02;
  805   
  806       /**
  807        * Permits whitespace and comments in pattern.
  808        *
  809        * <p> In this mode, whitespace is ignored, and embedded comments starting
  810        * with <tt>#</tt> are ignored until the end of a line.
  811        *
  812        * <p> Comments mode can also be enabled via the embedded flag
  813        * expression&nbsp;<tt>(?x)</tt>.
  814        */
  815       public static final int COMMENTS = 0x04;
  816   
  817       /**
  818        * Enables multiline mode.
  819        *
  820        * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
  821        * just after or just before, respectively, a line terminator or the end of
  822        * the input sequence.  By default these expressions only match at the
  823        * beginning and the end of the entire input sequence.
  824        *
  825        * <p> Multiline mode can also be enabled via the embedded flag
  826        * expression&nbsp;<tt>(?m)</tt>.  </p>
  827        */
  828       public static final int MULTILINE = 0x08;
  829   
  830       /**
  831        * Enables literal parsing of the pattern.
  832        *
  833        * <p> When this flag is specified then the input string that specifies
  834        * the pattern is treated as a sequence of literal characters.
  835        * Metacharacters or escape sequences in the input sequence will be
  836        * given no special meaning.
  837        *
  838        * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
  839        * matching when used in conjunction with this flag. The other flags
  840        * become superfluous.
  841        *
  842        * <p> There is no embedded flag character for enabling literal parsing.
  843        * @since 1.5
  844        */
  845       public static final int LITERAL = 0x10;
  846   
  847       /**
  848        * Enables dotall mode.
  849        *
  850        * <p> In dotall mode, the expression <tt>.</tt> matches any character,
  851        * including a line terminator.  By default this expression does not match
  852        * line terminators.
  853        *
  854        * <p> Dotall mode can also be enabled via the embedded flag
  855        * expression&nbsp;<tt>(?s)</tt>.  (The <tt>s</tt> is a mnemonic for
  856        * "single-line" mode, which is what this is called in Perl.)  </p>
  857        */
  858       public static final int DOTALL = 0x20;
  859   
  860       /**
  861        * Enables Unicode-aware case folding.
  862        *
  863        * <p> When this flag is specified then case-insensitive matching, when
  864        * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
  865        * consistent with the Unicode Standard.  By default, case-insensitive
  866        * matching assumes that only characters in the US-ASCII charset are being
  867        * matched.
  868        *
  869        * <p> Unicode-aware case folding can also be enabled via the embedded flag
  870        * expression&nbsp;<tt>(?u)</tt>.
  871        *
  872        * <p> Specifying this flag may impose a performance penalty.  </p>
  873        */
  874       public static final int UNICODE_CASE = 0x40;
  875   
  876       /**
  877        * Enables canonical equivalence.
  878        *
  879        * <p> When this flag is specified then two characters will be considered
  880        * to match if, and only if, their full canonical decompositions match.
  881        * The expression <tt>"a&#92;u030A"</tt>, for example, will match the
  882        * string <tt>"&#92;u00E5"</tt> when this flag is specified.  By default,
  883        * matching does not take canonical equivalence into account.
  884        *
  885        * <p> There is no embedded flag character for enabling canonical
  886        * equivalence.
  887        *
  888        * <p> Specifying this flag may impose a performance penalty.  </p>
  889        */
  890       public static final int CANON_EQ = 0x80;
  891   
  892       /**
  893        * Enables the Unicode version of <i>Predefined character classes</i> and
  894        * <i>POSIX character classes</i>.
  895        *
  896        * <p> When this flag is specified then the (US-ASCII only)
  897        * <i>Predefined character classes</i> and <i>POSIX character classes</i>
  898        * are in conformance with
  899        * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
  900        * Standard #18: Unicode Regular Expression</i></a>
  901        * <i>Annex C: Compatibility Properties</i>.
  902        * <p>
  903        * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
  904        * flag expression&nbsp;<tt>(?U)</tt>.
  905        * <p>
  906        * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
  907        * folding.
  908        * <p>
  909        * Specifying this flag may impose a performance penalty.  </p>
  910        * @since 1.7
  911        */
  912       public static final int UNICODE_CHARACTER_CLASS = 0x100;
  913   
  914       /* Pattern has only two serialized components: The pattern string
  915        * and the flags, which are all that is needed to recompile the pattern
  916        * when it is deserialized.
  917        */
  918   
  919       /** use serialVersionUID from Merlin b59 for interoperability */
  920       private static final long serialVersionUID = 5073258162644648461L;
  921   
  922       /**
  923        * The original regular-expression pattern string.
  924        *
  925        * @serial
  926        */
  927       private String pattern;
  928   
  929       /**
  930        * The original pattern flags.
  931        *
  932        * @serial
  933        */
  934       private int flags;
  935   
  936       /**
  937        * Boolean indicating this Pattern is compiled; this is necessary in order
  938        * to lazily compile deserialized Patterns.
  939        */
  940       private transient volatile boolean compiled = false;
  941   
  942       /**
  943        * The normalized pattern string.
  944        */
  945       private transient String normalizedPattern;
  946   
  947       /**
  948        * The starting point of state machine for the find operation.  This allows
  949        * a match to start anywhere in the input.
  950        */
  951       transient Node root;
  952   
  953       /**
  954        * The root of object tree for a match operation.  The pattern is matched
  955        * at the beginning.  This may include a find that uses BnM or a First
  956        * node.
  957        */
  958       transient Node matchRoot;
  959   
  960       /**
  961        * Temporary storage used by parsing pattern slice.
  962        */
  963       transient int[] buffer;
  964   
  965       /**
  966        * Map the "name" of the "named capturing group" to its group id
  967        * node.
  968        */
  969       transient volatile Map<String, Integer> namedGroups;
  970   
  971       /**
  972        * Temporary storage used while parsing group references.
  973        */
  974       transient GroupHead[] groupNodes;
  975   
  976       /**
  977        * Temporary null terminated code point array used by pattern compiling.
  978        */
  979       private transient int[] temp;
  980   
  981       /**
  982        * The number of capturing groups in this Pattern. Used by matchers to
  983        * allocate storage needed to perform a match.
  984        */
  985       transient int capturingGroupCount;
  986   
  987       /**
  988        * The local variable count used by parsing tree. Used by matchers to
  989        * allocate storage needed to perform a match.
  990        */
  991       transient int localCount;
  992   
  993       /**
  994        * Index into the pattern string that keeps track of how much has been
  995        * parsed.
  996        */
  997       private transient int cursor;
  998   
  999       /**
 1000        * Holds the length of the pattern string.
 1001        */
 1002       private transient int patternLength;
 1003   
 1004       /**
 1005        * If the Start node might possibly match supplementary characters.
 1006        * It is set to true during compiling if
 1007        * (1) There is supplementary char in pattern, or
 1008        * (2) There is complement node of Category or Block
 1009        */
 1010       private transient boolean hasSupplementary;
 1011   
 1012       /**
 1013        * Compiles the given regular expression into a pattern.  </p>
 1014        *
 1015        * @param  regex
 1016        *         The expression to be compiled
 1017        *
 1018        * @throws  PatternSyntaxException
 1019        *          If the expression's syntax is invalid
 1020        */
 1021       public static Pattern compile(String regex) {
 1022           return new Pattern(regex, 0);
 1023       }
 1024   
 1025       /**
 1026        * Compiles the given regular expression into a pattern with the given
 1027        * flags.  </p>
 1028        *
 1029        * @param  regex
 1030        *         The expression to be compiled
 1031        *
 1032        * @param  flags
 1033        *         Match flags, a bit mask that may include
 1034        *         {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
 1035        *         {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
 1036        *         {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
 1037        *         and {@link #COMMENTS}
 1038        *
 1039        * @throws  IllegalArgumentException
 1040        *          If bit values other than those corresponding to the defined
 1041        *          match flags are set in <tt>flags</tt>
 1042        *
 1043        * @throws  PatternSyntaxException
 1044        *          If the expression's syntax is invalid
 1045        */
 1046       public static Pattern compile(String regex, int flags) {
 1047           return new Pattern(regex, flags);
 1048       }
 1049   
 1050       /**
 1051        * Returns the regular expression from which this pattern was compiled.
 1052        * </p>
 1053        *
 1054        * @return  The source of this pattern
 1055        */
 1056       public String pattern() {
 1057           return pattern;
 1058       }
 1059   
 1060       /**
 1061        * <p>Returns the string representation of this pattern. This
 1062        * is the regular expression from which this pattern was
 1063        * compiled.</p>
 1064        *
 1065        * @return  The string representation of this pattern
 1066        * @since 1.5
 1067        */
 1068       public String toString() {
 1069           return pattern;
 1070       }
 1071   
 1072       /**
 1073        * Creates a matcher that will match the given input against this pattern.
 1074        * </p>
 1075        *
 1076        * @param  input
 1077        *         The character sequence to be matched
 1078        *
 1079        * @return  A new matcher for this pattern
 1080        */
 1081       public Matcher matcher(CharSequence input) {
 1082           if (!compiled) {
 1083               synchronized(this) {
 1084                   if (!compiled)
 1085                       compile();
 1086               }
 1087           }
 1088           Matcher m = new Matcher(this, input);
 1089           return m;
 1090       }
 1091   
 1092       /**
 1093        * Returns this pattern's match flags.  </p>
 1094        *
 1095        * @return  The match flags specified when this pattern was compiled
 1096        */
 1097       public int flags() {
 1098           return flags;
 1099       }
 1100   
 1101       /**
 1102        * Compiles the given regular expression and attempts to match the given
 1103        * input against it.
 1104        *
 1105        * <p> An invocation of this convenience method of the form
 1106        *
 1107        * <blockquote><pre>
 1108        * Pattern.matches(regex, input);</pre></blockquote>
 1109        *
 1110        * behaves in exactly the same way as the expression
 1111        *
 1112        * <blockquote><pre>
 1113        * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
 1114        *
 1115        * <p> If a pattern is to be used multiple times, compiling it once and reusing
 1116        * it will be more efficient than invoking this method each time.  </p>
 1117        *
 1118        * @param  regex
 1119        *         The expression to be compiled
 1120        *
 1121        * @param  input
 1122        *         The character sequence to be matched
 1123        *
 1124        * @throws  PatternSyntaxException
 1125        *          If the expression's syntax is invalid
 1126        */
 1127       public static boolean matches(String regex, CharSequence input) {
 1128           Pattern p = Pattern.compile(regex);
 1129           Matcher m = p.matcher(input);
 1130           return m.matches();
 1131       }
 1132   
 1133       /**
 1134        * Splits the given input sequence around matches of this pattern.
 1135        *
 1136        * <p> The array returned by this method contains each substring of the
 1137        * input sequence that is terminated by another subsequence that matches
 1138        * this pattern or is terminated by the end of the input sequence.  The
 1139        * substrings in the array are in the order in which they occur in the
 1140        * input.  If this pattern does not match any subsequence of the input then
 1141        * the resulting array has just one element, namely the input sequence in
 1142        * string form.
 1143        *
 1144        * <p> The <tt>limit</tt> parameter controls the number of times the
 1145        * pattern is applied and therefore affects the length of the resulting
 1146        * array.  If the limit <i>n</i> is greater than zero then the pattern
 1147        * will be applied at most <i>n</i>&nbsp;-&nbsp;1 times, the array's
 1148        * length will be no greater than <i>n</i>, and the array's last entry
 1149        * will contain all input beyond the last matched delimiter.  If <i>n</i>
 1150        * is non-positive then the pattern will be applied as many times as
 1151        * possible and the array can have any length.  If <i>n</i> is zero then
 1152        * the pattern will be applied as many times as possible, the array can
 1153        * have any length, and trailing empty strings will be discarded.
 1154        *
 1155        * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
 1156        * results with these parameters:
 1157        *
 1158        * <blockquote><table cellpadding=1 cellspacing=0
 1159        *              summary="Split examples showing regex, limit, and result">
 1160        * <tr><th><P align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
 1161        *     <th><P align="left"><i>Limit&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
 1162        *     <th><P align="left"><i>Result&nbsp;&nbsp;&nbsp;&nbsp;</i></th></tr>
 1163        * <tr><td align=center>:</td>
 1164        *     <td align=center>2</td>
 1165        *     <td><tt>{ "boo", "and:foo" }</tt></td></tr>
 1166        * <tr><td align=center>:</td>
 1167        *     <td align=center>5</td>
 1168        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
 1169        * <tr><td align=center>:</td>
 1170        *     <td align=center>-2</td>
 1171        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
 1172        * <tr><td align=center>o</td>
 1173        *     <td align=center>5</td>
 1174        *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
 1175        * <tr><td align=center>o</td>
 1176        *     <td align=center>-2</td>
 1177        *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
 1178        * <tr><td align=center>o</td>
 1179        *     <td align=center>0</td>
 1180        *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
 1181        * </table></blockquote>
 1182        *
 1183        *
 1184        * @param  input
 1185        *         The character sequence to be split
 1186        *
 1187        * @param  limit
 1188        *         The result threshold, as described above
 1189        *
 1190        * @return  The array of strings computed by splitting the input
 1191        *          around matches of this pattern
 1192        */
 1193       public String[] split(CharSequence input, int limit) {
 1194           int index = 0;
 1195           boolean matchLimited = limit > 0;
 1196           ArrayList<String> matchList = new ArrayList<>();
 1197           Matcher m = matcher(input);
 1198   
 1199           // Add segments before each match found
 1200           while(m.find()) {
 1201               if (!matchLimited || matchList.size() < limit - 1) {
 1202                   String match = input.subSequence(index, m.start()).toString();
 1203                   matchList.add(match);
 1204                   index = m.end();
 1205               } else if (matchList.size() == limit - 1) { // last one
 1206                   String match = input.subSequence(index,
 1207                                                    input.length()).toString();
 1208                   matchList.add(match);
 1209                   index = m.end();
 1210               }
 1211           }
 1212   
 1213           // If no match was found, return this
 1214           if (index == 0)
 1215               return new String[] {input.toString()};
 1216   
 1217           // Add remaining segment
 1218           if (!matchLimited || matchList.size() < limit)
 1219               matchList.add(input.subSequence(index, input.length()).toString());
 1220   
 1221           // Construct result
 1222           int resultSize = matchList.size();
 1223           if (limit == 0)
 1224               while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
 1225                   resultSize--;
 1226           String[] result = new String[resultSize];
 1227           return matchList.subList(0, resultSize).toArray(result);
 1228       }
 1229   
 1230       /**
 1231        * Splits the given input sequence around matches of this pattern.
 1232        *
 1233        * <p> This method works as if by invoking the two-argument {@link
 1234        * #split(java.lang.CharSequence, int) split} method with the given input
 1235        * sequence and a limit argument of zero.  Trailing empty strings are
 1236        * therefore not included in the resulting array. </p>
 1237        *
 1238        * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
 1239        * results with these expressions:
 1240        *
 1241        * <blockquote><table cellpadding=1 cellspacing=0
 1242        *              summary="Split examples showing regex and result">
 1243        * <tr><th><P align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
 1244        *     <th><P align="left"><i>Result</i></th></tr>
 1245        * <tr><td align=center>:</td>
 1246        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
 1247        * <tr><td align=center>o</td>
 1248        *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
 1249        * </table></blockquote>
 1250        *
 1251        *
 1252        * @param  input
 1253        *         The character sequence to be split
 1254        *
 1255        * @return  The array of strings computed by splitting the input
 1256        *          around matches of this pattern
 1257        */
 1258       public String[] split(CharSequence input) {
 1259           return split(input, 0);
 1260       }
 1261   
 1262       /**
 1263        * Returns a literal pattern <code>String</code> for the specified
 1264        * <code>String</code>.
 1265        *
 1266        * <p>This method produces a <code>String</code> that can be used to
 1267        * create a <code>Pattern</code> that would match the string
 1268        * <code>s</code> as if it were a literal pattern.</p> Metacharacters
 1269        * or escape sequences in the input sequence will be given no special
 1270        * meaning.
 1271        *
 1272        * @param  s The string to be literalized
 1273        * @return  A literal string replacement
 1274        * @since 1.5
 1275        */
 1276       public static String quote(String s) {
 1277           int slashEIndex = s.indexOf("\\E");
 1278           if (slashEIndex == -1)
 1279               return "\\Q" + s + "\\E";
 1280   
 1281           StringBuilder sb = new StringBuilder(s.length() * 2);
 1282           sb.append("\\Q");
 1283           slashEIndex = 0;
 1284           int current = 0;
 1285           while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
 1286               sb.append(s.substring(current, slashEIndex));
 1287               current = slashEIndex + 2;
 1288               sb.append("\\E\\\\E\\Q");
 1289           }
 1290           sb.append(s.substring(current, s.length()));
 1291           sb.append("\\E");
 1292           return sb.toString();
 1293       }
 1294   
 1295       /**
 1296        * Recompile the Pattern instance from a stream.  The original pattern
 1297        * string is read in and the object tree is recompiled from it.
 1298        */
 1299       private void readObject(java.io.ObjectInputStream s)
 1300           throws java.io.IOException, ClassNotFoundException {
 1301   
 1302           // Read in all fields
 1303           s.defaultReadObject();
 1304   
 1305           // Initialize counts
 1306           capturingGroupCount = 1;
 1307           localCount = 0;
 1308   
 1309           // if length > 0, the Pattern is lazily compiled
 1310           compiled = false;
 1311           if (pattern.length() == 0) {
 1312               root = new Start(lastAccept);
 1313               matchRoot = lastAccept;
 1314               compiled = true;
 1315           }
 1316       }
 1317   
 1318       /**
 1319        * This private constructor is used to create all Patterns. The pattern
 1320        * string and match flags are all that is needed to completely describe
 1321        * a Pattern. An empty pattern string results in an object tree with
 1322        * only a Start node and a LastNode node.
 1323        */
 1324       private Pattern(String p, int f) {
 1325           pattern = p;
 1326           flags = f;
 1327   
 1328           // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
 1329           if ((flags & UNICODE_CHARACTER_CLASS) != 0)
 1330               flags |= UNICODE_CASE;
 1331   
 1332           // Reset group index count
 1333           capturingGroupCount = 1;
 1334           localCount = 0;
 1335   
 1336           if (pattern.length() > 0) {
 1337               compile();
 1338           } else {
 1339               root = new Start(lastAccept);
 1340               matchRoot = lastAccept;
 1341           }
 1342       }
 1343   
 1344       /**
 1345        * The pattern is converted to normalizedD form and then a pure group
 1346        * is constructed to match canonical equivalences of the characters.
 1347        */
 1348       private void normalize() {
 1349           boolean inCharClass = false;
 1350           int lastCodePoint = -1;
 1351   
 1352           // Convert pattern into normalizedD form
 1353           normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
 1354           patternLength = normalizedPattern.length();
 1355   
 1356           // Modify pattern to match canonical equivalences
 1357           StringBuilder newPattern = new StringBuilder(patternLength);
 1358           for(int i=0; i<patternLength; ) {
 1359               int c = normalizedPattern.codePointAt(i);
 1360               StringBuilder sequenceBuffer;
 1361               if ((Character.getType(c) == Character.NON_SPACING_MARK)
 1362                   && (lastCodePoint != -1)) {
 1363                   sequenceBuffer = new StringBuilder();
 1364                   sequenceBuffer.appendCodePoint(lastCodePoint);
 1365                   sequenceBuffer.appendCodePoint(c);
 1366                   while(Character.getType(c) == Character.NON_SPACING_MARK) {
 1367                       i += Character.charCount(c);
 1368                       if (i >= patternLength)
 1369                           break;
 1370                       c = normalizedPattern.codePointAt(i);
 1371                       sequenceBuffer.appendCodePoint(c);
 1372                   }
 1373                   String ea = produceEquivalentAlternation(
 1374                                                  sequenceBuffer.toString());
 1375                   newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
 1376                   newPattern.append("(?:").append(ea).append(")");
 1377               } else if (c == '[' && lastCodePoint != '\\') {
 1378                   i = normalizeCharClass(newPattern, i);
 1379               } else {
 1380                   newPattern.appendCodePoint(c);
 1381               }
 1382               lastCodePoint = c;
 1383               i += Character.charCount(c);
 1384           }
 1385           normalizedPattern = newPattern.toString();
 1386       }
 1387   
 1388       /**
 1389        * Complete the character class being parsed and add a set
 1390        * of alternations to it that will match the canonical equivalences
 1391        * of the characters within the class.
 1392        */
 1393       private int normalizeCharClass(StringBuilder newPattern, int i) {
 1394           StringBuilder charClass = new StringBuilder();
 1395           StringBuilder eq = null;
 1396           int lastCodePoint = -1;
 1397           String result;
 1398   
 1399           i++;
 1400           charClass.append("[");
 1401           while(true) {
 1402               int c = normalizedPattern.codePointAt(i);
 1403               StringBuilder sequenceBuffer;
 1404   
 1405               if (c == ']' && lastCodePoint != '\\') {
 1406                   charClass.append((char)c);
 1407                   break;
 1408               } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
 1409                   sequenceBuffer = new StringBuilder();
 1410                   sequenceBuffer.appendCodePoint(lastCodePoint);
 1411                   while(Character.getType(c) == Character.NON_SPACING_MARK) {
 1412                       sequenceBuffer.appendCodePoint(c);
 1413                       i += Character.charCount(c);
 1414                       if (i >= normalizedPattern.length())
 1415                           break;
 1416                       c = normalizedPattern.codePointAt(i);
 1417                   }
 1418                   String ea = produceEquivalentAlternation(
 1419                                                     sequenceBuffer.toString());
 1420   
 1421                   charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
 1422                   if (eq == null)
 1423                       eq = new StringBuilder();
 1424                   eq.append('|');
 1425                   eq.append(ea);
 1426               } else {
 1427                   charClass.appendCodePoint(c);
 1428                   i++;
 1429               }
 1430               if (i == normalizedPattern.length())
 1431                   throw error("Unclosed character class");
 1432               lastCodePoint = c;
 1433           }
 1434   
 1435           if (eq != null) {
 1436               result = "(?:"+charClass.toString()+eq.toString()+")";
 1437           } else {
 1438               result = charClass.toString();
 1439           }
 1440   
 1441           newPattern.append(result);
 1442           return i;
 1443       }
 1444   
 1445       /**
 1446        * Given a specific sequence composed of a regular character and
 1447        * combining marks that follow it, produce the alternation that will
 1448        * match all canonical equivalences of that sequence.
 1449        */
 1450       private String produceEquivalentAlternation(String source) {
 1451           int len = countChars(source, 0, 1);
 1452           if (source.length() == len)
 1453               // source has one character.
 1454               return source;
 1455   
 1456           String base = source.substring(0,len);
 1457           String combiningMarks = source.substring(len);
 1458   
 1459           String[] perms = producePermutations(combiningMarks);
 1460           StringBuilder result = new StringBuilder(source);
 1461   
 1462           // Add combined permutations
 1463           for(int x=0; x<perms.length; x++) {
 1464               String next = base + perms[x];
 1465               if (x>0)
 1466                   result.append("|"+next);
 1467               next = composeOneStep(next);
 1468               if (next != null)
 1469                   result.append("|"+produceEquivalentAlternation(next));
 1470           }
 1471           return result.toString();
 1472       }
 1473   
 1474       /**
 1475        * Returns an array of strings that have all the possible
 1476        * permutations of the characters in the input string.
 1477        * This is used to get a list of all possible orderings
 1478        * of a set of combining marks. Note that some of the permutations
 1479        * are invalid because of combining class collisions, and these
 1480        * possibilities must be removed because they are not canonically
 1481        * equivalent.
 1482        */
 1483       private String[] producePermutations(String input) {
 1484           if (input.length() == countChars(input, 0, 1))
 1485               return new String[] {input};
 1486   
 1487           if (input.length() == countChars(input, 0, 2)) {
 1488               int c0 = Character.codePointAt(input, 0);
 1489               int c1 = Character.codePointAt(input, Character.charCount(c0));
 1490               if (getClass(c1) == getClass(c0)) {
 1491                   return new String[] {input};
 1492               }
 1493               String[] result = new String[2];
 1494               result[0] = input;
 1495               StringBuilder sb = new StringBuilder(2);
 1496               sb.appendCodePoint(c1);
 1497               sb.appendCodePoint(c0);
 1498               result[1] = sb.toString();
 1499               return result;
 1500           }
 1501   
 1502           int length = 1;
 1503           int nCodePoints = countCodePoints(input);
 1504           for(int x=1; x<nCodePoints; x++)
 1505               length = length * (x+1);
 1506   
 1507           String[] temp = new String[length];
 1508   
 1509           int combClass[] = new int[nCodePoints];
 1510           for(int x=0, i=0; x<nCodePoints; x++) {
 1511               int c = Character.codePointAt(input, i);
 1512               combClass[x] = getClass(c);
 1513               i +=  Character.charCount(c);
 1514           }
 1515   
 1516           // For each char, take it out and add the permutations
 1517           // of the remaining chars
 1518           int index = 0;
 1519           int len;
 1520           // offset maintains the index in code units.
 1521   loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
 1522               len = countChars(input, offset, 1);
 1523               boolean skip = false;
 1524               for(int y=x-1; y>=0; y--) {
 1525                   if (combClass[y] == combClass[x]) {
 1526                       continue loop;
 1527                   }
 1528               }
 1529               StringBuilder sb = new StringBuilder(input);
 1530               String otherChars = sb.delete(offset, offset+len).toString();
 1531               String[] subResult = producePermutations(otherChars);
 1532   
 1533               String prefix = input.substring(offset, offset+len);
 1534               for(int y=0; y<subResult.length; y++)
 1535                   temp[index++] =  prefix + subResult[y];
 1536           }
 1537           String[] result = new String[index];
 1538           for (int x=0; x<index; x++)
 1539               result[x] = temp[x];
 1540           return result;
 1541       }
 1542   
 1543       private int getClass(int c) {
 1544           return sun.text.Normalizer.getCombiningClass(c);
 1545       }
 1546   
 1547       /**
 1548        * Attempts to compose input by combining the first character
 1549        * with the first combining mark following it. Returns a String
 1550        * that is the composition of the leading character with its first
 1551        * combining mark followed by the remaining combining marks. Returns
 1552        * null if the first two characters cannot be further composed.
 1553        */
 1554       private String composeOneStep(String input) {
 1555           int len = countChars(input, 0, 2);
 1556           String firstTwoCharacters = input.substring(0, len);
 1557           String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
 1558   
 1559           if (result.equals(firstTwoCharacters))
 1560               return null;
 1561           else {
 1562               String remainder = input.substring(len);
 1563               return result + remainder;
 1564           }
 1565       }
 1566   
 1567       /**
 1568        * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
 1569        * See the description of `quotemeta' in perlfunc(1).
 1570        */
 1571       private void RemoveQEQuoting() {
 1572           final int pLen = patternLength;
 1573           int i = 0;
 1574           while (i < pLen-1) {
 1575               if (temp[i] != '\\')
 1576                   i += 1;
 1577               else if (temp[i + 1] != 'Q')
 1578                   i += 2;
 1579               else
 1580                   break;
 1581           }
 1582           if (i >= pLen - 1)    // No \Q sequence found
 1583               return;
 1584           int j = i;
 1585           i += 2;
 1586           int[] newtemp = new int[j + 2*(pLen-i) + 2];
 1587           System.arraycopy(temp, 0, newtemp, 0, j);
 1588   
 1589           boolean inQuote = true;
 1590           while (i < pLen) {
 1591               int c = temp[i++];
 1592               if (! ASCII.isAscii(c) || ASCII.isAlnum(c)) {
 1593                   newtemp[j++] = c;
 1594               } else if (c != '\\') {
 1595                   if (inQuote) newtemp[j++] = '\\';
 1596                   newtemp[j++] = c;
 1597               } else if (inQuote) {
 1598                   if (temp[i] == 'E') {
 1599                       i++;
 1600                       inQuote = false;
 1601                   } else {
 1602                       newtemp[j++] = '\\';
 1603                       newtemp[j++] = '\\';
 1604                   }
 1605               } else {
 1606                   if (temp[i] == 'Q') {
 1607                       i++;
 1608                       inQuote = true;
 1609                   } else {
 1610                       newtemp[j++] = c;
 1611                       if (i != pLen)
 1612                           newtemp[j++] = temp[i++];
 1613                   }
 1614               }
 1615           }
 1616   
 1617           patternLength = j;
 1618           temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
 1619       }
 1620   
 1621       /**
 1622        * Copies regular expression to an int array and invokes the parsing
 1623        * of the expression which will create the object tree.
 1624        */
 1625       private void compile() {
 1626           // Handle canonical equivalences
 1627           if (has(CANON_EQ) && !has(LITERAL)) {
 1628               normalize();
 1629           } else {
 1630               normalizedPattern = pattern;
 1631           }
 1632           patternLength = normalizedPattern.length();
 1633   
 1634           // Copy pattern to int array for convenience
 1635           // Use double zero to terminate pattern
 1636           temp = new int[patternLength + 2];
 1637   
 1638           hasSupplementary = false;
 1639           int c, count = 0;
 1640           // Convert all chars into code points
 1641           for (int x = 0; x < patternLength; x += Character.charCount(c)) {
 1642               c = normalizedPattern.codePointAt(x);
 1643               if (isSupplementary(c)) {
 1644                   hasSupplementary = true;
 1645               }
 1646               temp[count++] = c;
 1647           }
 1648   
 1649           patternLength = count;   // patternLength now in code points
 1650   
 1651           if (! has(LITERAL))
 1652               RemoveQEQuoting();
 1653   
 1654           // Allocate all temporary objects here.
 1655           buffer = new int[32];
 1656           groupNodes = new GroupHead[10];
 1657           namedGroups = null;
 1658   
 1659           if (has(LITERAL)) {
 1660               // Literal pattern handling
 1661               matchRoot = newSlice(temp, patternLength, hasSupplementary);
 1662               matchRoot.next = lastAccept;
 1663           } else {
 1664               // Start recursive descent parsing
 1665               matchRoot = expr(lastAccept);
 1666               // Check extra pattern characters
 1667               if (patternLength != cursor) {
 1668                   if (peek() == ')') {
 1669                       throw error("Unmatched closing ')'");
 1670                   } else {
 1671                       throw error("Unexpected internal error");
 1672                   }
 1673               }
 1674           }
 1675   
 1676           // Peephole optimization
 1677           if (matchRoot instanceof Slice) {
 1678               root = BnM.optimize(matchRoot);
 1679               if (root == matchRoot) {
 1680                   root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
 1681               }
 1682           } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
 1683               root = matchRoot;
 1684           } else {
 1685               root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
 1686           }
 1687   
 1688           // Release temporary storage
 1689           temp = null;
 1690           buffer = null;
 1691           groupNodes = null;
 1692           patternLength = 0;
 1693           compiled = true;
 1694       }
 1695   
 1696       Map<String, Integer> namedGroups() {
 1697           if (namedGroups == null)
 1698               namedGroups = new HashMap<>(2);
 1699           return namedGroups;
 1700       }
 1701   
 1702       /**
 1703        * Used to print out a subtree of the Pattern to help with debugging.
 1704        */
 1705       private static void printObjectTree(Node node) {
 1706           while(node != null) {
 1707               if (node instanceof Prolog) {
 1708                   System.out.println(node);
 1709                   printObjectTree(((Prolog)node).loop);
 1710                   System.out.println("**** end contents prolog loop");
 1711               } else if (node instanceof Loop) {
 1712                   System.out.println(node);
 1713                   printObjectTree(((Loop)node).body);
 1714                   System.out.println("**** end contents Loop body");
 1715               } else if (node instanceof Curly) {
 1716                   System.out.println(node);
 1717                   printObjectTree(((Curly)node).atom);
 1718                   System.out.println("**** end contents Curly body");
 1719               } else if (node instanceof GroupCurly) {
 1720                   System.out.println(node);
 1721                   printObjectTree(((GroupCurly)node).atom);
 1722                   System.out.println("**** end contents GroupCurly body");
 1723               } else if (node instanceof GroupTail) {
 1724                   System.out.println(node);
 1725                   System.out.println("Tail next is "+node.next);
 1726                   return;
 1727               } else {
 1728                   System.out.println(node);
 1729               }
 1730               node = node.next;
 1731               if (node != null)
 1732                   System.out.println("->next:");
 1733               if (node == Pattern.accept) {
 1734                   System.out.println("Accept Node");
 1735                   node = null;
 1736               }
 1737          }
 1738       }
 1739   
 1740       /**
 1741        * Used to accumulate information about a subtree of the object graph
 1742        * so that optimizations can be applied to the subtree.
 1743        */
 1744       static final class TreeInfo {
 1745           int minLength;
 1746           int maxLength;
 1747           boolean maxValid;
 1748           boolean deterministic;
 1749   
 1750           TreeInfo() {
 1751               reset();
 1752           }
 1753           void reset() {
 1754               minLength = 0;
 1755               maxLength = 0;
 1756               maxValid = true;
 1757               deterministic = true;
 1758           }
 1759       }
 1760   
 1761       /*
 1762        * The following private methods are mainly used to improve the
 1763        * readability of the code. In order to let the Java compiler easily
 1764        * inline them, we should not put many assertions or error checks in them.
 1765        */
 1766   
 1767       /**
 1768        * Indicates whether a particular flag is set or not.
 1769        */
 1770       private boolean has(int f) {
 1771           return (flags & f) != 0;
 1772       }
 1773   
 1774       /**
 1775        * Match next character, signal error if failed.
 1776        */
 1777       private void accept(int ch, String s) {
 1778           int testChar = temp[cursor++];
 1779           if (has(COMMENTS))
 1780               testChar = parsePastWhitespace(testChar);
 1781           if (ch != testChar) {
 1782               throw error(s);
 1783           }
 1784       }
 1785   
 1786       /**
 1787        * Mark the end of pattern with a specific character.
 1788        */
 1789       private void mark(int c) {
 1790           temp[patternLength] = c;
 1791       }
 1792   
 1793       /**
 1794        * Peek the next character, and do not advance the cursor.
 1795        */
 1796       private int peek() {
 1797           int ch = temp[cursor];
 1798           if (has(COMMENTS))
 1799               ch = peekPastWhitespace(ch);
 1800           return ch;
 1801       }
 1802   
 1803       /**
 1804        * Read the next character, and advance the cursor by one.
 1805        */
 1806       private int read() {
 1807           int ch = temp[cursor++];
 1808           if (has(COMMENTS))
 1809               ch = parsePastWhitespace(ch);
 1810           return ch;
 1811       }
 1812   
 1813       /**
 1814        * Read the next character, and advance the cursor by one,
 1815        * ignoring the COMMENTS setting
 1816        */
 1817       private int readEscaped() {
 1818           int ch = temp[cursor++];
 1819           return ch;
 1820       }
 1821   
 1822       /**
 1823        * Advance the cursor by one, and peek the next character.
 1824        */
 1825       private int next() {
 1826           int ch = temp[++cursor];
 1827           if (has(COMMENTS))
 1828               ch = peekPastWhitespace(ch);
 1829           return ch;
 1830       }
 1831   
 1832       /**
 1833        * Advance the cursor by one, and peek the next character,
 1834        * ignoring the COMMENTS setting
 1835        */
 1836       private int nextEscaped() {
 1837           int ch = temp[++cursor];
 1838           return ch;
 1839       }
 1840   
 1841       /**
 1842        * If in xmode peek past whitespace and comments.
 1843        */
 1844       private int peekPastWhitespace(int ch) {
 1845           while (ASCII.isSpace(ch) || ch == '#') {
 1846               while (ASCII.isSpace(ch))
 1847                   ch = temp[++cursor];
 1848               if (ch == '#') {
 1849                   ch = peekPastLine();
 1850               }
 1851           }
 1852           return ch;
 1853       }
 1854   
 1855       /**
 1856        * If in xmode parse past whitespace and comments.
 1857        */
 1858       private int parsePastWhitespace(int ch) {
 1859           while (ASCII.isSpace(ch) || ch == '#') {
 1860               while (ASCII.isSpace(ch))
 1861                   ch = temp[cursor++];
 1862               if (ch == '#')
 1863                   ch = parsePastLine();
 1864           }
 1865           return ch;
 1866       }
 1867   
 1868       /**
 1869        * xmode parse past comment to end of line.
 1870        */
 1871       private int parsePastLine() {
 1872           int ch = temp[cursor++];
 1873           while (ch != 0 && !isLineSeparator(ch))
 1874               ch = temp[cursor++];
 1875           return ch;
 1876       }
 1877   
 1878       /**
 1879        * xmode peek past comment to end of line.
 1880        */
 1881       private int peekPastLine() {
 1882           int ch = temp[++cursor];
 1883           while (ch != 0 && !isLineSeparator(ch))
 1884               ch = temp[++cursor];
 1885           return ch;
 1886       }
 1887   
 1888       /**
 1889        * Determines if character is a line separator in the current mode
 1890        */
 1891       private boolean isLineSeparator(int ch) {
 1892           if (has(UNIX_LINES)) {
 1893               return ch == '\n';
 1894           } else {
 1895               return (ch == '\n' ||
 1896                       ch == '\r' ||
 1897                       (ch|1) == '\u2029' ||
 1898                       ch == '\u0085');
 1899           }
 1900       }
 1901   
 1902       /**
 1903        * Read the character after the next one, and advance the cursor by two.
 1904        */
 1905       private int skip() {
 1906           int i = cursor;
 1907           int ch = temp[i+1];
 1908           cursor = i + 2;
 1909           return ch;
 1910       }
 1911   
 1912       /**
 1913        * Unread one next character, and retreat cursor by one.
 1914        */
 1915       private void unread() {
 1916           cursor--;
 1917       }
 1918   
 1919       /**
 1920        * Internal method used for handling all syntax errors. The pattern is
 1921        * displayed with a pointer to aid in locating the syntax error.
 1922        */
 1923       private PatternSyntaxException error(String s) {
 1924           return new PatternSyntaxException(s, normalizedPattern,  cursor - 1);
 1925       }
 1926   
 1927       /**
 1928        * Determines if there is any supplementary character or unpaired
 1929        * surrogate in the specified range.
 1930        */
 1931       private boolean findSupplementary(int start, int end) {
 1932           for (int i = start; i < end; i++) {
 1933               if (isSupplementary(temp[i]))
 1934                   return true;
 1935           }
 1936           return false;
 1937       }
 1938   
 1939       /**
 1940        * Determines if the specified code point is a supplementary
 1941        * character or unpaired surrogate.
 1942        */
 1943       private static final boolean isSupplementary(int ch) {
 1944           return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
 1945                  Character.isSurrogate((char)ch);
 1946       }
 1947   
 1948       /**
 1949        *  The following methods handle the main parsing. They are sorted
 1950        *  according to their precedence order, the lowest one first.
 1951        */
 1952   
 1953       /**
 1954        * The expression is parsed with branch nodes added for alternations.
 1955        * This may be called recursively to parse sub expressions that may
 1956        * contain alternations.
 1957        */
 1958       private Node expr(Node end) {
 1959           Node prev = null;
 1960           Node firstTail = null;
 1961           Node branchConn = null;
 1962   
 1963           for (;;) {
 1964               Node node = sequence(end);
 1965               Node nodeTail = root;      //double return
 1966               if (prev == null) {
 1967                   prev = node;
 1968                   firstTail = nodeTail;
 1969               } else {
 1970                   // Branch
 1971                   if (branchConn == null) {
 1972                       branchConn = new BranchConn();
 1973                       branchConn.next = end;
 1974                   }
 1975                   if (node == end) {
 1976                       // if the node returned from sequence() is "end"
 1977                       // we have an empty expr, set a null atom into
 1978                       // the branch to indicate to go "next" directly.
 1979                       node = null;
 1980                   } else {
 1981                       // the "tail.next" of each atom goes to branchConn
 1982                       nodeTail.next = branchConn;
 1983                   }
 1984                   if (prev instanceof Branch) {
 1985                       ((Branch)prev).add(node);
 1986                   } else {
 1987                       if (prev == end) {
 1988                           prev = null;
 1989                       } else {
 1990                           // replace the "end" with "branchConn" at its tail.next
 1991                           // when put the "prev" into the branch as the first atom.
 1992                           firstTail.next = branchConn;
 1993                       }
 1994                       prev = new Branch(prev, node, branchConn);
 1995                   }
 1996               }
 1997               if (peek() != '|') {
 1998                   return prev;
 1999               }
 2000               next();
 2001           }
 2002       }
 2003   
 2004       /**
 2005        * Parsing of sequences between alternations.
 2006        */
 2007       private Node sequence(Node end) {
 2008           Node head = null;
 2009           Node tail = null;
 2010           Node node = null;
 2011       LOOP:
 2012           for (;;) {
 2013               int ch = peek();
 2014               switch (ch) {
 2015               case '(':
 2016                   // Because group handles its own closure,
 2017                   // we need to treat it differently
 2018                   node = group0();
 2019                   // Check for comment or flag group
 2020                   if (node == null)
 2021                       continue;
 2022                   if (head == null)
 2023                       head = node;
 2024                   else
 2025                       tail.next = node;
 2026                   // Double return: Tail was returned in root
 2027                   tail = root;
 2028                   continue;
 2029               case '[':
 2030                   node = clazz(true);
 2031                   break;
 2032               case '\\':
 2033                   ch = nextEscaped();
 2034                   if (ch == 'p' || ch == 'P') {
 2035                       boolean oneLetter = true;
 2036                       boolean comp = (ch == 'P');
 2037                       ch = next(); // Consume { if present
 2038                       if (ch != '{') {
 2039                           unread();
 2040                       } else {
 2041                           oneLetter = false;
 2042                       }
 2043                       node = family(oneLetter, comp);
 2044                   } else {
 2045                       unread();
 2046                       node = atom();
 2047                   }
 2048                   break;
 2049               case '^':
 2050                   next();
 2051                   if (has(MULTILINE)) {
 2052                       if (has(UNIX_LINES))
 2053                           node = new UnixCaret();
 2054                       else
 2055                           node = new Caret();
 2056                   } else {
 2057                       node = new Begin();
 2058                   }
 2059                   break;
 2060               case '$':
 2061                   next();
 2062                   if (has(UNIX_LINES))
 2063                       node = new UnixDollar(has(MULTILINE));
 2064                   else
 2065                       node = new Dollar(has(MULTILINE));
 2066                   break;
 2067               case '.':
 2068                   next();
 2069                   if (has(DOTALL)) {
 2070                       node = new All();
 2071                   } else {
 2072                       if (has(UNIX_LINES))
 2073                           node = new UnixDot();
 2074                       else {
 2075                           node = new Dot();
 2076                       }
 2077                   }
 2078                   break;
 2079               case '|':
 2080               case ')':
 2081                   break LOOP;
 2082               case ']': // Now interpreting dangling ] and } as literals
 2083               case '}':
 2084                   node = atom();
 2085                   break;
 2086               case '?':
 2087               case '*':
 2088               case '+':
 2089                   next();
 2090                   throw error("Dangling meta character '" + ((char)ch) + "'");
 2091               case 0:
 2092                   if (cursor >= patternLength) {
 2093                       break LOOP;
 2094                   }
 2095                   // Fall through
 2096               default:
 2097                   node = atom();
 2098                   break;
 2099               }
 2100   
 2101               node = closure(node);
 2102   
 2103               if (head == null) {
 2104                   head = tail = node;
 2105               } else {
 2106                   tail.next = node;
 2107                   tail = node;
 2108               }
 2109           }
 2110           if (head == null) {
 2111               return end;
 2112           }
 2113           tail.next = end;
 2114           root = tail;      //double return
 2115           return head;
 2116       }
 2117   
 2118       /**
 2119        * Parse and add a new Single or Slice.
 2120        */
 2121       private Node atom() {
 2122           int first = 0;
 2123           int prev = -1;
 2124           boolean hasSupplementary = false;
 2125           int ch = peek();
 2126           for (;;) {
 2127               switch (ch) {
 2128               case '*':
 2129               case '+':
 2130               case '?':
 2131               case '{':
 2132                   if (first > 1) {
 2133                       cursor = prev;    // Unwind one character
 2134                       first--;
 2135                   }
 2136                   break;
 2137               case '$':
 2138               case '.':
 2139               case '^':
 2140               case '(':
 2141               case '[':
 2142               case '|':
 2143               case ')':
 2144                   break;
 2145               case '\\':
 2146                   ch = nextEscaped();
 2147                   if (ch == 'p' || ch == 'P') { // Property
 2148                       if (first > 0) { // Slice is waiting; handle it first
 2149                           unread();
 2150                           break;
 2151                       } else { // No slice; just return the family node
 2152                           boolean comp = (ch == 'P');
 2153                           boolean oneLetter = true;
 2154                           ch = next(); // Consume { if present
 2155                           if (ch != '{')
 2156                               unread();
 2157                           else
 2158                               oneLetter = false;
 2159                           return family(oneLetter, comp);
 2160                       }
 2161                   }
 2162                   unread();
 2163                   prev = cursor;
 2164                   ch = escape(false, first == 0);
 2165                   if (ch >= 0) {
 2166                       append(ch, first);
 2167                       first++;
 2168                       if (isSupplementary(ch)) {
 2169                           hasSupplementary = true;
 2170                       }
 2171                       ch = peek();
 2172                       continue;
 2173                   } else if (first == 0) {
 2174                       return root;
 2175                   }
 2176                   // Unwind meta escape sequence
 2177                   cursor = prev;
 2178                   break;
 2179               case 0:
 2180                   if (cursor >= patternLength) {
 2181                       break;
 2182                   }
 2183                   // Fall through
 2184               default:
 2185                   prev = cursor;
 2186                   append(ch, first);
 2187                   first++;
 2188                   if (isSupplementary(ch)) {
 2189                       hasSupplementary = true;
 2190                   }
 2191                   ch = next();
 2192                   continue;
 2193               }
 2194               break;
 2195           }
 2196           if (first == 1) {
 2197               return newSingle(buffer[0]);
 2198           } else {
 2199               return newSlice(buffer, first, hasSupplementary);
 2200           }
 2201       }
 2202   
 2203       private void append(int ch, int len) {
 2204           if (len >= buffer.length) {
 2205               int[] tmp = new int[len+len];
 2206               System.arraycopy(buffer, 0, tmp, 0, len);
 2207               buffer = tmp;
 2208           }
 2209           buffer[len] = ch;
 2210       }
 2211   
 2212       /**
 2213        * Parses a backref greedily, taking as many numbers as it
 2214        * can. The first digit is always treated as a backref, but
 2215        * multi digit numbers are only treated as a backref if at
 2216        * least that many backrefs exist at this point in the regex.
 2217        */
 2218       private Node ref(int refNum) {
 2219           boolean done = false;
 2220           while(!done) {
 2221               int ch = peek();
 2222               switch(ch) {
 2223               case '0':
 2224               case '1':
 2225               case '2':
 2226               case '3':
 2227               case '4':
 2228               case '5':
 2229               case '6':
 2230               case '7':
 2231               case '8':
 2232               case '9':
 2233                   int newRefNum = (refNum * 10) + (ch - '0');
 2234                   // Add another number if it doesn't make a group
 2235                   // that doesn't exist
 2236                   if (capturingGroupCount - 1 < newRefNum) {
 2237                       done = true;
 2238                       break;
 2239                   }
 2240                   refNum = newRefNum;
 2241                   read();
 2242                   break;
 2243               default:
 2244                   done = true;
 2245                   break;
 2246               }
 2247           }
 2248           if (has(CASE_INSENSITIVE))
 2249               return new CIBackRef(refNum, has(UNICODE_CASE));
 2250           else
 2251               return new BackRef(refNum);
 2252       }
 2253   
 2254       /**
 2255        * Parses an escape sequence to determine the actual value that needs
 2256        * to be matched.
 2257        * If -1 is returned and create was true a new object was added to the tree
 2258        * to handle the escape sequence.
 2259        * If the returned value is greater than zero, it is the value that
 2260        * matches the escape sequence.
 2261        */
 2262       private int escape(boolean inclass, boolean create) {
 2263           int ch = skip();
 2264           switch (ch) {
 2265           case '0':
 2266               return o();
 2267           case '1':
 2268           case '2':
 2269           case '3':
 2270           case '4':
 2271           case '5':
 2272           case '6':
 2273           case '7':
 2274           case '8':
 2275           case '9':
 2276               if (inclass) break;
 2277               if (create) {
 2278                   root = ref((ch - '0'));
 2279               }
 2280               return -1;
 2281           case 'A':
 2282               if (inclass) break;
 2283               if (create) root = new Begin();
 2284               return -1;
 2285           case 'B':
 2286               if (inclass) break;
 2287               if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
 2288               return -1;
 2289           case 'C':
 2290               break;
 2291           case 'D':
 2292               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2293                                  ? new Utype(UnicodeProp.DIGIT).complement()
 2294                                  : new Ctype(ASCII.DIGIT).complement();
 2295               return -1;
 2296           case 'E':
 2297           case 'F':
 2298               break;
 2299           case 'G':
 2300               if (inclass) break;
 2301               if (create) root = new LastMatch();
 2302               return -1;
 2303           case 'H':
 2304           case 'I':
 2305           case 'J':
 2306           case 'K':
 2307           case 'L':
 2308           case 'M':
 2309           case 'N':
 2310           case 'O':
 2311           case 'P':
 2312           case 'Q':
 2313           case 'R':
 2314               break;
 2315           case 'S':
 2316               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2317                                  ? new Utype(UnicodeProp.WHITE_SPACE).complement()
 2318                                  : new Ctype(ASCII.SPACE).complement();
 2319               return -1;
 2320           case 'T':
 2321           case 'U':
 2322           case 'V':
 2323               break;
 2324           case 'W':
 2325               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2326                                  ? new Utype(UnicodeProp.WORD).complement()
 2327                                  : new Ctype(ASCII.WORD).complement();
 2328               return -1;
 2329           case 'X':
 2330           case 'Y':
 2331               break;
 2332           case 'Z':
 2333               if (inclass) break;
 2334               if (create) {
 2335                   if (has(UNIX_LINES))
 2336                       root = new UnixDollar(false);
 2337                   else
 2338                       root = new Dollar(false);
 2339               }
 2340               return -1;
 2341           case 'a':
 2342               return '\007';
 2343           case 'b':
 2344               if (inclass) break;
 2345               if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
 2346               return -1;
 2347           case 'c':
 2348               return c();
 2349           case 'd':
 2350               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2351                                  ? new Utype(UnicodeProp.DIGIT)
 2352                                  : new Ctype(ASCII.DIGIT);
 2353               return -1;
 2354           case 'e':
 2355               return '\033';
 2356           case 'f':
 2357               return '\f';
 2358           case 'g':
 2359           case 'h':
 2360           case 'i':
 2361           case 'j':
 2362               break;
 2363           case 'k':
 2364               if (inclass)
 2365                   break;
 2366               if (read() != '<')
 2367                   throw error("\\k is not followed by '<' for named capturing group");
 2368               String name = groupname(read());
 2369               if (!namedGroups().containsKey(name))
 2370                   throw error("(named capturing group <"+ name+"> does not exit");
 2371               if (create) {
 2372                   if (has(CASE_INSENSITIVE))
 2373                       root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
 2374                   else
 2375                       root = new BackRef(namedGroups().get(name));
 2376               }
 2377               return -1;
 2378           case 'l':
 2379           case 'm':
 2380               break;
 2381           case 'n':
 2382               return '\n';
 2383           case 'o':
 2384           case 'p':
 2385           case 'q':
 2386               break;
 2387           case 'r':
 2388               return '\r';
 2389           case 's':
 2390               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2391                                  ? new Utype(UnicodeProp.WHITE_SPACE)
 2392                                  : new Ctype(ASCII.SPACE);
 2393               return -1;
 2394           case 't':
 2395               return '\t';
 2396           case 'u':
 2397               return u();
 2398           case 'v':
 2399               return '\013';
 2400           case 'w':
 2401               if (create) root = has(UNICODE_CHARACTER_CLASS)
 2402                                  ? new Utype(UnicodeProp.WORD)
 2403                                  : new Ctype(ASCII.WORD);
 2404               return -1;
 2405           case 'x':
 2406               return x();
 2407           case 'y':
 2408               break;
 2409           case 'z':
 2410               if (inclass) break;
 2411               if (create) root = new End();
 2412               return -1;
 2413           default:
 2414               return ch;
 2415           }
 2416           throw error("Illegal/unsupported escape sequence");
 2417       }
 2418   
 2419       /**
 2420        * Parse a character class, and return the node that matches it.
 2421        *
 2422        * Consumes a ] on the way out if consume is true. Usually consume
 2423        * is true except for the case of [abc&&def] where def is a separate
 2424        * right hand node with "understood" brackets.
 2425        */
 2426       private CharProperty clazz(boolean consume) {
 2427           CharProperty prev = null;
 2428           CharProperty node = null;
 2429           BitClass bits = new BitClass();
 2430           boolean include = true;
 2431           boolean firstInClass = true;
 2432           int ch = next();
 2433           for (;;) {
 2434               switch (ch) {
 2435                   case '^':
 2436                       // Negates if first char in a class, otherwise literal
 2437                       if (firstInClass) {
 2438                           if (temp[cursor-1] != '[')
 2439                               break;
 2440                           ch = next();
 2441                           include = !include;
 2442                           continue;
 2443                       } else {
 2444                           // ^ not first in class, treat as literal
 2445                           break;
 2446                       }
 2447                   case '[':
 2448                       firstInClass = false;
 2449                       node = clazz(true);
 2450                       if (prev == null)
 2451                           prev = node;
 2452                       else
 2453                           prev = union(prev, node);
 2454                       ch = peek();
 2455                       continue;
 2456                   case '&':
 2457                       firstInClass = false;
 2458                       ch = next();
 2459                       if (ch == '&') {
 2460                           ch = next();
 2461                           CharProperty rightNode = null;
 2462                           while (ch != ']' && ch != '&') {
 2463                               if (ch == '[') {
 2464                                   if (rightNode == null)
 2465                                       rightNode = clazz(true);
 2466                                   else
 2467                                       rightNode = union(rightNode, clazz(true));
 2468                               } else { // abc&&def
 2469                                   unread();
 2470                                   rightNode = clazz(false);
 2471                               }
 2472                               ch = peek();
 2473                           }
 2474                           if (rightNode != null)
 2475                               node = rightNode;
 2476                           if (prev == null) {
 2477                               if (rightNode == null)
 2478                                   throw error("Bad class syntax");
 2479                               else
 2480                                   prev = rightNode;
 2481                           } else {
 2482                               prev = intersection(prev, node);
 2483                           }
 2484                       } else {
 2485                           // treat as a literal &
 2486                           unread();
 2487                           break;
 2488                       }
 2489                       continue;
 2490                   case 0:
 2491                       firstInClass = false;
 2492                       if (cursor >= patternLength)
 2493                           throw error("Unclosed character class");
 2494                       break;
 2495                   case ']':
 2496                       firstInClass = false;
 2497                       if (prev != null) {
 2498                           if (consume)
 2499                               next();
 2500                           return prev;
 2501                       }
 2502                       break;
 2503                   default:
 2504                       firstInClass = false;
 2505                       break;
 2506               }
 2507               node = range(bits);
 2508               if (include) {
 2509                   if (prev == null) {
 2510                       prev = node;
 2511                   } else {
 2512                       if (prev != node)
 2513                           prev = union(prev, node);
 2514                   }
 2515               } else {
 2516                   if (prev == null) {
 2517                       prev = node.complement();
 2518                   } else {
 2519                       if (prev != node)
 2520                           prev = setDifference(prev, node);
 2521                   }
 2522               }
 2523               ch = peek();
 2524           }
 2525       }
 2526   
 2527       private CharProperty bitsOrSingle(BitClass bits, int ch) {
 2528           /* Bits can only handle codepoints in [u+0000-u+00ff] range.
 2529              Use "single" node instead of bits when dealing with unicode
 2530              case folding for codepoints listed below.
 2531              (1)Uppercase out of range: u+00ff, u+00b5
 2532                 toUpperCase(u+00ff) -> u+0178
 2533                 toUpperCase(u+00b5) -> u+039c
 2534              (2)LatinSmallLetterLongS u+17f
 2535                 toUpperCase(u+017f) -> u+0053
 2536              (3)LatinSmallLetterDotlessI u+131
 2537                 toUpperCase(u+0131) -> u+0049
 2538              (4)LatinCapitalLetterIWithDotAbove u+0130
 2539                 toLowerCase(u+0130) -> u+0069
 2540              (5)KelvinSign u+212a
 2541                 toLowerCase(u+212a) ==> u+006B
 2542              (6)AngstromSign u+212b
 2543                 toLowerCase(u+212b) ==> u+00e5
 2544           */
 2545           int d;
 2546           if (ch < 256 &&
 2547               !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
 2548                 (ch == 0xff || ch == 0xb5 ||
 2549                  ch == 0x49 || ch == 0x69 ||  //I and i
 2550                  ch == 0x53 || ch == 0x73 ||  //S and s
 2551                  ch == 0x4b || ch == 0x6b ||  //K and k
 2552                  ch == 0xc5 || ch == 0xe5)))  //A+ring
 2553               return bits.add(ch, flags());
 2554           return newSingle(ch);
 2555       }
 2556   
 2557       /**
 2558        * Parse a single character or a character range in a character class
 2559        * and return its representative node.
 2560        */
 2561       private CharProperty range(BitClass bits) {
 2562           int ch = peek();
 2563           if (ch == '\\') {
 2564               ch = nextEscaped();
 2565               if (ch == 'p' || ch == 'P') { // A property
 2566                   boolean comp = (ch == 'P');
 2567                   boolean oneLetter = true;
 2568                   // Consume { if present
 2569                   ch = next();
 2570                   if (ch != '{')
 2571                       unread();
 2572                   else
 2573                       oneLetter = false;
 2574                   return family(oneLetter, comp);
 2575               } else { // ordinary escape
 2576                   unread();
 2577                   ch = escape(true, true);
 2578                   if (ch == -1)
 2579                       return (CharProperty) root;
 2580               }
 2581           } else {
 2582               ch = single();
 2583           }
 2584           if (ch >= 0) {
 2585               if (peek() == '-') {
 2586                   int endRange = temp[cursor+1];
 2587                   if (endRange == '[') {
 2588                       return bitsOrSingle(bits, ch);
 2589                   }
 2590                   if (endRange != ']') {
 2591                       next();
 2592                       int m = single();
 2593                       if (m < ch)
 2594                           throw error("Illegal character range");
 2595                       if (has(CASE_INSENSITIVE))
 2596                           return caseInsensitiveRangeFor(ch, m);
 2597                       else
 2598                           return rangeFor(ch, m);
 2599                   }
 2600               }
 2601               return bitsOrSingle(bits, ch);
 2602           }
 2603           throw error("Unexpected character '"+((char)ch)+"'");
 2604       }
 2605   
 2606       private int single() {
 2607           int ch = peek();
 2608           switch (ch) {
 2609           case '\\':
 2610               return escape(true, false);
 2611           default:
 2612               next();
 2613               return ch;
 2614           }
 2615       }
 2616   
 2617       /**
 2618        * Parses a Unicode character family and returns its representative node.
 2619        */
 2620       private CharProperty family(boolean singleLetter,
 2621                                   boolean maybeComplement)
 2622       {
 2623           next();
 2624           String name;
 2625           CharProperty node = null;
 2626   
 2627           if (singleLetter) {
 2628               int c = temp[cursor];
 2629               if (!Character.isSupplementaryCodePoint(c)) {
 2630                   name = String.valueOf((char)c);
 2631               } else {
 2632                   name = new String(temp, cursor, 1);
 2633               }
 2634               read();
 2635           } else {
 2636               int i = cursor;
 2637               mark('}');
 2638               while(read() != '}') {
 2639               }
 2640               mark('\000');
 2641               int j = cursor;
 2642               if (j > patternLength)
 2643                   throw error("Unclosed character family");
 2644               if (i + 1 >= j)
 2645                   throw error("Empty character family");
 2646               name = new String(temp, i, j-i-1);
 2647           }
 2648   
 2649           int i = name.indexOf('=');
 2650           if (i != -1) {
 2651               // property construct \p{name=value}
 2652               String value = name.substring(i + 1);
 2653               name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
 2654               if ("sc".equals(name) || "script".equals(name)) {
 2655                   node = unicodeScriptPropertyFor(value);
 2656               } else if ("blk".equals(name) || "block".equals(name)) {
 2657                   node = unicodeBlockPropertyFor(value);
 2658               } else if ("gc".equals(name) || "general_category".equals(name)) {
 2659                   node = charPropertyNodeFor(value);
 2660               } else {
 2661                   throw error("Unknown Unicode property {name=<" + name + ">, "
 2662                                + "value=<" + value + ">}");
 2663               }
 2664           } else {
 2665               if (name.startsWith("In")) {
 2666                   // \p{inBlockName}
 2667                   node = unicodeBlockPropertyFor(name.substring(2));
 2668               } else if (name.startsWith("Is")) {
 2669                   // \p{isGeneralCategory} and \p{isScriptName}
 2670                   name = name.substring(2);
 2671                   UnicodeProp uprop = UnicodeProp.forName(name);
 2672                   if (uprop != null)
 2673                       node = new Utype(uprop);
 2674                   if (node == null)
 2675                       node = CharPropertyNames.charPropertyFor(name);
 2676                   if (node == null)
 2677                       node = unicodeScriptPropertyFor(name);
 2678               } else {
 2679                   if (has(UNICODE_CHARACTER_CLASS)) {
 2680                       UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
 2681                       if (uprop != null)
 2682                           node = new Utype(uprop);
 2683                   }
 2684                   if (node == null)
 2685                       node = charPropertyNodeFor(name);
 2686               }
 2687           }
 2688           if (maybeComplement) {
 2689               if (node instanceof Category || node instanceof Block)
 2690                   hasSupplementary = true;
 2691               node = node.complement();
 2692           }
 2693           return node;
 2694       }
 2695   
 2696   
 2697       /**
 2698        * Returns a CharProperty matching all characters belong to
 2699        * a UnicodeScript.
 2700        */
 2701       private CharProperty unicodeScriptPropertyFor(String name) {
 2702           final Character.UnicodeScript script;
 2703           try {
 2704               script = Character.UnicodeScript.forName(name);
 2705           } catch (IllegalArgumentException iae) {
 2706               throw error("Unknown character script name {" + name + "}");
 2707           }
 2708           return new Script(script);
 2709       }
 2710   
 2711       /**
 2712        * Returns a CharProperty matching all characters in a UnicodeBlock.
 2713        */
 2714       private CharProperty unicodeBlockPropertyFor(String name) {
 2715           final Character.UnicodeBlock block;
 2716           try {
 2717               block = Character.UnicodeBlock.forName(name);
 2718           } catch (IllegalArgumentException iae) {
 2719               throw error("Unknown character block name {" + name + "}");
 2720           }
 2721           return new Block(block);
 2722       }
 2723   
 2724       /**
 2725        * Returns a CharProperty matching all characters in a named property.
 2726        */
 2727       private CharProperty charPropertyNodeFor(String name) {
 2728           CharProperty p = CharPropertyNames.charPropertyFor(name);
 2729           if (p == null)
 2730               throw error("Unknown character property name {" + name + "}");
 2731           return p;
 2732       }
 2733   
 2734       /**
 2735        * Parses and returns the name of a "named capturing group", the trailing
 2736        * ">" is consumed after parsing.
 2737        */
 2738       private String groupname(int ch) {
 2739           StringBuilder sb = new StringBuilder();
 2740           sb.append(Character.toChars(ch));
 2741           while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
 2742                  ASCII.isDigit(ch)) {
 2743               sb.append(Character.toChars(ch));
 2744           }
 2745           if (sb.length() == 0)
 2746               throw error("named capturing group has 0 length name");
 2747           if (ch != '>')
 2748               throw error("named capturing group is missing trailing '>'");
 2749           return sb.toString();
 2750       }
 2751   
 2752       /**
 2753        * Parses a group and returns the head node of a set of nodes that process
 2754        * the group. Sometimes a double return system is used where the tail is
 2755        * returned in root.
 2756        */
 2757       private Node group0() {
 2758           boolean capturingGroup = false;
 2759           Node head = null;
 2760           Node tail = null;
 2761           int save = flags;
 2762           root = null;
 2763           int ch = next();
 2764           if (ch == '?') {
 2765               ch = skip();
 2766               switch (ch) {
 2767               case ':':   //  (?:xxx) pure group
 2768                   head = createGroup(true);
 2769                   tail = root;
 2770                   head.next = expr(tail);
 2771                   break;
 2772               case '=':   // (?=xxx) and (?!xxx) lookahead
 2773               case '!':
 2774                   head = createGroup(true);
 2775                   tail = root;
 2776                   head.next = expr(tail);
 2777                   if (ch == '=') {
 2778                       head = tail = new Pos(head);
 2779                   } else {
 2780                       head = tail = new Neg(head);
 2781                   }
 2782                   break;
 2783               case '>':   // (?>xxx)  independent group
 2784                   head = createGroup(true);
 2785                   tail = root;
 2786                   head.next = expr(tail);
 2787                   head = tail = new Ques(head, INDEPENDENT);
 2788                   break;
 2789               case '<':   // (?<xxx)  look behind
 2790                   ch = read();
 2791                   if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
 2792                       // named captured group
 2793                       String name = groupname(ch);
 2794                       if (namedGroups().containsKey(name))
 2795                           throw error("Named capturing group <" + name
 2796                                       + "> is already defined");
 2797                       capturingGroup = true;
 2798                       head = createGroup(false);
 2799                       tail = root;
 2800                       namedGroups().put(name, capturingGroupCount-1);
 2801                       head.next = expr(tail);
 2802                       break;
 2803                   }
 2804                   int start = cursor;
 2805                   head = createGroup(true);
 2806                   tail = root;
 2807                   head.next = expr(tail);
 2808                   tail.next = lookbehindEnd;
 2809                   TreeInfo info = new TreeInfo();
 2810                   head.study(info);
 2811                   if (info.maxValid == false) {
 2812                       throw error("Look-behind group does not have "
 2813                                   + "an obvious maximum length");
 2814                   }
 2815                   boolean hasSupplementary = findSupplementary(start, patternLength);
 2816                   if (ch == '=') {
 2817                       head = tail = (hasSupplementary ?
 2818                                      new BehindS(head, info.maxLength,
 2819                                                  info.minLength) :
 2820                                      new Behind(head, info.maxLength,
 2821                                                 info.minLength));
 2822                   } else if (ch == '!') {
 2823                       head = tail = (hasSupplementary ?
 2824                                      new NotBehindS(head, info.maxLength,
 2825                                                     info.minLength) :
 2826                                      new NotBehind(head, info.maxLength,
 2827                                                    info.minLength));
 2828                   } else {
 2829                       throw error("Unknown look-behind group");
 2830                   }
 2831                   break;
 2832               case '$':
 2833               case '@':
 2834                   throw error("Unknown group type");
 2835               default:    // (?xxx:) inlined match flags
 2836                   unread();
 2837                   addFlag();
 2838                   ch = read();
 2839                   if (ch == ')') {
 2840                       return null;    // Inline modifier only
 2841                   }
 2842                   if (ch != ':') {
 2843                       throw error("Unknown inline modifier");
 2844                   }
 2845                   head = createGroup(true);
 2846                   tail = root;
 2847                   head.next = expr(tail);
 2848                   break;
 2849               }
 2850           } else { // (xxx) a regular group
 2851               capturingGroup = true;
 2852               head = createGroup(false);
 2853               tail = root;
 2854               head.next = expr(tail);
 2855           }
 2856   
 2857           accept(')', "Unclosed group");
 2858           flags = save;
 2859   
 2860           // Check for quantifiers
 2861           Node node = closure(head);
 2862           if (node == head) { // No closure
 2863               root = tail;
 2864               return node;    // Dual return
 2865           }
 2866           if (head == tail) { // Zero length assertion
 2867               root = node;
 2868               return node;    // Dual return
 2869           }
 2870   
 2871           if (node instanceof Ques) {
 2872               Ques ques = (Ques) node;
 2873               if (ques.type == POSSESSIVE) {
 2874                   root = node;
 2875                   return node;
 2876               }
 2877               tail.next = new BranchConn();
 2878               tail = tail.next;
 2879               if (ques.type == GREEDY) {
 2880                   head = new Branch(head, null, tail);
 2881               } else { // Reluctant quantifier
 2882                   head = new Branch(null, head, tail);
 2883               }
 2884               root = tail;
 2885               return head;
 2886           } else if (node instanceof Curly) {
 2887               Curly curly = (Curly) node;
 2888               if (curly.type == POSSESSIVE) {
 2889                   root = node;
 2890                   return node;
 2891               }
 2892               // Discover if the group is deterministic
 2893               TreeInfo info = new TreeInfo();
 2894               if (head.study(info)) { // Deterministic
 2895                   GroupTail temp = (GroupTail) tail;
 2896                   head = root = new GroupCurly(head.next, curly.cmin,
 2897                                      curly.cmax, curly.type,
 2898                                      ((GroupTail)tail).localIndex,
 2899                                      ((GroupTail)tail).groupIndex,
 2900                                                capturingGroup);
 2901                   return head;
 2902               } else { // Non-deterministic
 2903                   int temp = ((GroupHead) head).localIndex;
 2904                   Loop loop;
 2905                   if (curly.type == GREEDY)
 2906                       loop = new Loop(this.localCount, temp);
 2907                   else  // Reluctant Curly
 2908                       loop = new LazyLoop(this.localCount, temp);
 2909                   Prolog prolog = new Prolog(loop);
 2910                   this.localCount += 1;
 2911                   loop.cmin = curly.cmin;
 2912                   loop.cmax = curly.cmax;
 2913                   loop.body = head;
 2914                   tail.next = loop;
 2915                   root = loop;
 2916                   return prolog; // Dual return
 2917               }
 2918           }
 2919           throw error("Internal logic error");
 2920       }
 2921   
 2922       /**
 2923        * Create group head and tail nodes using double return. If the group is
 2924        * created with anonymous true then it is a pure group and should not
 2925        * affect group counting.
 2926        */
 2927       private Node createGroup(boolean anonymous) {
 2928           int localIndex = localCount++;
 2929           int groupIndex = 0;
 2930           if (!anonymous)
 2931               groupIndex = capturingGroupCount++;
 2932           GroupHead head = new GroupHead(localIndex);
 2933           root = new GroupTail(localIndex, groupIndex);
 2934           if (!anonymous && groupIndex < 10)
 2935               groupNodes[groupIndex] = head;
 2936           return head;
 2937       }
 2938   
 2939       /**
 2940        * Parses inlined match flags and set them appropriately.
 2941        */
 2942       private void addFlag() {
 2943           int ch = peek();
 2944           for (;;) {
 2945               switch (ch) {
 2946               case 'i':
 2947                   flags |= CASE_INSENSITIVE;
 2948                   break;
 2949               case 'm':
 2950                   flags |= MULTILINE;
 2951                   break;
 2952               case 's':
 2953                   flags |= DOTALL;
 2954                   break;
 2955               case 'd':
 2956                   flags |= UNIX_LINES;
 2957                   break;
 2958               case 'u':
 2959                   flags |= UNICODE_CASE;
 2960                   break;
 2961               case 'c':
 2962                   flags |= CANON_EQ;
 2963                   break;
 2964               case 'x':
 2965                   flags |= COMMENTS;
 2966                   break;
 2967               case 'U':
 2968                   flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
 2969                   break;
 2970               case '-': // subFlag then fall through
 2971                   ch = next();
 2972                   subFlag();
 2973               default:
 2974                   return;
 2975               }
 2976               ch = next();
 2977           }
 2978       }
 2979   
 2980       /**
 2981        * Parses the second part of inlined match flags and turns off
 2982        * flags appropriately.
 2983        */
 2984       private void subFlag() {
 2985           int ch = peek();
 2986           for (;;) {
 2987               switch (ch) {
 2988               case 'i':
 2989                   flags &= ~CASE_INSENSITIVE;
 2990                   break;
 2991               case 'm':
 2992                   flags &= ~MULTILINE;
 2993                   break;
 2994               case 's':
 2995                   flags &= ~DOTALL;
 2996                   break;
 2997               case 'd':
 2998                   flags &= ~UNIX_LINES;
 2999                   break;
 3000               case 'u':
 3001                   flags &= ~UNICODE_CASE;
 3002                   break;
 3003               case 'c':
 3004                   flags &= ~CANON_EQ;
 3005                   break;
 3006               case 'x':
 3007                   flags &= ~COMMENTS;
 3008                   break;
 3009               case 'U':
 3010                   flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
 3011               default:
 3012                   return;
 3013               }
 3014               ch = next();
 3015           }
 3016       }
 3017   
 3018       static final int MAX_REPS   = 0x7FFFFFFF;
 3019   
 3020       static final int GREEDY     = 0;
 3021   
 3022       static final int LAZY       = 1;
 3023   
 3024       static final int POSSESSIVE = 2;
 3025   
 3026       static final int INDEPENDENT = 3;
 3027   
 3028       /**
 3029        * Processes repetition. If the next character peeked is a quantifier
 3030        * then new nodes must be appended to handle the repetition.
 3031        * Prev could be a single or a group, so it could be a chain of nodes.
 3032        */
 3033       private Node closure(Node prev) {
 3034           Node atom;
 3035           int ch = peek();
 3036           switch (ch) {
 3037           case '?':
 3038               ch = next();
 3039               if (ch == '?') {
 3040                   next();
 3041                   return new Ques(prev, LAZY);
 3042               } else if (ch == '+') {
 3043                   next();
 3044                   return new Ques(prev, POSSESSIVE);
 3045               }
 3046               return new Ques(prev, GREEDY);
 3047           case '*':
 3048               ch = next();
 3049               if (ch == '?') {
 3050                   next();
 3051                   return new Curly(prev, 0, MAX_REPS, LAZY);
 3052               } else if (ch == '+') {
 3053                   next();
 3054                   return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
 3055               }
 3056               return new Curly(prev, 0, MAX_REPS, GREEDY);
 3057           case '+':
 3058               ch = next();
 3059               if (ch == '?') {
 3060                   next();
 3061                   return new Curly(prev, 1, MAX_REPS, LAZY);
 3062               } else if (ch == '+') {
 3063                   next();
 3064                   return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
 3065               }
 3066               return new Curly(prev, 1, MAX_REPS, GREEDY);
 3067           case '{':
 3068               ch = temp[cursor+1];
 3069               if (ASCII.isDigit(ch)) {
 3070                   skip();
 3071                   int cmin = 0;
 3072                   do {
 3073                       cmin = cmin * 10 + (ch - '0');
 3074                   } while (ASCII.isDigit(ch = read()));
 3075                   int cmax = cmin;
 3076                   if (ch == ',') {
 3077                       ch = read();
 3078                       cmax = MAX_REPS;
 3079                       if (ch != '}') {
 3080                           cmax = 0;
 3081                           while (ASCII.isDigit(ch)) {
 3082                               cmax = cmax * 10 + (ch - '0');
 3083                               ch = read();
 3084                           }
 3085                       }
 3086                   }
 3087                   if (ch != '}')
 3088                       throw error("Unclosed counted closure");
 3089                   if (((cmin) | (cmax) | (cmax - cmin)) < 0)
 3090                       throw error("Illegal repetition range");
 3091                   Curly curly;
 3092                   ch = peek();
 3093                   if (ch == '?') {
 3094                       next();
 3095                       curly = new Curly(prev, cmin, cmax, LAZY);
 3096                   } else if (ch == '+') {
 3097                       next();
 3098                       curly = new Curly(prev, cmin, cmax, POSSESSIVE);
 3099                   } else {
 3100                       curly = new Curly(prev, cmin, cmax, GREEDY);
 3101                   }
 3102                   return curly;
 3103               } else {
 3104                   throw error("Illegal repetition");
 3105               }
 3106           default:
 3107               return prev;
 3108           }
 3109       }
 3110   
 3111       /**
 3112        *  Utility method for parsing control escape sequences.
 3113        */
 3114       private int c() {
 3115           if (cursor < patternLength) {
 3116               return read() ^ 64;
 3117           }
 3118           throw error("Illegal control escape sequence");
 3119       }
 3120   
 3121       /**
 3122        *  Utility method for parsing octal escape sequences.
 3123        */
 3124       private int o() {
 3125           int n = read();
 3126           if (((n-'0')|('7'-n)) >= 0) {
 3127               int m = read();
 3128               if (((m-'0')|('7'-m)) >= 0) {
 3129                   int o = read();
 3130                   if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
 3131                       return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
 3132                   }
 3133                   unread();
 3134                   return (n - '0') * 8 + (m - '0');
 3135               }
 3136               unread();
 3137               return (n - '0');
 3138           }
 3139           throw error("Illegal octal escape sequence");
 3140       }
 3141   
 3142       /**
 3143        *  Utility method for parsing hexadecimal escape sequences.
 3144        */
 3145       private int x() {
 3146           int n = read();
 3147           if (ASCII.isHexDigit(n)) {
 3148               int m = read();
 3149               if (ASCII.isHexDigit(m)) {
 3150                   return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
 3151               }
 3152           } else if (n == '{' && ASCII.isHexDigit(peek())) {
 3153               int ch = 0;
 3154               while (ASCII.isHexDigit(n = read())) {
 3155                   ch = (ch << 4) + ASCII.toDigit(n);
 3156                   if (ch > Character.MAX_CODE_POINT)
 3157                       throw error("Hexadecimal codepoint is too big");
 3158               }
 3159               if (n != '}')
 3160                   throw error("Unclosed hexadecimal escape sequence");
 3161               return ch;
 3162           }
 3163           throw error("Illegal hexadecimal escape sequence");
 3164       }
 3165   
 3166       /**
 3167        *  Utility method for parsing unicode escape sequences.
 3168        */
 3169       private int cursor() {
 3170           return cursor;
 3171       }
 3172   
 3173       private void setcursor(int pos) {
 3174           cursor = pos;
 3175       }
 3176   
 3177       private int uxxxx() {
 3178           int n = 0;
 3179           for (int i = 0; i < 4; i++) {
 3180               int ch = read();
 3181               if (!ASCII.isHexDigit(ch)) {
 3182                   throw error("Illegal Unicode escape sequence");
 3183               }
 3184               n = n * 16 + ASCII.toDigit(ch);
 3185           }
 3186           return n;
 3187       }
 3188   
 3189       private int u() {
 3190           int n = uxxxx();
 3191           if (Character.isHighSurrogate((char)n)) {
 3192               int cur = cursor();
 3193               if (read() == '\\' && read() == 'u') {
 3194                   int n2 = uxxxx();
 3195                   if (Character.isLowSurrogate((char)n2))
 3196                       return Character.toCodePoint((char)n, (char)n2);
 3197               }
 3198               setcursor(cur);
 3199           }
 3200           return n;
 3201       }
 3202   
 3203       //
 3204       // Utility methods for code point support
 3205       //
 3206   
 3207       private static final int countChars(CharSequence seq, int index,
 3208                                           int lengthInCodePoints) {
 3209           // optimization
 3210           if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
 3211               assert (index >= 0 && index < seq.length());
 3212               return 1;
 3213           }
 3214           int length = seq.length();
 3215           int x = index;
 3216           if (lengthInCodePoints >= 0) {
 3217               assert (index >= 0 && index < length);
 3218               for (int i = 0; x < length && i < lengthInCodePoints; i++) {
 3219                   if (Character.isHighSurrogate(seq.charAt(x++))) {
 3220                       if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
 3221                           x++;
 3222                       }
 3223                   }
 3224               }
 3225               return x - index;
 3226           }
 3227   
 3228           assert (index >= 0 && index <= length);
 3229           if (index == 0) {
 3230               return 0;
 3231           }
 3232           int len = -lengthInCodePoints;
 3233           for (int i = 0; x > 0 && i < len; i++) {
 3234               if (Character.isLowSurrogate(seq.charAt(--x))) {
 3235                   if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
 3236                       x--;
 3237                   }
 3238               }
 3239           }
 3240           return index - x;
 3241       }
 3242   
 3243       private static final int countCodePoints(CharSequence seq) {
 3244           int length = seq.length();
 3245           int n = 0;
 3246           for (int i = 0; i < length; ) {
 3247               n++;
 3248               if (Character.isHighSurrogate(seq.charAt(i++))) {
 3249                   if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
 3250                       i++;
 3251                   }
 3252               }
 3253           }
 3254           return n;
 3255       }
 3256   
 3257       /**
 3258        *  Creates a bit vector for matching Latin-1 values. A normal BitClass
 3259        *  never matches values above Latin-1, and a complemented BitClass always
 3260        *  matches values above Latin-1.
 3261        */
 3262       private static final class BitClass extends BmpCharProperty {
 3263           final boolean[] bits;
 3264           BitClass() { bits = new boolean[256]; }
 3265           private BitClass(boolean[] bits) { this.bits = bits; }
 3266           BitClass add(int c, int flags) {
 3267               assert c >= 0 && c <= 255;
 3268               if ((flags & CASE_INSENSITIVE) != 0) {
 3269                   if (ASCII.isAscii(c)) {
 3270                       bits[ASCII.toUpper(c)] = true;
 3271                       bits[ASCII.toLower(c)] = true;
 3272                   } else if ((flags & UNICODE_CASE) != 0) {
 3273                       bits[Character.toLowerCase(c)] = true;
 3274                       bits[Character.toUpperCase(c)] = true;
 3275                   }
 3276               }
 3277               bits[c] = true;
 3278               return this;
 3279           }
 3280           boolean isSatisfiedBy(int ch) {
 3281               return ch < 256 && bits[ch];
 3282           }
 3283       }
 3284   
 3285       /**
 3286        *  Returns a suitably optimized, single character matcher.
 3287        */
 3288       private CharProperty newSingle(final int ch) {
 3289           if (has(CASE_INSENSITIVE)) {
 3290               int lower, upper;
 3291               if (has(UNICODE_CASE)) {
 3292                   upper = Character.toUpperCase(ch);
 3293                   lower = Character.toLowerCase(upper);
 3294                   if (upper != lower)
 3295                       return new SingleU(lower);
 3296               } else if (ASCII.isAscii(ch)) {
 3297                   lower = ASCII.toLower(ch);
 3298                   upper = ASCII.toUpper(ch);
 3299                   if (lower != upper)
 3300                       return new SingleI(lower, upper);
 3301               }
 3302           }
 3303           if (isSupplementary(ch))
 3304               return new SingleS(ch);    // Match a given Unicode character
 3305           return new Single(ch);         // Match a given BMP character
 3306       }
 3307   
 3308       /**
 3309        *  Utility method for creating a string slice matcher.
 3310        */
 3311       private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
 3312           int[] tmp = new int[count];
 3313           if (has(CASE_INSENSITIVE)) {
 3314               if (has(UNICODE_CASE)) {
 3315                   for (int i = 0; i < count; i++) {
 3316                       tmp[i] = Character.toLowerCase(
 3317                                    Character.toUpperCase(buf[i]));
 3318                   }
 3319                   return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
 3320               }
 3321               for (int i = 0; i < count; i++) {
 3322                   tmp[i] = ASCII.toLower(buf[i]);
 3323               }
 3324               return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
 3325           }
 3326           for (int i = 0; i < count; i++) {
 3327               tmp[i] = buf[i];
 3328           }
 3329           return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
 3330       }
 3331   
 3332       /**
 3333        * The following classes are the building components of the object
 3334        * tree that represents a compiled regular expression. The object tree
 3335        * is made of individual elements that handle constructs in the Pattern.
 3336        * Each type of object knows how to match its equivalent construct with
 3337        * the match() method.
 3338        */
 3339   
 3340       /**
 3341        * Base class for all node classes. Subclasses should override the match()
 3342        * method as appropriate. This class is an accepting node, so its match()
 3343        * always returns true.
 3344        */
 3345       static class Node extends Object {
 3346           Node next;
 3347           Node() {
 3348               next = Pattern.accept;
 3349           }
 3350           /**
 3351            * This method implements the classic accept node.
 3352            */
 3353           boolean match(Matcher matcher, int i, CharSequence seq) {
 3354               matcher.last = i;
 3355               matcher.groups[0] = matcher.first;
 3356               matcher.groups[1] = matcher.last;
 3357               return true;
 3358           }
 3359           /**
 3360            * This method is good for all zero length assertions.
 3361            */
 3362           boolean study(TreeInfo info) {
 3363               if (next != null) {
 3364                   return next.study(info);
 3365               } else {
 3366                   return info.deterministic;
 3367               }
 3368           }
 3369       }
 3370   
 3371       static class LastNode extends Node {
 3372           /**
 3373            * This method implements the classic accept node with
 3374            * the addition of a check to see if the match occurred
 3375            * using all of the input.
 3376            */
 3377           boolean match(Matcher matcher, int i, CharSequence seq) {
 3378               if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
 3379                   return false;
 3380               matcher.last = i;
 3381               matcher.groups[0] = matcher.first;
 3382               matcher.groups[1] = matcher.last;
 3383               return true;
 3384           }
 3385       }
 3386   
 3387       /**
 3388        * Used for REs that can start anywhere within the input string.
 3389        * This basically tries to match repeatedly at each spot in the
 3390        * input string, moving forward after each try. An anchored search
 3391        * or a BnM will bypass this node completely.
 3392        */
 3393       static class Start extends Node {
 3394           int minLength;
 3395           Start(Node node) {
 3396               this.next = node;
 3397               TreeInfo info = new TreeInfo();
 3398               next.study(info);
 3399               minLength = info.minLength;
 3400           }
 3401           boolean match(Matcher matcher, int i, CharSequence seq) {
 3402               if (i > matcher.to - minLength) {
 3403                   matcher.hitEnd = true;
 3404                   return false;
 3405               }
 3406               int guard = matcher.to - minLength;
 3407               for (; i <= guard; i++) {
 3408                   if (next.match(matcher, i, seq)) {
 3409                       matcher.first = i;
 3410                       matcher.groups[0] = matcher.first;
 3411                       matcher.groups[1] = matcher.last;
 3412                       return true;
 3413                   }
 3414               }
 3415               matcher.hitEnd = true;
 3416               return false;
 3417           }
 3418           boolean study(TreeInfo info) {
 3419               next.study(info);
 3420               info.maxValid = false;
 3421               info.deterministic = false;
 3422               return false;
 3423           }
 3424       }
 3425   
 3426       /*
 3427        * StartS supports supplementary characters, including unpaired surrogates.
 3428        */
 3429       static final class StartS extends Start {
 3430           StartS(Node node) {
 3431               super(node);
 3432           }
 3433           boolean match(Matcher matcher, int i, CharSequence seq) {
 3434               if (i > matcher.to - minLength) {
 3435                   matcher.hitEnd = true;
 3436                   return false;
 3437               }
 3438               int guard = matcher.to - minLength;
 3439               while (i <= guard) {
 3440                   //if ((ret = next.match(matcher, i, seq)) || i == guard)
 3441                   if (next.match(matcher, i, seq)) {
 3442                       matcher.first = i;
 3443                       matcher.groups[0] = matcher.first;
 3444                       matcher.groups[1] = matcher.last;
 3445                       return true;
 3446                   }
 3447                   if (i == guard)
 3448                       break;
 3449                   // Optimization to move to the next character. This is
 3450                   // faster than countChars(seq, i, 1).
 3451                   if (Character.isHighSurrogate(seq.charAt(i++))) {
 3452                       if (i < seq.length() &&
 3453                           Character.isLowSurrogate(seq.charAt(i))) {
 3454                           i++;
 3455                       }
 3456                   }
 3457               }
 3458               matcher.hitEnd = true;
 3459               return false;
 3460           }
 3461       }
 3462   
 3463       /**
 3464        * Node to anchor at the beginning of input. This object implements the
 3465        * match for a \A sequence, and the caret anchor will use this if not in
 3466        * multiline mode.
 3467        */
 3468       static final class Begin extends Node {
 3469           boolean match(Matcher matcher, int i, CharSequence seq) {
 3470               int fromIndex = (matcher.anchoringBounds) ?
 3471                   matcher.from : 0;
 3472               if (i == fromIndex && next.match(matcher, i, seq)) {
 3473                   matcher.first = i;
 3474                   matcher.groups[0] = i;
 3475                   matcher.groups[1] = matcher.last;
 3476                   return true;
 3477               } else {
 3478                   return false;
 3479               }
 3480           }
 3481       }
 3482   
 3483       /**
 3484        * Node to anchor at the end of input. This is the absolute end, so this
 3485        * should not match at the last newline before the end as $ will.
 3486        */
 3487       static final class End extends Node {
 3488           boolean match(Matcher matcher, int i, CharSequence seq) {
 3489               int endIndex = (matcher.anchoringBounds) ?
 3490                   matcher.to : matcher.getTextLength();
 3491               if (i == endIndex) {
 3492                   matcher.hitEnd = true;
 3493                   return next.match(matcher, i, seq);
 3494               }
 3495               return false;
 3496           }
 3497       }
 3498   
 3499       /**
 3500        * Node to anchor at the beginning of a line. This is essentially the
 3501        * object to match for the multiline ^.
 3502        */
 3503       static final class Caret extends Node {
 3504           boolean match(Matcher matcher, int i, CharSequence seq) {
 3505               int startIndex = matcher.from;
 3506               int endIndex = matcher.to;
 3507               if (!matcher.anchoringBounds) {
 3508                   startIndex = 0;
 3509                   endIndex = matcher.getTextLength();
 3510               }
 3511               // Perl does not match ^ at end of input even after newline
 3512               if (i == endIndex) {
 3513                   matcher.hitEnd = true;
 3514                   return false;
 3515               }
 3516               if (i > startIndex) {
 3517                   char ch = seq.charAt(i-1);
 3518                   if (ch != '\n' && ch != '\r'
 3519                       && (ch|1) != '\u2029'
 3520                       && ch != '\u0085' ) {
 3521                       return false;
 3522                   }
 3523                   // Should treat /r/n as one newline
 3524                   if (ch == '\r' && seq.charAt(i) == '\n')
 3525                       return false;
 3526               }
 3527               return next.match(matcher, i, seq);
 3528           }
 3529       }
 3530   
 3531       /**
 3532        * Node to anchor at the beginning of a line when in unixdot mode.
 3533        */
 3534       static final class UnixCaret extends Node {
 3535           boolean match(Matcher matcher, int i, CharSequence seq) {
 3536               int startIndex = matcher.from;
 3537               int endIndex = matcher.to;
 3538               if (!matcher.anchoringBounds) {
 3539                   startIndex = 0;
 3540                   endIndex = matcher.getTextLength();
 3541               }
 3542               // Perl does not match ^ at end of input even after newline
 3543               if (i == endIndex) {
 3544                   matcher.hitEnd = true;
 3545                   return false;
 3546               }
 3547               if (i > startIndex) {
 3548                   char ch = seq.charAt(i-1);
 3549                   if (ch != '\n') {
 3550                       return false;
 3551                   }
 3552               }
 3553               return next.match(matcher, i, seq);
 3554           }
 3555       }
 3556   
 3557       /**
 3558        * Node to match the location where the last match ended.
 3559        * This is used for the \G construct.
 3560        */
 3561       static final class LastMatch extends Node {
 3562           boolean match(Matcher matcher, int i, CharSequence seq) {
 3563               if (i != matcher.oldLast)
 3564                   return false;
 3565               return next.match(matcher, i, seq);
 3566           }
 3567       }
 3568   
 3569       /**
 3570        * Node to anchor at the end of a line or the end of input based on the
 3571        * multiline mode.
 3572        *
 3573        * When not in multiline mode, the $ can only match at the very end
 3574        * of the input, unless the input ends in a line terminator in which
 3575        * it matches right before the last line terminator.
 3576        *
 3577        * Note that \r\n is considered an atomic line terminator.
 3578        *
 3579        * Like ^ the $ operator matches at a position, it does not match the
 3580        * line terminators themselves.
 3581        */
 3582       static final class Dollar extends Node {
 3583           boolean multiline;
 3584           Dollar(boolean mul) {
 3585               multiline = mul;
 3586           }
 3587           boolean match(Matcher matcher, int i, CharSequence seq) {
 3588               int endIndex = (matcher.anchoringBounds) ?
 3589                   matcher.to : matcher.getTextLength();
 3590               if (!multiline) {
 3591                   if (i < endIndex - 2)
 3592                       return false;
 3593                   if (i == endIndex - 2) {
 3594                       char ch = seq.charAt(i);
 3595                       if (ch != '\r')
 3596                           return false;
 3597                       ch = seq.charAt(i + 1);
 3598                       if (ch != '\n')
 3599                           return false;
 3600                   }
 3601               }
 3602               // Matches before any line terminator; also matches at the
 3603               // end of input
 3604               // Before line terminator:
 3605               // If multiline, we match here no matter what
 3606               // If not multiline, fall through so that the end
 3607               // is marked as hit; this must be a /r/n or a /n
 3608               // at the very end so the end was hit; more input
 3609               // could make this not match here
 3610               if (i < endIndex) {
 3611                   char ch = seq.charAt(i);
 3612                    if (ch == '\n') {
 3613                        // No match between \r\n
 3614                        if (i > 0 && seq.charAt(i-1) == '\r')
 3615                            return false;
 3616                        if (multiline)
 3617                            return next.match(matcher, i, seq);
 3618                    } else if (ch == '\r' || ch == '\u0085' ||
 3619                               (ch|1) == '\u2029') {
 3620                        if (multiline)
 3621                            return next.match(matcher, i, seq);
 3622                    } else { // No line terminator, no match
 3623                        return false;
 3624                    }
 3625               }
 3626               // Matched at current end so hit end
 3627               matcher.hitEnd = true;
 3628               // If a $ matches because of end of input, then more input
 3629               // could cause it to fail!
 3630               matcher.requireEnd = true;
 3631               return next.match(matcher, i, seq);
 3632           }
 3633           boolean study(TreeInfo info) {
 3634               next.study(info);
 3635               return info.deterministic;
 3636           }
 3637       }
 3638   
 3639       /**
 3640        * Node to anchor at the end of a line or the end of input based on the
 3641        * multiline mode when in unix lines mode.
 3642        */
 3643       static final class UnixDollar extends Node {
 3644           boolean multiline;
 3645           UnixDollar(boolean mul) {
 3646               multiline = mul;
 3647           }
 3648           boolean match(Matcher matcher, int i, CharSequence seq) {
 3649               int endIndex = (matcher.anchoringBounds) ?
 3650                   matcher.to : matcher.getTextLength();
 3651               if (i < endIndex) {
 3652                   char ch = seq.charAt(i);
 3653                   if (ch == '\n') {
 3654                       // If not multiline, then only possible to
 3655                       // match at very end or one before end
 3656                       if (multiline == false && i != endIndex - 1)
 3657                           return false;
 3658                       // If multiline return next.match without setting
 3659                       // matcher.hitEnd
 3660                       if (multiline)
 3661                           return next.match(matcher, i, seq);
 3662                   } else {
 3663                       return false;
 3664                   }
 3665               }
 3666               // Matching because at the end or 1 before the end;
 3667               // more input could change this so set hitEnd
 3668               matcher.hitEnd = true;
 3669               // If a $ matches because of end of input, then more input
 3670               // could cause it to fail!
 3671               matcher.requireEnd = true;
 3672               return next.match(matcher, i, seq);
 3673           }
 3674           boolean study(TreeInfo info) {
 3675               next.study(info);
 3676               return info.deterministic;
 3677           }
 3678       }
 3679   
 3680       /**
 3681        * Abstract node class to match one character satisfying some
 3682        * boolean property.
 3683        */
 3684       private static abstract class CharProperty extends Node {
 3685           abstract boolean isSatisfiedBy(int ch);
 3686           CharProperty complement() {
 3687               return new CharProperty() {
 3688                       boolean isSatisfiedBy(int ch) {
 3689                           return ! CharProperty.this.isSatisfiedBy(ch);}};
 3690           }
 3691           boolean match(Matcher matcher, int i, CharSequence seq) {
 3692               if (i < matcher.to) {
 3693                   int ch = Character.codePointAt(seq, i);
 3694                   return isSatisfiedBy(ch)
 3695                       && next.match(matcher, i+Character.charCount(ch), seq);
 3696               } else {
 3697                   matcher.hitEnd = true;
 3698                   return false;
 3699               }
 3700           }
 3701           boolean study(TreeInfo info) {
 3702               info.minLength++;
 3703               info.maxLength++;
 3704               return next.study(info);
 3705           }
 3706       }
 3707   
 3708       /**
 3709        * Optimized version of CharProperty that works only for
 3710        * properties never satisfied by Supplementary characters.
 3711        */
 3712       private static abstract class BmpCharProperty extends CharProperty {
 3713           boolean match(Matcher matcher, int i, CharSequence seq) {
 3714               if (i < matcher.to) {
 3715                   return isSatisfiedBy(seq.charAt(i))
 3716                       && next.match(matcher, i+1, seq);
 3717               } else {
 3718                   matcher.hitEnd = true;
 3719                   return false;
 3720               }
 3721           }
 3722       }
 3723   
 3724       /**
 3725        * Node class that matches a Supplementary Unicode character
 3726        */
 3727       static final class SingleS extends CharProperty {
 3728           final int c;
 3729           SingleS(int c) { this.c = c; }
 3730           boolean isSatisfiedBy(int ch) {
 3731               return ch == c;
 3732           }
 3733       }
 3734   
 3735       /**
 3736        * Optimization -- matches a given BMP character
 3737        */
 3738       static final class Single extends BmpCharProperty {
 3739           final int c;
 3740           Single(int c) { this.c = c; }
 3741           boolean isSatisfiedBy(int ch) {
 3742               return ch == c;
 3743           }
 3744       }
 3745   
 3746       /**
 3747        * Case insensitive matches a given BMP character
 3748        */
 3749       static final class SingleI extends BmpCharProperty {
 3750           final int lower;
 3751           final int upper;
 3752           SingleI(int lower, int upper) {
 3753               this.lower = lower;
 3754               this.upper = upper;
 3755           }
 3756           boolean isSatisfiedBy(int ch) {
 3757               return ch == lower || ch == upper;
 3758           }
 3759       }
 3760   
 3761       /**
 3762        * Unicode case insensitive matches a given Unicode character
 3763        */
 3764       static final class SingleU extends CharProperty {
 3765           final int lower;
 3766           SingleU(int lower) {
 3767               this.lower = lower;
 3768           }
 3769           boolean isSatisfiedBy(int ch) {
 3770               return lower == ch ||
 3771                   lower == Character.toLowerCase(Character.toUpperCase(ch));
 3772           }
 3773       }
 3774   
 3775   
 3776       /**
 3777        * Node class that matches a Unicode block.
 3778        */
 3779       static final class Block extends CharProperty {
 3780           final Character.UnicodeBlock block;
 3781           Block(Character.UnicodeBlock block) {
 3782               this.block = block;
 3783           }
 3784           boolean isSatisfiedBy(int ch) {
 3785               return block == Character.UnicodeBlock.of(ch);
 3786           }
 3787       }
 3788   
 3789       /**
 3790        * Node class that matches a Unicode script
 3791        */
 3792       static final class Script extends CharProperty {
 3793           final Character.UnicodeScript script;
 3794           Script(Character.UnicodeScript script) {
 3795               this.script = script;
 3796           }
 3797           boolean isSatisfiedBy(int ch) {
 3798               return script == Character.UnicodeScript.of(ch);
 3799           }
 3800       }
 3801   
 3802       /**
 3803        * Node class that matches a Unicode category.
 3804        */
 3805       static final class Category extends CharProperty {
 3806           final int typeMask;
 3807           Category(int typeMask) { this.typeMask = typeMask; }
 3808           boolean isSatisfiedBy(int ch) {
 3809               return (typeMask & (1 << Character.getType(ch))) != 0;
 3810           }
 3811       }
 3812   
 3813       /**
 3814        * Node class that matches a Unicode "type"
 3815        */
 3816       static final class Utype extends CharProperty {
 3817           final UnicodeProp uprop;
 3818           Utype(UnicodeProp uprop) { this.uprop = uprop; }
 3819           boolean isSatisfiedBy(int ch) {
 3820               return uprop.is(ch);
 3821           }
 3822       }
 3823   
 3824   
 3825       /**
 3826        * Node class that matches a POSIX type.
 3827        */
 3828       static final class Ctype extends BmpCharProperty {
 3829           final int ctype;
 3830           Ctype(int ctype) { this.ctype = ctype; }
 3831           boolean isSatisfiedBy(int ch) {
 3832               return ch < 128 && ASCII.isType(ch, ctype);
 3833           }
 3834       }
 3835   
 3836       /**
 3837        * Base class for all Slice nodes
 3838        */
 3839       static class SliceNode extends Node {
 3840           int[] buffer;
 3841           SliceNode(int[] buf) {
 3842               buffer = buf;
 3843           }
 3844           boolean study(TreeInfo info) {
 3845               info.minLength += buffer.length;
 3846               info.maxLength += buffer.length;
 3847               return next.study(info);
 3848           }
 3849       }
 3850   
 3851       /**
 3852        * Node class for a case sensitive/BMP-only sequence of literal
 3853        * characters.
 3854        */
 3855       static final class Slice extends SliceNode {
 3856           Slice(int[] buf) {
 3857               super(buf);
 3858           }
 3859           boolean match(Matcher matcher, int i, CharSequence seq) {
 3860               int[] buf = buffer;
 3861               int len = buf.length;
 3862               for (int j=0; j<len; j++) {
 3863                   if ((i+j) >= matcher.to) {
 3864                       matcher.hitEnd = true;
 3865                       return false;
 3866                   }
 3867                   if (buf[j] != seq.charAt(i+j))
 3868                       return false;
 3869               }
 3870               return next.match(matcher, i+len, seq);
 3871           }
 3872       }
 3873   
 3874       /**
 3875        * Node class for a case_insensitive/BMP-only sequence of literal
 3876        * characters.
 3877        */
 3878       static class SliceI extends SliceNode {
 3879           SliceI(int[] buf) {
 3880               super(buf);
 3881           }
 3882           boolean match(Matcher matcher, int i, CharSequence seq) {
 3883               int[] buf = buffer;
 3884               int len = buf.length;
 3885               for (int j=0; j<len; j++) {
 3886                   if ((i+j) >= matcher.to) {
 3887                       matcher.hitEnd = true;
 3888                       return false;
 3889                   }
 3890                   int c = seq.charAt(i+j);
 3891                   if (buf[j] != c &&
 3892                       buf[j] != ASCII.toLower(c))
 3893                       return false;
 3894               }
 3895               return next.match(matcher, i+len, seq);
 3896           }
 3897       }
 3898   
 3899       /**
 3900        * Node class for a unicode_case_insensitive/BMP-only sequence of
 3901        * literal characters. Uses unicode case folding.
 3902        */
 3903       static final class SliceU extends SliceNode {
 3904           SliceU(int[] buf) {
 3905               super(buf);
 3906           }
 3907           boolean match(Matcher matcher, int i, CharSequence seq) {
 3908               int[] buf = buffer;
 3909               int len = buf.length;
 3910               for (int j=0; j<len; j++) {
 3911                   if ((i+j) >= matcher.to) {
 3912                       matcher.hitEnd = true;
 3913                       return false;
 3914                   }
 3915                   int c = seq.charAt(i+j);
 3916                   if (buf[j] != c &&
 3917                       buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
 3918                       return false;
 3919               }
 3920               return next.match(matcher, i+len, seq);
 3921           }
 3922       }
 3923   
 3924       /**
 3925        * Node class for a case sensitive sequence of literal characters
 3926        * including supplementary characters.
 3927        */
 3928       static final class SliceS extends SliceNode {
 3929           SliceS(int[] buf) {
 3930               super(buf);
 3931           }
 3932           boolean match(Matcher matcher, int i, CharSequence seq) {
 3933               int[] buf = buffer;
 3934               int x = i;
 3935               for (int j = 0; j < buf.length; j++) {
 3936                   if (x >= matcher.to) {
 3937                       matcher.hitEnd = true;
 3938                       return false;
 3939                   }
 3940                   int c = Character.codePointAt(seq, x);
 3941                   if (buf[j] != c)
 3942                       return false;
 3943                   x += Character.charCount(c);
 3944                   if (x > matcher.to) {
 3945                       matcher.hitEnd = true;
 3946                       return false;
 3947                   }
 3948               }
 3949               return next.match(matcher, x, seq);
 3950           }
 3951       }
 3952   
 3953       /**
 3954        * Node class for a case insensitive sequence of literal characters
 3955        * including supplementary characters.
 3956        */
 3957       static class SliceIS extends SliceNode {
 3958           SliceIS(int[] buf) {
 3959               super(buf);
 3960           }
 3961           int toLower(int c) {
 3962               return ASCII.toLower(c);
 3963           }
 3964           boolean match(Matcher matcher, int i, CharSequence seq) {
 3965               int[] buf = buffer;
 3966               int x = i;
 3967               for (int j = 0; j < buf.length; j++) {
 3968                   if (x >= matcher.to) {
 3969                       matcher.hitEnd = true;
 3970                       return false;
 3971                   }
 3972                   int c = Character.codePointAt(seq, x);
 3973                   if (buf[j] != c && buf[j] != toLower(c))
 3974                       return false;
 3975                   x += Character.charCount(c);
 3976                   if (x > matcher.to) {
 3977                       matcher.hitEnd = true;
 3978                       return false;
 3979                   }
 3980               }
 3981               return next.match(matcher, x, seq);
 3982           }
 3983       }
 3984   
 3985       /**
 3986        * Node class for a case insensitive sequence of literal characters.
 3987        * Uses unicode case folding.
 3988        */
 3989       static final class SliceUS extends SliceIS {
 3990           SliceUS(int[] buf) {
 3991               super(buf);
 3992           }
 3993           int toLower(int c) {
 3994               return Character.toLowerCase(Character.toUpperCase(c));
 3995           }
 3996       }
 3997   
 3998       private static boolean inRange(int lower, int ch, int upper) {
 3999           return lower <= ch && ch <= upper;
 4000       }
 4001   
 4002       /**
 4003        * Returns node for matching characters within an explicit value range.
 4004        */
 4005       private static CharProperty rangeFor(final int lower,
 4006                                            final int upper) {
 4007           return new CharProperty() {
 4008                   boolean isSatisfiedBy(int ch) {
 4009                       return inRange(lower, ch, upper);}};
 4010       }
 4011   
 4012       /**
 4013        * Returns node for matching characters within an explicit value
 4014        * range in a case insensitive manner.
 4015        */
 4016       private CharProperty caseInsensitiveRangeFor(final int lower,
 4017                                                    final int upper) {
 4018           if (has(UNICODE_CASE))
 4019               return new CharProperty() {
 4020                   boolean isSatisfiedBy(int ch) {
 4021                       if (inRange(lower, ch, upper))
 4022                           return true;
 4023                       int up = Character.toUpperCase(ch);
 4024                       return inRange(lower, up, upper) ||
 4025                              inRange(lower, Character.toLowerCase(up), upper);}};
 4026           return new CharProperty() {
 4027               boolean isSatisfiedBy(int ch) {
 4028                   return inRange(lower, ch, upper) ||
 4029                       ASCII.isAscii(ch) &&
 4030                           (inRange(lower, ASCII.toUpper(ch), upper) ||
 4031                            inRange(lower, ASCII.toLower(ch), upper));
 4032               }};
 4033       }
 4034   
 4035       /**
 4036        * Implements the Unicode category ALL and the dot metacharacter when
 4037        * in dotall mode.
 4038        */
 4039       static final class All extends CharProperty {
 4040           boolean isSatisfiedBy(int ch) {
 4041               return true;
 4042           }
 4043       }
 4044   
 4045       /**
 4046        * Node class for the dot metacharacter when dotall is not enabled.
 4047        */
 4048       static final class Dot extends CharProperty {
 4049           boolean isSatisfiedBy(int ch) {
 4050               return (ch != '\n' && ch != '\r'
 4051                       && (ch|1) != '\u2029'
 4052                       && ch != '\u0085');
 4053           }
 4054       }
 4055   
 4056       /**
 4057        * Node class for the dot metacharacter when dotall is not enabled
 4058        * but UNIX_LINES is enabled.
 4059        */
 4060       static final class UnixDot extends CharProperty {
 4061           boolean isSatisfiedBy(int ch) {
 4062               return ch != '\n';
 4063           }
 4064       }
 4065   
 4066       /**
 4067        * The 0 or 1 quantifier. This one class implements all three types.
 4068        */
 4069       static final class Ques extends Node {
 4070           Node atom;
 4071           int type;
 4072           Ques(Node node, int type) {
 4073               this.atom = node;
 4074               this.type = type;
 4075           }
 4076           boolean match(Matcher matcher, int i, CharSequence seq) {
 4077               switch (type) {
 4078               case GREEDY:
 4079                   return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
 4080                       || next.match(matcher, i, seq);
 4081               case LAZY:
 4082                   return next.match(matcher, i, seq)
 4083                       || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
 4084               case POSSESSIVE:
 4085                   if (atom.match(matcher, i, seq)) i = matcher.last;
 4086                   return next.match(matcher, i, seq);
 4087               default:
 4088                   return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
 4089               }
 4090           }
 4091           boolean study(TreeInfo info) {
 4092               if (type != INDEPENDENT) {
 4093                   int minL = info.minLength;
 4094                   atom.study(info);
 4095                   info.minLength = minL;
 4096                   info.deterministic = false;
 4097                   return next.study(info);
 4098               } else {
 4099                   atom.study(info);
 4100                   return next.study(info);
 4101               }
 4102           }
 4103       }
 4104   
 4105       /**
 4106        * Handles the curly-brace style repetition with a specified minimum and
 4107        * maximum occurrences. The * quantifier is handled as a special case.
 4108        * This class handles the three types.
 4109        */
 4110       static final class Curly extends Node {
 4111           Node atom;
 4112           int type;
 4113           int cmin;
 4114           int cmax;
 4115   
 4116           Curly(Node node, int cmin, int cmax, int type) {
 4117               this.atom = node;
 4118               this.type = type;
 4119               this.cmin = cmin;
 4120               this.cmax = cmax;
 4121           }
 4122           boolean match(Matcher matcher, int i, CharSequence seq) {
 4123               int j;
 4124               for (j = 0; j < cmin; j++) {
 4125                   if (atom.match(matcher, i, seq)) {
 4126                       i = matcher.last;
 4127                       continue;
 4128                   }
 4129                   return false;
 4130               }
 4131               if (type == GREEDY)
 4132                   return match0(matcher, i, j, seq);
 4133               else if (type == LAZY)
 4134                   return match1(matcher, i, j, seq);
 4135               else
 4136                   return match2(matcher, i, j, seq);
 4137           }
 4138           // Greedy match.
 4139           // i is the index to start matching at
 4140           // j is the number of atoms that have matched
 4141           boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
 4142               if (j >= cmax) {
 4143                   // We have matched the maximum... continue with the rest of
 4144                   // the regular expression
 4145                   return next.match(matcher, i, seq);
 4146               }
 4147               int backLimit = j;
 4148               while (atom.match(matcher, i, seq)) {
 4149                   // k is the length of this match
 4150                   int k = matcher.last - i;
 4151                   if (k == 0) // Zero length match
 4152                       break;
 4153                   // Move up index and number matched
 4154                   i = matcher.last;
 4155                   j++;
 4156                   // We are greedy so match as many as we can
 4157                   while (j < cmax) {
 4158                       if (!atom.match(matcher, i, seq))
 4159                           break;
 4160                       if (i + k != matcher.last) {
 4161                           if (match0(matcher, matcher.last, j+1, seq))
 4162                               return true;
 4163                           break;
 4164                       }
 4165                       i += k;
 4166                       j++;
 4167                   }
 4168                   // Handle backing off if match fails
 4169                   while (j >= backLimit) {
 4170                      if (next.match(matcher, i, seq))
 4171                           return true;
 4172                       i -= k;
 4173                       j--;
 4174                   }
 4175                   return false;
 4176               }
 4177               return next.match(matcher, i, seq);
 4178           }
 4179           // Reluctant match. At this point, the minimum has been satisfied.
 4180           // i is the index to start matching at
 4181           // j is the number of atoms that have matched
 4182           boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
 4183               for (;;) {
 4184                   // Try finishing match without consuming any more
 4185                   if (next.match(matcher, i, seq))
 4186                       return true;
 4187                   // At the maximum, no match found
 4188                   if (j >= cmax)
 4189                       return false;
 4190                   // Okay, must try one more atom
 4191                   if (!atom.match(matcher, i, seq))
 4192                       return false;
 4193                   // If we haven't moved forward then must break out
 4194                   if (i == matcher.last)
 4195                       return false;
 4196                   // Move up index and number matched
 4197                   i = matcher.last;
 4198                   j++;
 4199               }
 4200           }
 4201           boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
 4202               for (; j < cmax; j++) {
 4203                   if (!atom.match(matcher, i, seq))
 4204                       break;
 4205                   if (i == matcher.last)
 4206                       break;
 4207                   i = matcher.last;
 4208               }
 4209               return next.match(matcher, i, seq);
 4210           }
 4211           boolean study(TreeInfo info) {
 4212               // Save original info
 4213               int minL = info.minLength;
 4214               int maxL = info.maxLength;
 4215               boolean maxV = info.maxValid;
 4216               boolean detm = info.deterministic;
 4217               info.reset();
 4218   
 4219               atom.study(info);
 4220   
 4221               int temp = info.minLength * cmin + minL;
 4222               if (temp < minL) {
 4223                   temp = 0xFFFFFFF; // arbitrary large number
 4224               }
 4225               info.minLength = temp;
 4226   
 4227               if (maxV & info.maxValid) {
 4228                   temp = info.maxLength * cmax + maxL;
 4229                   info.maxLength = temp;
 4230                   if (temp < maxL) {
 4231                       info.maxValid = false;
 4232                   }
 4233               } else {
 4234                   info.maxValid = false;
 4235               }
 4236   
 4237               if (info.deterministic && cmin == cmax)
 4238                   info.deterministic = detm;
 4239               else
 4240                   info.deterministic = false;
 4241   
 4242               return next.study(info);
 4243           }
 4244       }
 4245   
 4246       /**
 4247        * Handles the curly-brace style repetition with a specified minimum and
 4248        * maximum occurrences in deterministic cases. This is an iterative
 4249        * optimization over the Prolog and Loop system which would handle this
 4250        * in a recursive way. The * quantifier is handled as a special case.
 4251        * If capture is true then this class saves group settings and ensures
 4252        * that groups are unset when backing off of a group match.
 4253        */
 4254       static final class GroupCurly extends Node {
 4255           Node atom;
 4256           int type;
 4257           int cmin;
 4258           int cmax;
 4259           int localIndex;
 4260           int groupIndex;
 4261           boolean capture;
 4262   
 4263           GroupCurly(Node node, int cmin, int cmax, int type, int local,
 4264                      int group, boolean capture) {
 4265               this.atom = node;
 4266               this.type = type;
 4267               this.cmin = cmin;
 4268               this.cmax = cmax;
 4269               this.localIndex = local;
 4270               this.groupIndex = group;
 4271               this.capture = capture;
 4272           }
 4273           boolean match(Matcher matcher, int i, CharSequence seq) {
 4274               int[] groups = matcher.groups;
 4275               int[] locals = matcher.locals;
 4276               int save0 = locals[localIndex];
 4277               int save1 = 0;
 4278               int save2 = 0;
 4279   
 4280               if (capture) {
 4281                   save1 = groups[groupIndex];
 4282                   save2 = groups[groupIndex+1];
 4283               }
 4284   
 4285               // Notify GroupTail there is no need to setup group info
 4286               // because it will be set here
 4287               locals[localIndex] = -1;
 4288   
 4289               boolean ret = true;
 4290               for (int j = 0; j < cmin; j++) {
 4291                   if (atom.match(matcher, i, seq)) {
 4292                       if (capture) {
 4293                           groups[groupIndex] = i;
 4294                           groups[groupIndex+1] = matcher.last;
 4295                       }
 4296                       i = matcher.last;
 4297                   } else {
 4298                       ret = false;
 4299                       break;
 4300                   }
 4301               }
 4302               if (ret) {
 4303                   if (type == GREEDY) {
 4304                       ret = match0(matcher, i, cmin, seq);
 4305                   } else if (type == LAZY) {
 4306                       ret = match1(matcher, i, cmin, seq);
 4307                   } else {
 4308                       ret = match2(matcher, i, cmin, seq);
 4309                   }
 4310               }
 4311               if (!ret) {
 4312                   locals[localIndex] = save0;
 4313                   if (capture) {
 4314                       groups[groupIndex] = save1;
 4315                       groups[groupIndex+1] = save2;
 4316                   }
 4317               }
 4318               return ret;
 4319           }
 4320           // Aggressive group match
 4321           boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
 4322               int[] groups = matcher.groups;
 4323               int save0 = 0;
 4324               int save1 = 0;
 4325               if (capture) {
 4326                   save0 = groups[groupIndex];
 4327                   save1 = groups[groupIndex+1];
 4328               }
 4329               for (;;) {
 4330                   if (j >= cmax)
 4331                       break;
 4332                   if (!atom.match(matcher, i, seq))
 4333                       break;
 4334                   int k = matcher.last - i;
 4335                   if (k <= 0) {
 4336                       if (capture) {
 4337                           groups[groupIndex] = i;
 4338                           groups[groupIndex+1] = i + k;
 4339                       }
 4340                       i = i + k;
 4341                       break;
 4342                   }
 4343                   for (;;) {
 4344                       if (capture) {
 4345                           groups[groupIndex] = i;
 4346                           groups[groupIndex+1] = i + k;
 4347                       }
 4348                       i = i + k;
 4349                       if (++j >= cmax)
 4350                           break;
 4351                       if (!atom.match(matcher, i, seq))
 4352                           break;
 4353                       if (i + k != matcher.last) {
 4354                           if (match0(matcher, i, j, seq))
 4355                               return true;
 4356                           break;
 4357                       }
 4358                   }
 4359                   while (j > cmin) {
 4360                       if (next.match(matcher, i, seq)) {
 4361                           if (capture) {
 4362                               groups[groupIndex+1] = i;
 4363                               groups[groupIndex] = i - k;
 4364                           }
 4365                           i = i - k;
 4366                           return true;
 4367                       }
 4368                       // backing off
 4369                       if (capture) {
 4370                           groups[groupIndex+1] = i;
 4371                           groups[groupIndex] = i - k;
 4372                       }
 4373                       i = i - k;
 4374                       j--;
 4375                   }
 4376                   break;
 4377               }
 4378               if (capture) {
 4379                   groups[groupIndex] = save0;
 4380                   groups[groupIndex+1] = save1;
 4381               }
 4382               return next.match(matcher, i, seq);
 4383           }
 4384           // Reluctant matching
 4385           boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
 4386               for (;;) {
 4387                   if (next.match(matcher, i, seq))
 4388                       return true;
 4389                   if (j >= cmax)
 4390                       return false;
 4391                   if (!atom.match(matcher, i, seq))
 4392                       return false;
 4393                   if (i == matcher.last)
 4394                       return false;
 4395                   if (capture) {
 4396                       matcher.groups[groupIndex] = i;
 4397                       matcher.groups[groupIndex+1] = matcher.last;
 4398                   }
 4399                   i = matcher.last;
 4400                   j++;
 4401               }
 4402           }
 4403           // Possessive matching
 4404           boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
 4405               for (; j < cmax; j++) {
 4406                   if (!atom.match(matcher, i, seq)) {
 4407                       break;
 4408                   }
 4409                   if (capture) {
 4410                       matcher.groups[groupIndex] = i;
 4411                       matcher.groups[groupIndex+1] = matcher.last;
 4412                   }
 4413                   if (i == matcher.last) {
 4414                       break;
 4415                   }
 4416                   i = matcher.last;
 4417               }
 4418               return next.match(matcher, i, seq);
 4419           }
 4420           boolean study(TreeInfo info) {
 4421               // Save original info
 4422               int minL = info.minLength;
 4423               int maxL = info.maxLength;
 4424               boolean maxV = info.maxValid;
 4425               boolean detm = info.deterministic;
 4426               info.reset();
 4427   
 4428               atom.study(info);
 4429   
 4430               int temp = info.minLength * cmin + minL;
 4431               if (temp < minL) {
 4432                   temp = 0xFFFFFFF; // Arbitrary large number
 4433               }
 4434               info.minLength = temp;
 4435   
 4436               if (maxV & info.maxValid) {
 4437                   temp = info.maxLength * cmax + maxL;
 4438                   info.maxLength = temp;
 4439                   if (temp < maxL) {
 4440                       info.maxValid = false;
 4441                   }
 4442               } else {
 4443                   info.maxValid = false;
 4444               }
 4445   
 4446               if (info.deterministic && cmin == cmax) {
 4447                   info.deterministic = detm;
 4448               } else {
 4449                   info.deterministic = false;
 4450               }
 4451   
 4452               return next.study(info);
 4453           }
 4454       }
 4455   
 4456       /**
 4457        * A Guard node at the end of each atom node in a Branch. It
 4458        * serves the purpose of chaining the "match" operation to
 4459        * "next" but not the "study", so we can collect the TreeInfo
 4460        * of each atom node without including the TreeInfo of the
 4461        * "next".
 4462        */
 4463       static final class BranchConn extends Node {
 4464           BranchConn() {};
 4465           boolean match(Matcher matcher, int i, CharSequence seq) {
 4466               return next.match(matcher, i, seq);
 4467           }
 4468           boolean study(TreeInfo info) {
 4469               return info.deterministic;
 4470           }
 4471       }
 4472   
 4473       /**
 4474        * Handles the branching of alternations. Note this is also used for
 4475        * the ? quantifier to branch between the case where it matches once
 4476        * and where it does not occur.
 4477        */
 4478       static final class Branch extends Node {
 4479           Node[] atoms = new Node[2];
 4480           int size = 2;
 4481           Node conn;
 4482           Branch(Node first, Node second, Node branchConn) {
 4483               conn = branchConn;
 4484               atoms[0] = first;
 4485               atoms[1] = second;
 4486           }
 4487   
 4488           void add(Node node) {
 4489               if (size >= atoms.length) {
 4490                   Node[] tmp = new Node[atoms.length*2];
 4491                   System.arraycopy(atoms, 0, tmp, 0, atoms.length);
 4492                   atoms = tmp;
 4493               }
 4494               atoms[size++] = node;
 4495           }
 4496   
 4497           boolean match(Matcher matcher, int i, CharSequence seq) {
 4498               for (int n = 0; n < size; n++) {
 4499                   if (atoms[n] == null) {
 4500                       if (conn.next.match(matcher, i, seq))
 4501                           return true;
 4502                   } else if (atoms[n].match(matcher, i, seq)) {
 4503                       return true;
 4504                   }
 4505               }
 4506               return false;
 4507           }
 4508   
 4509           boolean study(TreeInfo info) {
 4510               int minL = info.minLength;
 4511               int maxL = info.maxLength;
 4512               boolean maxV = info.maxValid;
 4513   
 4514               int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
 4515               int maxL2 = -1;
 4516               for (int n = 0; n < size; n++) {
 4517                   info.reset();
 4518                   if (atoms[n] != null)
 4519                       atoms[n].study(info);
 4520                   minL2 = Math.min(minL2, info.minLength);
 4521                   maxL2 = Math.max(maxL2, info.maxLength);
 4522                   maxV = (maxV & info.maxValid);
 4523               }
 4524   
 4525               minL += minL2;
 4526               maxL += maxL2;
 4527   
 4528               info.reset();
 4529               conn.next.study(info);
 4530   
 4531               info.minLength += minL;
 4532               info.maxLength += maxL;
 4533               info.maxValid &= maxV;
 4534               info.deterministic = false;
 4535               return false;
 4536           }
 4537       }
 4538   
 4539       /**
 4540        * The GroupHead saves the location where the group begins in the locals
 4541        * and restores them when the match is done.
 4542        *
 4543        * The matchRef is used when a reference to this group is accessed later
 4544        * in the expression. The locals will have a negative value in them to
 4545        * indicate that we do not want to unset the group if the reference
 4546        * doesn't match.
 4547        */
 4548       static final class GroupHead extends Node {
 4549           int localIndex;
 4550           GroupHead(int localCount) {
 4551               localIndex = localCount;
 4552           }
 4553           boolean match(Matcher matcher, int i, CharSequence seq) {
 4554               int save = matcher.locals[localIndex];
 4555               matcher.locals[localIndex] = i;
 4556               boolean ret = next.match(matcher, i, seq);
 4557               matcher.locals[localIndex] = save;
 4558               return ret;
 4559           }
 4560           boolean matchRef(Matcher matcher, int i, CharSequence seq) {
 4561               int save = matcher.locals[localIndex];
 4562               matcher.locals[localIndex] = ~i; // HACK
 4563               boolean ret = next.match(matcher, i, seq);
 4564               matcher.locals[localIndex] = save;
 4565               return ret;
 4566           }
 4567       }
 4568   
 4569       /**
 4570        * Recursive reference to a group in the regular expression. It calls
 4571        * matchRef because if the reference fails to match we would not unset
 4572        * the group.
 4573        */
 4574       static final class GroupRef extends Node {
 4575           GroupHead head;
 4576           GroupRef(GroupHead head) {
 4577               this.head = head;
 4578           }
 4579           boolean match(Matcher matcher, int i, CharSequence seq) {
 4580               return head.matchRef(matcher, i, seq)
 4581                   && next.match(matcher, matcher.last, seq);
 4582           }
 4583           boolean study(TreeInfo info) {
 4584               info.maxValid = false;
 4585               info.deterministic = false;
 4586               return next.study(info);
 4587           }
 4588       }
 4589   
 4590       /**
 4591        * The GroupTail handles the setting of group beginning and ending
 4592        * locations when groups are successfully matched. It must also be able to
 4593        * unset groups that have to be backed off of.
 4594        *
 4595        * The GroupTail node is also used when a previous group is referenced,
 4596        * and in that case no group information needs to be set.
 4597        */
 4598       static final class GroupTail extends Node {
 4599           int localIndex;
 4600           int groupIndex;
 4601           GroupTail(int localCount, int groupCount) {
 4602               localIndex = localCount;
 4603               groupIndex = groupCount + groupCount;
 4604           }
 4605           boolean match(Matcher matcher, int i, CharSequence seq) {
 4606               int tmp = matcher.locals[localIndex];
 4607               if (tmp >= 0) { // This is the normal group case.
 4608                   // Save the group so we can unset it if it
 4609                   // backs off of a match.
 4610                   int groupStart = matcher.groups[groupIndex];
 4611                   int groupEnd = matcher.groups[groupIndex+1];
 4612   
 4613                   matcher.groups[groupIndex] = tmp;
 4614                   matcher.groups[groupIndex+1] = i;
 4615                   if (next.match(matcher, i, seq)) {
 4616                       return true;
 4617                   }
 4618                   matcher.groups[groupIndex] = groupStart;
 4619                   matcher.groups[groupIndex+1] = groupEnd;
 4620                   return false;
 4621               } else {
 4622                   // This is a group reference case. We don't need to save any
 4623                   // group info because it isn't really a group.
 4624                   matcher.last = i;
 4625                   return true;
 4626               }
 4627           }
 4628       }
 4629   
 4630       /**
 4631        * This sets up a loop to handle a recursive quantifier structure.
 4632        */
 4633       static final class Prolog extends Node {
 4634           Loop loop;
 4635           Prolog(Loop loop) {
 4636               this.loop = loop;
 4637           }
 4638           boolean match(Matcher matcher, int i, CharSequence seq) {
 4639               return loop.matchInit(matcher, i, seq);
 4640           }
 4641           boolean study(TreeInfo info) {
 4642               return loop.study(info);
 4643           }
 4644       }
 4645   
 4646       /**
 4647        * Handles the repetition count for a greedy Curly. The matchInit
 4648        * is called from the Prolog to save the index of where the group
 4649        * beginning is stored. A zero length group check occurs in the
 4650        * normal match but is skipped in the matchInit.
 4651        */
 4652       static class Loop extends Node {
 4653           Node body;
 4654           int countIndex; // local count index in matcher locals
 4655           int beginIndex; // group beginning index
 4656           int cmin, cmax;
 4657           Loop(int countIndex, int beginIndex) {
 4658               this.countIndex = countIndex;
 4659               this.beginIndex = beginIndex;
 4660           }
 4661           boolean match(Matcher matcher, int i, CharSequence seq) {
 4662               // Avoid infinite loop in zero-length case.
 4663               if (i > matcher.locals[beginIndex]) {
 4664                   int count = matcher.locals[countIndex];
 4665   
 4666                   // This block is for before we reach the minimum
 4667                   // iterations required for the loop to match
 4668                   if (count < cmin) {
 4669                       matcher.locals[countIndex] = count + 1;
 4670                       boolean b = body.match(matcher, i, seq);
 4671                       // If match failed we must backtrack, so
 4672                       // the loop count should NOT be incremented
 4673                       if (!b)
 4674                           matcher.locals[countIndex] = count;
 4675                       // Return success or failure since we are under
 4676                       // minimum
 4677                       return b;
 4678                   }
 4679                   // This block is for after we have the minimum
 4680                   // iterations required for the loop to match
 4681                   if (count < cmax) {
 4682                       matcher.locals[countIndex] = count + 1;
 4683                       boolean b = body.match(matcher, i, seq);
 4684                       // If match failed we must backtrack, so
 4685                       // the loop count should NOT be incremented
 4686                       if (!b)
 4687                           matcher.locals[countIndex] = count;
 4688                       else
 4689                           return true;
 4690                   }
 4691               }
 4692               return next.match(matcher, i, seq);
 4693           }
 4694           boolean matchInit(Matcher matcher, int i, CharSequence seq) {
 4695               int save = matcher.locals[countIndex];
 4696               boolean ret = false;
 4697               if (0 < cmin) {
 4698                   matcher.locals[countIndex] = 1;
 4699                   ret = body.match(matcher, i, seq);
 4700               } else if (0 < cmax) {
 4701                   matcher.locals[countIndex] = 1;
 4702                   ret = body.match(matcher, i, seq);
 4703                   if (ret == false)
 4704                       ret = next.match(matcher, i, seq);
 4705               } else {
 4706                   ret = next.match(matcher, i, seq);
 4707               }
 4708               matcher.locals[countIndex] = save;
 4709               return ret;
 4710           }
 4711           boolean study(TreeInfo info) {
 4712               info.maxValid = false;
 4713               info.deterministic = false;
 4714               return false;
 4715           }
 4716       }
 4717   
 4718       /**
 4719        * Handles the repetition count for a reluctant Curly. The matchInit
 4720        * is called from the Prolog to save the index of where the group
 4721        * beginning is stored. A zero length group check occurs in the
 4722        * normal match but is skipped in the matchInit.
 4723        */
 4724       static final class LazyLoop extends Loop {
 4725           LazyLoop(int countIndex, int beginIndex) {
 4726               super(countIndex, beginIndex);
 4727           }
 4728           boolean match(Matcher matcher, int i, CharSequence seq) {
 4729               // Check for zero length group
 4730               if (i > matcher.locals[beginIndex]) {
 4731                   int count = matcher.locals[countIndex];
 4732                   if (count < cmin) {
 4733                       matcher.locals[countIndex] = count + 1;
 4734                       boolean result = body.match(matcher, i, seq);
 4735                       // If match failed we must backtrack, so
 4736                       // the loop count should NOT be incremented
 4737                       if (!result)
 4738                           matcher.locals[countIndex] = count;
 4739                       return result;
 4740                   }
 4741                   if (next.match(matcher, i, seq))
 4742                       return true;
 4743                   if (count < cmax) {
 4744                       matcher.locals[countIndex] = count + 1;
 4745                       boolean result = body.match(matcher, i, seq);
 4746                       // If match failed we must backtrack, so
 4747                       // the loop count should NOT be incremented
 4748                       if (!result)
 4749                           matcher.locals[countIndex] = count;
 4750                       return result;
 4751                   }
 4752                   return false;
 4753               }
 4754               return next.match(matcher, i, seq);
 4755           }
 4756           boolean matchInit(Matcher matcher, int i, CharSequence seq) {
 4757               int save = matcher.locals[countIndex];
 4758               boolean ret = false;
 4759               if (0 < cmin) {
 4760                   matcher.locals[countIndex] = 1;
 4761                   ret = body.match(matcher, i, seq);
 4762               } else if (next.match(matcher, i, seq)) {
 4763                   ret = true;
 4764               } else if (0 < cmax) {
 4765                   matcher.locals[countIndex] = 1;
 4766                   ret = body.match(matcher, i, seq);
 4767               }
 4768               matcher.locals[countIndex] = save;
 4769               return ret;
 4770           }
 4771           boolean study(TreeInfo info) {
 4772               info.maxValid = false;
 4773               info.deterministic = false;
 4774               return false;
 4775           }
 4776       }
 4777   
 4778       /**
 4779        * Refers to a group in the regular expression. Attempts to match
 4780        * whatever the group referred to last matched.
 4781        */
 4782       static class BackRef extends Node {
 4783           int groupIndex;
 4784           BackRef(int groupCount) {
 4785               super();
 4786               groupIndex = groupCount + groupCount;
 4787           }
 4788           boolean match(Matcher matcher, int i, CharSequence seq) {
 4789               int j = matcher.groups[groupIndex];
 4790               int k = matcher.groups[groupIndex+1];
 4791   
 4792               int groupSize = k - j;
 4793   
 4794               // If the referenced group didn't match, neither can this
 4795               if (j < 0)
 4796                   return false;
 4797   
 4798               // If there isn't enough input left no match
 4799               if (i + groupSize > matcher.to) {
 4800                   matcher.hitEnd = true;
 4801                   return false;
 4802               }
 4803   
 4804               // Check each new char to make sure it matches what the group
 4805               // referenced matched last time around
 4806               for (int index=0; index<groupSize; index++)
 4807                   if (seq.charAt(i+index) != seq.charAt(j+index))
 4808                       return false;
 4809   
 4810               return next.match(matcher, i+groupSize, seq);
 4811           }
 4812           boolean study(TreeInfo info) {
 4813               info.maxValid = false;
 4814               return next.study(info);
 4815           }
 4816       }
 4817   
 4818       static class CIBackRef extends Node {
 4819           int groupIndex;
 4820           boolean doUnicodeCase;
 4821           CIBackRef(int groupCount, boolean doUnicodeCase) {
 4822               super();
 4823               groupIndex = groupCount + groupCount;
 4824               this.doUnicodeCase = doUnicodeCase;
 4825           }
 4826           boolean match(Matcher matcher, int i, CharSequence seq) {
 4827               int j = matcher.groups[groupIndex];
 4828               int k = matcher.groups[groupIndex+1];
 4829   
 4830               int groupSize = k - j;
 4831   
 4832               // If the referenced group didn't match, neither can this
 4833               if (j < 0)
 4834                   return false;
 4835   
 4836               // If there isn't enough input left no match
 4837               if (i + groupSize > matcher.to) {
 4838                   matcher.hitEnd = true;
 4839                   return false;
 4840               }
 4841   
 4842               // Check each new char to make sure it matches what the group
 4843               // referenced matched last time around
 4844               int x = i;
 4845               for (int index=0; index<groupSize; index++) {
 4846                   int c1 = Character.codePointAt(seq, x);
 4847                   int c2 = Character.codePointAt(seq, j);
 4848                   if (c1 != c2) {
 4849                       if (doUnicodeCase) {
 4850                           int cc1 = Character.toUpperCase(c1);
 4851                           int cc2 = Character.toUpperCase(c2);
 4852                           if (cc1 != cc2 &&
 4853                               Character.toLowerCase(cc1) !=
 4854                               Character.toLowerCase(cc2))
 4855                               return false;
 4856                       } else {
 4857                           if (ASCII.toLower(c1) != ASCII.toLower(c2))
 4858                               return false;
 4859                       }
 4860                   }
 4861                   x += Character.charCount(c1);
 4862                   j += Character.charCount(c2);
 4863               }
 4864   
 4865               return next.match(matcher, i+groupSize, seq);
 4866           }
 4867           boolean study(TreeInfo info) {
 4868               info.maxValid = false;
 4869               return next.study(info);
 4870           }
 4871       }
 4872   
 4873       /**
 4874        * Searches until the next instance of its atom. This is useful for
 4875        * finding the atom efficiently without passing an instance of it
 4876        * (greedy problem) and without a lot of wasted search time (reluctant
 4877        * problem).
 4878        */
 4879       static final class First extends Node {
 4880           Node atom;
 4881           First(Node node) {
 4882               this.atom = BnM.optimize(node);
 4883           }
 4884           boolean match(Matcher matcher, int i, CharSequence seq) {
 4885               if (atom instanceof BnM) {
 4886                   return atom.match(matcher, i, seq)
 4887                       && next.match(matcher, matcher.last, seq);
 4888               }
 4889               for (;;) {
 4890                   if (i > matcher.to) {
 4891                       matcher.hitEnd = true;
 4892                       return false;
 4893                   }
 4894                   if (atom.match(matcher, i, seq)) {
 4895                       return next.match(matcher, matcher.last, seq);
 4896                   }
 4897                   i += countChars(seq, i, 1);
 4898                   matcher.first++;
 4899               }
 4900           }
 4901           boolean study(TreeInfo info) {
 4902               atom.study(info);
 4903               info.maxValid = false;
 4904               info.deterministic = false;
 4905               return next.study(info);
 4906           }
 4907       }
 4908   
 4909       static final class Conditional extends Node {
 4910           Node cond, yes, not;
 4911           Conditional(Node cond, Node yes, Node not) {
 4912               this.cond = cond;
 4913               this.yes = yes;
 4914               this.not = not;
 4915           }
 4916           boolean match(Matcher matcher, int i, CharSequence seq) {
 4917               if (cond.match(matcher, i, seq)) {
 4918                   return yes.match(matcher, i, seq);
 4919               } else {
 4920                   return not.match(matcher, i, seq);
 4921               }
 4922           }
 4923           boolean study(TreeInfo info) {
 4924               int minL = info.minLength;
 4925               int maxL = info.maxLength;
 4926               boolean maxV = info.maxValid;
 4927               info.reset();
 4928               yes.study(info);
 4929   
 4930               int minL2 = info.minLength;
 4931               int maxL2 = info.maxLength;
 4932               boolean maxV2 = info.maxValid;
 4933               info.reset();
 4934               not.study(info);
 4935   
 4936               info.minLength = minL + Math.min(minL2, info.minLength);
 4937               info.maxLength = maxL + Math.max(maxL2, info.maxLength);
 4938               info.maxValid = (maxV & maxV2 & info.maxValid);
 4939               info.deterministic = false;
 4940               return next.study(info);
 4941           }
 4942       }
 4943   
 4944       /**
 4945        * Zero width positive lookahead.
 4946        */
 4947       static final class Pos extends Node {
 4948           Node cond;
 4949           Pos(Node cond) {
 4950               this.cond = cond;
 4951           }
 4952           boolean match(Matcher matcher, int i, CharSequence seq) {
 4953               int savedTo = matcher.to;
 4954               boolean conditionMatched = false;
 4955   
 4956               // Relax transparent region boundaries for lookahead
 4957               if (matcher.transparentBounds)
 4958                   matcher.to = matcher.getTextLength();
 4959               try {
 4960                   conditionMatched = cond.match(matcher, i, seq);
 4961               } finally {
 4962                   // Reinstate region boundaries
 4963                   matcher.to = savedTo;
 4964               }
 4965               return conditionMatched && next.match(matcher, i, seq);
 4966           }
 4967       }
 4968   
 4969       /**
 4970        * Zero width negative lookahead.
 4971        */
 4972       static final class Neg extends Node {
 4973           Node cond;
 4974           Neg(Node cond) {
 4975               this.cond = cond;
 4976           }
 4977           boolean match(Matcher matcher, int i, CharSequence seq) {
 4978               int savedTo = matcher.to;
 4979               boolean conditionMatched = false;
 4980   
 4981               // Relax transparent region boundaries for lookahead
 4982               if (matcher.transparentBounds)
 4983                   matcher.to = matcher.getTextLength();
 4984               try {
 4985                   if (i < matcher.to) {
 4986                       conditionMatched = !cond.match(matcher, i, seq);
 4987                   } else {
 4988                       // If a negative lookahead succeeds then more input
 4989                       // could cause it to fail!
 4990                       matcher.requireEnd = true;
 4991                       conditionMatched = !cond.match(matcher, i, seq);
 4992                   }
 4993               } finally {
 4994                   // Reinstate region boundaries
 4995                   matcher.to = savedTo;
 4996               }
 4997               return conditionMatched && next.match(matcher, i, seq);
 4998           }
 4999       }
 5000   
 5001       /**
 5002        * For use with lookbehinds; matches the position where the lookbehind
 5003        * was encountered.
 5004        */
 5005       static Node lookbehindEnd = new Node() {
 5006           boolean match(Matcher matcher, int i, CharSequence seq) {
 5007               return i == matcher.lookbehindTo;
 5008           }
 5009       };
 5010   
 5011       /**
 5012        * Zero width positive lookbehind.
 5013        */
 5014       static class Behind extends Node {
 5015           Node cond;
 5016           int rmax, rmin;
 5017           Behind(Node cond, int rmax, int rmin) {
 5018               this.cond = cond;
 5019               this.rmax = rmax;
 5020               this.rmin = rmin;
 5021           }
 5022   
 5023           boolean match(Matcher matcher, int i, CharSequence seq) {
 5024               int savedFrom = matcher.from;
 5025               boolean conditionMatched = false;
 5026               int startIndex = (!matcher.transparentBounds) ?
 5027                                matcher.from : 0;
 5028               int from = Math.max(i - rmax, startIndex);
 5029               // Set end boundary
 5030               int savedLBT = matcher.lookbehindTo;
 5031               matcher.lookbehindTo = i;
 5032               // Relax transparent region boundaries for lookbehind
 5033               if (matcher.transparentBounds)
 5034                   matcher.from = 0;
 5035               for (int j = i - rmin; !conditionMatched && j >= from; j--) {
 5036                   conditionMatched = cond.match(matcher, j, seq);
 5037               }
 5038               matcher.from = savedFrom;
 5039               matcher.lookbehindTo = savedLBT;
 5040               return conditionMatched && next.match(matcher, i, seq);
 5041           }
 5042       }
 5043   
 5044       /**
 5045        * Zero width positive lookbehind, including supplementary
 5046        * characters or unpaired surrogates.
 5047        */
 5048       static final class BehindS extends Behind {
 5049           BehindS(Node cond, int rmax, int rmin) {
 5050               super(cond, rmax, rmin);
 5051           }
 5052           boolean match(Matcher matcher, int i, CharSequence seq) {
 5053               int rmaxChars = countChars(seq, i, -rmax);
 5054               int rminChars = countChars(seq, i, -rmin);
 5055               int savedFrom = matcher.from;
 5056               int startIndex = (!matcher.transparentBounds) ?
 5057                                matcher.from : 0;
 5058               boolean conditionMatched = false;
 5059               int from = Math.max(i - rmaxChars, startIndex);
 5060               // Set end boundary
 5061               int savedLBT = matcher.lookbehindTo;
 5062               matcher.lookbehindTo = i;
 5063               // Relax transparent region boundaries for lookbehind
 5064               if (matcher.transparentBounds)
 5065                   matcher.from = 0;
 5066   
 5067               for (int j = i - rminChars;
 5068                    !conditionMatched && j >= from;
 5069                    j -= j>from ? countChars(seq, j, -1) : 1) {
 5070                   conditionMatched = cond.match(matcher, j, seq);
 5071               }
 5072               matcher.from = savedFrom;
 5073               matcher.lookbehindTo = savedLBT;
 5074               return conditionMatched && next.match(matcher, i, seq);
 5075           }
 5076       }
 5077   
 5078       /**
 5079        * Zero width negative lookbehind.
 5080        */
 5081       static class NotBehind extends Node {
 5082           Node cond;
 5083           int rmax, rmin;
 5084           NotBehind(Node cond, int rmax, int rmin) {
 5085               this.cond = cond;
 5086               this.rmax = rmax;
 5087               this.rmin = rmin;
 5088           }
 5089   
 5090           boolean match(Matcher matcher, int i, CharSequence seq) {
 5091               int savedLBT = matcher.lookbehindTo;
 5092               int savedFrom = matcher.from;
 5093               boolean conditionMatched = false;
 5094               int startIndex = (!matcher.transparentBounds) ?
 5095                                matcher.from : 0;
 5096               int from = Math.max(i - rmax, startIndex);
 5097               matcher.lookbehindTo = i;
 5098               // Relax transparent region boundaries for lookbehind
 5099               if (matcher.transparentBounds)
 5100                   matcher.from = 0;
 5101               for (int j = i - rmin; !conditionMatched && j >= from; j--) {
 5102                   conditionMatched = cond.match(matcher, j, seq);
 5103               }
 5104               // Reinstate region boundaries
 5105               matcher.from = savedFrom;
 5106               matcher.lookbehindTo = savedLBT;
 5107               return !conditionMatched && next.match(matcher, i, seq);
 5108           }
 5109       }
 5110   
 5111       /**
 5112        * Zero width negative lookbehind, including supplementary
 5113        * characters or unpaired surrogates.
 5114        */
 5115       static final class NotBehindS extends NotBehind {
 5116           NotBehindS(Node cond, int rmax, int rmin) {
 5117               super(cond, rmax, rmin);
 5118           }
 5119           boolean match(Matcher matcher, int i, CharSequence seq) {
 5120               int rmaxChars = countChars(seq, i, -rmax);
 5121               int rminChars = countChars(seq, i, -rmin);
 5122               int savedFrom = matcher.from;
 5123               int savedLBT = matcher.lookbehindTo;
 5124               boolean conditionMatched = false;
 5125               int startIndex = (!matcher.transparentBounds) ?
 5126                                matcher.from : 0;
 5127               int from = Math.max(i - rmaxChars, startIndex);
 5128               matcher.lookbehindTo = i;
 5129               // Relax transparent region boundaries for lookbehind
 5130               if (matcher.transparentBounds)
 5131                   matcher.from = 0;
 5132               for (int j = i - rminChars;
 5133                    !conditionMatched && j >= from;
 5134                    j -= j>from ? countChars(seq, j, -1) : 1) {
 5135                   conditionMatched = cond.match(matcher, j, seq);
 5136               }
 5137               //Reinstate region boundaries
 5138               matcher.from = savedFrom;
 5139               matcher.lookbehindTo = savedLBT;
 5140               return !conditionMatched && next.match(matcher, i, seq);
 5141           }
 5142       }
 5143   
 5144       /**
 5145        * Returns the set union of two CharProperty nodes.
 5146        */
 5147       private static CharProperty union(final CharProperty lhs,
 5148                                         final CharProperty rhs) {
 5149           return new CharProperty() {
 5150                   boolean isSatisfiedBy(int ch) {
 5151                       return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
 5152       }
 5153   
 5154       /**
 5155        * Returns the set intersection of two CharProperty nodes.
 5156        */
 5157       private static CharProperty intersection(final CharProperty lhs,
 5158                                                final CharProperty rhs) {
 5159           return new CharProperty() {
 5160                   boolean isSatisfiedBy(int ch) {
 5161                       return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
 5162       }
 5163   
 5164       /**
 5165        * Returns the set difference of two CharProperty nodes.
 5166        */
 5167       private static CharProperty setDifference(final CharProperty lhs,
 5168                                                 final CharProperty rhs) {
 5169           return new CharProperty() {
 5170                   boolean isSatisfiedBy(int ch) {
 5171                       return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
 5172       }
 5173   
 5174       /**
 5175        * Handles word boundaries. Includes a field to allow this one class to
 5176        * deal with the different types of word boundaries we can match. The word
 5177        * characters include underscores, letters, and digits. Non spacing marks
 5178        * can are also part of a word if they have a base character, otherwise
 5179        * they are ignored for purposes of finding word boundaries.
 5180        */
 5181       static final class Bound extends Node {
 5182           static int LEFT = 0x1;
 5183           static int RIGHT= 0x2;
 5184           static int BOTH = 0x3;
 5185           static int NONE = 0x4;
 5186           int type;
 5187           boolean useUWORD;
 5188           Bound(int n, boolean useUWORD) {
 5189               type = n;
 5190               this.useUWORD = useUWORD;
 5191           }
 5192   
 5193           boolean isWord(int ch) {
 5194               return useUWORD ? UnicodeProp.WORD.is(ch)
 5195                               : (ch == '_' || Character.isLetterOrDigit(ch));
 5196           }
 5197   
 5198           int check(Matcher matcher, int i, CharSequence seq) {
 5199               int ch;
 5200               boolean left = false;
 5201               int startIndex = matcher.from;
 5202               int endIndex = matcher.to;
 5203               if (matcher.transparentBounds) {
 5204                   startIndex = 0;
 5205                   endIndex = matcher.getTextLength();
 5206               }
 5207               if (i > startIndex) {
 5208                   ch = Character.codePointBefore(seq, i);
 5209                   left = (isWord(ch) ||
 5210                       ((Character.getType(ch) == Character.NON_SPACING_MARK)
 5211                        && hasBaseCharacter(matcher, i-1, seq)));
 5212               }
 5213               boolean right = false;
 5214               if (i < endIndex) {
 5215                   ch = Character.codePointAt(seq, i);
 5216                   right = (isWord(ch) ||
 5217                       ((Character.getType(ch) == Character.NON_SPACING_MARK)
 5218                        && hasBaseCharacter(matcher, i, seq)));
 5219               } else {
 5220                   // Tried to access char past the end
 5221                   matcher.hitEnd = true;
 5222                   // The addition of another char could wreck a boundary
 5223                   matcher.requireEnd = true;
 5224               }
 5225               return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
 5226           }
 5227           boolean match(Matcher matcher, int i, CharSequence seq) {
 5228               return (check(matcher, i, seq) & type) > 0
 5229                   && next.match(matcher, i, seq);
 5230           }
 5231       }
 5232   
 5233       /**
 5234        * Non spacing marks only count as word characters in bounds calculations
 5235        * if they have a base character.
 5236        */
 5237       private static boolean hasBaseCharacter(Matcher matcher, int i,
 5238                                               CharSequence seq)
 5239       {
 5240           int start = (!matcher.transparentBounds) ?
 5241               matcher.from : 0;
 5242           for (int x=i; x >= start; x--) {
 5243               int ch = Character.codePointAt(seq, x);
 5244               if (Character.isLetterOrDigit(ch))
 5245                   return true;
 5246               if (Character.getType(ch) == Character.NON_SPACING_MARK)
 5247                   continue;
 5248               return false;
 5249           }
 5250           return false;
 5251       }
 5252   
 5253       /**
 5254        * Attempts to match a slice in the input using the Boyer-Moore string
 5255        * matching algorithm. The algorithm is based on the idea that the
 5256        * pattern can be shifted farther ahead in the search text if it is
 5257        * matched right to left.
 5258        * <p>
 5259        * The pattern is compared to the input one character at a time, from
 5260        * the rightmost character in the pattern to the left. If the characters
 5261        * all match the pattern has been found. If a character does not match,
 5262        * the pattern is shifted right a distance that is the maximum of two
 5263        * functions, the bad character shift and the good suffix shift. This
 5264        * shift moves the attempted match position through the input more
 5265        * quickly than a naive one position at a time check.
 5266        * <p>
 5267        * The bad character shift is based on the character from the text that
 5268        * did not match. If the character does not appear in the pattern, the
 5269        * pattern can be shifted completely beyond the bad character. If the
 5270        * character does occur in the pattern, the pattern can be shifted to
 5271        * line the pattern up with the next occurrence of that character.
 5272        * <p>
 5273        * The good suffix shift is based on the idea that some subset on the right
 5274        * side of the pattern has matched. When a bad character is found, the
 5275        * pattern can be shifted right by the pattern length if the subset does
 5276        * not occur again in pattern, or by the amount of distance to the
 5277        * next occurrence of the subset in the pattern.
 5278        *
 5279        * Boyer-Moore search methods adapted from code by Amy Yu.
 5280        */
 5281       static class BnM extends Node {
 5282           int[] buffer;
 5283           int[] lastOcc;
 5284           int[] optoSft;
 5285   
 5286           /**
 5287            * Pre calculates arrays needed to generate the bad character
 5288            * shift and the good suffix shift. Only the last seven bits
 5289            * are used to see if chars match; This keeps the tables small
 5290            * and covers the heavily used ASCII range, but occasionally
 5291            * results in an aliased match for the bad character shift.
 5292            */
 5293           static Node optimize(Node node) {
 5294               if (!(node instanceof Slice)) {
 5295                   return node;
 5296               }
 5297   
 5298               int[] src = ((Slice) node).buffer;
 5299               int patternLength = src.length;
 5300               // The BM algorithm requires a bit of overhead;
 5301               // If the pattern is short don't use it, since
 5302               // a shift larger than the pattern length cannot
 5303               // be used anyway.
 5304               if (patternLength < 4) {
 5305                   return node;
 5306               }
 5307               int i, j, k;
 5308               int[] lastOcc = new int[128];
 5309               int[] optoSft = new int[patternLength];
 5310               // Precalculate part of the bad character shift
 5311               // It is a table for where in the pattern each
 5312               // lower 7-bit value occurs
 5313               for (i = 0; i < patternLength; i++) {
 5314                   lastOcc[src[i]&0x7F] = i + 1;
 5315               }
 5316               // Precalculate the good suffix shift
 5317               // i is the shift amount being considered
 5318   NEXT:       for (i = patternLength; i > 0; i--) {
 5319                   // j is the beginning index of suffix being considered
 5320                   for (j = patternLength - 1; j >= i; j--) {
 5321                       // Testing for good suffix
 5322                       if (src[j] == src[j-i]) {
 5323                           // src[j..len] is a good suffix
 5324                           optoSft[j-1] = i;
 5325                       } else {
 5326                           // No match. The array has already been
 5327                           // filled up with correct values before.
 5328                           continue NEXT;
 5329                       }
 5330                   }
 5331                   // This fills up the remaining of optoSft
 5332                   // any suffix can not have larger shift amount
 5333                   // then its sub-suffix. Why???
 5334                   while (j > 0) {
 5335                       optoSft[--j] = i;
 5336                   }
 5337               }
 5338               // Set the guard value because of unicode compression
 5339               optoSft[patternLength-1] = 1;
 5340               if (node instanceof SliceS)
 5341                   return new BnMS(src, lastOcc, optoSft, node.next);
 5342               return new BnM(src, lastOcc, optoSft, node.next);
 5343           }
 5344           BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
 5345               this.buffer = src;
 5346               this.lastOcc = lastOcc;
 5347               this.optoSft = optoSft;
 5348               this.next = next;
 5349           }
 5350           boolean match(Matcher matcher, int i, CharSequence seq) {
 5351               int[] src = buffer;
 5352               int patternLength = src.length;
 5353               int last = matcher.to - patternLength;
 5354   
 5355               // Loop over all possible match positions in text
 5356   NEXT:       while (i <= last) {
 5357                   // Loop over pattern from right to left
 5358                   for (int j = patternLength - 1; j >= 0; j--) {
 5359                       int ch = seq.charAt(i+j);
 5360                       if (ch != src[j]) {
 5361                           // Shift search to the right by the maximum of the
 5362                           // bad character shift and the good suffix shift
 5363                           i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
 5364                           continue NEXT;
 5365                       }
 5366                   }
 5367                   // Entire pattern matched starting at i
 5368                   matcher.first = i;
 5369                   boolean ret = next.match(matcher, i + patternLength, seq);
 5370                   if (ret) {
 5371                       matcher.first = i;
 5372                       matcher.groups[0] = matcher.first;
 5373                       matcher.groups[1] = matcher.last;
 5374                       return true;
 5375                   }
 5376                   i++;
 5377               }
 5378               // BnM is only used as the leading node in the unanchored case,
 5379               // and it replaced its Start() which always searches to the end
 5380               // if it doesn't find what it's looking for, so hitEnd is true.
 5381               matcher.hitEnd = true;
 5382               return false;
 5383           }
 5384           boolean study(TreeInfo info) {
 5385               info.minLength += buffer.length;
 5386               info.maxValid = false;
 5387               return next.study(info);
 5388           }
 5389       }
 5390   
 5391       /**
 5392        * Supplementary support version of BnM(). Unpaired surrogates are
 5393        * also handled by this class.
 5394        */
 5395       static final class BnMS extends BnM {
 5396           int lengthInChars;
 5397   
 5398           BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
 5399               super(src, lastOcc, optoSft, next);
 5400               for (int x = 0; x < buffer.length; x++) {
 5401                   lengthInChars += Character.charCount(buffer[x]);
 5402               }
 5403           }
 5404           boolean match(Matcher matcher, int i, CharSequence seq) {
 5405               int[] src = buffer;
 5406               int patternLength = src.length;
 5407               int last = matcher.to - lengthInChars;
 5408   
 5409               // Loop over all possible match positions in text
 5410   NEXT:       while (i <= last) {
 5411                   // Loop over pattern from right to left
 5412                   int ch;
 5413                   for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
 5414                        j > 0; j -= Character.charCount(ch), x--) {
 5415                       ch = Character.codePointBefore(seq, i+j);
 5416                       if (ch != src[x]) {
 5417                           // Shift search to the right by the maximum of the
 5418                           // bad character shift and the good suffix shift
 5419                           int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
 5420                           i += countChars(seq, i, n);
 5421                           continue NEXT;
 5422                       }
 5423                   }
 5424                   // Entire pattern matched starting at i
 5425                   matcher.first = i;
 5426                   boolean ret = next.match(matcher, i + lengthInChars, seq);
 5427                   if (ret) {
 5428                       matcher.first = i;
 5429                       matcher.groups[0] = matcher.first;
 5430                       matcher.groups[1] = matcher.last;
 5431                       return true;
 5432                   }
 5433                   i += countChars(seq, i, 1);
 5434               }
 5435               matcher.hitEnd = true;
 5436               return false;
 5437           }
 5438       }
 5439   
 5440   ///////////////////////////////////////////////////////////////////////////////
 5441   ///////////////////////////////////////////////////////////////////////////////
 5442   
 5443       /**
 5444        *  This must be the very first initializer.
 5445        */
 5446       static Node accept = new Node();
 5447   
 5448       static Node lastAccept = new LastNode();
 5449   
 5450       private static class CharPropertyNames {
 5451   
 5452           static CharProperty charPropertyFor(String name) {
 5453               CharPropertyFactory m = map.get(name);
 5454               return m == null ? null : m.make();
 5455           }
 5456   
 5457           private static abstract class CharPropertyFactory {
 5458               abstract CharProperty make();
 5459           }
 5460   
 5461           private static void defCategory(String name,
 5462                                           final int typeMask) {
 5463               map.put(name, new CharPropertyFactory() {
 5464                       CharProperty make() { return new Category(typeMask);}});
 5465           }
 5466   
 5467           private static void defRange(String name,
 5468                                        final int lower, final int upper) {
 5469               map.put(name, new CharPropertyFactory() {
 5470                       CharProperty make() { return rangeFor(lower, upper);}});
 5471           }
 5472   
 5473           private static void defCtype(String name,
 5474                                        final int ctype) {
 5475               map.put(name, new CharPropertyFactory() {
 5476                       CharProperty make() { return new Ctype(ctype);}});
 5477           }
 5478   
 5479           private static abstract class CloneableProperty
 5480               extends CharProperty implements Cloneable
 5481           {
 5482               public CloneableProperty clone() {
 5483                   try {
 5484                       return (CloneableProperty) super.clone();
 5485                   } catch (CloneNotSupportedException e) {
 5486                       throw new AssertionError(e);
 5487                   }
 5488               }
 5489           }
 5490   
 5491           private static void defClone(String name,
 5492                                        final CloneableProperty p) {
 5493               map.put(name, new CharPropertyFactory() {
 5494                       CharProperty make() { return p.clone();}});
 5495           }
 5496   
 5497           private static final HashMap<String, CharPropertyFactory> map
 5498               = new HashMap<>();
 5499   
 5500           static {
 5501               // Unicode character property aliases, defined in
 5502               // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
 5503               defCategory("Cn", 1<<Character.UNASSIGNED);
 5504               defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
 5505               defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
 5506               defCategory("Lt", 1<<Character.TITLECASE_LETTER);
 5507               defCategory("Lm", 1<<Character.MODIFIER_LETTER);
 5508               defCategory("Lo", 1<<Character.OTHER_LETTER);
 5509               defCategory("Mn", 1<<Character.NON_SPACING_MARK);
 5510               defCategory("Me", 1<<Character.ENCLOSING_MARK);
 5511               defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
 5512               defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
 5513               defCategory("Nl", 1<<Character.LETTER_NUMBER);
 5514               defCategory("No", 1<<Character.OTHER_NUMBER);
 5515               defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
 5516               defCategory("Zl", 1<<Character.LINE_SEPARATOR);
 5517               defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
 5518               defCategory("Cc", 1<<Character.CONTROL);
 5519               defCategory("Cf", 1<<Character.FORMAT);
 5520               defCategory("Co", 1<<Character.PRIVATE_USE);
 5521               defCategory("Cs", 1<<Character.SURROGATE);
 5522               defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
 5523               defCategory("Ps", 1<<Character.START_PUNCTUATION);
 5524               defCategory("Pe", 1<<Character.END_PUNCTUATION);
 5525               defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
 5526               defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
 5527               defCategory("Sm", 1<<Character.MATH_SYMBOL);
 5528               defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
 5529               defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
 5530               defCategory("So", 1<<Character.OTHER_SYMBOL);
 5531               defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
 5532               defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
 5533               defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
 5534                                 (1<<Character.LOWERCASE_LETTER) |
 5535                                 (1<<Character.TITLECASE_LETTER) |
 5536                                 (1<<Character.MODIFIER_LETTER)  |
 5537                                 (1<<Character.OTHER_LETTER)));
 5538               defCategory("M", ((1<<Character.NON_SPACING_MARK) |
 5539                                 (1<<Character.ENCLOSING_MARK)   |
 5540                                 (1<<Character.COMBINING_SPACING_MARK)));
 5541               defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
 5542                                 (1<<Character.LETTER_NUMBER)        |
 5543                                 (1<<Character.OTHER_NUMBER)));
 5544               defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
 5545                                 (1<<Character.LINE_SEPARATOR)  |
 5546                                 (1<<Character.PARAGRAPH_SEPARATOR)));
 5547               defCategory("C", ((1<<Character.CONTROL)     |
 5548                                 (1<<Character.FORMAT)      |
 5549                                 (1<<Character.PRIVATE_USE) |
 5550                                 (1<<Character.SURROGATE))); // Other
 5551               defCategory("P", ((1<<Character.DASH_PUNCTUATION)      |
 5552                                 (1<<Character.START_PUNCTUATION)     |
 5553                                 (1<<Character.END_PUNCTUATION)       |
 5554                                 (1<<Character.CONNECTOR_PUNCTUATION) |
 5555                                 (1<<Character.OTHER_PUNCTUATION)     |
 5556                                 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
 5557                                 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
 5558               defCategory("S", ((1<<Character.MATH_SYMBOL)     |
 5559                                 (1<<Character.CURRENCY_SYMBOL) |
 5560                                 (1<<Character.MODIFIER_SYMBOL) |
 5561                                 (1<<Character.OTHER_SYMBOL)));
 5562               defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
 5563                                  (1<<Character.LOWERCASE_LETTER) |
 5564                                  (1<<Character.TITLECASE_LETTER)));
 5565               defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
 5566                                  (1<<Character.LOWERCASE_LETTER) |
 5567                                  (1<<Character.TITLECASE_LETTER) |
 5568                                  (1<<Character.MODIFIER_LETTER)  |
 5569                                  (1<<Character.OTHER_LETTER)     |
 5570                                  (1<<Character.DECIMAL_DIGIT_NUMBER)));
 5571               defRange("L1", 0x00, 0xFF); // Latin-1
 5572               map.put("all", new CharPropertyFactory() {
 5573                       CharProperty make() { return new All(); }});
 5574   
 5575               // Posix regular expression character classes, defined in
 5576               // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
 5577               defRange("ASCII", 0x00, 0x7F);   // ASCII
 5578               defCtype("Alnum", ASCII.ALNUM);  // Alphanumeric characters
 5579               defCtype("Alpha", ASCII.ALPHA);  // Alphabetic characters
 5580               defCtype("Blank", ASCII.BLANK);  // Space and tab characters
 5581               defCtype("Cntrl", ASCII.CNTRL);  // Control characters
 5582               defRange("Digit", '0', '9');     // Numeric characters
 5583               defCtype("Graph", ASCII.GRAPH);  // printable and visible
 5584               defRange("Lower", 'a', 'z');     // Lower-case alphabetic
 5585               defRange("Print", 0x20, 0x7E);   // Printable characters
 5586               defCtype("Punct", ASCII.PUNCT);  // Punctuation characters
 5587               defCtype("Space", ASCII.SPACE);  // Space characters
 5588               defRange("Upper", 'A', 'Z');     // Upper-case alphabetic
 5589               defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
 5590   
 5591               // Java character properties, defined by methods in Character.java
 5592               defClone("javaLowerCase", new CloneableProperty() {
 5593                   boolean isSatisfiedBy(int ch) {
 5594                       return Character.isLowerCase(ch);}});
 5595               defClone("javaUpperCase", new CloneableProperty() {
 5596                   boolean isSatisfiedBy(int ch) {
 5597                       return Character.isUpperCase(ch);}});
 5598               defClone("javaAlphabetic", new CloneableProperty() {
 5599                   boolean isSatisfiedBy(int ch) {
 5600                       return Character.isAlphabetic(ch);}});
 5601               defClone("javaIdeographic", new CloneableProperty() {
 5602                   boolean isSatisfiedBy(int ch) {
 5603                       return Character.isIdeographic(ch);}});
 5604               defClone("javaTitleCase", new CloneableProperty() {
 5605                   boolean isSatisfiedBy(int ch) {
 5606                       return Character.isTitleCase(ch);}});
 5607               defClone("javaDigit", new CloneableProperty() {
 5608                   boolean isSatisfiedBy(int ch) {
 5609                       return Character.isDigit(ch);}});
 5610               defClone("javaDefined", new CloneableProperty() {
 5611                   boolean isSatisfiedBy(int ch) {
 5612                       return Character.isDefined(ch);}});
 5613               defClone("javaLetter", new CloneableProperty() {
 5614                   boolean isSatisfiedBy(int ch) {
 5615                       return Character.isLetter(ch);}});
 5616               defClone("javaLetterOrDigit", new CloneableProperty() {
 5617                   boolean isSatisfiedBy(int ch) {
 5618                       return Character.isLetterOrDigit(ch);}});
 5619               defClone("javaJavaIdentifierStart", new CloneableProperty() {
 5620                   boolean isSatisfiedBy(int ch) {
 5621                       return Character.isJavaIdentifierStart(ch);}});
 5622               defClone("javaJavaIdentifierPart", new CloneableProperty() {
 5623                   boolean isSatisfiedBy(int ch) {
 5624                       return Character.isJavaIdentifierPart(ch);}});
 5625               defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
 5626                   boolean isSatisfiedBy(int ch) {
 5627                       return Character.isUnicodeIdentifierStart(ch);}});
 5628               defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
 5629                   boolean isSatisfiedBy(int ch) {
 5630                       return Character.isUnicodeIdentifierPart(ch);}});
 5631               defClone("javaIdentifierIgnorable", new CloneableProperty() {
 5632                   boolean isSatisfiedBy(int ch) {
 5633                       return Character.isIdentifierIgnorable(ch);}});
 5634               defClone("javaSpaceChar", new CloneableProperty() {
 5635                   boolean isSatisfiedBy(int ch) {
 5636                       return Character.isSpaceChar(ch);}});
 5637               defClone("javaWhitespace", new CloneableProperty() {
 5638                   boolean isSatisfiedBy(int ch) {
 5639                       return Character.isWhitespace(ch);}});
 5640               defClone("javaISOControl", new CloneableProperty() {
 5641                   boolean isSatisfiedBy(int ch) {
 5642                       return Character.isISOControl(ch);}});
 5643               defClone("javaMirrored", new CloneableProperty() {
 5644                   boolean isSatisfiedBy(int ch) {
 5645                       return Character.isMirrored(ch);}});
 5646           }
 5647       }
 5648   }

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