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    1   /*
    2    * Copyright 1999-2007 Sun Microsystems, Inc.  All Rights Reserved.
    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.  Sun designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Sun 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).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   22    * CA 95054 USA or visit www.sun.com if you need additional information or
   23    * have any questions.
   24    */
   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.ArrayList;
   33   import java.util.HashMap;
   34   import java.util.Arrays;
   35   
   36   
   37   /**
   38    * A compiled representation of a regular expression.
   39    *
   40    * <p> A regular expression, specified as a string, must first be compiled into
   41    * an instance of this class.  The resulting pattern can then be used to create
   42    * a {@link Matcher} object that can match arbitrary {@link
   43    * java.lang.CharSequence </code>character sequences<code>} against the regular
   44    * expression.  All of the state involved in performing a match resides in the
   45    * matcher, so many matchers can share the same pattern.
   46    *
   47    * <p> A typical invocation sequence is thus
   48    *
   49    * <blockquote><pre>
   50    * Pattern p = Pattern.{@link #compile compile}("a*b");
   51    * Matcher m = p.{@link #matcher matcher}("aaaaab");
   52    * boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
   53    *
   54    * <p> A {@link #matches matches} method is defined by this class as a
   55    * convenience for when a regular expression is used just once.  This method
   56    * compiles an expression and matches an input sequence against it in a single
   57    * invocation.  The statement
   58    *
   59    * <blockquote><pre>
   60    * boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
   61    *
   62    * is equivalent to the three statements above, though for repeated matches it
   63    * is less efficient since it does not allow the compiled pattern to be reused.
   64    *
   65    * <p> Instances of this class are immutable and are safe for use by multiple
   66    * concurrent threads.  Instances of the {@link Matcher} class are not safe for
   67    * such use.
   68    *
   69    *
   70    * <a name="sum">
   71    * <h4> Summary of regular-expression constructs </h4>
   72    *
   73    * <table border="0" cellpadding="1" cellspacing="0"
   74    *  summary="Regular expression constructs, and what they match">
   75    *
   76    * <tr align="left">
   77    * <th bgcolor="#CCCCFF" align="left" id="construct">Construct</th>
   78    * <th bgcolor="#CCCCFF" align="left" id="matches">Matches</th>
   79    * </tr>
   80    *
   81    * <tr><th>&nbsp;</th></tr>
   82    * <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
   83    *
   84    * <tr><td valign="top" headers="construct characters"><i>x</i></td>
   85    *     <td headers="matches">The character <i>x</i></td></tr>
   86    * <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
   87    *     <td headers="matches">The backslash character</td></tr>
   88    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
   89    *     <td headers="matches">The character with octal value <tt>0</tt><i>n</i>
   90    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
   91    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
   92    *     <td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
   93    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
   94    * <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
   95    *     <td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
   96    *         (0&nbsp;<tt>&lt;=</tt>&nbsp;<i>m</i>&nbsp;<tt>&lt;=</tt>&nbsp;3,
   97    *         0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
   98    * <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
   99    *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hh</i></td></tr>
  100    * <tr><td valign="top" headers="construct characters"><tt>&#92;u</tt><i>hhhh</i></td>
  101    *     <td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hhhh</i></td></tr>
  102    * <tr><td valign="top" headers="matches"><tt>\t</tt></td>
  103    *     <td headers="matches">The tab character (<tt>'&#92;u0009'</tt>)</td></tr>
  104    * <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
  105    *     <td headers="matches">The newline (line feed) character (<tt>'&#92;u000A'</tt>)</td></tr>
  106    * <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
  107    *     <td headers="matches">The carriage-return character (<tt>'&#92;u000D'</tt>)</td></tr>
  108    * <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
  109    *     <td headers="matches">The form-feed character (<tt>'&#92;u000C'</tt>)</td></tr>
  110    * <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
  111    *     <td headers="matches">The alert (bell) character (<tt>'&#92;u0007'</tt>)</td></tr>
  112    * <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
  113    *     <td headers="matches">The escape character (<tt>'&#92;u001B'</tt>)</td></tr>
  114    * <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
  115    *     <td headers="matches">The control character corresponding to <i>x</i></td></tr>
  116    *
  117    * <tr><th>&nbsp;</th></tr>
  118    * <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
  119    *
  120    * <tr><td valign="top" headers="construct classes"><tt>[abc]</tt></td>
  121    *     <td headers="matches"><tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (simple class)</td></tr>
  122    * <tr><td valign="top" headers="construct classes"><tt>[^abc]</tt></td>
  123    *     <td headers="matches">Any character except <tt>a</tt>, <tt>b</tt>, or <tt>c</tt> (negation)</td></tr>
  124    * <tr><td valign="top" headers="construct classes"><tt>[a-zA-Z]</tt></td>
  125    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>
  126    *         or <tt>A</tt> through <tt>Z</tt>, inclusive (range)</td></tr>
  127    * <tr><td valign="top" headers="construct classes"><tt>[a-d[m-p]]</tt></td>
  128    *     <td headers="matches"><tt>a</tt> through <tt>d</tt>,
  129    *      or <tt>m</tt> through <tt>p</tt>: <tt>[a-dm-p]</tt> (union)</td></tr>
  130    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[def]]</tt></td>
  131    *     <td headers="matches"><tt>d</tt>, <tt>e</tt>, or <tt>f</tt> (intersection)</tr>
  132    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^bc]]</tt></td>
  133    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
  134    *         except for <tt>b</tt> and <tt>c</tt>: <tt>[ad-z]</tt> (subtraction)</td></tr>
  135    * <tr><td valign="top" headers="construct classes"><tt>[a-z&&[^m-p]]</tt></td>
  136    *     <td headers="matches"><tt>a</tt> through <tt>z</tt>,
  137    *          and not <tt>m</tt> through <tt>p</tt>: <tt>[a-lq-z]</tt>(subtraction)</td></tr>
  138    * <tr><th>&nbsp;</th></tr>
  139    *
  140    * <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
  141    *
  142    * <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
  143    *     <td headers="matches">Any character (may or may not match <a href="#lt">line terminators</a>)</td></tr>
  144    * <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
  145    *     <td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
  146    * <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
  147    *     <td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
  148    * <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
  149    *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
  150    * <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
  151    *     <td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
  152    * <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
  153    *     <td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
  154    * <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
  155    *     <td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
  156    *
  157    * <tr><th>&nbsp;</th></tr>
  158    * <tr align="left"><th colspan="2" id="posix">POSIX character classes</b> (US-ASCII only)<b></th></tr>
  159    *
  160    * <tr><td valign="top" headers="construct posix"><tt>\p{Lower}</tt></td>
  161    *     <td headers="matches">A lower-case alphabetic character: <tt>[a-z]</tt></td></tr>
  162    * <tr><td valign="top" headers="construct posix"><tt>\p{Upper}</tt></td>
  163    *     <td headers="matches">An upper-case alphabetic character:<tt>[A-Z]</tt></td></tr>
  164    * <tr><td valign="top" headers="construct posix"><tt>\p{ASCII}</tt></td>
  165    *     <td headers="matches">All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
  166    * <tr><td valign="top" headers="construct posix"><tt>\p{Alpha}</tt></td>
  167    *     <td headers="matches">An alphabetic character:<tt>[\p{Lower}\p{Upper}]</tt></td></tr>
  168    * <tr><td valign="top" headers="construct posix"><tt>\p{Digit}</tt></td>
  169    *     <td headers="matches">A decimal digit: <tt>[0-9]</tt></td></tr>
  170    * <tr><td valign="top" headers="construct posix"><tt>\p{Alnum}</tt></td>
  171    *     <td headers="matches">An alphanumeric character:<tt>[\p{Alpha}\p{Digit}]</tt></td></tr>
  172    * <tr><td valign="top" headers="construct posix"><tt>\p{Punct}</tt></td>
  173    *     <td headers="matches">Punctuation: One of <tt>!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~</tt></td></tr>
  174    *     <!-- <tt>[\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]</tt>
  175    *          <tt>[\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]</tt> -->
  176    * <tr><td valign="top" headers="construct posix"><tt>\p{Graph}</tt></td>
  177    *     <td headers="matches">A visible character: <tt>[\p{Alnum}\p{Punct}]</tt></td></tr>
  178    * <tr><td valign="top" headers="construct posix"><tt>\p{Print}</tt></td>
  179    *     <td headers="matches">A printable character: <tt>[\p{Graph}\x20]</tt></td></tr>
  180    * <tr><td valign="top" headers="construct posix"><tt>\p{Blank}</tt></td>
  181    *     <td headers="matches">A space or a tab: <tt>[ \t]</tt></td></tr>
  182    * <tr><td valign="top" headers="construct posix"><tt>\p{Cntrl}</tt></td>
  183    *     <td headers="matches">A control character: <tt>[\x00-\x1F\x7F]</tt></td></tr>
  184    * <tr><td valign="top" headers="construct posix"><tt>\p{XDigit}</tt></td>
  185    *     <td headers="matches">A hexadecimal digit: <tt>[0-9a-fA-F]</tt></td></tr>
  186    * <tr><td valign="top" headers="construct posix"><tt>\p{Space}</tt></td>
  187    *     <td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
  188    *
  189    * <tr><th>&nbsp;</th></tr>
  190    * <tr align="left"><th colspan="2">java.lang.Character classes (simple <a href="#jcc">java character type</a>)</th></tr>
  191    *
  192    * <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
  193    *     <td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
  194    * <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
  195    *     <td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
  196    * <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
  197    *     <td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
  198    * <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
  199    *     <td>Equivalent to java.lang.Character.isMirrored()</td></tr>
  200    *
  201    * <tr><th>&nbsp;</th></tr>
  202    * <tr align="left"><th colspan="2" id="unicode">Classes for Unicode blocks and categories</th></tr>
  203    *
  204    * <tr><td valign="top" headers="construct unicode"><tt>\p{InGreek}</tt></td>
  205    *     <td headers="matches">A character in the Greek&nbsp;block (simple <a href="#ubc">block</a>)</td></tr>
  206    * <tr><td valign="top" headers="construct unicode"><tt>\p{Lu}</tt></td>
  207    *     <td headers="matches">An uppercase letter (simple <a href="#ubc">category</a>)</td></tr>
  208    * <tr><td valign="top" headers="construct unicode"><tt>\p{Sc}</tt></td>
  209    *     <td headers="matches">A currency symbol</td></tr>
  210    * <tr><td valign="top" headers="construct unicode"><tt>\P{InGreek}</tt></td>
  211    *     <td headers="matches">Any character except one in the Greek block (negation)</td></tr>
  212    * <tr><td valign="top" headers="construct unicode"><tt>[\p{L}&&[^\p{Lu}]]&nbsp;</tt></td>
  213    *     <td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
  214    *
  215    * <tr><th>&nbsp;</th></tr>
  216    * <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
  217    *
  218    * <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
  219    *     <td headers="matches">The beginning of a line</td></tr>
  220    * <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
  221    *     <td headers="matches">The end of a line</td></tr>
  222    * <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
  223    *     <td headers="matches">A word boundary</td></tr>
  224    * <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
  225    *     <td headers="matches">A non-word boundary</td></tr>
  226    * <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
  227    *     <td headers="matches">The beginning of the input</td></tr>
  228    * <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
  229    *     <td headers="matches">The end of the previous match</td></tr>
  230    * <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
  231    *     <td headers="matches">The end of the input but for the final
  232    *         <a href="#lt">terminator</a>, if&nbsp;any</td></tr>
  233    * <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
  234    *     <td headers="matches">The end of the input</td></tr>
  235    *
  236    * <tr><th>&nbsp;</th></tr>
  237    * <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
  238    *
  239    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
  240    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  241    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
  242    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  243    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
  244    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  245    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
  246    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  247    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
  248    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  249    * <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
  250    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  251    *
  252    * <tr><th>&nbsp;</th></tr>
  253    * <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
  254    *
  255    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
  256    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  257    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
  258    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  259    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
  260    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  261    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
  262    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  263    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
  264    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  265    * <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
  266    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  267    *
  268    * <tr><th>&nbsp;</th></tr>
  269    * <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
  270    *
  271    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
  272    *     <td headers="matches"><i>X</i>, once or not at all</td></tr>
  273    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
  274    *     <td headers="matches"><i>X</i>, zero or more times</td></tr>
  275    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
  276    *     <td headers="matches"><i>X</i>, one or more times</td></tr>
  277    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
  278    *     <td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
  279    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
  280    *     <td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
  281    * <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
  282    *     <td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
  283    *
  284    * <tr><th>&nbsp;</th></tr>
  285    * <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
  286    *
  287    * <tr><td valign="top" headers="construct logical"><i>XY</i></td>
  288    *     <td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
  289    * <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
  290    *     <td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
  291    * <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
  292    *     <td headers="matches">X, as a <a href="#cg">capturing group</a></td></tr>
  293    *
  294    * <tr><th>&nbsp;</th></tr>
  295    * <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
  296    *
  297    * <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
  298    *     <td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
  299    *     <a href="#cg">capturing group</a> matched</td></tr>
  300    *
  301    * <tr><th>&nbsp;</th></tr>
  302    * <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
  303    *
  304    * <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
  305    *     <td headers="matches">Nothing, but quotes the following character</td></tr>
  306    * <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
  307    *     <td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
  308    * <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
  309    *     <td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
  310    *     <!-- Metachars: !$()*+.<>?[\]^{|} -->
  311    *
  312    * <tr><th>&nbsp;</th></tr>
  313    * <tr align="left"><th colspan="2" id="special">Special constructs (non-capturing)</th></tr>
  314    *
  315    * <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
  316    *     <td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
  317    * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux)&nbsp;</tt></td>
  318    *     <td headers="matches">Nothing, but turns match flags <a href="#CASE_INSENSITIVE">i</a>
  319    * <a href="#UNIX_LINES">d</a> <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
  320    * <a href="#UNICODE_CASE">u</a> <a href="#COMMENTS">x</a> on - off</td></tr>
  321    * <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt>&nbsp;&nbsp;</td>
  322    *     <td headers="matches"><i>X</i>, as a <a href="#cg">non-capturing group</a> with the
  323    *         given flags <a href="#CASE_INSENSITIVE">i</a> <a href="#UNIX_LINES">d</a>
  324    * <a href="#MULTILINE">m</a> <a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
  325    * <a href="#COMMENTS">x</a> on - off</td></tr>
  326    * <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
  327    *     <td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
  328    * <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
  329    *     <td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
  330    * <tr><td valign="top" headers="construct special"><tt>(?&lt;=</tt><i>X</i><tt>)</tt></td>
  331    *     <td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
  332    * <tr><td valign="top" headers="construct special"><tt>(?&lt;!</tt><i>X</i><tt>)</tt></td>
  333    *     <td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
  334    * <tr><td valign="top" headers="construct special"><tt>(?&gt;</tt><i>X</i><tt>)</tt></td>
  335    *     <td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
  336    *
  337    * </table>
  338    *
  339    * <hr>
  340    *
  341    *
  342    * <a name="bs">
  343    * <h4> Backslashes, escapes, and quoting </h4>
  344    *
  345    * <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
  346    * constructs, as defined in the table above, as well as to quote characters
  347    * that otherwise would be interpreted as unescaped constructs.  Thus the
  348    * expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
  349    * left brace.
  350    *
  351    * <p> It is an error to use a backslash prior to any alphabetic character that
  352    * does not denote an escaped construct; these are reserved for future
  353    * extensions to the regular-expression language.  A backslash may be used
  354    * prior to a non-alphabetic character regardless of whether that character is
  355    * part of an unescaped construct.
  356    *
  357    * <p> Backslashes within string literals in Java source code are interpreted
  358    * as required by the <a
  359    * href="http://java.sun.com/docs/books/jls">Java Language
  360    * Specification</a> as either <a
  361    * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#100850">Unicode
  362    * escapes</a> or other <a
  363    * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">character
  364    * escapes</a>.  It is therefore necessary to double backslashes in string
  365    * literals that represent regular expressions to protect them from
  366    * interpretation by the Java bytecode compiler.  The string literal
  367    * <tt>"&#92;b"</tt>, for example, matches a single backspace character when
  368    * interpreted as a regular expression, while <tt>"&#92;&#92;b"</tt> matches a
  369    * word boundary.  The string literal <tt>"&#92;(hello&#92;)"</tt> is illegal
  370    * and leads to a compile-time error; in order to match the string
  371    * <tt>(hello)</tt> the string literal <tt>"&#92;&#92;(hello&#92;&#92;)"</tt>
  372    * must be used.
  373    *
  374    * <a name="cc">
  375    * <h4> Character Classes </h4>
  376    *
  377    *    <p> Character classes may appear within other character classes, and
  378    *    may be composed by the union operator (implicit) and the intersection
  379    *    operator (<tt>&amp;&amp;</tt>).
  380    *    The union operator denotes a class that contains every character that is
  381    *    in at least one of its operand classes.  The intersection operator
  382    *    denotes a class that contains every character that is in both of its
  383    *    operand classes.
  384    *
  385    *    <p> The precedence of character-class operators is as follows, from
  386    *    highest to lowest:
  387    *
  388    *    <blockquote><table border="0" cellpadding="1" cellspacing="0"
  389    *                 summary="Precedence of character class operators.">
  390    *      <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
  391    *        <td>Literal escape&nbsp;&nbsp;&nbsp;&nbsp;</td>
  392    *        <td><tt>\x</tt></td></tr>
  393    *     <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
  394    *        <td>Grouping</td>
  395    *        <td><tt>[...]</tt></td></tr>
  396    *     <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
  397    *        <td>Range</td>
  398    *        <td><tt>a-z</tt></td></tr>
  399    *      <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
  400    *        <td>Union</td>
  401    *        <td><tt>[a-e][i-u]</tt></td></tr>
  402    *      <tr><th>5&nbsp;&nbsp;&nbsp;&nbsp;</th>
  403    *        <td>Intersection</td>
  404    *        <td><tt>[a-z&&[aeiou]]</tt></td></tr>
  405    *    </table></blockquote>
  406    *
  407    *    <p> Note that a different set of metacharacters are in effect inside
  408    *    a character class than outside a character class. For instance, the
  409    *    regular expression <tt>.</tt> loses its special meaning inside a
  410    *    character class, while the expression <tt>-</tt> becomes a range
  411    *    forming metacharacter.
  412    *
  413    * <a name="lt">
  414    * <h4> Line terminators </h4>
  415    *
  416    * <p> A <i>line terminator</i> is a one- or two-character sequence that marks
  417    * the end of a line of the input character sequence.  The following are
  418    * recognized as line terminators:
  419    *
  420    * <ul>
  421    *
  422    *   <li> A newline (line feed) character&nbsp;(<tt>'\n'</tt>),
  423    *
  424    *   <li> A carriage-return character followed immediately by a newline
  425    *   character&nbsp;(<tt>"\r\n"</tt>),
  426    *
  427    *   <li> A standalone carriage-return character&nbsp;(<tt>'\r'</tt>),
  428    *
  429    *   <li> A next-line character&nbsp;(<tt>'&#92;u0085'</tt>),
  430    *
  431    *   <li> A line-separator character&nbsp;(<tt>'&#92;u2028'</tt>), or
  432    *
  433    *   <li> A paragraph-separator character&nbsp;(<tt>'&#92;u2029</tt>).
  434    *
  435    * </ul>
  436    * <p>If {@link #UNIX_LINES} mode is activated, then the only line terminators
  437    * recognized are newline characters.
  438    *
  439    * <p> The regular expression <tt>.</tt> matches any character except a line
  440    * terminator unless the {@link #DOTALL} flag is specified.
  441    *
  442    * <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
  443    * line terminators and only match at the beginning and the end, respectively,
  444    * of the entire input sequence. If {@link #MULTILINE} mode is activated then
  445    * <tt>^</tt> matches at the beginning of input and after any line terminator
  446    * except at the end of input. When in {@link #MULTILINE} mode <tt>$</tt>
  447    * matches just before a line terminator or the end of the input sequence.
  448    *
  449    * <a name="cg">
  450    * <h4> Groups and capturing </h4>
  451    *
  452    * <p> Capturing groups are numbered by counting their opening parentheses from
  453    * left to right.  In the expression <tt>((A)(B(C)))</tt>, for example, there
  454    * are four such groups: </p>
  455    *
  456    * <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
  457    * <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
  458    *     <td><tt>((A)(B(C)))</tt></td></tr>
  459    * <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
  460    *     <td><tt>(A)</tt></td></tr>
  461    * <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
  462    *     <td><tt>(B(C))</tt></td></tr>
  463    * <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
  464    *     <td><tt>(C)</tt></td></tr>
  465    * </table></blockquote>
  466    *
  467    * <p> Group zero always stands for the entire expression.
  468    *
  469    * <p> Capturing groups are so named because, during a match, each subsequence
  470    * of the input sequence that matches such a group is saved.  The captured
  471    * subsequence may be used later in the expression, via a back reference, and
  472    * may also be retrieved from the matcher once the match operation is complete.
  473    *
  474    * <p> The captured input associated with a group is always the subsequence
  475    * that the group most recently matched.  If a group is evaluated a second time
  476    * because of quantification then its previously-captured value, if any, will
  477    * be retained if the second evaluation fails.  Matching the string
  478    * <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
  479    * group two set to <tt>"b"</tt>.  All captured input is discarded at the
  480    * beginning of each match.
  481    *
  482    * <p> Groups beginning with <tt>(?</tt> are pure, <i>non-capturing</i> groups
  483    * that do not capture text and do not count towards the group total.
  484    *
  485    *
  486    * <h4> Unicode support </h4>
  487    *
  488    * <p> This class is in conformance with Level 1 of <a
  489    * href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
  490    * Standard #18: Unicode Regular Expression Guidelines</i></a>, plus RL2.1
  491    * Canonical Equivalents.
  492    *
  493    * <p> Unicode escape sequences such as <tt>&#92;u2014</tt> in Java source code
  494    * are processed as described in <a
  495    * href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#100850">\u00A73.3</a>
  496    * of the Java Language Specification.  Such escape sequences are also
  497    * implemented directly by the regular-expression parser so that Unicode
  498    * escapes can be used in expressions that are read from files or from the
  499    * keyboard.  Thus the strings <tt>"&#92;u2014"</tt> and <tt>"\\u2014"</tt>,
  500    * while not equal, compile into the same pattern, which matches the character
  501    * with hexadecimal value <tt>0x2014</tt>.
  502    *
  503    * <a name="ubc"> <p>Unicode blocks and categories are written with the
  504    * <tt>\p</tt> and <tt>\P</tt> constructs as in
  505    * Perl. <tt>\p{</tt><i>prop</i><tt>}</tt> matches if the input has the
  506    * property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt> does not match if
  507    * the input has that property.  Blocks are specified with the prefix
  508    * <tt>In</tt>, as in <tt>InMongolian</tt>.  Categories may be specified with
  509    * the optional prefix <tt>Is</tt>: Both <tt>\p{L}</tt> and <tt>\p{IsL}</tt>
  510    * denote the category of Unicode letters.  Blocks and categories can be used
  511    * both inside and outside of a character class.
  512    *
  513    * <p> The supported categories are those of
  514    * <a href="http://www.unicode.org/unicode/standard/standard.html">
  515    * <i>The Unicode Standard</i></a> in the version specified by the
  516    * {@link java.lang.Character Character} class. The category names are those
  517    * defined in the Standard, both normative and informative.
  518    * The block names supported by <code>Pattern</code> are the valid block names
  519    * accepted and defined by
  520    * {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
  521    *
  522    * <a name="jcc"> <p>Categories that behave like the java.lang.Character
  523    * boolean is<i>methodname</i> methods (except for the deprecated ones) are
  524    * available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
  525    * the specified property has the name <tt>java<i>methodname</i></tt>.
  526    *
  527    * <h4> Comparison to Perl 5 </h4>
  528    *
  529    * <p>The <code>Pattern</code> engine performs traditional NFA-based matching
  530    * with ordered alternation as occurs in Perl 5.
  531    *
  532    * <p> Perl constructs not supported by this class: </p>
  533    *
  534    * <ul>
  535    *
  536    *    <li><p> The conditional constructs <tt>(?{</tt><i>X</i><tt>})</tt> and
  537    *    <tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
  538    *    </p></li>
  539    *
  540    *    <li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
  541    *    and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
  542    *
  543    *    <li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
  544    *
  545    *    <li><p> The preprocessing operations <tt>\l</tt> <tt>&#92;u</tt>,
  546    *    <tt>\L</tt>, and <tt>\U</tt>.  </p></li>
  547    *
  548    * </ul>
  549    *
  550    * <p> Constructs supported by this class but not by Perl: </p>
  551    *
  552    * <ul>
  553    *
  554    *    <li><p> Possessive quantifiers, which greedily match as much as they can
  555    *    and do not back off, even when doing so would allow the overall match to
  556    *    succeed.  </p></li>
  557    *
  558    *    <li><p> Character-class union and intersection as described
  559    *    <a href="#cc">above</a>.</p></li>
  560    *
  561    * </ul>
  562    *
  563    * <p> Notable differences from Perl: </p>
  564    *
  565    * <ul>
  566    *
  567    *    <li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
  568    *    as back references; a backslash-escaped number greater than <tt>9</tt> is
  569    *    treated as a back reference if at least that many subexpressions exist,
  570    *    otherwise it is interpreted, if possible, as an octal escape.  In this
  571    *    class octal escapes must always begin with a zero. In this class,
  572    *    <tt>\1</tt> through <tt>\9</tt> are always interpreted as back
  573    *    references, and a larger number is accepted as a back reference if at
  574    *    least that many subexpressions exist at that point in the regular
  575    *    expression, otherwise the parser will drop digits until the number is
  576    *    smaller or equal to the existing number of groups or it is one digit.
  577    *    </p></li>
  578    *
  579    *    <li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
  580    *    where the last match left off.  This functionality is provided implicitly
  581    *    by the {@link Matcher} class: Repeated invocations of the {@link
  582    *    Matcher#find find} method will resume where the last match left off,
  583    *    unless the matcher is reset.  </p></li>
  584    *
  585    *    <li><p> In Perl, embedded flags at the top level of an expression affect
  586    *    the whole expression.  In this class, embedded flags always take effect
  587    *    at the point at which they appear, whether they are at the top level or
  588    *    within a group; in the latter case, flags are restored at the end of the
  589    *    group just as in Perl.  </p></li>
  590    *
  591    *    <li><p> Perl is forgiving about malformed matching constructs, as in the
  592    *    expression <tt>*a</tt>, as well as dangling brackets, as in the
  593    *    expression <tt>abc]</tt>, and treats them as literals.  This
  594    *    class also accepts dangling brackets but is strict about dangling
  595    *    metacharacters like +, ? and *, and will throw a
  596    *    {@link PatternSyntaxException} if it encounters them. </p></li>
  597    *
  598    * </ul>
  599    *
  600    *
  601    * <p> For a more precise description of the behavior of regular expression
  602    * constructs, please see <a href="http://www.oreilly.com/catalog/regex3/">
  603    * <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
  604    * O'Reilly and Associates, 2006.</a>
  605    * </p>
  606    *
  607    * @see java.lang.String#split(String, int)
  608    * @see java.lang.String#split(String)
  609    *
  610    * @author      Mike McCloskey
  611    * @author      Mark Reinhold
  612    * @author      JSR-51 Expert Group
  613    * @since       1.4
  614    * @spec        JSR-51
  615    */
  616   
  617   public final class Pattern
  618       implements java.io.Serializable
  619   {
  620   
  621       /**
  622        * Regular expression modifier values.  Instead of being passed as
  623        * arguments, they can also be passed as inline modifiers.
  624        * For example, the following statements have the same effect.
  625        * <pre>
  626        * RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
  627        * RegExp r2 = RegExp.compile("(?im)abc", 0);
  628        * </pre>
  629        *
  630        * The flags are duplicated so that the familiar Perl match flag
  631        * names are available.
  632        */
  633   
  634       /**
  635        * Enables Unix lines mode.
  636        *
  637        * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
  638        * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
  639        *
  640        * <p> Unix lines mode can also be enabled via the embedded flag
  641        * expression&nbsp;<tt>(?d)</tt>.
  642        */
  643       public static final int UNIX_LINES = 0x01;
  644   
  645       /**
  646        * Enables case-insensitive matching.
  647        *
  648        * <p> By default, case-insensitive matching assumes that only characters
  649        * in the US-ASCII charset are being matched.  Unicode-aware
  650        * case-insensitive matching can be enabled by specifying the {@link
  651        * #UNICODE_CASE} flag in conjunction with this flag.
  652        *
  653        * <p> Case-insensitive matching can also be enabled via the embedded flag
  654        * expression&nbsp;<tt>(?i)</tt>.
  655        *
  656        * <p> Specifying this flag may impose a slight performance penalty.  </p>
  657        */
  658       public static final int CASE_INSENSITIVE = 0x02;
  659   
  660       /**
  661        * Permits whitespace and comments in pattern.
  662        *
  663        * <p> In this mode, whitespace is ignored, and embedded comments starting
  664        * with <tt>#</tt> are ignored until the end of a line.
  665        *
  666        * <p> Comments mode can also be enabled via the embedded flag
  667        * expression&nbsp;<tt>(?x)</tt>.
  668        */
  669       public static final int COMMENTS = 0x04;
  670   
  671       /**
  672        * Enables multiline mode.
  673        *
  674        * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
  675        * just after or just before, respectively, a line terminator or the end of
  676        * the input sequence.  By default these expressions only match at the
  677        * beginning and the end of the entire input sequence.
  678        *
  679        * <p> Multiline mode can also be enabled via the embedded flag
  680        * expression&nbsp;<tt>(?m)</tt>.  </p>
  681        */
  682       public static final int MULTILINE = 0x08;
  683   
  684       /**
  685        * Enables literal parsing of the pattern.
  686        *
  687        * <p> When this flag is specified then the input string that specifies
  688        * the pattern is treated as a sequence of literal characters.
  689        * Metacharacters or escape sequences in the input sequence will be
  690        * given no special meaning.
  691        *
  692        * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
  693        * matching when used in conjunction with this flag. The other flags
  694        * become superfluous.
  695        *
  696        * <p> There is no embedded flag character for enabling literal parsing.
  697        * @since 1.5
  698        */
  699       public static final int LITERAL = 0x10;
  700   
  701       /**
  702        * Enables dotall mode.
  703        *
  704        * <p> In dotall mode, the expression <tt>.</tt> matches any character,
  705        * including a line terminator.  By default this expression does not match
  706        * line terminators.
  707        *
  708        * <p> Dotall mode can also be enabled via the embedded flag
  709        * expression&nbsp;<tt>(?s)</tt>.  (The <tt>s</tt> is a mnemonic for
  710        * "single-line" mode, which is what this is called in Perl.)  </p>
  711        */
  712       public static final int DOTALL = 0x20;
  713   
  714       /**
  715        * Enables Unicode-aware case folding.
  716        *
  717        * <p> When this flag is specified then case-insensitive matching, when
  718        * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
  719        * consistent with the Unicode Standard.  By default, case-insensitive
  720        * matching assumes that only characters in the US-ASCII charset are being
  721        * matched.
  722        *
  723        * <p> Unicode-aware case folding can also be enabled via the embedded flag
  724        * expression&nbsp;<tt>(?u)</tt>.
  725        *
  726        * <p> Specifying this flag may impose a performance penalty.  </p>
  727        */
  728       public static final int UNICODE_CASE = 0x40;
  729   
  730       /**
  731        * Enables canonical equivalence.
  732        *
  733        * <p> When this flag is specified then two characters will be considered
  734        * to match if, and only if, their full canonical decompositions match.
  735        * The expression <tt>"a&#92;u030A"</tt>, for example, will match the
  736        * string <tt>"&#92;u00E5"</tt> when this flag is specified.  By default,
  737        * matching does not take canonical equivalence into account.
  738        *
  739        * <p> There is no embedded flag character for enabling canonical
  740        * equivalence.
  741        *
  742        * <p> Specifying this flag may impose a performance penalty.  </p>
  743        */
  744       public static final int CANON_EQ = 0x80;
  745   
  746       /* Pattern has only two serialized components: The pattern string
  747        * and the flags, which are all that is needed to recompile the pattern
  748        * when it is deserialized.
  749        */
  750   
  751       /** use serialVersionUID from Merlin b59 for interoperability */
  752       private static final long serialVersionUID = 5073258162644648461L;
  753   
  754       /**
  755        * The original regular-expression pattern string.
  756        *
  757        * @serial
  758        */
  759       private String pattern;
  760   
  761       /**
  762        * The original pattern flags.
  763        *
  764        * @serial
  765        */
  766       private int flags;
  767   
  768       /**
  769        * Boolean indicating this Pattern is compiled; this is necessary in order
  770        * to lazily compile deserialized Patterns.
  771        */
  772       private transient volatile boolean compiled = false;
  773   
  774       /**
  775        * The normalized pattern string.
  776        */
  777       private transient String normalizedPattern;
  778   
  779       /**
  780        * The starting point of state machine for the find operation.  This allows
  781        * a match to start anywhere in the input.
  782        */
  783       transient Node root;
  784   
  785       /**
  786        * The root of object tree for a match operation.  The pattern is matched
  787        * at the beginning.  This may include a find that uses BnM or a First
  788        * node.
  789        */
  790       transient Node matchRoot;
  791   
  792       /**
  793        * Temporary storage used by parsing pattern slice.
  794        */
  795       transient int[] buffer;
  796   
  797       /**
  798        * Temporary storage used while parsing group references.
  799        */
  800       transient GroupHead[] groupNodes;
  801   
  802       /**
  803        * Temporary null terminated code point array used by pattern compiling.
  804        */
  805       private transient int[] temp;
  806   
  807       /**
  808        * The number of capturing groups in this Pattern. Used by matchers to
  809        * allocate storage needed to perform a match.
  810        */
  811       transient int capturingGroupCount;
  812   
  813       /**
  814        * The local variable count used by parsing tree. Used by matchers to
  815        * allocate storage needed to perform a match.
  816        */
  817       transient int localCount;
  818   
  819       /**
  820        * Index into the pattern string that keeps track of how much has been
  821        * parsed.
  822        */
  823       private transient int cursor;
  824   
  825       /**
  826        * Holds the length of the pattern string.
  827        */
  828       private transient int patternLength;
  829   
  830       /**
  831        * Compiles the given regular expression into a pattern.  </p>
  832        *
  833        * @param  regex
  834        *         The expression to be compiled
  835        *
  836        * @throws  PatternSyntaxException
  837        *          If the expression's syntax is invalid
  838        */
  839       public static Pattern compile(String regex) {
  840           return new Pattern(regex, 0);
  841       }
  842   
  843       /**
  844        * Compiles the given regular expression into a pattern with the given
  845        * flags.  </p>
  846        *
  847        * @param  regex
  848        *         The expression to be compiled
  849        *
  850        * @param  flags
  851        *         Match flags, a bit mask that may include
  852        *         {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
  853        *         {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
  854        *         {@link #LITERAL} and {@link #COMMENTS}
  855        *
  856        * @throws  IllegalArgumentException
  857        *          If bit values other than those corresponding to the defined
  858        *          match flags are set in <tt>flags</tt>
  859        *
  860        * @throws  PatternSyntaxException
  861        *          If the expression's syntax is invalid
  862        */
  863       public static Pattern compile(String regex, int flags) {
  864           return new Pattern(regex, flags);
  865       }
  866   
  867       /**
  868        * Returns the regular expression from which this pattern was compiled.
  869        * </p>
  870        *
  871        * @return  The source of this pattern
  872        */
  873       public String pattern() {
  874           return pattern;
  875       }
  876   
  877       /**
  878        * <p>Returns the string representation of this pattern. This
  879        * is the regular expression from which this pattern was
  880        * compiled.</p>
  881        *
  882        * @return  The string representation of this pattern
  883        * @since 1.5
  884        */
  885       public String toString() {
  886           return pattern;
  887       }
  888   
  889       /**
  890        * Creates a matcher that will match the given input against this pattern.
  891        * </p>
  892        *
  893        * @param  input
  894        *         The character sequence to be matched
  895        *
  896        * @return  A new matcher for this pattern
  897        */
  898       public Matcher matcher(CharSequence input) {
  899           if (!compiled) {
  900               synchronized(this) {
  901                   if (!compiled)
  902                       compile();
  903               }
  904           }
  905           Matcher m = new Matcher(this, input);
  906           return m;
  907       }
  908   
  909       /**
  910        * Returns this pattern's match flags.  </p>
  911        *
  912        * @return  The match flags specified when this pattern was compiled
  913        */
  914       public int flags() {
  915           return flags;
  916       }
  917   
  918       /**
  919        * Compiles the given regular expression and attempts to match the given
  920        * input against it.
  921        *
  922        * <p> An invocation of this convenience method of the form
  923        *
  924        * <blockquote><pre>
  925        * Pattern.matches(regex, input);</pre></blockquote>
  926        *
  927        * behaves in exactly the same way as the expression
  928        *
  929        * <blockquote><pre>
  930        * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
  931        *
  932        * <p> If a pattern is to be used multiple times, compiling it once and reusing
  933        * it will be more efficient than invoking this method each time.  </p>
  934        *
  935        * @param  regex
  936        *         The expression to be compiled
  937        *
  938        * @param  input
  939        *         The character sequence to be matched
  940        *
  941        * @throws  PatternSyntaxException
  942        *          If the expression's syntax is invalid
  943        */
  944       public static boolean matches(String regex, CharSequence input) {
  945           Pattern p = Pattern.compile(regex);
  946           Matcher m = p.matcher(input);
  947           return m.matches();
  948       }
  949   
  950       /**
  951        * Splits the given input sequence around matches of this pattern.
  952        *
  953        * <p> The array returned by this method contains each substring of the
  954        * input sequence that is terminated by another subsequence that matches
  955        * this pattern or is terminated by the end of the input sequence.  The
  956        * substrings in the array are in the order in which they occur in the
  957        * input.  If this pattern does not match any subsequence of the input then
  958        * the resulting array has just one element, namely the input sequence in
  959        * string form.
  960        *
  961        * <p> The <tt>limit</tt> parameter controls the number of times the
  962        * pattern is applied and therefore affects the length of the resulting
  963        * array.  If the limit <i>n</i> is greater than zero then the pattern
  964        * will be applied at most <i>n</i>&nbsp;-&nbsp;1 times, the array's
  965        * length will be no greater than <i>n</i>, and the array's last entry
  966        * will contain all input beyond the last matched delimiter.  If <i>n</i>
  967        * is non-positive then the pattern will be applied as many times as
  968        * possible and the array can have any length.  If <i>n</i> is zero then
  969        * the pattern will be applied as many times as possible, the array can
  970        * have any length, and trailing empty strings will be discarded.
  971        *
  972        * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
  973        * results with these parameters:
  974        *
  975        * <blockquote><table cellpadding=1 cellspacing=0
  976        *              summary="Split examples showing regex, limit, and result">
  977        * <tr><th><P align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
  978        *     <th><P align="left"><i>Limit&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
  979        *     <th><P align="left"><i>Result&nbsp;&nbsp;&nbsp;&nbsp;</i></th></tr>
  980        * <tr><td align=center>:</td>
  981        *     <td align=center>2</td>
  982        *     <td><tt>{ "boo", "and:foo" }</tt></td></tr>
  983        * <tr><td align=center>:</td>
  984        *     <td align=center>5</td>
  985        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
  986        * <tr><td align=center>:</td>
  987        *     <td align=center>-2</td>
  988        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
  989        * <tr><td align=center>o</td>
  990        *     <td align=center>5</td>
  991        *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
  992        * <tr><td align=center>o</td>
  993        *     <td align=center>-2</td>
  994        *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
  995        * <tr><td align=center>o</td>
  996        *     <td align=center>0</td>
  997        *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
  998        * </table></blockquote>
  999        *
 1000        *
 1001        * @param  input
 1002        *         The character sequence to be split
 1003        *
 1004        * @param  limit
 1005        *         The result threshold, as described above
 1006        *
 1007        * @return  The array of strings computed by splitting the input
 1008        *          around matches of this pattern
 1009        */
 1010       public String[] split(CharSequence input, int limit) {
 1011           int index = 0;
 1012           boolean matchLimited = limit > 0;
 1013           ArrayList<String> matchList = new ArrayList<String>();
 1014           Matcher m = matcher(input);
 1015   
 1016           // Add segments before each match found
 1017           while(m.find()) {
 1018               if (!matchLimited || matchList.size() < limit - 1) {
 1019                   String match = input.subSequence(index, m.start()).toString();
 1020                   matchList.add(match);
 1021                   index = m.end();
 1022               } else if (matchList.size() == limit - 1) { // last one
 1023                   String match = input.subSequence(index,
 1024                                                    input.length()).toString();
 1025                   matchList.add(match);
 1026                   index = m.end();
 1027               }
 1028           }
 1029   
 1030           // If no match was found, return this
 1031           if (index == 0)
 1032               return new String[] {input.toString()};
 1033   
 1034           // Add remaining segment
 1035           if (!matchLimited || matchList.size() < limit)
 1036               matchList.add(input.subSequence(index, input.length()).toString());
 1037   
 1038           // Construct result
 1039           int resultSize = matchList.size();
 1040           if (limit == 0)
 1041               while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
 1042                   resultSize--;
 1043           String[] result = new String[resultSize];
 1044           return matchList.subList(0, resultSize).toArray(result);
 1045       }
 1046   
 1047       /**
 1048        * Splits the given input sequence around matches of this pattern.
 1049        *
 1050        * <p> This method works as if by invoking the two-argument {@link
 1051        * #split(java.lang.CharSequence, int) split} method with the given input
 1052        * sequence and a limit argument of zero.  Trailing empty strings are
 1053        * therefore not included in the resulting array. </p>
 1054        *
 1055        * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
 1056        * results with these expressions:
 1057        *
 1058        * <blockquote><table cellpadding=1 cellspacing=0
 1059        *              summary="Split examples showing regex and result">
 1060        * <tr><th><P align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
 1061        *     <th><P align="left"><i>Result</i></th></tr>
 1062        * <tr><td align=center>:</td>
 1063        *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
 1064        * <tr><td align=center>o</td>
 1065        *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
 1066        * </table></blockquote>
 1067        *
 1068        *
 1069        * @param  input
 1070        *         The character sequence to be split
 1071        *
 1072        * @return  The array of strings computed by splitting the input
 1073        *          around matches of this pattern
 1074        */
 1075       public String[] split(CharSequence input) {
 1076           return split(input, 0);
 1077       }
 1078   
 1079       /**
 1080        * Returns a literal pattern <code>String</code> for the specified
 1081        * <code>String</code>.
 1082        *
 1083        * <p>This method produces a <code>String</code> that can be used to
 1084        * create a <code>Pattern</code> that would match the string
 1085        * <code>s</code> as if it were a literal pattern.</p> Metacharacters
 1086        * or escape sequences in the input sequence will be given no special
 1087        * meaning.
 1088        *
 1089        * @param  s The string to be literalized
 1090        * @return  A literal string replacement
 1091        * @since 1.5
 1092        */
 1093       public static String quote(String s) {
 1094           int slashEIndex = s.indexOf("\\E");
 1095           if (slashEIndex == -1)
 1096               return "\\Q" + s + "\\E";
 1097   
 1098           StringBuilder sb = new StringBuilder(s.length() * 2);
 1099           sb.append("\\Q");
 1100           slashEIndex = 0;
 1101           int current = 0;
 1102           while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
 1103               sb.append(s.substring(current, slashEIndex));
 1104               current = slashEIndex + 2;
 1105               sb.append("\\E\\\\E\\Q");
 1106           }
 1107           sb.append(s.substring(current, s.length()));
 1108           sb.append("\\E");
 1109           return sb.toString();
 1110       }
 1111   
 1112       /**
 1113        * Recompile the Pattern instance from a stream.  The original pattern
 1114        * string is read in and the object tree is recompiled from it.
 1115        */
 1116       private void readObject(java.io.ObjectInputStream s)
 1117           throws java.io.IOException, ClassNotFoundException {
 1118   
 1119           // Read in all fields
 1120           s.defaultReadObject();
 1121   
 1122           // Initialize counts
 1123           capturingGroupCount = 1;
 1124           localCount = 0;
 1125   
 1126           // if length > 0, the Pattern is lazily compiled
 1127           compiled = false;
 1128           if (pattern.length() == 0) {
 1129               root = new Start(lastAccept);
 1130               matchRoot = lastAccept;
 1131               compiled = true;
 1132           }
 1133       }
 1134   
 1135       /**
 1136        * This private constructor is used to create all Patterns. The pattern
 1137        * string and match flags are all that is needed to completely describe
 1138        * a Pattern. An empty pattern string results in an object tree with
 1139        * only a Start node and a LastNode node.
 1140        */
 1141       private Pattern(String p, int f) {
 1142           pattern = p;
 1143           flags = f;
 1144   
 1145           // Reset group index count
 1146           capturingGroupCount = 1;
 1147           localCount = 0;
 1148   
 1149           if (pattern.length() > 0) {
 1150               compile();
 1151           } else {
 1152               root = new Start(lastAccept);
 1153               matchRoot = lastAccept;
 1154           }
 1155       }
 1156   
 1157       /**
 1158        * The pattern is converted to normalizedD form and then a pure group
 1159        * is constructed to match canonical equivalences of the characters.
 1160        */
 1161       private void normalize() {
 1162           boolean inCharClass = false;
 1163           int lastCodePoint = -1;
 1164   
 1165           // Convert pattern into normalizedD form
 1166           normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
 1167           patternLength = normalizedPattern.length();
 1168   
 1169           // Modify pattern to match canonical equivalences
 1170           StringBuilder newPattern = new StringBuilder(patternLength);
 1171           for(int i=0; i<patternLength; ) {
 1172               int c = normalizedPattern.codePointAt(i);
 1173               StringBuilder sequenceBuffer;
 1174               if ((Character.getType(c) == Character.NON_SPACING_MARK)
 1175                   && (lastCodePoint != -1)) {
 1176                   sequenceBuffer = new StringBuilder();
 1177                   sequenceBuffer.appendCodePoint(lastCodePoint);
 1178                   sequenceBuffer.appendCodePoint(c);
 1179                   while(Character.getType(c) == Character.NON_SPACING_MARK) {
 1180                       i += Character.charCount(c);
 1181                       if (i >= patternLength)
 1182                           break;
 1183                       c = normalizedPattern.codePointAt(i);
 1184                       sequenceBuffer.appendCodePoint(c);
 1185                   }
 1186                   String ea = produceEquivalentAlternation(
 1187                                                  sequenceBuffer.toString());
 1188                   newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
 1189                   newPattern.append("(?:").append(ea).append(")");
 1190               } else if (c == '[' && lastCodePoint != '\\') {
 1191                   i = normalizeCharClass(newPattern, i);
 1192               } else {
 1193                   newPattern.appendCodePoint(c);
 1194               }
 1195               lastCodePoint = c;
 1196               i += Character.charCount(c);
 1197           }
 1198           normalizedPattern = newPattern.toString();
 1199       }
 1200   
 1201       /**
 1202        * Complete the character class being parsed and add a set
 1203        * of alternations to it that will match the canonical equivalences
 1204        * of the characters within the class.
 1205        */
 1206       private int normalizeCharClass(StringBuilder newPattern, int i) {
 1207           StringBuilder charClass = new StringBuilder();
 1208           StringBuilder eq = null;
 1209           int lastCodePoint = -1;
 1210           String result;
 1211   
 1212           i++;
 1213           charClass.append("[");
 1214           while(true) {
 1215               int c = normalizedPattern.codePointAt(i);
 1216               StringBuilder sequenceBuffer;
 1217   
 1218               if (c == ']' && lastCodePoint != '\\') {
 1219                   charClass.append((char)c);
 1220                   break;
 1221               } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
 1222                   sequenceBuffer = new StringBuilder();
 1223                   sequenceBuffer.appendCodePoint(lastCodePoint);
 1224                   while(Character.getType(c) == Character.NON_SPACING_MARK) {
 1225                       sequenceBuffer.appendCodePoint(c);
 1226                       i += Character.charCount(c);
 1227                       if (i >= normalizedPattern.length())
 1228                           break;
 1229                       c = normalizedPattern.codePointAt(i);
 1230                   }
 1231                   String ea = produceEquivalentAlternation(
 1232                                                     sequenceBuffer.toString());
 1233   
 1234                   charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
 1235                   if (eq == null)
 1236                       eq = new StringBuilder();
 1237                   eq.append('|');
 1238                   eq.append(ea);
 1239               } else {
 1240                   charClass.appendCodePoint(c);
 1241                   i++;
 1242               }
 1243               if (i == normalizedPattern.length())
 1244                   throw error("Unclosed character class");
 1245               lastCodePoint = c;
 1246           }
 1247   
 1248           if (eq != null) {
 1249               result = "(?:"+charClass.toString()+eq.toString()+")";
 1250           } else {
 1251               result = charClass.toString();
 1252           }
 1253   
 1254           newPattern.append(result);
 1255           return i;
 1256       }
 1257   
 1258       /**
 1259        * Given a specific sequence composed of a regular character and
 1260        * combining marks that follow it, produce the alternation that will
 1261        * match all canonical equivalences of that sequence.
 1262        */
 1263       private String produceEquivalentAlternation(String source) {
 1264           int len = countChars(source, 0, 1);
 1265           if (source.length() == len)
 1266               // source has one character.
 1267               return source;
 1268   
 1269           String base = source.substring(0,len);
 1270           String combiningMarks = source.substring(len);
 1271   
 1272           String[] perms = producePermutations(combiningMarks);
 1273           StringBuilder result = new StringBuilder(source);
 1274   
 1275           // Add combined permutations
 1276           for(int x=0; x<perms.length; x++) {
 1277               String next = base + perms[x];
 1278               if (x>0)
 1279                   result.append("|"+next);
 1280               next = composeOneStep(next);
 1281               if (next != null)
 1282                   result.append("|"+produceEquivalentAlternation(next));
 1283           }
 1284           return result.toString();
 1285       }
 1286   
 1287       /**
 1288        * Returns an array of strings that have all the possible
 1289        * permutations of the characters in the input string.
 1290        * This is used to get a list of all possible orderings
 1291        * of a set of combining marks. Note that some of the permutations
 1292        * are invalid because of combining class collisions, and these
 1293        * possibilities must be removed because they are not canonically
 1294        * equivalent.
 1295        */
 1296       private String[] producePermutations(String input) {
 1297           if (input.length() == countChars(input, 0, 1))
 1298               return new String[] {input};
 1299   
 1300           if (input.length() == countChars(input, 0, 2)) {
 1301               int c0 = Character.codePointAt(input, 0);
 1302               int c1 = Character.codePointAt(input, Character.charCount(c0));
 1303               if (getClass(c1) == getClass(c0)) {
 1304                   return new String[] {input};
 1305               }
 1306               String[] result = new String[2];
 1307               result[0] = input;
 1308               StringBuilder sb = new StringBuilder(2);
 1309               sb.appendCodePoint(c1);
 1310               sb.appendCodePoint(c0);
 1311               result[1] = sb.toString();
 1312               return result;
 1313           }
 1314   
 1315           int length = 1;
 1316           int nCodePoints = countCodePoints(input);
 1317           for(int x=1; x<nCodePoints; x++)
 1318               length = length * (x+1);
 1319   
 1320           String[] temp = new String[length];
 1321   
 1322           int combClass[] = new int[nCodePoints];
 1323           for(int x=0, i=0; x<nCodePoints; x++) {
 1324               int c = Character.codePointAt(input, i);
 1325               combClass[x] = getClass(c);
 1326               i +=  Character.charCount(c);
 1327           }
 1328   
 1329           // For each char, take it out and add the permutations
 1330           // of the remaining chars
 1331           int index = 0;
 1332           int len;
 1333           // offset maintains the index in code units.
 1334   loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
 1335               len = countChars(input, offset, 1);
 1336               boolean skip = false;
 1337               for(int y=x-1; y>=0; y--) {
 1338                   if (combClass[y] == combClass[x]) {
 1339                       continue loop;
 1340                   }
 1341               }
 1342               StringBuilder sb = new StringBuilder(input);
 1343               String otherChars = sb.delete(offset, offset+len).toString();
 1344               String[] subResult = producePermutations(otherChars);
 1345   
 1346               String prefix = input.substring(offset, offset+len);
 1347               for(int y=0; y<subResult.length; y++)
 1348                   temp[index++] =  prefix + subResult[y];
 1349           }
 1350           String[] result = new String[index];
 1351           for (int x=0; x<index; x++)
 1352               result[x] = temp[x];
 1353           return result;
 1354       }
 1355   
 1356       private int getClass(int c) {
 1357           return sun.text.Normalizer.getCombiningClass(c);
 1358       }
 1359   
 1360       /**
 1361        * Attempts to compose input by combining the first character
 1362        * with the first combining mark following it. Returns a String
 1363        * that is the composition of the leading character with its first
 1364        * combining mark followed by the remaining combining marks. Returns
 1365        * null if the first two characters cannot be further composed.
 1366        */
 1367       private String composeOneStep(String input) {
 1368           int len = countChars(input, 0, 2);
 1369           String firstTwoCharacters = input.substring(0, len);
 1370           String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
 1371   
 1372           if (result.equals(firstTwoCharacters))
 1373               return null;
 1374           else {
 1375               String remainder = input.substring(len);
 1376               return result + remainder;
 1377           }
 1378       }
 1379   
 1380       /**
 1381        * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
 1382        * See the description of `quotemeta' in perlfunc(1).
 1383        */
 1384       private void RemoveQEQuoting() {
 1385           final int pLen = patternLength;
 1386           int i = 0;
 1387           while (i < pLen-1) {
 1388               if (temp[i] != '\\')
 1389                   i += 1;
 1390               else if (temp[i + 1] != 'Q')
 1391                   i += 2;
 1392               else
 1393                   break;
 1394           }
 1395           if (i >= pLen - 1)    // No \Q sequence found
 1396               return;
 1397           int j = i;
 1398           i += 2;
 1399           int[] newtemp = new int[j + 2*(pLen-i) + 2];
 1400           System.arraycopy(temp, 0, newtemp, 0, j);
 1401   
 1402           boolean inQuote = true;
 1403           while (i < pLen) {
 1404               int c = temp[i++];
 1405               if (! ASCII.isAscii(c) || ASCII.isAlnum(c)) {
 1406                   newtemp[j++] = c;
 1407               } else if (c != '\\') {
 1408                   if (inQuote) newtemp[j++] = '\\';
 1409                   newtemp[j++] = c;
 1410               } else if (inQuote) {
 1411                   if (temp[i] == 'E') {
 1412                       i++;
 1413                       inQuote = false;
 1414                   } else {
 1415                       newtemp[j++] = '\\';
 1416                       newtemp[j++] = '\\';
 1417                   }
 1418               } else {
 1419                   if (temp[i] == 'Q') {
 1420                       i++;
 1421                       inQuote = true;
 1422                   } else {
 1423                       newtemp[j++] = c;
 1424                       if (i != pLen)
 1425                           newtemp[j++] = temp[i++];
 1426                   }
 1427               }
 1428           }
 1429   
 1430           patternLength = j;
 1431           temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
 1432       }
 1433   
 1434       /**
 1435        * Copies regular expression to an int array and invokes the parsing
 1436        * of the expression which will create the object tree.
 1437        */
 1438       private void compile() {
 1439           // Handle canonical equivalences
 1440           if (has(CANON_EQ) && !has(LITERAL)) {
 1441               normalize();
 1442           } else {
 1443               normalizedPattern = pattern;
 1444           }
 1445           patternLength = normalizedPattern.length();
 1446   
 1447           // Copy pattern to int array for convenience
 1448           // Use double zero to terminate pattern
 1449           temp = new int[patternLength + 2];
 1450   
 1451           boolean hasSupplementary = false;
 1452           int c, count = 0;
 1453           // Convert all chars into code points
 1454           for (int x = 0; x < patternLength; x += Character.charCount(c)) {
 1455               c = normalizedPattern.codePointAt(x);
 1456               if (isSupplementary(c)) {
 1457                   hasSupplementary = true;
 1458               }
 1459               temp[count++] = c;
 1460           }
 1461   
 1462           patternLength = count;   // patternLength now in code points
 1463   
 1464           if (! has(LITERAL))
 1465               RemoveQEQuoting();
 1466   
 1467           // Allocate all temporary objects here.
 1468           buffer = new int[32];
 1469           groupNodes = new GroupHead[10];
 1470   
 1471           if (has(LITERAL)) {
 1472               // Literal pattern handling
 1473               matchRoot = newSlice(temp, patternLength, hasSupplementary);
 1474               matchRoot.next = lastAccept;
 1475           } else {
 1476               // Start recursive descent parsing
 1477               matchRoot = expr(lastAccept);
 1478               // Check extra pattern characters
 1479               if (patternLength != cursor) {
 1480                   if (peek() == ')') {
 1481                       throw error("Unmatched closing ')'");
 1482                   } else {
 1483                       throw error("Unexpected internal error");
 1484                   }
 1485               }
 1486           }
 1487   
 1488           // Peephole optimization
 1489           if (matchRoot instanceof Slice) {
 1490               root = BnM.optimize(matchRoot);
 1491               if (root == matchRoot) {
 1492                   root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
 1493               }
 1494           } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
 1495               root = matchRoot;
 1496           } else {
 1497               root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
 1498           }
 1499   
 1500           // Release temporary storage
 1501           temp = null;
 1502           buffer = null;
 1503           groupNodes = null;
 1504           patternLength = 0;
 1505           compiled = true;
 1506       }
 1507   
 1508       /**
 1509        * Used to print out a subtree of the Pattern to help with debugging.
 1510        */
 1511       private static void printObjectTree(Node node) {
 1512           while(node != null) {
 1513               if (node instanceof Prolog) {
 1514                   System.out.println(node);
 1515                   printObjectTree(((Prolog)node).loop);
 1516                   System.out.println("**** end contents prolog loop");
 1517               } else if (node instanceof Loop) {
 1518                   System.out.println(node);
 1519                   printObjectTree(((Loop)node).body);
 1520                   System.out.println("**** end contents Loop body");
 1521               } else if (node instanceof Curly) {
 1522                   System.out.println(node);
 1523                   printObjectTree(((Curly)node).atom);
 1524                   System.out.println("**** end contents Curly body");
 1525               } else if (node instanceof GroupCurly) {
 1526                   System.out.println(node);
 1527                   printObjectTree(((GroupCurly)node).atom);
 1528                   System.out.println("**** end contents GroupCurly body");
 1529               } else if (node instanceof GroupTail) {
 1530                   System.out.println(node);
 1531                   System.out.println("Tail next is "+node.next);
 1532                   return;
 1533               } else {
 1534                   System.out.println(node);
 1535               }
 1536               node = node.next;
 1537               if (node != null)
 1538                   System.out.println("->next:");
 1539               if (node == Pattern.accept) {
 1540                   System.out.println("Accept Node");
 1541                   node = null;
 1542               }
 1543          }
 1544       }
 1545   
 1546       /**
 1547        * Used to accumulate information about a subtree of the object graph
 1548        * so that optimizations can be applied to the subtree.
 1549        */
 1550       static final class TreeInfo {
 1551           int minLength;
 1552           int maxLength;
 1553           boolean maxValid;
 1554           boolean deterministic;
 1555   
 1556           TreeInfo() {
 1557               reset();
 1558           }
 1559           void reset() {
 1560               minLength = 0;
 1561               maxLength = 0;
 1562               maxValid = true;
 1563               deterministic = true;
 1564           }
 1565       }
 1566   
 1567       /*
 1568        * The following private methods are mainly used to improve the
 1569        * readability of the code. In order to let the Java compiler easily
 1570        * inline them, we should not put many assertions or error checks in them.
 1571        */
 1572   
 1573       /**
 1574        * Indicates whether a particular flag is set or not.
 1575        */
 1576       private boolean has(int f) {
 1577           return (flags & f) != 0;
 1578       }
 1579   
 1580       /**
 1581        * Match next character, signal error if failed.
 1582        */
 1583       private void accept(int ch, String s) {
 1584           int testChar = temp[cursor++];
 1585           if (has(COMMENTS))
 1586               testChar = parsePastWhitespace(testChar);
 1587           if (ch != testChar) {
 1588               throw error(s);
 1589           }
 1590       }
 1591   
 1592       /**
 1593        * Mark the end of pattern with a specific character.
 1594        */
 1595       private void mark(int c) {
 1596           temp[patternLength] = c;
 1597       }
 1598   
 1599       /**
 1600        * Peek the next character, and do not advance the cursor.
 1601        */
 1602       private int peek() {
 1603           int ch = temp[cursor];
 1604           if (has(COMMENTS))
 1605               ch = peekPastWhitespace(ch);
 1606           return ch;
 1607       }
 1608   
 1609       /**
 1610        * Read the next character, and advance the cursor by one.
 1611        */
 1612       private int read() {
 1613           int ch = temp[cursor++];
 1614           if (has(COMMENTS))
 1615               ch = parsePastWhitespace(ch);
 1616           return ch;
 1617       }
 1618   
 1619       /**
 1620        * Read the next character, and advance the cursor by one,
 1621        * ignoring the COMMENTS setting
 1622        */
 1623       private int readEscaped() {
 1624           int ch = temp[cursor++];
 1625           return ch;
 1626       }
 1627   
 1628       /**
 1629        * Advance the cursor by one, and peek the next character.
 1630        */
 1631       private int next() {
 1632           int ch = temp[++cursor];
 1633           if (has(COMMENTS))
 1634               ch = peekPastWhitespace(ch);
 1635           return ch;
 1636       }
 1637   
 1638       /**
 1639        * Advance the cursor by one, and peek the next character,
 1640        * ignoring the COMMENTS setting
 1641        */
 1642       private int nextEscaped() {
 1643           int ch = temp[++cursor];
 1644           return ch;
 1645       }
 1646   
 1647       /**
 1648        * If in xmode peek past whitespace and comments.
 1649        */
 1650       private int peekPastWhitespace(int ch) {
 1651           while (ASCII.isSpace(ch) || ch == '#') {
 1652               while (ASCII.isSpace(ch))
 1653                   ch = temp[++cursor];
 1654               if (ch == '#') {
 1655                   ch = peekPastLine();
 1656               }
 1657           }
 1658           return ch;
 1659       }
 1660   
 1661       /**
 1662        * If in xmode parse past whitespace and comments.
 1663        */
 1664       private int parsePastWhitespace(int ch) {
 1665           while (ASCII.isSpace(ch) || ch == '#') {
 1666               while (ASCII.isSpace(ch))
 1667                   ch = temp[cursor++];
 1668               if (ch == '#')
 1669                   ch = parsePastLine();
 1670           }
 1671           return ch;
 1672       }
 1673   
 1674       /**
 1675        * xmode parse past comment to end of line.
 1676        */
 1677       private int parsePastLine() {
 1678           int ch = temp[cursor++];
 1679           while (ch != 0 && !isLineSeparator(ch))
 1680               ch = temp[cursor++];
 1681           return ch;
 1682       }
 1683   
 1684       /**
 1685        * xmode peek past comment to end of line.
 1686        */
 1687       private int peekPastLine() {
 1688           int ch = temp[++cursor];
 1689           while (ch != 0 && !isLineSeparator(ch))
 1690               ch = temp[++cursor];
 1691           return ch;
 1692       }
 1693   
 1694       /**
 1695        * Determines if character is a line separator in the current mode
 1696        */
 1697       private boolean isLineSeparator(int ch) {
 1698           if (has(UNIX_LINES)) {
 1699               return ch == '\n';
 1700           } else {
 1701               return (ch == '\n' ||
 1702                       ch == '\r' ||
 1703                       (ch|1) == '\u2029' ||
 1704                       ch == '\u0085');
 1705           }
 1706       }
 1707   
 1708       /**
 1709        * Read the character after the next one, and advance the cursor by two.
 1710        */
 1711       private int skip() {
 1712           int i = cursor;
 1713           int ch = temp[i+1];
 1714           cursor = i + 2;
 1715           return ch;
 1716       }
 1717   
 1718       /**
 1719        * Unread one next character, and retreat cursor by one.
 1720        */
 1721       private void unread() {
 1722           cursor--;
 1723       }
 1724   
 1725       /**
 1726        * Internal method used for handling all syntax errors. The pattern is
 1727        * displayed with a pointer to aid in locating the syntax error.
 1728        */
 1729       private PatternSyntaxException error(String s) {
 1730           return new PatternSyntaxException(s, normalizedPattern,  cursor - 1);
 1731       }
 1732   
 1733       /**
 1734        * Determines if there is any supplementary character or unpaired
 1735        * surrogate in the specified range.
 1736        */
 1737       private boolean findSupplementary(int start, int end) {
 1738           for (int i = start; i < end; i++) {
 1739               if (isSupplementary(temp[i]))
 1740                   return true;
 1741           }
 1742           return false;
 1743       }
 1744   
 1745       /**
 1746        * Determines if the specified code point is a supplementary
 1747        * character or unpaired surrogate.
 1748        */
 1749       private static final boolean isSupplementary(int ch) {
 1750           return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT || isSurrogate(ch);
 1751       }
 1752   
 1753       /**
 1754        *  The following methods handle the main parsing. They are sorted
 1755        *  according to their precedence order, the lowest one first.
 1756        */
 1757   
 1758       /**
 1759        * The expression is parsed with branch nodes added for alternations.
 1760        * This may be called recursively to parse sub expressions that may
 1761        * contain alternations.
 1762        */
 1763       private Node expr(Node end) {
 1764           Node prev = null;
 1765           Node firstTail = null;
 1766           Node branchConn = null;
 1767   
 1768           for (;;) {
 1769               Node node = sequence(end);
 1770               Node nodeTail = root;      //double return
 1771               if (prev == null) {
 1772                   prev = node;
 1773                   firstTail = nodeTail;
 1774               } else {
 1775                   // Branch
 1776                   if (branchConn == null) {
 1777                       branchConn = new BranchConn();
 1778                       branchConn.next = end;
 1779                   }
 1780                   if (node == end) {
 1781                       // if the node returned from sequence() is "end"
 1782                       // we have an empty expr, set a null atom into
 1783                       // the branch to indicate to go "next" directly.
 1784                       node = null;
 1785                   } else {
 1786                       // the "tail.next" of each atom goes to branchConn
 1787                       nodeTail.next = branchConn;
 1788                   }
 1789                   if (prev instanceof Branch) {
 1790                       ((Branch)prev).add(node);
 1791                   } else {
 1792                       if (prev == end) {
 1793                           prev = null;
 1794                       } else {
 1795                           // replace the "end" with "branchConn" at its tail.next
 1796                           // when put the "prev" into the branch as the first atom.
 1797                           firstTail.next = branchConn;
 1798                       }
 1799                       prev = new Branch(prev, node, branchConn);
 1800                   }
 1801               }
 1802               if (peek() != '|') {
 1803                   return prev;
 1804               }
 1805               next();
 1806           }
 1807       }
 1808   
 1809       /**
 1810        * Parsing of sequences between alternations.
 1811        */
 1812       private Node sequence(Node end) {
 1813           Node head = null;
 1814           Node tail = null;
 1815           Node node = null;
 1816       LOOP:
 1817           for (;;) {
 1818               int ch = peek();
 1819               switch (ch) {
 1820               case '(':
 1821                   // Because group handles its own closure,
 1822                   // we need to treat it differently
 1823                   node = group0();
 1824                   // Check for comment or flag group
 1825                   if (node == null)
 1826                       continue;
 1827                   if (head == null)
 1828                       head = node;
 1829                   else
 1830                       tail.next = node;
 1831                   // Double return: Tail was returned in root
 1832                   tail = root;
 1833                   continue;
 1834               case '[':
 1835                   node = clazz(true);
 1836                   break;
 1837               case '\\':
 1838                   ch = nextEscaped();
 1839                   if (ch == 'p' || ch == 'P') {
 1840                       boolean oneLetter = true;
 1841                       boolean comp = (ch == 'P');
 1842                       ch = next(); // Consume { if present
 1843                       if (ch != '{') {
 1844                           unread();
 1845                       } else {
 1846                           oneLetter = false;
 1847                       }
 1848                       node = family(oneLetter).maybeComplement(comp);
 1849                   } else {
 1850                       unread();
 1851                       node = atom();
 1852                   }
 1853                   break;
 1854               case '^':
 1855                   next();
 1856                   if (has(MULTILINE)) {
 1857                       if (has(UNIX_LINES))
 1858                           node = new UnixCaret();
 1859                       else
 1860                           node = new Caret();
 1861                   } else {
 1862                       node = new Begin();
 1863                   }
 1864                   break;
 1865               case '$':
 1866                   next();
 1867                   if (has(UNIX_LINES))
 1868                       node = new UnixDollar(has(MULTILINE));
 1869                   else
 1870                       node = new Dollar(has(MULTILINE));
 1871                   break;
 1872               case '.':
 1873                   next();
 1874                   if (has(DOTALL)) {
 1875                       node = new All();
 1876                   } else {
 1877                       if (has(UNIX_LINES))
 1878                           node = new UnixDot();
 1879                       else {
 1880                           node = new Dot();
 1881                       }
 1882                   }
 1883                   break;
 1884               case '|':
 1885               case ')':
 1886                   break LOOP;
 1887               case ']': // Now interpreting dangling ] and } as literals
 1888               case '}':
 1889                   node = atom();
 1890                   break;
 1891               case '?':
 1892               case '*':
 1893               case '+':
 1894                   next();
 1895                   throw error("Dangling meta character '" + ((char)ch) + "'");
 1896               case 0:
 1897                   if (cursor >= patternLength) {
 1898                       break LOOP;
 1899                   }
 1900                   // Fall through
 1901               default:
 1902                   node = atom();
 1903                   break;
 1904               }
 1905   
 1906               node = closure(node);
 1907   
 1908               if (head == null) {
 1909                   head = tail = node;
 1910               } else {
 1911                   tail.next = node;
 1912                   tail = node;
 1913               }
 1914           }
 1915           if (head == null) {
 1916               return end;
 1917           }
 1918           tail.next = end;
 1919           root = tail;      //double return
 1920           return head;
 1921       }
 1922   
 1923       /**
 1924        * Parse and add a new Single or Slice.
 1925        */
 1926       private Node atom() {
 1927           int first = 0;
 1928           int prev = -1;
 1929           boolean hasSupplementary = false;
 1930           int ch = peek();
 1931           for (;;) {
 1932               switch (ch) {
 1933               case '*':
 1934               case '+':
 1935               case '?':
 1936               case '{':
 1937                   if (first > 1) {
 1938                       cursor = prev;    // Unwind one character
 1939                       first--;
 1940                   }
 1941                   break;
 1942               case '$':
 1943               case '.':
 1944               case '^':
 1945               case '(':
 1946               case '[':
 1947               case '|':
 1948               case ')':
 1949                   break;
 1950               case '\\':
 1951                   ch = nextEscaped();
 1952                   if (ch == 'p' || ch == 'P') { // Property
 1953                       if (first > 0) { // Slice is waiting; handle it first
 1954                           unread();
 1955                           break;
 1956                       } else { // No slice; just return the family node
 1957                           boolean comp = (ch == 'P');
 1958                           boolean oneLetter = true;
 1959                           ch = next(); // Consume { if present
 1960                           if (ch != '{')
 1961                               unread();
 1962                           else
 1963                               oneLetter = false;
 1964                           return family(oneLetter).maybeComplement(comp);
 1965                       }
 1966                   }
 1967                   unread();
 1968                   prev = cursor;
 1969                   ch = escape(false, first == 0);
 1970                   if (ch >= 0) {
 1971                       append(ch, first);
 1972                       first++;
 1973                       if (isSupplementary(ch)) {
 1974                           hasSupplementary = true;
 1975                       }
 1976                       ch = peek();
 1977                       continue;
 1978                   } else if (first == 0) {
 1979                       return root;
 1980                   }
 1981                   // Unwind meta escape sequence
 1982                   cursor = prev;
 1983                   break;
 1984               case 0:
 1985                   if (cursor >= patternLength) {
 1986                       break;
 1987                   }
 1988                   // Fall through
 1989               default:
 1990                   prev = cursor;
 1991                   append(ch, first);
 1992                   first++;
 1993                   if (isSupplementary(ch)) {
 1994                       hasSupplementary = true;
 1995                   }
 1996                   ch = next();
 1997                   continue;
 1998               }
 1999               break;
 2000           }
 2001           if (first == 1) {
 2002               return newSingle(buffer[0]);
 2003           } else {
 2004               return newSlice(buffer, first, hasSupplementary);
 2005           }
 2006       }
 2007   
 2008       private void append(int ch, int len) {
 2009           if (len >= buffer.length) {
 2010               int[] tmp = new int[len+len];
 2011               System.arraycopy(buffer, 0, tmp, 0, len);
 2012               buffer = tmp;
 2013           }
 2014           buffer[len] = ch;
 2015       }
 2016   
 2017       /**
 2018        * Parses a backref greedily, taking as many numbers as it
 2019        * can. The first digit is always treated as a backref, but
 2020        * multi digit numbers are only treated as a backref if at
 2021        * least that many backrefs exist at this point in the regex.
 2022        */
 2023       private Node ref(int refNum) {
 2024           boolean done = false;
 2025           while(!done) {
 2026               int ch = peek();
 2027               switch(ch) {
 2028               case '0':
 2029               case '1':
 2030               case '2':
 2031               case '3':
 2032               case '4':
 2033               case '5':
 2034               case '6':
 2035               case '7':
 2036               case '8':
 2037               case '9':
 2038                   int newRefNum = (refNum * 10) + (ch - '0');
 2039                   // Add another number if it doesn't make a group
 2040                   // that doesn't exist
 2041                   if (capturingGroupCount - 1 < newRefNum) {
 2042                       done = true;
 2043                       break;
 2044                   }
 2045                   refNum = newRefNum;
 2046                   read();
 2047                   break;
 2048               default:
 2049                   done = true;
 2050                   break;
 2051               }
 2052           }
 2053           if (has(CASE_INSENSITIVE))
 2054               return new CIBackRef(refNum, has(UNICODE_CASE));
 2055           else
 2056               return new BackRef(refNum);
 2057       }
 2058   
 2059       /**
 2060        * Parses an escape sequence to determine the actual value that needs
 2061        * to be matched.
 2062        * If -1 is returned and create was true a new object was added to the tree
 2063        * to handle the escape sequence.
 2064        * If the returned value is greater than zero, it is the value that
 2065        * matches the escape sequence.
 2066        */
 2067       private int escape(boolean inclass, boolean create) {
 2068           int ch = skip();
 2069           switch (ch) {
 2070           case '0':
 2071               return o();
 2072           case '1':
 2073           case '2':
 2074           case '3':
 2075           case '4':
 2076           case '5':
 2077           case '6':
 2078           case '7':
 2079           case '8':
 2080           case '9':
 2081               if (inclass) break;
 2082               if (create) {
 2083                   root = ref((ch - '0'));
 2084               }
 2085               return -1;
 2086           case 'A':
 2087               if (inclass) break;
 2088               if (create) root = new Begin();
 2089               return -1;
 2090           case 'B':
 2091               if (inclass) break;
 2092               if (create) root = new Bound(Bound.NONE);
 2093               return -1;
 2094           case 'C':
 2095               break;
 2096           case 'D':
 2097               if (create) root = new Ctype(ASCII.DIGIT).complement();
 2098               return -1;
 2099           case 'E':
 2100           case 'F':
 2101               break;
 2102           case 'G':
 2103               if (inclass) break;
 2104               if (create) root = new LastMatch();
 2105               return -1;
 2106           case 'H':
 2107           case 'I':
 2108           case 'J':
 2109           case 'K':
 2110           case 'L':
 2111           case 'M':
 2112           case 'N':
 2113           case 'O':
 2114           case 'P':
 2115           case 'Q':
 2116           case 'R':
 2117               break;
 2118           case 'S':
 2119               if (create) root = new Ctype(ASCII.SPACE).complement();
 2120               return -1;
 2121           case 'T':
 2122           case 'U':
 2123           case 'V':
 2124               break;
 2125           case 'W':
 2126               if (create) root = new Ctype(ASCII.WORD).complement();
 2127               return -1;
 2128           case 'X':
 2129           case 'Y':
 2130               break;
 2131           case 'Z':
 2132               if (inclass) break;
 2133               if (create) {
 2134                   if (has(UNIX_LINES))
 2135                       root = new UnixDollar(false);
 2136                   else
 2137                       root = new Dollar(false);
 2138               }
 2139               return -1;
 2140           case 'a':
 2141               return '\007';
 2142           case 'b':
 2143               if (inclass) break;
 2144               if (create) root = new Bound(Bound.BOTH);
 2145               return -1;
 2146           case 'c':
 2147               return c();
 2148           case 'd':
 2149               if (create) root = new Ctype(ASCII.DIGIT);
 2150               return -1;
 2151           case 'e':
 2152               return '\033';
 2153           case 'f':
 2154               return '\f';
 2155           case 'g':
 2156           case 'h':
 2157           case 'i':
 2158           case 'j':
 2159           case 'k':
 2160           case 'l':
 2161           case 'm':
 2162               break;
 2163           case 'n':
 2164               return '\n';
 2165           case 'o':
 2166           case 'p':
 2167           case 'q':
 2168               break;
 2169           case 'r':
 2170               return '\r';
 2171           case 's':
 2172               if (create) root = new Ctype(ASCII.SPACE);
 2173               return -1;
 2174           case 't':
 2175               return '\t';
 2176           case 'u':
 2177               return u();
 2178           case 'v':
 2179               return '\013';
 2180           case 'w':
 2181               if (create) root = new Ctype(ASCII.WORD);
 2182               return -1;
 2183           case 'x':
 2184               return x();
 2185           case 'y':
 2186               break;
 2187           case 'z':
 2188               if (inclass) break;
 2189               if (create) root = new End();
 2190               return -1;
 2191           default:
 2192               return ch;
 2193           }
 2194           throw error("Illegal/unsupported escape sequence");
 2195       }
 2196   
 2197       /**
 2198        * Parse a character class, and return the node that matches it.
 2199        *
 2200        * Consumes a ] on the way out if consume is true. Usually consume
 2201        * is true except for the case of [abc&&def] where def is a separate
 2202        * right hand node with "understood" brackets.
 2203        */
 2204       private CharProperty clazz(boolean consume) {
 2205           CharProperty prev = null;
 2206           CharProperty node = null;
 2207           BitClass bits = new BitClass();
 2208           boolean include = true;
 2209           boolean firstInClass = true;
 2210           int ch = next();
 2211           for (;;) {
 2212               switch (ch) {
 2213                   case '^':
 2214                       // Negates if first char in a class, otherwise literal
 2215                       if (firstInClass) {
 2216                           if (temp[cursor-1] != '[')
 2217                               break;
 2218                           ch = next();
 2219                           include = !include;
 2220                           continue;
 2221                       } else {
 2222                           // ^ not first in class, treat as literal
 2223                           break;
 2224                       }
 2225                   case '[':
 2226                       firstInClass = false;
 2227                       node = clazz(true);
 2228                       if (prev == null)
 2229                           prev = node;
 2230                       else
 2231                           prev = union(prev, node);
 2232                       ch = peek();
 2233                       continue;
 2234                   case '&':
 2235                       firstInClass = false;
 2236                       ch = next();
 2237                       if (ch == '&') {
 2238                           ch = next();
 2239                           CharProperty rightNode = null;
 2240                           while (ch != ']' && ch != '&') {
 2241                               if (ch == '[') {
 2242                                   if (rightNode == null)
 2243                                       rightNode = clazz(true);
 2244                                   else
 2245                                       rightNode = union(rightNode, clazz(true));
 2246                               } else { // abc&&def
 2247                                   unread();
 2248                                   rightNode = clazz(false);
 2249                               }
 2250                               ch = peek();
 2251                           }
 2252                           if (rightNode != null)
 2253                               node = rightNode;
 2254                           if (prev == null) {
 2255                               if (rightNode == null)
 2256                                   throw error("Bad class syntax");
 2257                               else
 2258                                   prev = rightNode;
 2259                           } else {
 2260                               prev = intersection(prev, node);
 2261                           }
 2262                       } else {
 2263                           // treat as a literal &
 2264                           unread();
 2265                           break;
 2266                       }
 2267                       continue;
 2268                   case 0:
 2269                       firstInClass = false;
 2270                       if (cursor >= patternLength)
 2271                           throw error("Unclosed character class");
 2272                       break;
 2273                   case ']':
 2274                       firstInClass = false;
 2275                       if (prev != null) {
 2276                           if (consume)
 2277                               next();
 2278                           return prev;
 2279                       }
 2280                       break;
 2281                   default:
 2282                       firstInClass = false;
 2283                       break;
 2284               }
 2285               node = range(bits);
 2286               if (include) {
 2287                   if (prev == null) {
 2288                       prev = node;
 2289                   } else {
 2290                       if (prev != node)
 2291                           prev = union(prev, node);
 2292                   }
 2293               } else {
 2294                   if (prev == null) {
 2295                       prev = node.complement();
 2296                   } else {
 2297                       if (prev != node)
 2298                           prev = setDifference(prev, node);
 2299                   }
 2300               }
 2301               ch = peek();
 2302           }
 2303       }
 2304   
 2305       private CharProperty bitsOrSingle(BitClass bits, int ch) {
 2306           /* Bits can only handle codepoints in [u+0000-u+00ff] range.
 2307              Use "single" node instead of bits when dealing with unicode
 2308              case folding for codepoints listed below.
 2309              (1)Uppercase out of range: u+00ff, u+00b5
 2310                 toUpperCase(u+00ff) -> u+0178
 2311                 toUpperCase(u+00b5) -> u+039c
 2312              (2)LatinSmallLetterLongS u+17f
 2313                 toUpperCase(u+017f) -> u+0053
 2314              (3)LatinSmallLetterDotlessI u+131
 2315                 toUpperCase(u+0131) -> u+0049
 2316              (4)LatinCapitalLetterIWithDotAbove u+0130
 2317                 toLowerCase(u+0130) -> u+0069
 2318              (5)KelvinSign u+212a
 2319                 toLowerCase(u+212a) ==> u+006B
 2320              (6)AngstromSign u+212b
 2321                 toLowerCase(u+212b) ==> u+00e5
 2322           */
 2323           int d;
 2324           if (ch < 256 &&
 2325               !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
 2326                 (ch == 0xff || ch == 0xb5 ||
 2327                  ch == 0x49 || ch == 0x69 ||  //I and i
 2328                  ch == 0x53 || ch == 0x73 ||  //S and s
 2329                  ch == 0x4b || ch == 0x6b ||  //K and k
 2330                  ch == 0xc5 || ch == 0xe5)))  //A+ring
 2331               return bits.add(ch, flags());
 2332           return newSingle(ch);
 2333       }
 2334   
 2335       /**
 2336        * Parse a single character or a character range in a character class
 2337        * and return its representative node.
 2338        */
 2339       private CharProperty range(BitClass bits) {
 2340           int ch = peek();
 2341           if (ch == '\\') {
 2342               ch = nextEscaped();
 2343               if (ch == 'p' || ch == 'P') { // A property
 2344                   boolean comp = (ch == 'P');
 2345                   boolean oneLetter = true;
 2346                   // Consume { if present
 2347                   ch = next();
 2348                   if (ch != '{')
 2349                       unread();
 2350                   else
 2351                       oneLetter = false;
 2352                   return family(oneLetter).maybeComplement(comp);
 2353               } else { // ordinary escape
 2354                   unread();
 2355                   ch = escape(true, true);
 2356                   if (ch == -1)
 2357                       return (CharProperty) root;
 2358               }
 2359           } else {
 2360               ch = single();
 2361           }
 2362           if (ch >= 0) {
 2363               if (peek() == '-') {
 2364                   int endRange = temp[cursor+1];
 2365                   if (endRange == '[') {
 2366                       return bitsOrSingle(bits, ch);
 2367                   }
 2368                   if (endRange != ']') {
 2369                       next();
 2370                       int m = single();
 2371                       if (m < ch)
 2372                           throw error("Illegal character range");
 2373                       if (has(CASE_INSENSITIVE))
 2374                           return caseInsensitiveRangeFor(ch, m);
 2375                       else
 2376                           return rangeFor(ch, m);
 2377                   }
 2378               }
 2379               return bitsOrSingle(bits, ch);
 2380           }
 2381           throw error("Unexpected character '"+((char)ch)+"'");
 2382       }
 2383   
 2384       private int single() {
 2385           int ch = peek();
 2386           switch (ch) {
 2387           case '\\':
 2388               return escape(true, false);
 2389           default:
 2390               next();
 2391               return ch;
 2392           }
 2393       }
 2394   
 2395       /**
 2396        * Parses a Unicode character family and returns its representative node.
 2397        */
 2398       private CharProperty family(boolean singleLetter) {
 2399           next();
 2400           String name;
 2401   
 2402           if (singleLetter) {
 2403               int c = temp[cursor];
 2404               if (!Character.isSupplementaryCodePoint(c)) {
 2405                   name = String.valueOf((char)c);
 2406               } else {
 2407                   name = new String(temp, cursor, 1);
 2408               }
 2409               read();
 2410           } else {
 2411               int i = cursor;
 2412               mark('}');
 2413               while(read() != '}') {
 2414               }
 2415               mark('\000');
 2416               int j = cursor;
 2417               if (j > patternLength)
 2418                   throw error("Unclosed character family");
 2419               if (i + 1 >= j)
 2420                   throw error("Empty character family");
 2421               name = new String(temp, i, j-i-1);
 2422           }
 2423   
 2424           if (name.startsWith("In")) {
 2425               return unicodeBlockPropertyFor(name.substring(2));
 2426           } else {
 2427               if (name.startsWith("Is"))
 2428                   name = name.substring(2);
 2429               return charPropertyNodeFor(name);
 2430           }
 2431       }
 2432   
 2433       /**
 2434        * Returns a CharProperty matching all characters in a UnicodeBlock.
 2435        */
 2436       private CharProperty unicodeBlockPropertyFor(String name) {
 2437           final Character.UnicodeBlock block;
 2438           try {
 2439               block = Character.UnicodeBlock.forName(name);
 2440           } catch (IllegalArgumentException iae) {
 2441               throw error("Unknown character block name {" + name + "}");
 2442           }
 2443           return new CharProperty() {
 2444                   boolean isSatisfiedBy(int ch) {
 2445                       return block == Character.UnicodeBlock.of(ch);}};
 2446       }
 2447   
 2448       /**
 2449        * Returns a CharProperty matching all characters in a named property.
 2450        */
 2451       private CharProperty charPropertyNodeFor(String name) {
 2452           CharProperty p = CharPropertyNames.charPropertyFor(name);
 2453           if (p == null)
 2454               throw error("Unknown character property name {" + name + "}");
 2455           return p;
 2456       }
 2457   
 2458       /**
 2459        * Parses a group and returns the head node of a set of nodes that process
 2460        * the group. Sometimes a double return system is used where the tail is
 2461        * returned in root.
 2462        */
 2463       private Node group0() {
 2464           boolean capturingGroup = false;
 2465           Node head = null;
 2466           Node tail = null;
 2467           int save = flags;
 2468           root = null;
 2469           int ch = next();
 2470           if (ch == '?') {
 2471               ch = skip();
 2472               switch (ch) {
 2473               case ':':   //  (?:xxx) pure group
 2474                   head = createGroup(true);
 2475                   tail = root;
 2476                   head.next = expr(tail);
 2477                   break;
 2478               case '=':   // (?=xxx) and (?!xxx) lookahead
 2479               case '!':
 2480                   head = createGroup(true);
 2481                   tail = root;
 2482                   head.next = expr(tail);
 2483                   if (ch == '=') {
 2484                       head = tail = new Pos(head);
 2485                   } else {
 2486                       head = tail = new Neg(head);
 2487                   }
 2488                   break;
 2489               case '>':   // (?>xxx)  independent group
 2490                   head = createGroup(true);
 2491                   tail = root;
 2492                   head.next = expr(tail);
 2493                   head = tail = new Ques(head, INDEPENDENT);
 2494                   break;
 2495               case '<':   // (?<xxx)  look behind
 2496                   ch = read();
 2497                   int start = cursor;
 2498                   head = createGroup(true);
 2499                   tail = root;
 2500                   head.next = expr(tail);
 2501                   tail.next = lookbehindEnd;
 2502                   TreeInfo info = new TreeInfo();
 2503                   head.study(info);
 2504                   if (info.maxValid == false) {
 2505                       throw error("Look-behind group does not have "
 2506                                   + "an obvious maximum length");
 2507                   }
 2508                   boolean hasSupplementary = findSupplementary(start, patternLength);
 2509                   if (ch == '=') {
 2510                       head = tail = (hasSupplementary ?
 2511                                      new BehindS(head, info.maxLength,
 2512                                                  info.minLength) :
 2513                                      new Behind(head, info.maxLength,
 2514                                                 info.minLength));
 2515                   } else if (ch == '!') {
 2516                       head = tail = (hasSupplementary ?
 2517                                      new NotBehindS(head, info.maxLength,
 2518                                                     info.minLength) :
 2519                                      new NotBehind(head, info.maxLength,
 2520                                                    info.minLength));
 2521                   } else {
 2522                       throw error("Unknown look-behind group");
 2523                   }
 2524                   break;
 2525               case '$':
 2526               case '@':
 2527                   throw error("Unknown group type");
 2528               default:    // (?xxx:) inlined match flags
 2529                   unread();
 2530                   addFlag();
 2531                   ch = read();
 2532                   if (ch == ')') {
 2533                       return null;    // Inline modifier only
 2534                   }
 2535                   if (ch != ':') {
 2536                       throw error("Unknown inline modifier");
 2537                   }
 2538                   head = createGroup(true);
 2539                   tail = root;
 2540                   head.next = expr(tail);
 2541                   break;
 2542               }
 2543           } else { // (xxx) a regular group
 2544               capturingGroup = true;
 2545               head = createGroup(false);
 2546               tail = root;
 2547               head.next = expr(tail);
 2548           }
 2549   
 2550           accept(')', "Unclosed group");
 2551           flags = save;
 2552   
 2553           // Check for quantifiers
 2554           Node node = closure(head);
 2555           if (node == head) { // No closure
 2556               root = tail;
 2557               return node;    // Dual return
 2558           }
 2559           if (head == tail) { // Zero length assertion
 2560               root = node;
 2561               return node;    // Dual return
 2562           }
 2563   
 2564           if (node instanceof Ques) {
 2565               Ques ques = (Ques) node;
 2566               if (ques.type == POSSESSIVE) {
 2567                   root = node;
 2568                   return node;
 2569               }
 2570               tail.next = new BranchConn();
 2571               tail = tail.next;
 2572               if (ques.type == GREEDY) {
 2573                   head = new Branch(head, null, tail);
 2574               } else { // Reluctant quantifier
 2575                   head = new Branch(null, head, tail);
 2576               }
 2577               root = tail;
 2578               return head;
 2579           } else if (node instanceof Curly) {
 2580               Curly curly = (Curly) node;
 2581               if (curly.type == POSSESSIVE) {
 2582                   root = node;
 2583                   return node;
 2584               }
 2585               // Discover if the group is deterministic
 2586               TreeInfo info = new TreeInfo();
 2587               if (head.study(info)) { // Deterministic
 2588                   GroupTail temp = (GroupTail) tail;
 2589                   head = root = new GroupCurly(head.next, curly.cmin,
 2590                                      curly.cmax, curly.type,
 2591                                      ((GroupTail)tail).localIndex,
 2592                                      ((GroupTail)tail).groupIndex,
 2593                                                capturingGroup);
 2594                   return head;
 2595               } else { // Non-deterministic
 2596                   int temp = ((GroupHead) head).localIndex;
 2597                   Loop loop;
 2598                   if (curly.type == GREEDY)
 2599                       loop = new Loop(this.localCount, temp);
 2600                   else  // Reluctant Curly
 2601                       loop = new LazyLoop(this.localCount, temp);
 2602                   Prolog prolog = new Prolog(loop);
 2603                   this.localCount += 1;
 2604                   loop.cmin = curly.cmin;
 2605                   loop.cmax = curly.cmax;
 2606                   loop.body = head;
 2607                   tail.next = loop;
 2608                   root = loop;
 2609                   return prolog; // Dual return
 2610               }
 2611           }
 2612           throw error("Internal logic error");
 2613       }
 2614   
 2615       /**
 2616        * Create group head and tail nodes using double return. If the group is
 2617        * created with anonymous true then it is a pure group and should not
 2618        * affect group counting.
 2619        */
 2620       private Node createGroup(boolean anonymous) {
 2621           int localIndex = localCount++;
 2622           int groupIndex = 0;
 2623           if (!anonymous)
 2624               groupIndex = capturingGroupCount++;
 2625           GroupHead head = new GroupHead(localIndex);
 2626           root = new GroupTail(localIndex, groupIndex);
 2627           if (!anonymous && groupIndex < 10)
 2628               groupNodes[groupIndex] = head;
 2629           return head;
 2630       }
 2631   
 2632       /**
 2633        * Parses inlined match flags and set them appropriately.
 2634        */
 2635       private void addFlag() {
 2636           int ch = peek();
 2637           for (;;) {
 2638               switch (ch) {
 2639               case 'i':
 2640                   flags |= CASE_INSENSITIVE;
 2641                   break;
 2642               case 'm':
 2643                   flags |= MULTILINE;
 2644                   break;
 2645               case 's':
 2646                   flags |= DOTALL;
 2647                   break;
 2648               case 'd':
 2649                   flags |= UNIX_LINES;
 2650                   break;
 2651               case 'u':
 2652                   flags |= UNICODE_CASE;
 2653                   break;
 2654               case 'c':
 2655                   flags |= CANON_EQ;
 2656                   break;
 2657               case 'x':
 2658                   flags |= COMMENTS;
 2659                   break;
 2660               case '-': // subFlag then fall through
 2661                   ch = next();
 2662                   subFlag();
 2663               default:
 2664                   return;
 2665               }
 2666               ch = next();
 2667           }
 2668       }
 2669   
 2670       /**
 2671        * Parses the second part of inlined match flags and turns off
 2672        * flags appropriately.
 2673        */
 2674       private void subFlag() {
 2675           int ch = peek();
 2676           for (;;) {
 2677               switch (ch) {
 2678               case 'i':
 2679                   flags &= ~CASE_INSENSITIVE;
 2680                   break;
 2681               case 'm':
 2682                   flags &= ~MULTILINE;
 2683                   break;
 2684               case 's':
 2685                   flags &= ~DOTALL;
 2686                   break;
 2687               case 'd':
 2688                   flags &= ~UNIX_LINES;
 2689                   break;
 2690               case 'u':
 2691                   flags &= ~UNICODE_CASE;
 2692                   break;
 2693               case 'c':
 2694                   flags &= ~CANON_EQ;
 2695                   break;
 2696               case 'x':
 2697                   flags &= ~COMMENTS;
 2698                   break;
 2699               default:
 2700                   return;
 2701               }
 2702               ch = next();
 2703           }
 2704       }
 2705   
 2706       static final int MAX_REPS   = 0x7FFFFFFF;
 2707   
 2708       static final int GREEDY     = 0;
 2709   
 2710       static final int LAZY       = 1;
 2711   
 2712       static final int POSSESSIVE = 2;
 2713   
 2714       static final int INDEPENDENT = 3;
 2715   
 2716       /**
 2717        * Processes repetition. If the next character peeked is a quantifier
 2718        * then new nodes must be appended to handle the repetition.
 2719        * Prev could be a single or a group, so it could be a chain of nodes.
 2720        */
 2721       private Node closure(Node prev) {
 2722           Node atom;
 2723           int ch = peek();
 2724           switch (ch) {
 2725           case '?':
 2726               ch = next();
 2727               if (ch == '?') {
 2728                   next();
 2729                   return new Ques(prev, LAZY);
 2730               } else if (ch == '+') {
 2731                   next();
 2732                   return new Ques(prev, POSSESSIVE);
 2733               }
 2734               return new Ques(prev, GREEDY);
 2735           case '*':
 2736               ch = next();
 2737               if (ch == '?') {
 2738                   next();
 2739                   return new Curly(prev, 0, MAX_REPS, LAZY);
 2740               } else if (ch == '+') {
 2741                   next();
 2742                   return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
 2743               }
 2744               return new Curly(prev, 0, MAX_REPS, GREEDY);
 2745           case '+':
 2746               ch = next();
 2747               if (ch == '?') {
 2748                   next();
 2749                   return new Curly(prev, 1, MAX_REPS, LAZY);
 2750               } else if (ch == '+') {
 2751                   next();
 2752                   return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
 2753               }
 2754               return new Curly(prev, 1, MAX_REPS, GREEDY);
 2755           case '{':
 2756               ch = temp[cursor+1];
 2757               if (ASCII.isDigit(ch)) {
 2758                   skip();
 2759                   int cmin = 0;
 2760                   do {
 2761                       cmin = cmin * 10 + (ch - '0');
 2762                   } while (ASCII.isDigit(ch = read()));
 2763                   int cmax = cmin;
 2764                   if (ch == ',') {
 2765                       ch = read();
 2766                       cmax = MAX_REPS;
 2767                       if (ch != '}') {
 2768                           cmax = 0;
 2769                           while (ASCII.isDigit(ch)) {
 2770                               cmax = cmax * 10 + (ch - '0');
 2771                               ch = read();
 2772                           }
 2773                       }
 2774                   }
 2775                   if (ch != '}')
 2776                       throw error("Unclosed counted closure");
 2777                   if (((cmin) | (cmax) | (cmax - cmin)) < 0)
 2778                       throw error("Illegal repetition range");
 2779                   Curly curly;
 2780                   ch = peek();
 2781                   if (ch == '?') {
 2782                       next();
 2783                       curly = new Curly(prev, cmin, cmax, LAZY);
 2784                   } else if (ch == '+') {
 2785                       next();
 2786                       curly = new Curly(prev, cmin, cmax, POSSESSIVE);
 2787                   } else {
 2788                       curly = new Curly(prev, cmin, cmax, GREEDY);
 2789                   }
 2790                   return curly;
 2791               } else {
 2792                   throw error("Illegal repetition");
 2793               }
 2794           default:
 2795               return prev;
 2796           }
 2797       }
 2798   
 2799       /**
 2800        *  Utility method for parsing control escape sequences.
 2801        */
 2802       private int c() {
 2803           if (cursor < patternLength) {
 2804               return read() ^ 64;
 2805           }
 2806           throw error("Illegal control escape sequence");
 2807       }
 2808   
 2809       /**
 2810        *  Utility method for parsing octal escape sequences.
 2811        */
 2812       private int o() {
 2813           int n = read();
 2814           if (((n-'0')|('7'-n)) >= 0) {
 2815               int m = read();
 2816               if (((m-'0')|('7'-m)) >= 0) {
 2817                   int o = read();
 2818                   if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
 2819                       return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
 2820                   }
 2821                   unread();
 2822                   return (n - '0') * 8 + (m - '0');
 2823               }
 2824               unread();
 2825               return (n - '0');
 2826           }
 2827           throw error("Illegal octal escape sequence");
 2828       }
 2829   
 2830       /**
 2831        *  Utility method for parsing hexadecimal escape sequences.
 2832        */
 2833       private int x() {
 2834           int n = read();
 2835           if (ASCII.isHexDigit(n)) {
 2836               int m = read();
 2837               if (ASCII.isHexDigit(m)) {
 2838                   return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
 2839               }
 2840           }
 2841           throw error("Illegal hexadecimal escape sequence");
 2842       }
 2843   
 2844       /**
 2845        *  Utility method for parsing unicode escape sequences.
 2846        */
 2847       private int cursor() {
 2848           return cursor;
 2849       }
 2850   
 2851       private void setcursor(int pos) {
 2852           cursor = pos;
 2853       }
 2854   
 2855       private int uxxxx() {
 2856           int n = 0;
 2857           for (int i = 0; i < 4; i++) {
 2858               int ch = read();
 2859               if (!ASCII.isHexDigit(ch)) {
 2860                   throw error("Illegal Unicode escape sequence");
 2861               }
 2862               n = n * 16 + ASCII.toDigit(ch);
 2863           }
 2864           return n;
 2865       }
 2866   
 2867       private int u() {
 2868           int n = uxxxx();
 2869           if (Character.isHighSurrogate((char)n)) {
 2870               int cur = cursor();
 2871               if (read() == '\\' && read() == 'u') {
 2872                   int n2 = uxxxx();
 2873                   if (Character.isLowSurrogate((char)n2))
 2874                       return Character.toCodePoint((char)n, (char)n2);
 2875               }
 2876               setcursor(cur);
 2877           }
 2878           return n;
 2879       }
 2880   
 2881       //
 2882       // Utility methods for code point support
 2883       //
 2884   
 2885       /**
 2886        * Tests a surrogate value.
 2887        */
 2888       private static final boolean isSurrogate(int c) {
 2889           return c >= Character.MIN_HIGH_SURROGATE && c <= Character.MAX_LOW_SURROGATE;
 2890       }
 2891   
 2892       private static final int countChars(CharSequence seq, int index,
 2893                                           int lengthInCodePoints) {
 2894           // optimization
 2895           if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
 2896               assert (index >= 0 && index < seq.length());
 2897               return 1;
 2898           }
 2899           int length = seq.length();
 2900           int x = index;
 2901           if (lengthInCodePoints >= 0) {
 2902               assert (index >= 0 && index < length);
 2903               for (int i = 0; x < length && i < lengthInCodePoints; i++) {
 2904                   if (Character.isHighSurrogate(seq.charAt(x++))) {
 2905                       if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
 2906                           x++;
 2907                       }
 2908                   }
 2909               }
 2910               return x - index;
 2911           }
 2912   
 2913           assert (index >= 0 && index <= length);
 2914           if (index == 0) {
 2915               return 0;
 2916           }
 2917           int len = -lengthInCodePoints;
 2918           for (int i = 0; x > 0 && i < len; i++) {
 2919               if (Character.isLowSurrogate(seq.charAt(--x))) {
 2920                   if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
 2921                       x--;
 2922                   }
 2923               }
 2924           }
 2925           return index - x;
 2926       }
 2927   
 2928       private static final int countCodePoints(CharSequence seq) {
 2929           int length = seq.length();
 2930           int n = 0;
 2931           for (int i = 0; i < length; ) {
 2932               n++;
 2933               if (Character.isHighSurrogate(seq.charAt(i++))) {
 2934                   if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
 2935                       i++;
 2936                   }
 2937               }
 2938           }
 2939           return n;
 2940       }
 2941   
 2942       /**
 2943        *  Creates a bit vector for matching Latin-1 values. A normal BitClass
 2944        *  never matches values above Latin-1, and a complemented BitClass always
 2945        *  matches values above Latin-1.
 2946        */
 2947       private static final class BitClass extends BmpCharProperty {
 2948           final boolean[] bits;
 2949           BitClass() { bits = new boolean[256]; }
 2950           private BitClass(boolean[] bits) { this.bits = bits; }
 2951           BitClass add(int c, int flags) {
 2952               assert c >= 0 && c <= 255;
 2953               if ((flags & CASE_INSENSITIVE) != 0) {
 2954                   if (ASCII.isAscii(c)) {
 2955                       bits[ASCII.toUpper(c)] = true;
 2956                       bits[ASCII.toLower(c)] = true;
 2957                   } else if ((flags & UNICODE_CASE) != 0) {
 2958                       bits[Character.toLowerCase(c)] = true;
 2959                       bits[Character.toUpperCase(c)] = true;
 2960                   }
 2961               }
 2962               bits[c] = true;
 2963               return this;
 2964           }
 2965           boolean isSatisfiedBy(int ch) {
 2966               return ch < 256 && bits[ch];
 2967           }
 2968       }
 2969   
 2970       /**
 2971        *  Returns a suitably optimized, single character matcher.
 2972        */
 2973       private CharProperty newSingle(final int ch) {
 2974           if (has(CASE_INSENSITIVE)) {
 2975               int lower, upper;
 2976               if (has(UNICODE_CASE)) {
 2977                   upper = Character.toUpperCase(ch);
 2978                   lower = Character.toLowerCase(upper);
 2979                   if (upper != lower)
 2980                       return new SingleU(lower);
 2981               } else if (ASCII.isAscii(ch)) {
 2982                   lower = ASCII.toLower(ch);
 2983                   upper = ASCII.toUpper(ch);
 2984                   if (lower != upper)
 2985                       return new SingleI(lower, upper);
 2986               }
 2987           }
 2988           if (isSupplementary(ch))
 2989               return new SingleS(ch);    // Match a given Unicode character
 2990           return new Single(ch);         // Match a given BMP character
 2991       }
 2992   
 2993       /**
 2994        *  Utility method for creating a string slice matcher.
 2995        */
 2996       private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
 2997           int[] tmp = new int[count];
 2998           if (has(CASE_INSENSITIVE)) {
 2999               if (has(UNICODE_CASE)) {
 3000                   for (int i = 0; i < count; i++) {
 3001                       tmp[i] = Character.toLowerCase(
 3002                                    Character.toUpperCase(buf[i]));
 3003                   }
 3004                   return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
 3005               }
 3006               for (int i = 0; i < count; i++) {
 3007                   tmp[i] = ASCII.toLower(buf[i]);
 3008               }
 3009               return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
 3010           }
 3011           for (int i = 0; i < count; i++) {
 3012               tmp[i] = buf[i];
 3013           }
 3014           return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
 3015       }
 3016   
 3017       /**
 3018        * The following classes are the building components of the object
 3019        * tree that represents a compiled regular expression. The object tree
 3020        * is made of individual elements that handle constructs in the Pattern.
 3021        * Each type of object knows how to match its equivalent construct with
 3022        * the match() method.
 3023        */
 3024   
 3025       /**
 3026        * Base class for all node classes. Subclasses should override the match()
 3027        * method as appropriate. This class is an accepting node, so its match()
 3028        * always returns true.
 3029        */
 3030       static class Node extends Object {
 3031           Node next;
 3032           Node() {
 3033               next = Pattern.accept;
 3034           }
 3035           /**
 3036            * This method implements the classic accept node.
 3037            */
 3038           boolean match(Matcher matcher, int i, CharSequence seq) {
 3039               matcher.last = i;
 3040               matcher.groups[0] = matcher.first;
 3041               matcher.groups[1] = matcher.last;
 3042               return true;
 3043           }
 3044           /**
 3045            * This method is good for all zero length assertions.
 3046            */
 3047           boolean study(TreeInfo info) {
 3048               if (next != null) {
 3049                   return next.study(info);
 3050               } else {
 3051                   return info.deterministic;
 3052               }
 3053           }
 3054       }
 3055   
 3056       static class LastNode extends Node {
 3057           /**
 3058            * This method implements the classic accept node with
 3059            * the addition of a check to see if the match occurred
 3060            * using all of the input.
 3061            */
 3062           boolean match(Matcher matcher, int i, CharSequence seq) {
 3063               if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
 3064                   return false;
 3065               matcher.last = i;
 3066               matcher.groups[0] = matcher.first;
 3067               matcher.groups[1] = matcher.last;
 3068               return true;
 3069           }
 3070       }
 3071   
 3072       /**
 3073        * Used for REs that can start anywhere within the input string.
 3074        * This basically tries to match repeatedly at each spot in the
 3075        * input string, moving forward after each try. An anchored search
 3076        * or a BnM will bypass this node completely.
 3077        */
 3078       static class Start extends Node {
 3079           int minLength;
 3080           Start(Node node) {
 3081               this.next = node;
 3082               TreeInfo info = new TreeInfo();
 3083               next.study(info);
 3084               minLength = info.minLength;
 3085           }
 3086           boolean match(Matcher matcher, int i, CharSequence seq) {
 3087               if (i > matcher.to - minLength) {
 3088                   matcher.hitEnd = true;
 3089                   return false;
 3090               }
 3091               boolean ret = false;
 3092               int guard = matcher.to - minLength;
 3093               for (; i <= guard; i++) {
 3094                   if (ret = next.match(matcher, i, seq))
 3095                       break;
 3096                   if (i == guard)
 3097                       matcher.hitEnd = true;
 3098               }
 3099               if (ret) {
 3100                   matcher.first = i;
 3101                   matcher.groups[0] = matcher.first;
 3102                   matcher.groups[1] = matcher.last;
 3103               }
 3104               return ret;
 3105           }
 3106           boolean study(TreeInfo info) {
 3107               next.study(info);
 3108               info.maxValid = false;
 3109               info.deterministic = false;
 3110               return false;
 3111           }
 3112       }
 3113   
 3114       /*
 3115        * StartS supports supplementary characters, including unpaired surrogates.
 3116        */
 3117       static final class StartS extends Start {
 3118           StartS(Node node) {
 3119               super(node);
 3120           }
 3121           boolean match(Matcher matcher, int i, CharSequence seq) {
 3122               if (i > matcher.to - minLength) {
 3123                   matcher.hitEnd = true;
 3124                   return false;
 3125               }
 3126               boolean ret = false;
 3127               int guard = matcher.to - minLength;
 3128               while (i <= guard) {
 3129                   if ((ret = next.match(matcher, i, seq)) || i == guard)
 3130                       break;
 3131                   // Optimization to move to the next character. This is
 3132                   // faster than countChars(seq, i, 1).
 3133                   if (Character.isHighSurrogate(seq.charAt(i++))) {
 3134                       if (i < seq.length() && Character.isLowSurrogate(seq.charAt(i))) {
 3135                           i++;
 3136                       }
 3137                   }
 3138                   if (i == guard)
 3139                       matcher.hitEnd = true;
 3140               }
 3141               if (ret) {
 3142                   matcher.first = i;
 3143                   matcher.groups[0] = matcher.first;
 3144                   matcher.groups[1] = matcher.last;
 3145               }
 3146               return ret;
 3147           }
 3148       }
 3149   
 3150       /**
 3151        * Node to anchor at the beginning of input. This object implements the
 3152        * match for a \A sequence, and the caret anchor will use this if not in
 3153        * multiline mode.
 3154        */
 3155       static final class Begin extends Node {
 3156           boolean match(Matcher matcher, int i, CharSequence seq) {
 3157               int fromIndex = (matcher.anchoringBounds) ?
 3158                   matcher.from : 0;
 3159               if (i == fromIndex && next.match(matcher, i, seq)) {
 3160                   matcher.first = i;
 3161                   matcher.groups[0] = i;
 3162                   matcher.groups[1] = matcher.last;
 3163                   return true;
 3164               } else {
 3165                   return false;
 3166               }
 3167           }
 3168       }
 3169   
 3170       /**
 3171        * Node to anchor at the end of input. This is the absolute end, so this
 3172        * should not match at the last newline before the end as $ will.
 3173        */
 3174       static final class End extends Node {
 3175           boolean match(Matcher matcher, int i, CharSequence seq) {
 3176               int endIndex = (matcher.anchoringBounds) ?
 3177                   matcher.to : matcher.getTextLength();
 3178               if (i == endIndex) {
 3179                   matcher.hitEnd = true;
 3180                   return next.match(matcher, i, seq);
 3181               }
 3182               return false;
 3183           }
 3184       }
 3185   
 3186       /**
 3187        * Node to anchor at the beginning of a line. This is essentially the
 3188        * object to match for the multiline ^.
 3189        */
 3190       static final class Caret extends Node {
 3191           boolean match(Matcher matcher, int i, CharSequence seq) {
 3192               int startIndex = matcher.from;
 3193               int endIndex = matcher.to;
 3194               if (!matcher.anchoringBounds) {
 3195                   startIndex = 0;
 3196                   endIndex = matcher.getTextLength();
 3197               }
 3198               // Perl does not match ^ at end of input even after newline
 3199               if (i == endIndex) {
 3200                   matcher.hitEnd = true;
 3201                   return false;
 3202               }
 3203               if (i > startIndex) {
 3204                   char ch = seq.charAt(i-1);
 3205                   if (ch != '\n' && ch != '\r'
 3206                       && (ch|1) != '\u2029'
 3207                       && ch != '\u0085' ) {
 3208                       return false;
 3209                   }
 3210                   // Should treat /r/n as one newline
 3211                   if (ch == '\r' && seq.charAt(i) == '\n')
 3212                       return false;
 3213               }
 3214               return next.match(matcher, i, seq);
 3215           }
 3216       }
 3217   
 3218       /**
 3219        * Node to anchor at the beginning of a line when in unixdot mode.
 3220        */
 3221       static final class UnixCaret extends Node {
 3222           boolean match(Matcher matcher, int i, CharSequence seq) {
 3223               int startIndex = matcher.from;
 3224               int endIndex = matcher.to;
 3225               if (!matcher.anchoringBounds) {
 3226                   startIndex = 0;
 3227                   endIndex = matcher.getTextLength();
 3228               }
 3229               // Perl does not match ^ at end of input even after newline
 3230               if (i == endIndex) {
 3231                   matcher.hitEnd = true;
 3232                   return false;
 3233               }
 3234               if (i > startIndex) {
 3235                   char ch = seq.charAt(i-1);
 3236                   if (ch != '\n') {
 3237                       return false;
 3238                   }
 3239               }
 3240               return next.match(matcher, i, seq);
 3241           }
 3242       }
 3243   
 3244       /**
 3245        * Node to match the location where the last match ended.
 3246        * This is used for the \G construct.
 3247        */
 3248       static final class LastMatch extends Node {
 3249           boolean match(Matcher matcher, int i, CharSequence seq) {
 3250               if (i != matcher.oldLast)
 3251                   return false;
 3252               return next.match(matcher, i, seq);
 3253           }
 3254       }
 3255   
 3256       /**
 3257        * Node to anchor at the end of a line or the end of input based on the
 3258        * multiline mode.
 3259        *
 3260        * When not in multiline mode, the $ can only match at the very end
 3261        * of the input, unless the input ends in a line terminator in which
 3262        * it matches right before the last line terminator.
 3263        *
 3264        * Note that \r\n is considered an atomic line terminator.
 3265        *
 3266        * Like ^ the $ operator matches at a position, it does not match the
 3267        * line terminators themselves.
 3268        */
 3269       static final class Dollar extends Node {
 3270           boolean multiline;
 3271           Dollar(boolean mul) {
 3272               multiline = mul;
 3273           }
 3274           boolean match(Matcher matcher, int i, CharSequence seq) {
 3275               int endIndex = (matcher.anchoringBounds) ?
 3276                   matcher.to : matcher.getTextLength();
 3277               if (!multiline) {
 3278                   if (i < endIndex - 2)
 3279                       return false;
 3280                   if (i == endIndex - 2) {
 3281                       char ch = seq.charAt(i);
 3282                       if (ch != '\r')
 3283                           return false;
 3284                       ch = seq.charAt(i + 1);
 3285                       if (ch != '\n')
 3286                           return false;
 3287                   }
 3288               }
 3289               // Matches before any line terminator; also matches at the
 3290               // end of input
 3291               // Before line terminator:
 3292               // If multiline, we match here no matter what
 3293               // If not multiline, fall through so that the end
 3294               // is marked as hit; this must be a /r/n or a /n
 3295               // at the very end so the end was hit; more input
 3296               // could make this not match here
 3297               if (i < endIndex) {
 3298                   char ch = seq.charAt(i);
 3299                    if (ch == '\n') {
 3300                        // No match between \r\n
 3301                        if (i > 0 && seq.charAt(i-1) == '\r')
 3302                            return false;
 3303                        if (multiline)
 3304                            return next.match(matcher, i, seq);
 3305                    } else if (ch == '\r' || ch == '\u0085' ||
 3306                               (ch|1) == '\u2029') {
 3307                        if (multiline)
 3308                            return next.match(matcher, i, seq);
 3309                    } else { // No line terminator, no match
 3310                        return false;
 3311                    }
 3312               }
 3313               // Matched at current end so hit end
 3314               matcher.hitEnd = true;
 3315               // If a $ matches because of end of input, then more input
 3316               // could cause it to fail!
 3317               matcher.requireEnd = true;
 3318               return next.match(matcher, i, seq);
 3319           }
 3320           boolean study(TreeInfo info) {
 3321               next.study(info);
 3322               return info.deterministic;
 3323           }
 3324       }
 3325   
 3326       /**
 3327        * Node to anchor at the end of a line or the end of input based on the
 3328        * multiline mode when in unix lines mode.
 3329        */
 3330       static final class UnixDollar extends Node {
 3331           boolean multiline;
 3332           UnixDollar(boolean mul) {
 3333               multiline = mul;
 3334           }
 3335           boolean match(Matcher matcher, int i, CharSequence seq) {
 3336               int endIndex = (matcher.anchoringBounds) ?
 3337                   matcher.to : matcher.getTextLength();
 3338               if (i < endIndex) {
 3339                   char ch = seq.charAt(i);
 3340                   if (ch == '\n') {
 3341                       // If not multiline, then only possible to
 3342                       // match at very end or one before end
 3343                       if (multiline == false && i != endIndex - 1)
 3344                           return false;
 3345                       // If multiline return next.match without setting
 3346                       // matcher.hitEnd
 3347                       if (multiline)
 3348                           return next.match(matcher, i, seq);
 3349                   } else {
 3350                       return false;
 3351                   }
 3352               }
 3353               // Matching because at the end or 1 before the end;
 3354               // more input could change this so set hitEnd
 3355               matcher.hitEnd = true;
 3356               // If a $ matches because of end of input, then more input
 3357               // could cause it to fail!
 3358               matcher.requireEnd = true;
 3359               return next.match(matcher, i, seq);
 3360           }
 3361           boolean study(TreeInfo info) {
 3362               next.study(info);
 3363               return info.deterministic;
 3364           }
 3365       }
 3366   
 3367       /**
 3368        * Abstract node class to match one character satisfying some
 3369        * boolean property.
 3370        */
 3371       private static abstract class CharProperty extends Node {
 3372           abstract boolean isSatisfiedBy(int ch);
 3373           CharProperty complement() {
 3374               return new CharProperty() {
 3375                       boolean isSatisfiedBy(int ch) {
 3376                           return ! CharProperty.this.isSatisfiedBy(ch);}};
 3377           }
 3378           CharProperty maybeComplement(boolean complement) {
 3379               return complement ? complement() : this;
 3380           }
 3381           boolean match(Matcher matcher, int i, CharSequence seq) {
 3382               if (i < matcher.to) {
 3383                   int ch = Character.codePointAt(seq, i);
 3384                   return isSatisfiedBy(ch)
 3385                       && next.match(matcher, i+Character.charCount(ch), seq);
 3386               } else {
 3387                   matcher.hitEnd = true;
 3388                   return false;
 3389               }
 3390           }
 3391           boolean study(TreeInfo info) {
 3392               info.minLength++;
 3393               info.maxLength++;
 3394               return next.study(info);
 3395           }
 3396       }
 3397   
 3398       /**
 3399        * Optimized version of CharProperty that works only for
 3400        * properties never satisfied by Supplementary characters.
 3401        */
 3402       private static abstract class BmpCharProperty extends CharProperty {
 3403           boolean match(Matcher matcher, int i, CharSequence seq) {
 3404               if (i < matcher.to) {
 3405                   return isSatisfiedBy(seq.charAt(i))
 3406                       && next.match(matcher, i+1, seq);
 3407               } else {
 3408                   matcher.hitEnd = true;
 3409                   return false;
 3410               }
 3411           }
 3412       }
 3413   
 3414       /**
 3415        * Node class that matches a Supplementary Unicode character
 3416        */
 3417       static final class SingleS extends CharProperty {
 3418           final int c;
 3419           SingleS(int c) { this.c = c; }
 3420           boolean isSatisfiedBy(int ch) {
 3421               return ch == c;
 3422           }
 3423       }
 3424   
 3425       /**
 3426        * Optimization -- matches a given BMP character
 3427        */
 3428       static final class Single extends BmpCharProperty {
 3429           final int c;
 3430           Single(int c) { this.c = c; }
 3431           boolean isSatisfiedBy(int ch) {
 3432               return ch == c;
 3433           }
 3434       }
 3435   
 3436       /**
 3437        * Case insensitive matches a given BMP character
 3438        */
 3439       static final class SingleI extends BmpCharProperty {
 3440           final int lower;
 3441           final int upper;
 3442           SingleI(int lower, int upper) {
 3443               this.lower = lower;
 3444               this.upper = upper;
 3445           }
 3446           boolean isSatisfiedBy(int ch) {
 3447               return ch == lower || ch == upper;
 3448           }
 3449       }
 3450   
 3451       /**
 3452        * Unicode case insensitive matches a given Unicode character
 3453        */
 3454       static final class SingleU extends CharProperty {
 3455           final int lower;
 3456           SingleU(int lower) {
 3457               this.lower = lower;
 3458           }
 3459           boolean isSatisfiedBy(int ch) {
 3460               return lower == ch ||
 3461                   lower == Character.toLowerCase(Character.toUpperCase(ch));
 3462           }
 3463       }
 3464   
 3465       /**
 3466        * Node class that matches a Unicode category.
 3467        */
 3468       static final class Category extends CharProperty {
 3469           final int typeMask;
 3470           Category(int typeMask) { this.typeMask = typeMask; }
 3471           boolean isSatisfiedBy(int ch) {
 3472               return (typeMask & (1 << Character.getType(ch))) != 0;
 3473           }
 3474       }
 3475   
 3476       /**
 3477        * Node class that matches a POSIX type.
 3478        */
 3479       static final class Ctype extends BmpCharProperty {
 3480           final int ctype;
 3481           Ctype(int ctype) { this.ctype = ctype; }
 3482           boolean isSatisfiedBy(int ch) {
 3483               return ch < 128 && ASCII.isType(ch, ctype);
 3484           }
 3485       }
 3486   
 3487       /**
 3488        * Base class for all Slice nodes
 3489        */
 3490       static class SliceNode extends Node {
 3491           int[] buffer;
 3492           SliceNode(int[] buf) {
 3493               buffer = buf;
 3494           }
 3495           boolean study(TreeInfo info) {
 3496               info.minLength += buffer.length;
 3497               info.maxLength += buffer.length;
 3498               return next.study(info);
 3499           }
 3500       }
 3501   
 3502       /**
 3503        * Node class for a case sensitive/BMP-only sequence of literal
 3504        * characters.
 3505        */
 3506       static final class Slice extends SliceNode {
 3507           Slice(int[] buf) {
 3508               super(buf);
 3509           }
 3510           boolean match(Matcher matcher, int i, CharSequence seq) {
 3511               int[] buf = buffer;
 3512               int len = buf.length;
 3513               for (int j=0; j<len; j++) {
 3514                   if ((i+j) >= matcher.to) {
 3515                       matcher.hitEnd = true;
 3516                       return false;
 3517                   }
 3518                   if (buf[j] != seq.charAt(i+j))
 3519                       return false;
 3520               }
 3521               return next.match(matcher, i+len, seq);
 3522           }
 3523       }
 3524   
 3525       /**
 3526        * Node class for a case_insensitive/BMP-only sequence of literal
 3527        * characters.
 3528        */
 3529       static class SliceI extends SliceNode {
 3530           SliceI(int[] buf) {
 3531               super(buf);
 3532           }
 3533           boolean match(Matcher matcher, int i, CharSequence seq) {
 3534               int[] buf = buffer;
 3535               int len = buf.length;
 3536               for (int j=0; j<len; j++) {
 3537                   if ((i+j) >= matcher.to) {
 3538                       matcher.hitEnd = true;
 3539                       return false;
 3540                   }
 3541                   int c = seq.charAt(i+j);
 3542                   if (buf[j] != c &&
 3543                       buf[j] != ASCII.toLower(c))
 3544                       return false;
 3545               }
 3546               return next.match(matcher, i+len, seq);
 3547           }
 3548       }
 3549   
 3550       /**
 3551        * Node class for a unicode_case_insensitive/BMP-only sequence of
 3552        * literal characters. Uses unicode case folding.
 3553        */
 3554       static final class SliceU extends SliceNode {
 3555           SliceU(int[] buf) {
 3556               super(buf);
 3557           }
 3558           boolean match(Matcher matcher, int i, CharSequence seq) {
 3559               int[] buf = buffer;
 3560               int len = buf.length;
 3561               for (int j=0; j<len; j++) {
 3562                   if ((i+j) >= matcher.to) {
 3563                       matcher.hitEnd = true;
 3564                       return false;
 3565                   }
 3566                   int c = seq.charAt(i+j);
 3567                   if (buf[j] != c &&
 3568                       buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
 3569                       return false;
 3570               }
 3571               return next.match(matcher, i+len, seq);
 3572           }
 3573       }
 3574   
 3575       /**
 3576        * Node class for a case sensitive sequence of literal characters
 3577        * including supplementary characters.
 3578        */
 3579       static final class SliceS extends SliceNode {
 3580           SliceS(int[] buf) {
 3581               super(buf);
 3582           }
 3583           boolean match(Matcher matcher, int i, CharSequence seq) {
 3584               int[] buf = buffer;
 3585               int x = i;
 3586               for (int j = 0; j < buf.length; j++) {
 3587                   if (x >= matcher.to) {
 3588                       matcher.hitEnd = true;
 3589                       return false;
 3590                   }
 3591                   int c = Character.codePointAt(seq, x);
 3592                   if (buf[j] != c)
 3593                       return false;
 3594                   x += Character.charCount(c);
 3595                   if (x > matcher.to) {
 3596                       matcher.hitEnd = true;
 3597                       return false;
 3598                   }
 3599               }
 3600               return next.match(matcher, x, seq);
 3601           }
 3602       }
 3603   
 3604       /**
 3605        * Node class for a case insensitive sequence of literal characters
 3606        * including supplementary characters.
 3607        */
 3608       static class SliceIS extends SliceNode {
 3609           SliceIS(int[] buf) {
 3610               super(buf);
 3611           }
 3612           int toLower(int c) {
 3613               return ASCII.toLower(c);
 3614           }
 3615           boolean match(Matcher matcher, int i, CharSequence seq) {
 3616               int[] buf = buffer;
 3617               int x = i;
 3618               for (int j = 0; j < buf.length; j++) {
 3619                   if (x >= matcher.to) {
 3620                       matcher.hitEnd = true;
 3621                       return false;
 3622                   }
 3623                   int c = Character.codePointAt(seq, x);
 3624                   if (buf[j] != c && buf[j] != toLower(c))
 3625                       return false;
 3626                   x += Character.charCount(c);
 3627                   if (x > matcher.to) {
 3628                       matcher.hitEnd = true;
 3629                       return false;
 3630                   }
 3631               }
 3632               return next.match(matcher, x, seq);
 3633           }
 3634       }
 3635   
 3636       /**
 3637        * Node class for a case insensitive sequence of literal characters.
 3638        * Uses unicode case folding.
 3639        */
 3640       static final class SliceUS extends SliceIS {
 3641           SliceUS(int[] buf) {
 3642               super(buf);
 3643           }
 3644           int toLower(int c) {
 3645               return Character.toLowerCase(Character.toUpperCase(c));
 3646           }
 3647       }
 3648   
 3649       private static boolean inRange(int lower, int ch, int upper) {
 3650           return lower <= ch && ch <= upper;
 3651       }
 3652   
 3653       /**
 3654        * Returns node for matching characters within an explicit value range.
 3655        */
 3656       private static CharProperty rangeFor(final int lower,
 3657                                            final int upper) {
 3658           return new CharProperty() {
 3659                   boolean isSatisfiedBy(int ch) {
 3660                       return inRange(lower, ch, upper);}};
 3661       }
 3662   
 3663       /**
 3664        * Returns node for matching characters within an explicit value
 3665        * range in a case insensitive manner.
 3666        */
 3667       private CharProperty caseInsensitiveRangeFor(final int lower,
 3668                                                    final int upper) {
 3669           if (has(UNICODE_CASE))
 3670               return new CharProperty() {
 3671                   boolean isSatisfiedBy(int ch) {
 3672                       if (inRange(lower, ch, upper))
 3673                           return true;
 3674                       int up = Character.toUpperCase(ch);
 3675                       return inRange(lower, up, upper) ||
 3676                              inRange(lower, Character.toLowerCase(up), upper);}};
 3677           return new CharProperty() {
 3678               boolean isSatisfiedBy(int ch) {
 3679                   return inRange(lower, ch, upper) ||
 3680                       ASCII.isAscii(ch) &&
 3681                           (inRange(lower, ASCII.toUpper(ch), upper) ||
 3682                            inRange(lower, ASCII.toLower(ch), upper));
 3683               }};
 3684       }
 3685   
 3686       /**
 3687        * Implements the Unicode category ALL and the dot metacharacter when
 3688        * in dotall mode.
 3689        */
 3690       static final class All extends CharProperty {
 3691           boolean isSatisfiedBy(int ch) {
 3692               return true;
 3693           }
 3694       }
 3695   
 3696       /**
 3697        * Node class for the dot metacharacter when dotall is not enabled.
 3698        */
 3699       static final class Dot extends CharProperty {
 3700           boolean isSatisfiedBy(int ch) {
 3701               return (ch != '\n' && ch != '\r'
 3702                       && (ch|1) != '\u2029'
 3703                       && ch != '\u0085');
 3704           }
 3705       }
 3706   
 3707       /**
 3708        * Node class for the dot metacharacter when dotall is not enabled
 3709        * but UNIX_LINES is enabled.
 3710        */
 3711       static final class UnixDot extends CharProperty {
 3712           boolean isSatisfiedBy(int ch) {
 3713               return ch != '\n';
 3714           }
 3715       }
 3716   
 3717       /**
 3718        * The 0 or 1 quantifier. This one class implements all three types.
 3719        */
 3720       static final class Ques extends Node {
 3721           Node atom;
 3722           int type;
 3723           Ques(Node node, int type) {
 3724               this.atom = node;
 3725               this.type = type;
 3726           }
 3727           boolean match(Matcher matcher, int i, CharSequence seq) {
 3728               switch (type) {
 3729               case GREEDY:
 3730                   return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
 3731                       || next.match(matcher, i, seq);
 3732               case LAZY:
 3733                   return next.match(matcher, i, seq)
 3734                       || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
 3735               case POSSESSIVE:
 3736                   if (atom.match(matcher, i, seq)) i = matcher.last;
 3737                   return next.match(matcher, i, seq);
 3738               default:
 3739                   return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
 3740               }
 3741           }
 3742           boolean study(TreeInfo info) {
 3743               if (type != INDEPENDENT) {
 3744                   int minL = info.minLength;
 3745                   atom.study(info);
 3746                   info.minLength = minL;
 3747                   info.deterministic = false;
 3748                   return next.study(info);
 3749               } else {
 3750                   atom.study(info);
 3751                   return next.study(info);
 3752               }
 3753           }
 3754       }
 3755   
 3756       /**
 3757        * Handles the curly-brace style repetition with a specified minimum and
 3758        * maximum occurrences. The * quantifier is handled as a special case.
 3759        * This class handles the three types.
 3760        */
 3761       static final class Curly extends Node {
 3762           Node atom;
 3763           int type;
 3764           int cmin;
 3765           int cmax;
 3766   
 3767           Curly(Node node, int cmin, int cmax, int type) {
 3768               this.atom = node;
 3769               this.type = type;
 3770               this.cmin = cmin;
 3771               this.cmax = cmax;
 3772           }
 3773           boolean match(Matcher matcher, int i, CharSequence seq) {
 3774               int j;
 3775               for (j = 0; j < cmin; j++) {
 3776                   if (atom.match(matcher, i, seq)) {
 3777                       i = matcher.last;
 3778                       continue;
 3779                   }
 3780                   return false;
 3781               }
 3782               if (type == GREEDY)
 3783                   return match0(matcher, i, j, seq);
 3784               else if (type == LAZY)
 3785                   return match1(matcher, i, j, seq);
 3786               else
 3787                   return match2(matcher, i, j, seq);
 3788           }
 3789           // Greedy match.
 3790           // i is the index to start matching at
 3791           // j is the number of atoms that have matched
 3792           boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
 3793               if (j >= cmax) {
 3794                   // We have matched the maximum... continue with the rest of
 3795                   // the regular expression
 3796                   return next.match(matcher, i, seq);
 3797               }
 3798               int backLimit = j;
 3799               while (atom.match(matcher, i, seq)) {
 3800                   // k is the length of this match
 3801                   int k = matcher.last - i;
 3802                   if (k == 0) // Zero length match
 3803                       break;
 3804                   // Move up index and number matched
 3805                   i = matcher.last;
 3806                   j++;
 3807                   // We are greedy so match as many as we can
 3808                   while (j < cmax) {
 3809                       if (!atom.match(matcher, i, seq))
 3810                           break;
 3811                       if (i + k != matcher.last) {
 3812                           if (match0(matcher, matcher.last, j+1, seq))
 3813                               return true;
 3814                           break;
 3815                       }
 3816                       i += k;
 3817                       j++;
 3818                   }
 3819                   // Handle backing off if match fails
 3820                   while (j >= backLimit) {
 3821                      if (next.match(matcher, i, seq))
 3822                           return true;
 3823                       i -= k;
 3824                       j--;
 3825                   }
 3826                   return false;
 3827               }
 3828               return next.match(matcher, i, seq);
 3829           }
 3830           // Reluctant match. At this point, the minimum has been satisfied.
 3831           // i is the index to start matching at
 3832           // j is the number of atoms that have matched
 3833           boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
 3834               for (;;) {
 3835                   // Try finishing match without consuming any more
 3836                   if (next.match(matcher, i, seq))
 3837                       return true;
 3838                   // At the maximum, no match found
 3839                   if (j >= cmax)
 3840                       return false;
 3841                   // Okay, must try one more atom
 3842                   if (!atom.match(matcher, i, seq))
 3843                       return false;
 3844                   // If we haven't moved forward then must break out
 3845                   if (i == matcher.last)
 3846                       return false;
 3847                   // Move up index and number matched
 3848                   i = matcher.last;
 3849                   j++;
 3850               }
 3851           }
 3852           boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
 3853               for (; j < cmax; j++) {
 3854                   if (!atom.match(matcher, i, seq))
 3855                       break;
 3856                   if (i == matcher.last)
 3857                       break;
 3858                   i = matcher.last;
 3859               }
 3860               return next.match(matcher, i, seq);
 3861           }
 3862           boolean study(TreeInfo info) {
 3863               // Save original info
 3864               int minL = info.minLength;
 3865               int maxL = info.maxLength;
 3866               boolean maxV = info.maxValid;
 3867               boolean detm = info.deterministic;
 3868               info.reset();
 3869   
 3870               atom.study(info);
 3871   
 3872               int temp = info.minLength * cmin + minL;
 3873               if (temp < minL) {
 3874                   temp = 0xFFFFFFF; // arbitrary large number
 3875               }
 3876               info.minLength = temp;
 3877   
 3878               if (maxV & info.maxValid) {
 3879                   temp = info.maxLength * cmax + maxL;
 3880                   info.maxLength = temp;
 3881                   if (temp < maxL) {
 3882                       info.maxValid = false;
 3883                   }
 3884               } else {
 3885                   info.maxValid = false;
 3886               }
 3887   
 3888               if (info.deterministic && cmin == cmax)
 3889                   info.deterministic = detm;
 3890               else
 3891                   info.deterministic = false;
 3892   
 3893               return next.study(info);
 3894           }
 3895       }
 3896   
 3897       /**
 3898        * Handles the curly-brace style repetition with a specified minimum and
 3899        * maximum occurrences in deterministic cases. This is an iterative
 3900        * optimization over the Prolog and Loop system which would handle this
 3901        * in a recursive way. The * quantifier is handled as a special case.
 3902        * If capture is true then this class saves group settings and ensures
 3903        * that groups are unset when backing off of a group match.
 3904        */
 3905       static final class GroupCurly extends Node {
 3906           Node atom;
 3907           int type;
 3908           int cmin;
 3909           int cmax;
 3910           int localIndex;
 3911           int groupIndex;
 3912           boolean capture;
 3913   
 3914           GroupCurly(Node node, int cmin, int cmax, int type, int local,
 3915                      int group, boolean capture) {
 3916               this.atom = node;
 3917               this.type = type;
 3918               this.cmin = cmin;
 3919               this.cmax = cmax;
 3920               this.localIndex = local;
 3921               this.groupIndex = group;
 3922               this.capture = capture;
 3923           }
 3924           boolean match(Matcher matcher, int i, CharSequence seq) {
 3925               int[] groups = matcher.groups;
 3926               int[] locals = matcher.locals;
 3927               int save0 = locals[localIndex];
 3928               int save1 = 0;
 3929               int save2 = 0;
 3930   
 3931               if (capture) {
 3932                   save1 = groups[groupIndex];
 3933                   save2 = groups[groupIndex+1];
 3934               }
 3935   
 3936               // Notify GroupTail there is no need to setup group info
 3937               // because it will be set here
 3938               locals[localIndex] = -1;
 3939   
 3940               boolean ret = true;
 3941               for (int j = 0; j < cmin; j++) {
 3942                   if (atom.match(matcher, i, seq)) {
 3943                       if (capture) {
 3944                           groups[groupIndex] = i;
 3945                           groups[groupIndex+1] = matcher.last;
 3946                       }
 3947                       i = matcher.last;
 3948                   } else {
 3949                       ret = false;
 3950                       break;
 3951                   }
 3952               }
 3953               if (ret) {
 3954                   if (type == GREEDY) {
 3955                       ret = match0(matcher, i, cmin, seq);
 3956                   } else if (type == LAZY) {
 3957                       ret = match1(matcher, i, cmin, seq);
 3958                   } else {
 3959                       ret = match2(matcher, i, cmin, seq);
 3960                   }
 3961               }
 3962               if (!ret) {
 3963                   locals[localIndex] = save0;
 3964                   if (capture) {
 3965                       groups[groupIndex] = save1;
 3966                       groups[groupIndex+1] = save2;
 3967                   }
 3968               }
 3969               return ret;
 3970           }
 3971           // Aggressive group match
 3972           boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
 3973               int[] groups = matcher.groups;
 3974               int save0 = 0;
 3975               int save1 = 0;
 3976               if (capture) {
 3977                   save0 = groups[groupIndex];
 3978                   save1 = groups[groupIndex+1];
 3979               }
 3980               for (;;) {
 3981                   if (j >= cmax)
 3982                       break;
 3983                   if (!atom.match(matcher, i, seq))
 3984                       break;
 3985                   int k = matcher.last - i;
 3986                   if (k <= 0) {
 3987                       if (capture) {
 3988                           groups[groupIndex] = i;
 3989                           groups[groupIndex+1] = i + k;
 3990                       }
 3991                       i = i + k;
 3992                       break;
 3993                   }
 3994                   for (;;) {
 3995                       if (capture) {
 3996                           groups[groupIndex] = i;
 3997                           groups[groupIndex+1] = i + k;
 3998                       }
 3999                       i = i + k;
 4000                       if (++j >= cmax)
 4001                           break;
 4002                       if (!atom.match(matcher, i, seq))
 4003                           break;
 4004                       if (i + k != matcher.last) {
 4005                           if (match0(matcher, i, j, seq))
 4006                               return true;
 4007                           break;
 4008                       }
 4009                   }
 4010                   while (j > cmin) {
 4011                       if (next.match(matcher, i, seq)) {
 4012                           if (capture) {
 4013                               groups[groupIndex+1] = i;
 4014                               groups[groupIndex] = i - k;
 4015                           }
 4016                           i = i - k;
 4017                           return true;
 4018                       }
 4019                       // backing off
 4020                       if (capture) {
 4021                           groups[groupIndex+1] = i;
 4022                           groups[groupIndex] = i - k;
 4023                       }
 4024                       i = i - k;
 4025                       j--;
 4026                   }
 4027                   break;
 4028               }
 4029               if (capture) {
 4030                   groups[groupIndex] = save0;
 4031                   groups[groupIndex+1] = save1;
 4032               }
 4033               return next.match(matcher, i, seq);
 4034           }
 4035           // Reluctant matching
 4036           boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
 4037               for (;;) {
 4038                   if (next.match(matcher, i, seq))
 4039                       return true;
 4040                   if (j >= cmax)
 4041                       return false;
 4042                   if (!atom.match(matcher, i, seq))
 4043                       return false;
 4044                   if (i == matcher.last)
 4045                       return false;
 4046                   if (capture) {
 4047                       matcher.groups[groupIndex] = i;
 4048                       matcher.groups[groupIndex+1] = matcher.last;
 4049                   }
 4050                   i = matcher.last;
 4051                   j++;
 4052               }
 4053           }
 4054           // Possessive matching
 4055           boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
 4056               for (; j < cmax; j++) {
 4057                   if (!atom.match(matcher, i, seq)) {
 4058                       break;
 4059                   }
 4060                   if (capture) {
 4061                       matcher.groups[groupIndex] = i;
 4062                       matcher.groups[groupIndex+1] = matcher.last;
 4063                   }
 4064                   if (i == matcher.last) {
 4065                       break;
 4066                   }
 4067                   i = matcher.last;
 4068               }
 4069               return next.match(matcher, i, seq);
 4070           }
 4071           boolean study(TreeInfo info) {
 4072               // Save original info
 4073               int minL = info.minLength;
 4074               int maxL = info.maxLength;
 4075               boolean maxV = info.maxValid;
 4076               boolean detm = info.deterministic;
 4077               info.reset();
 4078   
 4079               atom.study(info);
 4080   
 4081               int temp = info.minLength * cmin + minL;
 4082               if (temp < minL) {
 4083                   temp = 0xFFFFFFF; // Arbitrary large number
 4084               }
 4085               info.minLength = temp;
 4086   
 4087               if (maxV & info.maxValid) {
 4088                   temp = info.maxLength * cmax + maxL;
 4089                   info.maxLength = temp;
 4090                   if (temp < maxL) {
 4091                       info.maxValid = false;
 4092                   }
 4093               } else {
 4094                   info.maxValid = false;
 4095               }
 4096   
 4097               if (info.deterministic && cmin == cmax) {
 4098                   info.deterministic = detm;
 4099               } else {
 4100                   info.deterministic = false;
 4101               }
 4102   
 4103               return next.study(info);
 4104           }
 4105       }
 4106   
 4107       /**
 4108        * A Guard node at the end of each atom node in a Branch. It
 4109        * serves the purpose of chaining the "match" operation to
 4110        * "next" but not the "study", so we can collect the TreeInfo
 4111        * of each atom node without including the TreeInfo of the
 4112        * "next".
 4113        */
 4114       static final class BranchConn extends Node {
 4115           BranchConn() {};
 4116           boolean match(Matcher matcher, int i, CharSequence seq) {
 4117               return next.match(matcher, i, seq);
 4118           }
 4119           boolean study(TreeInfo info) {
 4120               return info.deterministic;
 4121           }
 4122       }
 4123   
 4124       /**
 4125        * Handles the branching of alternations. Note this is also used for
 4126        * the ? quantifier to branch between the case where it matches once
 4127        * and where it does not occur.
 4128        */
 4129       static final class Branch extends Node {
 4130           Node[] atoms = new Node[2];
 4131           int size = 2;
 4132           Node conn;
 4133           Branch(Node first, Node second, Node branchConn) {
 4134               conn = branchConn;
 4135               atoms[0] = first;
 4136               atoms[1] = second;
 4137           }
 4138   
 4139           void add(Node node) {
 4140               if (size >= atoms.length) {
 4141                   Node[] tmp = new Node[atoms.length*2];
 4142                   System.arraycopy(atoms, 0, tmp, 0, atoms.length);
 4143                   atoms = tmp;
 4144               }
 4145               atoms[size++] = node;
 4146           }
 4147   
 4148           boolean match(Matcher matcher, int i, CharSequence seq) {
 4149               for (int n = 0; n < size; n++) {
 4150                   if (atoms[n] == null) {
 4151                       if (conn.next.match(matcher, i, seq))
 4152                           return true;
 4153                   } else if (atoms[n].match(matcher, i, seq)) {
 4154                       return true;
 4155                   }
 4156               }
 4157               return false;
 4158           }
 4159   
 4160           boolean study(TreeInfo info) {
 4161               int minL = info.minLength;
 4162               int maxL = info.maxLength;
 4163               boolean maxV = info.maxValid;
 4164   
 4165               int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
 4166               int maxL2 = -1;
 4167               for (int n = 0; n < size; n++) {
 4168                   info.reset();
 4169                   if (atoms[n] != null)
 4170                       atoms[n].study(info);
 4171                   minL2 = Math.min(minL2, info.minLength);
 4172                   maxL2 = Math.max(maxL2, info.maxLength);
 4173                   maxV = (maxV & info.maxValid);
 4174               }
 4175   
 4176               minL += minL2;
 4177               maxL += maxL2;
 4178   
 4179               info.reset();
 4180               conn.next.study(info);
 4181   
 4182               info.minLength += minL;
 4183               info.maxLength += maxL;
 4184               info.maxValid &= maxV;
 4185               info.deterministic = false;
 4186               return false;
 4187           }
 4188       }
 4189   
 4190       /**
 4191        * The GroupHead saves the location where the group begins in the locals
 4192        * and restores them when the match is done.
 4193        *
 4194        * The matchRef is used when a reference to this group is accessed later
 4195        * in the expression. The locals will have a negative value in them to
 4196        * indicate that we do not want to unset the group if the reference
 4197        * doesn't match.
 4198        */
 4199       static final class GroupHead extends Node {
 4200           int localIndex;
 4201           GroupHead(int localCount) {
 4202               localIndex = localCount;
 4203           }
 4204           boolean match(Matcher matcher, int i, CharSequence seq) {
 4205               int save = matcher.locals[localIndex];
 4206               matcher.locals[localIndex] = i;
 4207               boolean ret = next.match(matcher, i, seq);
 4208               matcher.locals[localIndex] = save;
 4209               return ret;
 4210           }
 4211           boolean matchRef(Matcher matcher, int i, CharSequence seq) {
 4212               int save = matcher.locals[localIndex];
 4213               matcher.locals[localIndex] = ~i; // HACK
 4214               boolean ret = next.match(matcher, i, seq);
 4215               matcher.locals[localIndex] = save;
 4216               return ret;
 4217           }
 4218       }
 4219   
 4220       /**
 4221        * Recursive reference to a group in the regular expression. It calls
 4222        * matchRef because if the reference fails to match we would not unset
 4223        * the group.
 4224        */
 4225       static final class GroupRef extends Node {
 4226           GroupHead head;
 4227           GroupRef(GroupHead head) {
 4228               this.head = head;
 4229           }
 4230           boolean match(Matcher matcher, int i, CharSequence seq) {
 4231               return head.matchRef(matcher, i, seq)
 4232                   && next.match(matcher, matcher.last, seq);
 4233           }
 4234           boolean study(TreeInfo info) {
 4235               info.maxValid = false;
 4236               info.deterministic = false;
 4237               return next.study(info);
 4238           }
 4239       }
 4240   
 4241       /**
 4242        * The GroupTail handles the setting of group beginning and ending
 4243        * locations when groups are successfully matched. It must also be able to
 4244        * unset groups that have to be backed off of.
 4245        *
 4246        * The GroupTail node is also used when a previous group is referenced,
 4247        * and in that case no group information needs to be set.
 4248        */
 4249       static final class GroupTail extends Node {
 4250           int localIndex;
 4251           int groupIndex;
 4252           GroupTail(int localCount, int groupCount) {
 4253               localIndex = localCount;
 4254               groupIndex = groupCount + groupCount;
 4255           }
 4256           boolean match(Matcher matcher, int i, CharSequence seq) {
 4257               int tmp = matcher.locals[localIndex];
 4258               if (tmp >= 0) { // This is the normal group case.
 4259                   // Save the group so we can unset it if it
 4260                   // backs off of a match.
 4261                   int groupStart = matcher.groups[groupIndex];
 4262                   int groupEnd = matcher.groups[groupIndex+1];
 4263   
 4264                   matcher.groups[groupIndex] = tmp;
 4265                   matcher.groups[groupIndex+1] = i;
 4266                   if (next.match(matcher, i, seq)) {
 4267                       return true;
 4268                   }
 4269                   matcher.groups[groupIndex] = groupStart;
 4270                   matcher.groups[groupIndex+1] = groupEnd;
 4271                   return false;
 4272               } else {
 4273                   // This is a group reference case. We don't need to save any
 4274                   // group info because it isn't really a group.
 4275                   matcher.last = i;
 4276                   return true;
 4277               }
 4278           }
 4279       }
 4280   
 4281       /**
 4282        * This sets up a loop to handle a recursive quantifier structure.
 4283        */
 4284       static final class Prolog extends Node {
 4285           Loop loop;
 4286           Prolog(Loop loop) {
 4287               this.loop = loop;
 4288           }
 4289           boolean match(Matcher matcher, int i, CharSequence seq) {
 4290               return loop.matchInit(matcher, i, seq);
 4291           }
 4292           boolean study(TreeInfo info) {
 4293               return loop.study(info);
 4294           }
 4295       }
 4296   
 4297       /**
 4298        * Handles the repetition count for a greedy Curly. The matchInit
 4299        * is called from the Prolog to save the index of where the group
 4300        * beginning is stored. A zero length group check occurs in the
 4301        * normal match but is skipped in the matchInit.
 4302        */
 4303       static class Loop extends Node {
 4304           Node body;
 4305           int countIndex; // local count index in matcher locals
 4306           int beginIndex; // group beginning index
 4307           int cmin, cmax;
 4308           Loop(int countIndex, int beginIndex) {
 4309               this.countIndex = countIndex;
 4310               this.beginIndex = beginIndex;
 4311           }
 4312           boolean match(Matcher matcher, int i, CharSequence seq) {
 4313               // Avoid infinite loop in zero-length case.
 4314               if (i > matcher.locals[beginIndex]) {
 4315                   int count = matcher.locals[countIndex];
 4316   
 4317                   // This block is for before we reach the minimum
 4318                   // iterations required for the loop to match
 4319                   if (count < cmin) {
 4320                       matcher.locals[countIndex] = count + 1;
 4321                       boolean b = body.match(matcher, i, seq);
 4322                       // If match failed we must backtrack, so
 4323                       // the loop count should NOT be incremented
 4324                       if (!b)
 4325                           matcher.locals[countIndex] = count;
 4326                       // Return success or failure since we are under
 4327                       // minimum
 4328                       return b;
 4329                   }
 4330                   // This block is for after we have the minimum
 4331                   // iterations required for the loop to match
 4332                   if (count < cmax) {
 4333                       matcher.locals[countIndex] = count + 1;
 4334                       boolean b = body.match(matcher, i, seq);
 4335                       // If match failed we must backtrack, so
 4336                       // the loop count should NOT be incremented
 4337                       if (!b)
 4338                           matcher.locals[countIndex] = count;
 4339                       else
 4340                           return true;
 4341                   }
 4342               }
 4343               return next.match(matcher, i, seq);
 4344           }
 4345           boolean matchInit(Matcher matcher, int i, CharSequence seq) {
 4346               int save = matcher.locals[countIndex];
 4347               boolean ret = false;
 4348               if (0 < cmin) {
 4349                   matcher.locals[countIndex] = 1;
 4350                   ret = body.match(matcher, i, seq);
 4351               } else if (0 < cmax) {
 4352                   matcher.locals[countIndex] = 1;
 4353                   ret = body.match(matcher, i, seq);
 4354                   if (ret == false)
 4355                       ret = next.match(matcher, i, seq);
 4356               } else {
 4357                   ret = next.match(matcher, i, seq);
 4358               }
 4359               matcher.locals[countIndex] = save;
 4360               return ret;
 4361           }
 4362           boolean study(TreeInfo info) {
 4363               info.maxValid = false;
 4364               info.deterministic = false;
 4365               return false;
 4366           }
 4367       }
 4368   
 4369       /**
 4370        * Handles the repetition count for a reluctant Curly. The matchInit
 4371        * is called from the Prolog to save the index of where the group
 4372        * beginning is stored. A zero length group check occurs in the
 4373        * normal match but is skipped in the matchInit.
 4374        */
 4375       static final class LazyLoop extends Loop {
 4376           LazyLoop(int countIndex, int beginIndex) {
 4377               super(countIndex, beginIndex);
 4378           }
 4379           boolean match(Matcher matcher, int i, CharSequence seq) {
 4380               // Check for zero length group
 4381               if (i > matcher.locals[beginIndex]) {
 4382                   int count = matcher.locals[countIndex];
 4383                   if (count < cmin) {
 4384                       matcher.locals[countIndex] = count + 1;
 4385                       boolean result = body.match(matcher, i, seq);
 4386                       // If match failed we must backtrack, so
 4387                       // the loop count should NOT be incremented
 4388                       if (!result)
 4389                           matcher.locals[countIndex] = count;
 4390                       return result;
 4391                   }
 4392                   if (next.match(matcher, i, seq))
 4393                       return true;
 4394                   if (count < cmax) {
 4395                       matcher.locals[countIndex] = count + 1;
 4396                       boolean result = body.match(matcher, i, seq);
 4397                       // If match failed we must backtrack, so
 4398                       // the loop count should NOT be incremented
 4399                       if (!result)
 4400                           matcher.locals[countIndex] = count;
 4401                       return result;
 4402                   }
 4403                   return false;
 4404               }
 4405               return next.match(matcher, i, seq);
 4406           }
 4407           boolean matchInit(Matcher matcher, int i, CharSequence seq) {
 4408               int save = matcher.locals[countIndex];
 4409               boolean ret = false;
 4410               if (0 < cmin) {
 4411                   matcher.locals[countIndex] = 1;
 4412                   ret = body.match(matcher, i, seq);
 4413               } else if (next.match(matcher, i, seq)) {
 4414                   ret = true;
 4415               } else if (0 < cmax) {
 4416                   matcher.locals[countIndex] = 1;
 4417                   ret = body.match(matcher, i, seq);
 4418               }
 4419               matcher.locals[countIndex] = save;
 4420               return ret;
 4421           }
 4422           boolean study(TreeInfo info) {
 4423               info.maxValid = false;
 4424               info.deterministic = false;
 4425               return false;
 4426           }
 4427       }
 4428   
 4429       /**
 4430        * Refers to a group in the regular expression. Attempts to match
 4431        * whatever the group referred to last matched.
 4432        */
 4433       static class BackRef extends Node {
 4434           int groupIndex;
 4435           BackRef(int groupCount) {
 4436               super();
 4437               groupIndex = groupCount + groupCount;
 4438           }
 4439           boolean match(Matcher matcher, int i, CharSequence seq) {
 4440               int j = matcher.groups[groupIndex];
 4441               int k = matcher.groups[groupIndex+1];
 4442   
 4443               int groupSize = k - j;
 4444   
 4445               // If the referenced group didn't match, neither can this
 4446               if (j < 0)
 4447                   return false;
 4448   
 4449               // If there isn't enough input left no match
 4450               if (i + groupSize > matcher.to) {
 4451                   matcher.hitEnd = true;
 4452                   return false;
 4453               }
 4454   
 4455               // Check each new char to make sure it matches what the group
 4456               // referenced matched last time around
 4457               for (int index=0; index<groupSize; index++)
 4458                   if (seq.charAt(i+index) != seq.charAt(j+index))
 4459                       return false;
 4460   
 4461               return next.match(matcher, i+groupSize, seq);
 4462           }
 4463           boolean study(TreeInfo info) {
 4464               info.maxValid = false;
 4465               return next.study(info);
 4466           }
 4467       }
 4468   
 4469       static class CIBackRef extends Node {
 4470           int groupIndex;
 4471           boolean doUnicodeCase;
 4472           CIBackRef(int groupCount, boolean doUnicodeCase) {
 4473               super();
 4474               groupIndex = groupCount + groupCount;
 4475               this.doUnicodeCase = doUnicodeCase;
 4476           }
 4477           boolean match(Matcher matcher, int i, CharSequence seq) {
 4478               int j = matcher.groups[groupIndex];
 4479               int k = matcher.groups[groupIndex+1];
 4480   
 4481               int groupSize = k - j;
 4482   
 4483               // If the referenced group didn't match, neither can this
 4484               if (j < 0)
 4485                   return false;
 4486   
 4487               // If there isn't enough input left no match
 4488               if (i + groupSize > matcher.to) {
 4489                   matcher.hitEnd = true;
 4490                   return false;
 4491               }
 4492   
 4493               // Check each new char to make sure it matches what the group
 4494               // referenced matched last time around
 4495               int x = i;
 4496               for (int index=0; index<groupSize; index++) {
 4497                   int c1 = Character.codePointAt(seq, x);
 4498                   int c2 = Character.codePointAt(seq, j);
 4499                   if (c1 != c2) {
 4500                       if (doUnicodeCase) {
 4501                           int cc1 = Character.toUpperCase(c1);
 4502                           int cc2 = Character.toUpperCase(c2);
 4503                           if (cc1 != cc2 &&
 4504                               Character.toLowerCase(cc1) !=
 4505                               Character.toLowerCase(cc2))
 4506                               return false;
 4507                       } else {
 4508                           if (ASCII.toLower(c1) != ASCII.toLower(c2))
 4509                               return false;
 4510                       }
 4511                   }
 4512                   x += Character.charCount(c1);
 4513                   j += Character.charCount(c2);
 4514               }
 4515   
 4516               return next.match(matcher, i+groupSize, seq);
 4517           }
 4518           boolean study(TreeInfo info) {
 4519               info.maxValid = false;
 4520               return next.study(info);
 4521           }
 4522       }
 4523   
 4524       /**
 4525        * Searches until the next instance of its atom. This is useful for
 4526        * finding the atom efficiently without passing an instance of it
 4527        * (greedy problem) and without a lot of wasted search time (reluctant
 4528        * problem).
 4529        */
 4530       static final class First extends Node {
 4531           Node atom;
 4532           First(Node node) {
 4533               this.atom = BnM.optimize(node);
 4534           }
 4535           boolean match(Matcher matcher, int i, CharSequence seq) {
 4536               if (atom instanceof BnM) {
 4537                   return atom.match(matcher, i, seq)
 4538                       && next.match(matcher, matcher.last, seq);
 4539               }
 4540               for (;;) {
 4541                   if (i > matcher.to) {
 4542                       matcher.hitEnd = true;
 4543                       return false;
 4544                   }
 4545                   if (atom.match(matcher, i, seq)) {
 4546                       return next.match(matcher, matcher.last, seq);
 4547                   }
 4548                   i += countChars(seq, i, 1);
 4549                   matcher.first++;
 4550               }
 4551           }
 4552           boolean study(TreeInfo info) {
 4553               atom.study(info);
 4554               info.maxValid = false;
 4555               info.deterministic = false;
 4556               return next.study(info);
 4557           }
 4558       }
 4559   
 4560       static final class Conditional extends Node {
 4561           Node cond, yes, not;
 4562           Conditional(Node cond, Node yes, Node not) {
 4563               this.cond = cond;
 4564               this.yes = yes;
 4565               this.not = not;
 4566           }
 4567           boolean match(Matcher matcher, int i, CharSequence seq) {
 4568               if (cond.match(matcher, i, seq)) {
 4569                   return yes.match(matcher, i, seq);
 4570               } else {
 4571                   return not.match(matcher, i, seq);
 4572               }
 4573           }
 4574           boolean study(TreeInfo info) {
 4575               int minL = info.minLength;
 4576               int maxL = info.maxLength;
 4577               boolean maxV = info.maxValid;
 4578               info.reset();
 4579               yes.study(info);
 4580   
 4581               int minL2 = info.minLength;
 4582               int maxL2 = info.maxLength;
 4583               boolean maxV2 = info.maxValid;
 4584               info.reset();
 4585               not.study(info);
 4586   
 4587               info.minLength = minL + Math.min(minL2, info.minLength);
 4588               info.maxLength = maxL + Math.max(maxL2, info.maxLength);
 4589               info.maxValid = (maxV & maxV2 & info.maxValid);
 4590               info.deterministic = false;
 4591               return next.study(info);
 4592           }
 4593       }
 4594   
 4595       /**
 4596        * Zero width positive lookahead.
 4597        */
 4598       static final class Pos extends Node {
 4599           Node cond;
 4600           Pos(Node cond) {
 4601               this.cond = cond;
 4602           }
 4603           boolean match(Matcher matcher, int i, CharSequence seq) {
 4604               int savedTo = matcher.to;
 4605               boolean conditionMatched = false;
 4606   
 4607               // Relax transparent region boundaries for lookahead
 4608               if (matcher.transparentBounds)
 4609                   matcher.to = matcher.getTextLength();
 4610               try {
 4611                   conditionMatched = cond.match(matcher, i, seq);
 4612               } finally {
 4613                   // Reinstate region boundaries
 4614                   matcher.to = savedTo;
 4615               }
 4616               return conditionMatched && next.match(matcher, i, seq);
 4617           }
 4618       }
 4619   
 4620       /**
 4621        * Zero width negative lookahead.
 4622        */
 4623       static final class Neg extends Node {
 4624           Node cond;
 4625           Neg(Node cond) {
 4626               this.cond = cond;
 4627           }
 4628           boolean match(Matcher matcher, int i, CharSequence seq) {
 4629               int savedTo = matcher.to;
 4630               boolean conditionMatched = false;
 4631   
 4632               // Relax transparent region boundaries for lookahead
 4633               if (matcher.transparentBounds)
 4634                   matcher.to = matcher.getTextLength();
 4635               try {
 4636                   if (i < matcher.to) {
 4637                       conditionMatched = !cond.match(matcher, i, seq);
 4638                   } else {
 4639                       // If a negative lookahead succeeds then more input
 4640                       // could cause it to fail!
 4641                       matcher.requireEnd = true;
 4642                       conditionMatched = !cond.match(matcher, i, seq);
 4643                   }
 4644               } finally {
 4645                   // Reinstate region boundaries
 4646                   matcher.to = savedTo;
 4647               }
 4648               return conditionMatched && next.match(matcher, i, seq);
 4649           }
 4650       }
 4651   
 4652       /**
 4653        * For use with lookbehinds; matches the position where the lookbehind
 4654        * was encountered.
 4655        */
 4656       static Node lookbehindEnd = new Node() {
 4657           boolean match(Matcher matcher, int i, CharSequence seq) {
 4658               return i == matcher.lookbehindTo;
 4659           }
 4660       };
 4661   
 4662       /**
 4663        * Zero width positive lookbehind.
 4664        */
 4665       static class Behind extends Node {
 4666           Node cond;
 4667           int rmax, rmin;
 4668           Behind(Node cond, int rmax, int rmin) {
 4669               this.cond = cond;
 4670               this.rmax = rmax;
 4671               this.rmin = rmin;
 4672           }
 4673   
 4674           boolean match(Matcher matcher, int i, CharSequence seq) {
 4675               int savedFrom = matcher.from;
 4676               boolean conditionMatched = false;
 4677               int startIndex = (!matcher.transparentBounds) ?
 4678                                matcher.from : 0;
 4679               int from = Math.max(i - rmax, startIndex);
 4680               // Set end boundary
 4681               int savedLBT = matcher.lookbehindTo;
 4682               matcher.lookbehindTo = i;
 4683               // Relax transparent region boundaries for lookbehind
 4684               if (matcher.transparentBounds)
 4685                   matcher.from = 0;
 4686               for (int j = i - rmin; !conditionMatched && j >= from; j--) {
 4687                   conditionMatched = cond.match(matcher, j, seq);
 4688               }
 4689               matcher.from = savedFrom;
 4690               matcher.lookbehindTo = savedLBT;
 4691               return conditionMatched && next.match(matcher, i, seq);
 4692           }
 4693       }
 4694   
 4695       /**
 4696        * Zero width positive lookbehind, including supplementary
 4697        * characters or unpaired surrogates.
 4698        */
 4699       static final class BehindS extends Behind {
 4700           BehindS(Node cond, int rmax, int rmin) {
 4701               super(cond, rmax, rmin);
 4702           }
 4703           boolean match(Matcher matcher, int i, CharSequence seq) {
 4704               int rmaxChars = countChars(seq, i, -rmax);
 4705               int rminChars = countChars(seq, i, -rmin);
 4706               int savedFrom = matcher.from;
 4707               int startIndex = (!matcher.transparentBounds) ?
 4708                                matcher.from : 0;
 4709               boolean conditionMatched = false;
 4710               int from = Math.max(i - rmaxChars, startIndex);
 4711               // Set end boundary
 4712               int savedLBT = matcher.lookbehindTo;
 4713               matcher.lookbehindTo = i;
 4714               // Relax transparent region boundaries for lookbehind
 4715               if (matcher.transparentBounds)
 4716                   matcher.from = 0;
 4717   
 4718               for (int j = i - rminChars;
 4719                    !conditionMatched && j >= from;
 4720                    j -= j>from ? countChars(seq, j, -1) : 1) {
 4721                   conditionMatched = cond.match(matcher, j, seq);
 4722               }
 4723               matcher.from = savedFrom;
 4724               matcher.lookbehindTo = savedLBT;
 4725               return conditionMatched && next.match(matcher, i, seq);
 4726           }
 4727       }
 4728   
 4729       /**
 4730        * Zero width negative lookbehind.
 4731        */
 4732       static class NotBehind extends Node {
 4733           Node cond;
 4734           int rmax, rmin;
 4735           NotBehind(Node cond, int rmax, int rmin) {
 4736               this.cond = cond;
 4737               this.rmax = rmax;
 4738               this.rmin = rmin;
 4739           }
 4740   
 4741           boolean match(Matcher matcher, int i, CharSequence seq) {
 4742               int savedLBT = matcher.lookbehindTo;
 4743               int savedFrom = matcher.from;
 4744               boolean conditionMatched = false;
 4745               int startIndex = (!matcher.transparentBounds) ?
 4746                                matcher.from : 0;
 4747               int from = Math.max(i - rmax, startIndex);
 4748               matcher.lookbehindTo = i;
 4749               // Relax transparent region boundaries for lookbehind
 4750               if (matcher.transparentBounds)
 4751                   matcher.from = 0;
 4752               for (int j = i - rmin; !conditionMatched && j >= from; j--) {
 4753                   conditionMatched = cond.match(matcher, j, seq);
 4754               }
 4755               // Reinstate region boundaries
 4756               matcher.from = savedFrom;
 4757               matcher.lookbehindTo = savedLBT;
 4758               return !conditionMatched && next.match(matcher, i, seq);
 4759           }
 4760       }
 4761   
 4762       /**
 4763        * Zero width negative lookbehind, including supplementary
 4764        * characters or unpaired surrogates.
 4765        */
 4766       static final class NotBehindS extends NotBehind {
 4767           NotBehindS(Node cond, int rmax, int rmin) {
 4768               super(cond, rmax, rmin);
 4769           }
 4770           boolean match(Matcher matcher, int i, CharSequence seq) {
 4771               int rmaxChars = countChars(seq, i, -rmax);
 4772               int rminChars = countChars(seq, i, -rmin);
 4773               int savedFrom = matcher.from;
 4774               int savedLBT = matcher.lookbehindTo;
 4775               boolean conditionMatched = false;
 4776               int startIndex = (!matcher.transparentBounds) ?
 4777                                matcher.from : 0;
 4778               int from = Math.max(i - rmaxChars, startIndex);
 4779               matcher.lookbehindTo = i;
 4780               // Relax transparent region boundaries for lookbehind
 4781               if (matcher.transparentBounds)
 4782                   matcher.from = 0;
 4783               for (int j = i - rminChars;
 4784                    !conditionMatched && j >= from;
 4785                    j -= j>from ? countChars(seq, j, -1) : 1) {
 4786                   conditionMatched = cond.match(matcher, j, seq);
 4787               }
 4788               //Reinstate region boundaries
 4789               matcher.from = savedFrom;
 4790               matcher.lookbehindTo = savedLBT;
 4791               return !conditionMatched && next.match(matcher, i, seq);
 4792           }
 4793       }
 4794   
 4795       /**
 4796        * Returns the set union of two CharProperty nodes.
 4797        */
 4798       private static CharProperty union(final CharProperty lhs,
 4799                                         final CharProperty rhs) {
 4800           return new CharProperty() {
 4801                   boolean isSatisfiedBy(int ch) {
 4802                       return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
 4803       }
 4804   
 4805       /**
 4806        * Returns the set intersection of two CharProperty nodes.
 4807        */
 4808       private static CharProperty intersection(final CharProperty lhs,
 4809                                                final CharProperty rhs) {
 4810           return new CharProperty() {
 4811                   boolean isSatisfiedBy(int ch) {
 4812                       return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
 4813       }
 4814   
 4815       /**
 4816        * Returns the set difference of two CharProperty nodes.
 4817        */
 4818       private static CharProperty setDifference(final CharProperty lhs,
 4819                                                 final CharProperty rhs) {
 4820           return new CharProperty() {
 4821                   boolean isSatisfiedBy(int ch) {
 4822                       return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
 4823       }
 4824   
 4825       /**
 4826        * Handles word boundaries. Includes a field to allow this one class to
 4827        * deal with the different types of word boundaries we can match. The word
 4828        * characters include underscores, letters, and digits. Non spacing marks
 4829        * can are also part of a word if they have a base character, otherwise
 4830        * they are ignored for purposes of finding word boundaries.
 4831        */
 4832       static final class Bound extends Node {
 4833           static int LEFT = 0x1;
 4834           static int RIGHT= 0x2;
 4835           static int BOTH = 0x3;
 4836           static int NONE = 0x4;
 4837           int type;
 4838           Bound(int n) {
 4839               type = n;
 4840           }
 4841           int check(Matcher matcher, int i, CharSequence seq) {
 4842               int ch;
 4843               boolean left = false;
 4844               int startIndex = matcher.from;
 4845               int endIndex = matcher.to;
 4846               if (matcher.transparentBounds) {
 4847                   startIndex = 0;
 4848                   endIndex = matcher.getTextLength();
 4849               }
 4850               if (i > startIndex) {
 4851                   ch = Character.codePointBefore(seq, i);
 4852                   left = (ch == '_' || Character.isLetterOrDigit(ch) ||
 4853                       ((Character.getType(ch) == Character.NON_SPACING_MARK)
 4854                        && hasBaseCharacter(matcher, i-1, seq)));
 4855               }
 4856               boolean right = false;
 4857               if (i < endIndex) {
 4858                   ch = Character.codePointAt(seq, i);
 4859                   right = (ch == '_' || Character.isLetterOrDigit(ch) ||
 4860                       ((Character.getType(ch) == Character.NON_SPACING_MARK)
 4861                        && hasBaseCharacter(matcher, i, seq)));
 4862               } else {
 4863                   // Tried to access char past the end
 4864                   matcher.hitEnd = true;
 4865                   // The addition of another char could wreck a boundary
 4866                   matcher.requireEnd = true;
 4867               }
 4868               return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
 4869           }
 4870           boolean match(Matcher matcher, int i, CharSequence seq) {
 4871               return (check(matcher, i, seq) & type) > 0
 4872                   && next.match(matcher, i, seq);
 4873           }
 4874       }
 4875   
 4876       /**
 4877        * Non spacing marks only count as word characters in bounds calculations
 4878        * if they have a base character.
 4879        */
 4880       private static boolean hasBaseCharacter(Matcher matcher, int i,
 4881                                               CharSequence seq)
 4882       {
 4883           int start = (!matcher.transparentBounds) ?
 4884               matcher.from : 0;
 4885           for (int x=i; x >= start; x--) {
 4886               int ch = Character.codePointAt(seq, x);
 4887               if (Character.isLetterOrDigit(ch))
 4888                   return true;
 4889               if (Character.getType(ch) == Character.NON_SPACING_MARK)
 4890                   continue;
 4891               return false;
 4892           }
 4893           return false;
 4894       }
 4895   
 4896       /**
 4897        * Attempts to match a slice in the input using the Boyer-Moore string
 4898        * matching algorithm. The algorithm is based on the idea that the
 4899        * pattern can be shifted farther ahead in the search text if it is
 4900        * matched right to left.
 4901        * <p>
 4902        * The pattern is compared to the input one character at a time, from
 4903        * the rightmost character in the pattern to the left. If the characters
 4904        * all match the pattern has been found. If a character does not match,
 4905        * the pattern is shifted right a distance that is the maximum of two
 4906        * functions, the bad character shift and the good suffix shift. This
 4907        * shift moves the attempted match position through the input more
 4908        * quickly than a naive one position at a time check.
 4909        * <p>
 4910        * The bad character shift is based on the character from the text that
 4911        * did not match. If the character does not appear in the pattern, the
 4912        * pattern can be shifted completely beyond the bad character. If the
 4913        * character does occur in the pattern, the pattern can be shifted to
 4914        * line the pattern up with the next occurrence of that character.
 4915        * <p>
 4916        * The good suffix shift is based on the idea that some subset on the right
 4917        * side of the pattern has matched. When a bad character is found, the
 4918        * pattern can be shifted right by the pattern length if the subset does
 4919        * not occur again in pattern, or by the amount of distance to the
 4920        * next occurrence of the subset in the pattern.
 4921        *
 4922        * Boyer-Moore search methods adapted from code by Amy Yu.
 4923        */
 4924       static class BnM extends Node {
 4925           int[] buffer;
 4926           int[] lastOcc;
 4927           int[] optoSft;
 4928   
 4929           /**
 4930            * Pre calculates arrays needed to generate the bad character
 4931            * shift and the good suffix shift. Only the last seven bits
 4932            * are used to see if chars match; This keeps the tables small
 4933            * and covers the heavily used ASCII range, but occasionally
 4934            * results in an aliased match for the bad character shift.
 4935            */
 4936           static Node optimize(Node node) {
 4937               if (!(node instanceof Slice)) {
 4938                   return node;
 4939               }
 4940   
 4941               int[] src = ((Slice) node).buffer;
 4942               int patternLength = src.length;
 4943               // The BM algorithm requires a bit of overhead;
 4944               // If the pattern is short don't use it, since
 4945               // a shift larger than the pattern length cannot
 4946               // be used anyway.
 4947               if (patternLength < 4) {
 4948                   return node;
 4949               }
 4950               int i, j, k;
 4951               int[] lastOcc = new int[128];
 4952               int[] optoSft = new int[patternLength];
 4953               // Precalculate part of the bad character shift
 4954               // It is a table for where in the pattern each
 4955               // lower 7-bit value occurs
 4956               for (i = 0; i < patternLength; i++) {
 4957                   lastOcc[src[i]&0x7F] = i + 1;
 4958               }
 4959               // Precalculate the good suffix shift
 4960               // i is the shift amount being considered
 4961   NEXT:       for (i = patternLength; i > 0; i--) {
 4962                   // j is the beginning index of suffix being considered
 4963                   for (j = patternLength - 1; j >= i; j--) {
 4964                       // Testing for good suffix
 4965                       if (src[j] == src[j-i]) {
 4966                           // src[j..len] is a good suffix
 4967                           optoSft[j-1] = i;
 4968                       } else {
 4969                           // No match. The array has already been
 4970                           // filled up with correct values before.
 4971                           continue NEXT;
 4972                       }
 4973                   }
 4974                   // This fills up the remaining of optoSft
 4975                   // any suffix can not have larger shift amount
 4976                   // then its sub-suffix. Why???
 4977                   while (j > 0) {
 4978                       optoSft[--j] = i;
 4979                   }
 4980               }
 4981               // Set the guard value because of unicode compression
 4982               optoSft[patternLength-1] = 1;
 4983               if (node instanceof SliceS)
 4984                   return new BnMS(src, lastOcc, optoSft, node.next);
 4985               return new BnM(src, lastOcc, optoSft, node.next);
 4986           }
 4987           BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
 4988               this.buffer = src;
 4989               this.lastOcc = lastOcc;
 4990               this.optoSft = optoSft;
 4991               this.next = next;
 4992           }
 4993           boolean match(Matcher matcher, int i, CharSequence seq) {
 4994               int[] src = buffer;
 4995               int patternLength = src.length;
 4996               int last = matcher.to - patternLength;
 4997   
 4998               // Loop over all possible match positions in text
 4999   NEXT:       while (i <= last) {
 5000                   // Loop over pattern from right to left
 5001                   for (int j = patternLength - 1; j >= 0; j--) {
 5002                       int ch = seq.charAt(i+j);
 5003                       if (ch != src[j]) {
 5004                           // Shift search to the right by the maximum of the
 5005                           // bad character shift and the good suffix shift
 5006                           i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
 5007                           continue NEXT;
 5008                       }
 5009                   }
 5010                   // Entire pattern matched starting at i
 5011                   matcher.first = i;
 5012                   boolean ret = next.match(matcher, i + patternLength, seq);
 5013                   if (ret) {
 5014                       matcher.first = i;
 5015                       matcher.groups[0] = matcher.first;
 5016                       matcher.groups[1] = matcher.last;
 5017                       return true;
 5018                   }
 5019                   i++;
 5020               }
 5021               // BnM is only used as the leading node in the unanchored case,
 5022               // and it replaced its Start() which always searches to the end
 5023               // if it doesn't find what it's looking for, so hitEnd is true.
 5024               matcher.hitEnd = true;
 5025               return false;
 5026           }
 5027           boolean study(TreeInfo info) {
 5028               info.minLength += buffer.length;
 5029               info.maxValid = false;
 5030               return next.study(info);
 5031           }
 5032       }
 5033   
 5034       /**
 5035        * Supplementary support version of BnM(). Unpaired surrogates are
 5036        * also handled by this class.
 5037        */
 5038       static final class BnMS extends BnM {
 5039           int lengthInChars;
 5040   
 5041           BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
 5042               super(src, lastOcc, optoSft, next);
 5043               for (int x = 0; x < buffer.length; x++) {
 5044                   lengthInChars += Character.charCount(buffer[x]);
 5045               }
 5046           }
 5047           boolean match(Matcher matcher, int i, CharSequence seq) {
 5048               int[] src = buffer;
 5049               int patternLength = src.length;
 5050               int last = matcher.to - lengthInChars;
 5051   
 5052               // Loop over all possible match positions in text
 5053   NEXT:       while (i <= last) {
 5054                   // Loop over pattern from right to left
 5055                   int ch;
 5056                   for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
 5057                        j > 0; j -= Character.charCount(ch), x--) {
 5058                       ch = Character.codePointBefore(seq, i+j);
 5059                       if (ch != src[x]) {
 5060                           // Shift search to the right by the maximum of the
 5061                           // bad character shift and the good suffix shift
 5062                           int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
 5063                           i += countChars(seq, i, n);
 5064                           continue NEXT;
 5065                       }
 5066                   }
 5067                   // Entire pattern matched starting at i
 5068                   matcher.first = i;
 5069                   boolean ret = next.match(matcher, i + lengthInChars, seq);
 5070                   if (ret) {
 5071                       matcher.first = i;
 5072                       matcher.groups[0] = matcher.first;
 5073                       matcher.groups[1] = matcher.last;
 5074                       return true;
 5075                   }
 5076                   i += countChars(seq, i, 1);
 5077               }
 5078               matcher.hitEnd = true;
 5079               return false;
 5080           }
 5081       }
 5082   
 5083   ///////////////////////////////////////////////////////////////////////////////
 5084   ///////////////////////////////////////////////////////////////////////////////
 5085   
 5086       /**
 5087        *  This must be the very first initializer.
 5088        */
 5089       static Node accept = new Node();
 5090   
 5091       static Node lastAccept = new LastNode();
 5092   
 5093       private static class CharPropertyNames {
 5094   
 5095           static CharProperty charPropertyFor(String name) {
 5096               CharPropertyFactory m = map.get(name);
 5097               return m == null ? null : m.make();
 5098           }
 5099   
 5100           private static abstract class CharPropertyFactory {
 5101               abstract CharProperty make();
 5102           }
 5103   
 5104           private static void defCategory(String name,
 5105                                           final int typeMask) {
 5106               map.put(name, new CharPropertyFactory() {
 5107                       CharProperty make() { return new Category(typeMask);}});
 5108           }
 5109   
 5110           private static void defRange(String name,
 5111                                        final int lower, final int upper) {
 5112               map.put(name, new CharPropertyFactory() {
 5113                       CharProperty make() { return rangeFor(lower, upper);}});
 5114           }
 5115   
 5116           private static void defCtype(String name,
 5117                                        final int ctype) {
 5118               map.put(name, new CharPropertyFactory() {
 5119                       CharProperty make() { return new Ctype(ctype);}});
 5120           }
 5121   
 5122           private static abstract class CloneableProperty
 5123               extends CharProperty implements Cloneable
 5124           {
 5125               public CloneableProperty clone() {
 5126                   try {
 5127                       return (CloneableProperty) super.clone();
 5128                   } catch (CloneNotSupportedException e) {
 5129                       throw new AssertionError(e);
 5130                   }
 5131               }
 5132           }
 5133   
 5134           private static void defClone(String name,
 5135                                        final CloneableProperty p) {
 5136               map.put(name, new CharPropertyFactory() {
 5137                       CharProperty make() { return p.clone();}});
 5138           }
 5139   
 5140           private static final HashMap<String, CharPropertyFactory> map
 5141               = new HashMap<String, CharPropertyFactory>();
 5142   
 5143           static {
 5144               // Unicode character property aliases, defined in
 5145               // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
 5146               defCategory("Cn", 1<<Character.UNASSIGNED);
 5147               defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
 5148               defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
 5149               defCategory("Lt", 1<<Character.TITLECASE_LETTER);
 5150               defCategory("Lm", 1<<Character.MODIFIER_LETTER);
 5151               defCategory("Lo", 1<<Character.OTHER_LETTER);
 5152               defCategory("Mn", 1<<Character.NON_SPACING_MARK);
 5153               defCategory("Me", 1<<Character.ENCLOSING_MARK);
 5154               defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
 5155               defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
 5156               defCategory("Nl", 1<<Character.LETTER_NUMBER);
 5157               defCategory("No", 1<<Character.OTHER_NUMBER);
 5158               defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
 5159               defCategory("Zl", 1<<Character.LINE_SEPARATOR);
 5160               defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
 5161               defCategory("Cc", 1<<Character.CONTROL);
 5162               defCategory("Cf", 1<<Character.FORMAT);
 5163               defCategory("Co", 1<<Character.PRIVATE_USE);
 5164               defCategory("Cs", 1<<Character.SURROGATE);
 5165               defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
 5166               defCategory("Ps", 1<<Character.START_PUNCTUATION);
 5167               defCategory("Pe", 1<<Character.END_PUNCTUATION);
 5168               defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
 5169               defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
 5170               defCategory("Sm", 1<<Character.MATH_SYMBOL);
 5171               defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
 5172               defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
 5173               defCategory("So", 1<<Character.OTHER_SYMBOL);
 5174               defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
 5175               defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
 5176               defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
 5177                                 (1<<Character.LOWERCASE_LETTER) |
 5178                                 (1<<Character.TITLECASE_LETTER) |
 5179                                 (1<<Character.MODIFIER_LETTER)  |
 5180                                 (1<<Character.OTHER_LETTER)));
 5181               defCategory("M", ((1<<Character.NON_SPACING_MARK) |
 5182                                 (1<<Character.ENCLOSING_MARK)   |
 5183                                 (1<<Character.COMBINING_SPACING_MARK)));
 5184               defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
 5185                                 (1<<Character.LETTER_NUMBER)        |
 5186                                 (1<<Character.OTHER_NUMBER)));
 5187               defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
 5188                                 (1<<Character.LINE_SEPARATOR)  |
 5189                                 (1<<Character.PARAGRAPH_SEPARATOR)));
 5190               defCategory("C", ((1<<Character.CONTROL)     |
 5191                                 (1<<Character.FORMAT)      |
 5192                                 (1<<Character.PRIVATE_USE) |
 5193                                 (1<<Character.SURROGATE))); // Other
 5194               defCategory("P", ((1<<Character.DASH_PUNCTUATION)      |
 5195                                 (1<<Character.START_PUNCTUATION)     |
 5196                                 (1<<Character.END_PUNCTUATION)       |
 5197                                 (1<<Character.CONNECTOR_PUNCTUATION) |
 5198                                 (1<<Character.OTHER_PUNCTUATION)     |
 5199                                 (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
 5200                                 (1<<Character.FINAL_QUOTE_PUNCTUATION)));
 5201               defCategory("S", ((1<<Character.MATH_SYMBOL)     |
 5202                                 (1<<Character.CURRENCY_SYMBOL) |
 5203                                 (1<<Character.MODIFIER_SYMBOL) |
 5204                                 (1<<Character.OTHER_SYMBOL)));
 5205               defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
 5206                                  (1<<Character.LOWERCASE_LETTER) |
 5207                                  (1<<Character.TITLECASE_LETTER)));
 5208               defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
 5209                                  (1<<Character.LOWERCASE_LETTER) |
 5210                                  (1<<Character.TITLECASE_LETTER) |
 5211                                  (1<<Character.MODIFIER_LETTER)  |
 5212                                  (1<<Character.OTHER_LETTER)     |
 5213                                  (1<<Character.DECIMAL_DIGIT_NUMBER)));
 5214               defRange("L1", 0x00, 0xFF); // Latin-1
 5215               map.put("all", new CharPropertyFactory() {
 5216                       CharProperty make() { return new All(); }});
 5217   
 5218               // Posix regular expression character classes, defined in
 5219               // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
 5220               defRange("ASCII", 0x00, 0x7F);   // ASCII
 5221               defCtype("Alnum", ASCII.ALNUM);  // Alphanumeric characters
 5222               defCtype("Alpha", ASCII.ALPHA);  // Alphabetic characters
 5223               defCtype("Blank", ASCII.BLANK);  // Space and tab characters
 5224               defCtype("Cntrl", ASCII.CNTRL);  // Control characters
 5225               defRange("Digit", '0', '9');     // Numeric characters
 5226               defCtype("Graph", ASCII.GRAPH);  // printable and visible
 5227               defRange("Lower", 'a', 'z');     // Lower-case alphabetic
 5228               defRange("Print", 0x20, 0x7E);   // Printable characters
 5229               defCtype("Punct", ASCII.PUNCT);  // Punctuation characters
 5230               defCtype("Space", ASCII.SPACE);  // Space characters
 5231               defRange("Upper", 'A', 'Z');     // Upper-case alphabetic
 5232               defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
 5233   
 5234               // Java character properties, defined by methods in Character.java
 5235               defClone("javaLowerCase", new CloneableProperty() {
 5236                   boolean isSatisfiedBy(int ch) {
 5237                       return Character.isLowerCase(ch);}});
 5238               defClone("javaUpperCase", new CloneableProperty() {
 5239                   boolean isSatisfiedBy(int ch) {
 5240                       return Character.isUpperCase(ch);}});
 5241               defClone("javaTitleCase", new CloneableProperty() {
 5242                   boolean isSatisfiedBy(int ch) {
 5243                       return Character.isTitleCase(ch);}});
 5244               defClone("javaDigit", new CloneableProperty() {
 5245                   boolean isSatisfiedBy(int ch) {
 5246                       return Character.isDigit(ch);}});
 5247               defClone("javaDefined", new CloneableProperty() {
 5248                   boolean isSatisfiedBy(int ch) {
 5249                       return Character.isDefined(ch);}});
 5250               defClone("javaLetter", new CloneableProperty() {
 5251                   boolean isSatisfiedBy(int ch) {
 5252                       return Character.isLetter(ch);}});
 5253               defClone("javaLetterOrDigit", new CloneableProperty() {
 5254                   boolean isSatisfiedBy(int ch) {
 5255                       return Character.isLetterOrDigit(ch);}});
 5256               defClone("javaJavaIdentifierStart", new CloneableProperty() {
 5257                   boolean isSatisfiedBy(int ch) {
 5258                       return Character.isJavaIdentifierStart(ch);}});
 5259               defClone("javaJavaIdentifierPart", new CloneableProperty() {
 5260                   boolean isSatisfiedBy(int ch) {
 5261                       return Character.isJavaIdentifierPart(ch);}});
 5262               defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
 5263                   boolean isSatisfiedBy(int ch) {
 5264                       return Character.isUnicodeIdentifierStart(ch);}});
 5265               defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
 5266                   boolean isSatisfiedBy(int ch) {
 5267                       return Character.isUnicodeIdentifierPart(ch);}});
 5268               defClone("javaIdentifierIgnorable", new CloneableProperty() {
 5269                   boolean isSatisfiedBy(int ch) {
 5270                       return Character.isIdentifierIgnorable(ch);}});
 5271               defClone("javaSpaceChar", new CloneableProperty() {
 5272                   boolean isSatisfiedBy(int ch) {
 5273                       return Character.isSpaceChar(ch);}});
 5274               defClone("javaWhitespace", new CloneableProperty() {
 5275                   boolean isSatisfiedBy(int ch) {
 5276                       return Character.isWhitespace(ch);}});
 5277               defClone("javaISOControl", new CloneableProperty() {
 5278                   boolean isSatisfiedBy(int ch) {
 5279                       return Character.isISOControl(ch);}});
 5280               defClone("javaMirrored", new CloneableProperty() {
 5281                   boolean isSatisfiedBy(int ch) {
 5282                       return Character.isMirrored(ch);}});
 5283           }
 5284       }
 5285   }

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