/*
 
* Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

package java.util.regex;

import java.text.Normalizer;
import java.util.Locale;
import java.util.Iterator;
import java.util.Map;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Predicate;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;


/**
 
* A compiled representation of a regular expression.
 
*
 
* <p> A regular expression, specified as a string, must first be compiled into
 
* an instance of this class.
  
The resulting pattern can then be used to create
 
* a {@link Matcher} object that can match arbitrary {@linkplain
 
* java.lang.CharSequence character sequences} against the regular
 
* expression.
  
All of the state involved in performing a match resides in the
 
* matcher, so many matchers can share the same pattern.
 
*
 
* <p> A typical invocation sequence is thus
 
*
 
* <blockquote><pre>
 
* Pattern p = Pattern.{@link #compile compile}("a*b");
 
* Matcher m = p.{@link #matcher matcher}("aaaaab");
 
* boolean b = m.{@link Matcher#matches matches}();</pre></blockquote>
 
*
 
* <p> A {@link #matches matches} method is defined by this class as a
 
* convenience for when a regular expression is used just once.
  
This method
 
* compiles an expression and matches an input sequence against it in a single
 
* invocation.
  
The statement
 
*
 
* <blockquote><pre>
 
* boolean b = Pattern.matches("a*b", "aaaaab");</pre></blockquote>
 
*
 
* is equivalent to the three statements above, though for repeated matches it
 
* is less efficient since it does not allow the compiled pattern to be reused.
 
*
 
* <p> Instances of this class are immutable and are safe for use by multiple
 
* concurrent threads.
  
Instances of the {@link Matcher} class are not safe for
 
* such use.
 
*
 
*
 
* <h3><a name="sum">Summary of regular-expression constructs</a></h3>
 
*
 
* <table border="0" cellpadding="1" cellspacing="0"
 
*
  
summary="Regular expression constructs, and what they match">
 
*
 
* <tr align="left">
 
* <th align="left" id="construct">Construct</th>
 
* <th align="left" id="matches">Matches</th>
 
* </tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="characters">Characters</th></tr>
 
*
 
* <tr><td valign="top" headers="construct characters"><i>x</i></td>
 
*
     
<td headers="matches">The character <i>x</i></td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\\</tt></td>
 
*
     
<td headers="matches">The backslash character</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>n</i></td>
 
*
     
<td headers="matches">The character with octal value <tt>0</tt><i>n</i>
 
*
         
(0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>nn</i></td>
 
*
     
<td headers="matches">The character with octal value <tt>0</tt><i>nn</i>
 
*
         
(0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\0</tt><i>mnn</i></td>
 
*
     
<td headers="matches">The character with octal value <tt>0</tt><i>mnn</i>
 
*
         
(0&nbsp;<tt>&lt;=</tt>&nbsp;<i>m</i>&nbsp;<tt>&lt;=</tt>&nbsp;3,
 
*
         
0&nbsp;<tt>&lt;=</tt>&nbsp;<i>n</i>&nbsp;<tt>&lt;=</tt>&nbsp;7)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
 
*
     
<td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hh</i></td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>&#92;u</tt><i>hhhh</i></td>
 
*
     
<td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>hhhh</i></td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>&#92;x</tt><i>{h...h}</i></td>
 
*
     
<td headers="matches">The character with hexadecimal&nbsp;value&nbsp;<tt>0x</tt><i>h...h</i>
 
*
         
({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
 
*
         
&nbsp;&lt;=&nbsp;<tt>0x</tt><i>h...h</i>&nbsp;&lt;=&nbsp;
 
*
          
{@link java.lang.Character#MAX_CODE_POINT Character.MAX_CODE_POINT})</td></tr>
 
* <tr><td valign="top" headers="matches"><tt>\t</tt></td>
 
*
     
<td headers="matches">The tab character (<tt>'&#92;u0009'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
 
*
     
<td headers="matches">The newline (line feed) character (<tt>'&#92;u000A'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
 
*
     
<td headers="matches">The carriage-return character (<tt>'&#92;u000D'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
 
*
     
<td headers="matches">The form-feed character (<tt>'&#92;u000C'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
 
*
     
<td headers="matches">The alert (bell) character (<tt>'&#92;u0007'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
 
*
     
<td headers="matches">The escape character (<tt>'&#92;u001B'</tt>)</td></tr>
 
* <tr><td valign="top" headers="construct characters"><tt>\c</tt><i>x</i></td>
 
*
     
<td headers="matches">The control character corresponding to <i>x</i></td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="classes">Character classes</th></tr>
 
*
 
* <tr><td valign="top" headers="construct classes">{@code [abc]}</td>
 
*
     
<td headers="matches">{@code a}, {@code b}, or {@code c} (simple class)</td></tr>
 
* <tr><td valign="top" headers="construct classes">{@code [^abc]}</td>
 
*
     
<td headers="matches">Any character except {@code a}, {@code b}, or {@code c} (negation)</td></tr>
 
* <tr><td valign="top" headers="construct classes">{@code [a-zA-Z]}</td>
 
*
     
<td headers="matches">{@code a} through {@code z}
 
*
         
or {@code A} through {@code Z}, inclusive (range)</td></tr>
 
* <tr><td valign="top" headers="construct classes">{@code [a-d[m-p]]}</td>
 
*
     
<td headers="matches">{@code a} through {@code d},
 
*
      
or {@code m} through {@code p}: {@code [a-dm-p]} (union)</td></tr>
 
* <tr><td valign="top" headers="construct classes">{@code [a-z&&[def]]}</td>
 
*
     
<td headers="matches">{@code d}, {@code e}, or {@code f} (intersection)</tr>
 
* <tr><td valign="top" headers="construct classes">{@code [a-z&&[^bc]]}</td>
 
*
     
<td headers="matches">{@code a} through {@code z},
 
*
         
except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
 
* <tr><td valign="top" headers="construct classes">{@code [a-z&&[^m-p]]}</td>
 
*
     
<td headers="matches">{@code a} through {@code z},
 
*
          
and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
 
* <tr><th>&nbsp;</th></tr>
 
*
 
* <tr align="left"><th colspan="2" id="predef">Predefined character classes</th></tr>
 
*
 
* <tr><td valign="top" headers="construct predef"><tt>.</tt></td>
 
*
     
<td headers="matches">Any character (may or may not match<a href="#lt">line terminators</a>)</td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\d</tt></td>
 
*
     
<td headers="matches">A digit: <tt>[0-9]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\D</tt></td>
 
*
     
<td headers="matches">A non-digit: <tt>[^0-9]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\h</tt></td>
 
*
     
<td headers="matches">A horizontal whitespace character:
 
*
     
<tt>[ \t\xA0&#92;u1680&#92;u180e&#92;u2000-&#92;u200a&#92;u202f&#92;u205f&#92;u3000]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\H</tt></td>
 
*
     
<td headers="matches">A non-horizontal whitespace character: <tt>[^\h]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\s</tt></td>
 
*
     
<td headers="matches">A whitespace character: <tt>[ \t\n\x0B\f\r]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\S</tt></td>
 
*
     
<td headers="matches">A non-whitespace character: <tt>[^\s]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\v</tt></td>
 
*
     
<td headers="matches">A vertical whitespace character: <tt>[\n\x0B\f\r\x85&#92;u2028&#92;u2029]</tt>
 
*
     
</td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\V</tt></td>
 
*
     
<td headers="matches">A non-vertical whitespace character: <tt>[^\v]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\w</tt></td>
 
*
     
<td headers="matches">A word character: <tt>[a-zA-Z_0-9]</tt></td></tr>
 
* <tr><td valign="top" headers="construct predef"><tt>\W</tt></td>
 
*
     
<td headers="matches">A non-word character: <tt>[^\w]</tt></td></tr>
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="posix"><b>POSIX character classes (US-ASCII only)</b></th></tr>
 
*
 
* <tr><td valign="top" headers="construct posix">{@code \p{Lower}}</td>
 
*
     
<td headers="matches">A lower-case alphabetic character: {@code [a-z]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Upper}}</td>
 
*
     
<td headers="matches">An upper-case alphabetic character:{@code [A-Z]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{ASCII}}</td>
 
*
     
<td headers="matches">All ASCII:{@code [\x00-\x7F]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Alpha}}</td>
 
*
     
<td headers="matches">An alphabetic character:{@code [\p{Lower}\p{Upper}]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Digit}}</td>
 
*
     
<td headers="matches">A decimal digit: {@code [0-9]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Alnum}}</td>
 
*
     
<td headers="matches">An alphanumeric character:{@code [\p{Alpha}\p{Digit}]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Punct}}</td>
 
*
     
<td headers="matches">Punctuation: One of {@code !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~}</td></tr>
 
*
     
<!-- {@code [\!"#\$%&'\(\)\*\+,\-\./:;\<=\>\?@\[\\\]\^_`\{\|\}~]}
 
*
          
{@code [\X21-\X2F\X31-\X40\X5B-\X60\X7B-\X7E]} -->
 
* <tr><td valign="top" headers="construct posix">{@code \p{Graph}}</td>
 
*
     
<td headers="matches">A visible character: {@code [\p{Alnum}\p{Punct}]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Print}}</td>
 
*
     
<td headers="matches">A printable character: {@code [\p{Graph}\x20]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Blank}}</td>
 
*
     
<td headers="matches">A space or a tab: {@code [ \t]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Cntrl}}</td>
 
*
     
<td headers="matches">A control character: {@code [\x00-\x1F\x7F]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{XDigit}}</td>
 
*
     
<td headers="matches">A hexadecimal digit: {@code [0-9a-fA-F]}</td></tr>
 
* <tr><td valign="top" headers="construct posix">{@code \p{Space}}</td>
 
*
     
<td headers="matches">A whitespace character: {@code [ \t\n\x0B\f\r]}</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2">java.lang.Character classes (simple<a href="#jcc">java character type</a>)</th></tr>
 
*
 
* <tr><td valign="top"><tt>\p{javaLowerCase}</tt></td>
 
*
     
<td>Equivalent to java.lang.Character.isLowerCase()</td></tr>
 
* <tr><td valign="top"><tt>\p{javaUpperCase}</tt></td>
 
*
     
<td>Equivalent to java.lang.Character.isUpperCase()</td></tr>
 
* <tr><td valign="top"><tt>\p{javaWhitespace}</tt></td>
 
*
     
<td>Equivalent to java.lang.Character.isWhitespace()</td></tr>
 
* <tr><td valign="top"><tt>\p{javaMirrored}</tt></td>
 
*
     
<td>Equivalent to java.lang.Character.isMirrored()</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="unicode">Classes for Unicode scripts, blocks, categories and binary properties</th></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \p{IsLatin}}</td>
 
*
     
<td headers="matches">A Latin&nbsp;script character (<a href="#usc">script</a>)</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \p{InGreek}}</td>
 
*
     
<td headers="matches">A character in the Greek&nbsp;block (<a href="#ubc">block</a>)</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \p{Lu}}</td>
 
*
     
<td headers="matches">An uppercase letter (<a href="#ucc">category</a>)</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \p{IsAlphabetic}}</td>
 
*
     
<td headers="matches">An alphabetic character (<a href="#ubpc">binary property</a>)</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \p{Sc}}</td>
 
*
     
<td headers="matches">A currency symbol</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code \P{InGreek}}</td>
 
*
     
<td headers="matches">Any character except one in the Greek block (negation)</td></tr>
 
* <tr><td valign="top" headers="construct unicode">{@code [\p{L}&&[^\p{Lu}]]}</td>
 
*
     
<td headers="matches">Any letter except an uppercase letter (subtraction)</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="bounds">Boundary matchers</th></tr>
 
*
 
* <tr><td valign="top" headers="construct bounds"><tt>^</tt></td>
 
*
     
<td headers="matches">The beginning of a line</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>$</tt></td>
 
*
     
<td headers="matches">The end of a line</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\b</tt></td>
 
*
     
<td headers="matches">A word boundary</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\B</tt></td>
 
*
     
<td headers="matches">A non-word boundary</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\A</tt></td>
 
*
     
<td headers="matches">The beginning of the input</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\G</tt></td>
 
*
     
<td headers="matches">The end of the previous match</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\Z</tt></td>
 
*
     
<td headers="matches">The end of the input but for the final
 
*
         
<a href="#lt">terminator</a>, if&nbsp;any</td></tr>
 
* <tr><td valign="top" headers="construct bounds"><tt>\z</tt></td>
 
*
     
<td headers="matches">The end of the input</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="lineending">Linebreak matcher</th></tr>
 
* <tr><td valign="top" headers="construct lineending"><tt>\R</tt></td>
 
*
     
<td headers="matches">Any Unicode linebreak sequence, is equivalent to
 
*
     
<tt>&#92;u000D&#92;u000A|[&#92;u000A&#92;u000B&#92;u000C&#92;u000D&#92;u0085&#92;u2028&#92;u2029]
 
*
     
</tt></td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="greedy">Greedy quantifiers</th></tr>
 
*
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, once or not at all</td></tr>
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>*</tt></td>
 
*
     
<td headers="matches"><i>X</i>, zero or more times</td></tr>
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, one or more times</td></tr>
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>}</tt></td>
 
*
     
<td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,}</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct greedy"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="reluc">Reluctant quantifiers</th></tr>
 
*
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>??</tt></td>
 
*
     
<td headers="matches"><i>X</i>, once or not at all</td></tr>
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>*?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, zero or more times</td></tr>
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>+?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, one or more times</td></tr>
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>}?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,}?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct reluc"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}?</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="poss">Possessive quantifiers</th></tr>
 
*
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>?+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, once or not at all</td></tr>
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>*+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, zero or more times</td></tr>
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>++</tt></td>
 
*
     
<td headers="matches"><i>X</i>, one or more times</td></tr>
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>}+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, exactly <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,}+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> times</td></tr>
 
* <tr><td valign="top" headers="construct poss"><i>X</i><tt>{</tt><i>n</i><tt>,</tt><i>m</i><tt>}+</tt></td>
 
*
     
<td headers="matches"><i>X</i>, at least <i>n</i> but not more than <i>m</i> times</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="logical">Logical operators</th></tr>
 
*
 
* <tr><td valign="top" headers="construct logical"><i>XY</i></td>
 
*
     
<td headers="matches"><i>X</i> followed by <i>Y</i></td></tr>
 
* <tr><td valign="top" headers="construct logical"><i>X</i><tt>|</tt><i>Y</i></td>
 
*
     
<td headers="matches">Either <i>X</i> or <i>Y</i></td></tr>
 
* <tr><td valign="top" headers="construct logical"><tt>(</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches">X, as a<a href="#cg">capturing group</a></td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="backref">Back references</th></tr>
 
*
 
* <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>n</i></td>
 
*
     
<td valign="bottom" headers="matches">Whatever the <i>n</i><sup>th</sup>
 
*
     
<a href="#cg">capturing group</a>
 
matched</td></tr>
 
*
 
* <tr><td valign="bottom" headers="construct backref"><tt>\</tt><i>k</i>&lt;<i>name</i>&gt;</td>
 
*
     
<td valign="bottom" headers="matches">Whatever the
 
*
     
<a href="#groupname">named-capturing group</a>
 
"name" matched</td></tr>
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="quot">Quotation</th></tr>
 
*
 
* <tr><td valign="top" headers="construct quot"><tt>\</tt></td>
 
*
     
<td headers="matches">Nothing, but quotes the following character</td></tr>
 
* <tr><td valign="top" headers="construct quot"><tt>\Q</tt></td>
 
*
     
<td headers="matches">Nothing, but quotes all characters until <tt>\E</tt></td></tr>
 
* <tr><td valign="top" headers="construct quot"><tt>\E</tt></td>
 
*
     
<td headers="matches">Nothing, but ends quoting started by <tt>\Q</tt></td></tr>
 
*
     
<!-- Metachars: !$()*+.<>?[\]^{|} -->
 
*
 
* <tr><th>&nbsp;</th></tr>
 
* <tr align="left"><th colspan="2" id="special">Special constructs (named-capturing and non-capturing)</th></tr>
 
*
 
* <tr><td valign="top" headers="construct special"><tt>(?&lt;<a href="#groupname">name</a>&gt;</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, as a named-capturing group</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?:</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, as a non-capturing group</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?idmsuxU-idmsuxU)&nbsp;</tt></td>
 
*
     
<td headers="matches">Nothing, but turns match flags<a href="#CASE_INSENSITIVE">i</a>
 
*<a href="#UNIX_LINES">d</a>
 
<a href="#MULTILINE">m</a> <a href="#DOTALL">s</a>
 
*<a href="#UNICODE_CASE">u</a>
 
<a href="#COMMENTS">x</a> <a href="#UNICODE_CHARACTER_CLASS">U</a>
 
* on - off</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?idmsux-idmsux:</tt><i>X</i><tt>)</tt>&nbsp;&nbsp;</td>
 
*
     
<td headers="matches"><i>X</i>, as a<a href="#cg">non-capturing group</a>
 
with the
 
*
         
given flags<a href="#CASE_INSENSITIVE">i</a>
 
<a href="#UNIX_LINES">d</a>
 
*<a href="#MULTILINE">m</a>
 
<a href="#DOTALL">s</a> <a href="#UNICODE_CASE">u</a >
 
*<a href="#COMMENTS">x</a>
 
on - off</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?=</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, via zero-width positive lookahead</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?!</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, via zero-width negative lookahead</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?&lt;=</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, via zero-width positive lookbehind</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?&lt;!</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, via zero-width negative lookbehind</td></tr>
 
* <tr><td valign="top" headers="construct special"><tt>(?&gt;</tt><i>X</i><tt>)</tt></td>
 
*
     
<td headers="matches"><i>X</i>, as an independent, non-capturing group</td></tr>
 
*
 
* </table>
 
*
 
* <hr>
 
*
 
*
 
* <h3><a name="bs">Backslashes, escapes, and quoting</a></h3>
 
*
 
* <p> The backslash character (<tt>'\'</tt>) serves to introduce escaped
 
* constructs, as defined in the table above, as well as to quote characters
 
* that otherwise would be interpreted as unescaped constructs.
  
Thus the
 
* expression <tt>\\</tt> matches a single backslash and <tt>\{</tt> matches a
 
* left brace.
 
*
 
* <p> It is an error to use a backslash prior to any alphabetic character that
 
* does not denote an escaped construct; these are reserved for future
 
* extensions to the regular-expression language.
  
A backslash may be used
 
* prior to a non-alphabetic character regardless of whether that character is
 
* part of an unescaped construct.
 
*
 
* <p> Backslashes within string literals in Java source code are interpreted
 
* as required by
 
* <cite>The Java&trade; Language Specification</cite>
 
* as either Unicode escapes (section 3.3) or other character escapes (section 3.10.6)
 
* It is therefore necessary to double backslashes in string
 
* literals that represent regular expressions to protect them from
 
* interpretation by the Java bytecode compiler.
  
The string literal
 
* <tt>"&#92;b"</tt>, for example, matches a single backspace character when
 
* interpreted as a regular expression, while <tt>"&#92;&#92;b"</tt> matches a
 
* word boundary.
  
The string literal <tt>"&#92;(hello&#92;)"</tt> is illegal
 
* and leads to a compile-time error; in order to match the string
 
* <tt>(hello)</tt> the string literal <tt>"&#92;&#92;(hello&#92;&#92;)"</tt>
 
* must be used.
 
*
 
* <h3><a name="cc">Character Classes</a></h3>
 
*
 
*
    
<p> Character classes may appear within other character classes, and
 
*
    
may be composed by the union operator (implicit) and the intersection
 
*
    
operator (<tt>&amp;&amp;</tt>).
 
*
    
The union operator denotes a class that contains every character that is
 
*
    
in at least one of its operand classes.
  
The intersection operator
 
*
    
denotes a class that contains every character that is in both of its
 
*
    
operand classes.
 
*
 
*
    
<p> The precedence of character-class operators is as follows, from
 
*
    
highest to lowest:
 
*
 
*
    
<blockquote><table border="0" cellpadding="1" cellspacing="0"
 
*
                 
summary="Precedence of character class operators.">
 
*
      
<tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
        
<td>Literal escape&nbsp;&nbsp;&nbsp;&nbsp;</td>
 
*
        
<td><tt>\x</tt></td></tr>
 
*
     
<tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
        
<td>Grouping</td>
 
*
        
<td><tt>[...]</tt></td></tr>
 
*
     
<tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
        
<td>Range</td>
 
*
        
<td><tt>a-z</tt></td></tr>
 
*
      
<tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
        
<td>Union</td>
 
*
        
<td><tt>[a-e][i-u]</tt></td></tr>
 
*
      
<tr><th>5&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
        
<td>Intersection</td>
 
*
        
<td>{@code [a-z&&[aeiou]]}</td></tr>
 
*
    
</table></blockquote>
 
*
 
*
    
<p> Note that a different set of metacharacters are in effect inside
 
*
    
a character class than outside a character class. For instance, the
 
*
    
regular expression <tt>.</tt> loses its special meaning inside a
 
*
    
character class, while the expression <tt>-</tt> becomes a range
 
*
    
forming metacharacter.
 
*
 
* <h3><a name="lt">Line terminators</a></h3>
 
*
 
* <p> A <i>line terminator</i> is a one- or two-character sequence that marks
 
* the end of a line of the input character sequence.
  
The following are
 
* recognized as line terminators:
 
*
 
* <ul>
 
*
 
*
   
<li> A newline (line feed) character&nbsp;(<tt>'\n'</tt>),
 
*
 
*
   
<li> A carriage-return character followed immediately by a newline
 
*
   
character&nbsp;(<tt>"\r\n"</tt>),
 
*
 
*
   
<li> A standalone carriage-return character&nbsp;(<tt>'\r'</tt>),
 
*
 
*
   
<li> A next-line character&nbsp;(<tt>'&#92;u0085'</tt>),
 
*
 
*
   
<li> A line-separator character&nbsp;(<tt>'&#92;u2028'</tt>), or
 
*
 
*
   
<li> A paragraph-separator character&nbsp;(<tt>'&#92;u2029</tt>).
 
*
 
* </ul>
 
* <p>If
 
mode is activated, then the only line terminators
 
* recognized are newline characters.
 
*
 
* <p> The regular expression <tt>.</tt> matches any character except a line
 
* terminator unless the
 
flag is specified.
 
*
 
* <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
 
* line terminators and only match at the beginning and the end, respectively,
 
* of the entire input sequence. If
 
mode is activated then
 
* <tt>^</tt> matches at the beginning of input and after any line terminator
 
* except at the end of input. When in
 
mode <tt>$</tt>
 
* matches just before a line terminator or the end of the input sequence.
 
*
 
* <h3><a name="cg">Groups and capturing</a></h3>
 
*
 
* <h4><a name="gnumber">Group number</a></h4>
 
* <p> Capturing groups are numbered by counting their opening parentheses from
 
* left to right.
  
In the expression <tt>((A)(B(C)))</tt>, for example, there
 
* are four such groups: </p>
 
*
 
* <blockquote><table cellpadding=1 cellspacing=0 summary="Capturing group numberings">
 
* <tr><th>1&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
     
<td><tt>((A)(B(C)))</tt></td></tr>
 
* <tr><th>2&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
     
<td><tt>(A)</tt></td></tr>
 
* <tr><th>3&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
     
<td><tt>(B(C))</tt></td></tr>
 
* <tr><th>4&nbsp;&nbsp;&nbsp;&nbsp;</th>
 
*
     
<td><tt>(C)</tt></td></tr>
 
* </table></blockquote>
 
*
 
* <p> Group zero always stands for the entire expression.
 
*
 
* <p> Capturing groups are so named because, during a match, each subsequence
 
* of the input sequence that matches such a group is saved.
  
The captured
 
* subsequence may be used later in the expression, via a back reference, and
 
* may also be retrieved from the matcher once the match operation is complete.
 
*
 
* <h4><a name="groupname">Group name</a></h4>
 
* <p>A capturing group can also be assigned a "name", a <tt>named-capturing group</tt>,
 
* and then be back-referenced later by the "name". Group names are composed of
 
* the following characters. The first character must be a <tt>letter</tt>.
 
*
 
* <ul>
 
*
   
<li> The uppercase letters <tt>'A'</tt> through <tt>'Z'</tt>
 
*
        
(<tt>'&#92;u0041'</tt>&nbsp;through&nbsp;<tt>'&#92;u005a'</tt>),
 
*
   
<li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
 
*
        
(<tt>'&#92;u0061'</tt>&nbsp;through&nbsp;<tt>'&#92;u007a'</tt>),
 
*
   
<li> The digits <tt>'0'</tt> through <tt>'9'</tt>
 
*
        
(<tt>'&#92;u0030'</tt>&nbsp;through&nbsp;<tt>'&#92;u0039'</tt>),
 
* </ul>
 
*
 
* <p> A <tt>named-capturing group</tt> is still numbered as described in
 
*<a href="#gnumber">Group number</a>.
 
*
 
* <p> The captured input associated with a group is always the subsequence
 
* that the group most recently matched.
  
If a group is evaluated a second time
 
* because of quantification then its previously-captured value, if any, will
 
* be retained if the second evaluation fails.
  
Matching the string
 
* <tt>"aba"</tt> against the expression <tt>(a(b)?)+</tt>, for example, leaves
 
* group two set to <tt>"b"</tt>.
  
All captured input is discarded at the
 
* beginning of each match.
 
*
 
* <p> Groups beginning with <tt>(?</tt> are either pure, <i>non-capturing</i> groups
 
* that do not capture text and do not count towards the group total, or
 
* <i>named-capturing</i> group.
 
*
 
* <h3> Unicode support </h3>
 
*
 
* <p> This class is in conformance with Level 1 of <a
 
* href=" http://www.unicode.org/reports/tr18/"><i>Unicode
 
Technical
 
* Standard #18: Unicode Regular Expression</i></a>, plus RL2.1
 
* Canonical Equivalents.
 
* <p>
 
* <b>Unicode escape sequences</b> such as <tt>&#92;u2014</tt> in Java source code
 
* are processed as described in section 3.3 of
 
* <cite>The Java&trade; Language Specification</cite>.
 
* Such escape sequences are also implemented directly by the regular-expression
 
* parser so that Unicode escapes can be used in expressions that are read from
 
* files or from the keyboard.
  
Thus the strings <tt>"&#92;u2014"</tt> and
 
* <tt>"\\u2014"</tt>, while not equal, compile into the same pattern, which
 
* matches the character with hexadecimal value <tt>0x2014</tt>.
 
* <p>
 
* A Unicode character can also be represented in a regular-expression by
 
* using its <b>Hex notation</b>(hexadecimal code point value) directly as described in construct
 
* <tt>&#92;x{...}</tt>, for example a supplementary character U+2011F
 
* can be specified as <tt>&#92;x{2011F}</tt>, instead of two consecutive
 
* Unicode escape sequences of the surrogate pair
 
* <tt>&#92;uD840</tt><tt>&#92;uDD1F</tt>.
 
* <p>
 
* Unicode scripts, blocks, categories and binary properties are written with
 
* the <tt>\p</tt> and <tt>\P</tt> constructs as in Perl.
 
* <tt>\p{</tt><i>prop</i><tt>}</tt> matches if
 
* the input has the property <i>prop</i>, while <tt>\P{</tt><i>prop</i><tt>}</tt>
 
* does not match if the input has that property.
 
* <p>
 
* Scripts, blocks, categories and binary properties can be used both inside
 
* and outside of a character class.
 
*
 
* <p>
 
* <b><a name="usc">Scripts</a></b> are specified either with the prefix {@code Is}, as in
 
* {@code IsHiragana}, or by using
  
the {@code script} keyword (or its short
 
* form {@code sc})as in {@code script=Hiragana} or {@code sc=Hiragana}.
 
* <p>
 
* The script names supported by <code>Pattern</code> are the valid script names
 
* accepted and defined by
 
* {@link java.lang.Character.UnicodeScript#forName(String) UnicodeScript.forName}.
 
*
 
* <p>
 
* <b><a name="ubc">Blocks</a></b> are specified with the prefix {@code In}, as in
 
* {@code InMongolian}, or by using the keyword {@code block} (or its short
 
* form {@code blk}) as in {@code block=Mongolian} or {@code blk=Mongolian}.
 
* <p>
 
* The block names supported by <code>Pattern</code> are the valid block names
 
* accepted and defined by
 
* {@link java.lang.Character.UnicodeBlock#forName(String) UnicodeBlock.forName}.
 
* <p>
 
*
 
* <b><a name="ucc">Categories</a></b> may be specified with the optional prefix {@code Is}:
 
* Both {@code \p{L}} and {@code \p{IsL}} denote the category of Unicode
 
* letters. Same as scripts and blocks, categories can also be specified
 
* by using the keyword {@code general_category} (or its short form
 
* {@code gc}) as in {@code general_category=Lu} or {@code gc=Lu}.
 
* <p>
 
* The supported categories are those of
 
* <a href=" http://www.unicode.org/unicode/standard/standard.html">
 
* <i>The Unicode Standard</i></a> in the version specified by the
 
* {@link java.lang.Character Character} class. The category names are those
 
* defined in the Standard, both normative and informative.
 
* <p>
 
*
 
* <b><a name="ubpc">Binary properties</a></b> are specified with the prefix {@code Is}, as in
 
* {@code IsAlphabetic}. The supported binary properties by <code>Pattern</code>
 
* are
 
* <ul>
 
*
   
<li> Alphabetic
 
*
   
<li> Ideographic
 
*
   
<li> Letter
 
*
   
<li> Lowercase
 
*
   
<li> Uppercase
 
*
   
<li> Titlecase
 
*
   
<li> Punctuation
 
*
   
<Li> Control
 
*
   
<li> White_Space
 
*
   
<li> Digit
 
*
   
<li> Hex_Digit
 
*
   
<li> Join_Control
 
*
   
<li> Noncharacter_Code_Point
 
*
   
<li> Assigned
 
* </ul>
 
* <p>
 
* The following <b>Predefined Character classes</b> and <b>POSIX character classes</b>
 
* are in conformance with the recommendation of <i>Annex C: Compatibility Properties</i>
 
* of <a href=" http://www.unicode.org/reports/tr18/"><i>Unicode
 
Regular Expression
 
* </i></a>, when
 
flag is specified.
 
*
 
* <table border="0" cellpadding="1" cellspacing="0"
 
*
  
summary="predefined and posix character classes in Unicode mode">
 
* <tr align="left">
 
* <th align="left" id="predef_classes">Classes</th>
 
* <th align="left" id="predef_matches">Matches</th>
 
*</tr>
 
* <tr><td><tt>\p{Lower}</tt></td>
 
*
     
<td>A lowercase character:<tt>\p{IsLowercase}</tt></td></tr>
 
* <tr><td><tt>\p{Upper}</tt></td>
 
*
     
<td>An uppercase character:<tt>\p{IsUppercase}</tt></td></tr>
 
* <tr><td><tt>\p{ASCII}</tt></td>
 
*
     
<td>All ASCII:<tt>[\x00-\x7F]</tt></td></tr>
 
* <tr><td><tt>\p{Alpha}</tt></td>
 
*
     
<td>An alphabetic character:<tt>\p{IsAlphabetic}</tt></td></tr>
 
* <tr><td><tt>\p{Digit}</tt></td>
 
*
     
<td>A decimal digit character:<tt>p{IsDigit}</tt></td></tr>
 
* <tr><td><tt>\p{Alnum}</tt></td>
 
*
     
<td>An alphanumeric character:<tt>[\p{IsAlphabetic}\p{IsDigit}]</tt></td></tr>
 
* <tr><td><tt>\p{Punct}</tt></td>
 
*
     
<td>A punctuation character:<tt>p{IsPunctuation}</tt></td></tr>
 
* <tr><td><tt>\p{Graph}</tt></td>
 
*
     
<td>A visible character: <tt>[^\p{IsWhite_Space}\p{gc=Cc}\p{gc=Cs}\p{gc=Cn}]</tt></td></tr>
 
* <tr><td><tt>\p{Print}</tt></td>
 
*
     
<td>A printable character: {@code [\p{Graph}\p{Blank}&&[^\p{Cntrl}]]}</td></tr>
 
* <tr><td><tt>\p{Blank}</tt></td>
 
*
     
<td>A space or a tab: {@code [\p{IsWhite_Space}&&[^\p{gc=Zl}\p{gc=Zp}\x0a\x0b\x0c\x0d\x85]]}</td></tr>
 
* <tr><td><tt>\p{Cntrl}</tt></td>
 
*
     
<td>A control character: <tt>\p{gc=Cc}</tt></td></tr>
 
* <tr><td><tt>\p{XDigit}</tt></td>
 
*
     
<td>A hexadecimal digit: <tt>[\p{gc=Nd}\p{IsHex_Digit}]</tt></td></tr>
 
* <tr><td><tt>\p{Space}</tt></td>
 
*
     
<td>A whitespace character:<tt>\p{IsWhite_Space}</tt></td></tr>
 
* <tr><td><tt>\d</tt></td>
 
*
     
<td>A digit: <tt>\p{IsDigit}</tt></td></tr>
 
* <tr><td><tt>\D</tt></td>
 
*
     
<td>A non-digit: <tt>[^\d]</tt></td></tr>
 
* <tr><td><tt>\s</tt></td>
 
*
     
<td>A whitespace character: <tt>\p{IsWhite_Space}</tt></td></tr>
 
* <tr><td><tt>\S</tt></td>
 
*
     
<td>A non-whitespace character: <tt>[^\s]</tt></td></tr>
 
* <tr><td><tt>\w</tt></td>
 
*
     
<td>A word character: <tt>[\p{Alpha}\p{gc=Mn}\p{gc=Me}\p{gc=Mc}\p{Digit}\p{gc=Pc}\p{IsJoin_Control}]</tt></td></tr>
 
* <tr><td><tt>\W</tt></td>
 
*
     
<td>A non-word character: <tt>[^\w]</tt></td></tr>
 
* </table>
 
* <p>
 
* <a name="jcc">
 
* Categories that behave like the java.lang.Character
 
* boolean is<i>methodname</i> methods (except for the deprecated ones) are
 
* available through the same <tt>\p{</tt><i>prop</i><tt>}</tt> syntax where
 
* the specified property has the name <tt>java<i>methodname</i></tt></a>.
 
*
 
* <h3> Comparison to Perl 5 </h3>
 
*
 
* <p>The <code>Pattern</code> engine performs traditional NFA-based matching
 
* with ordered alternation as occurs in Perl 5.
 
*
 
* <p> Perl constructs not supported by this class: </p>
 
*
 
* <ul>
 
*
    
<li><p> Predefined character classes (Unicode character)
 
*
    
<p><tt>\X&nbsp;&nbsp;&nbsp;&nbsp;</tt>Match Unicode
 
*
    
<a href=" http://www.unicode.org/reports/tr18/#Default_Grapheme_Clusters">
 
*
    
<i>extended grapheme cluster</i></a>
 
*
    
</p></li>
 
*
 
*
    
<li><p> The backreference constructs, <tt>\g{</tt><i>n</i><tt>}</tt> for
 
*
    
the <i>n</i><sup>th</sup><a href="#cg">capturing group</a>
 
and
 
*
    
<tt>\g{</tt><i>name</i><tt>}</tt> for
 
*
    
<a href="#groupname">named-capturing group</a>.
 
*
    
</p></li>
 
*
 
*
    
<li><p> The named character construct, <tt>\N{</tt><i>name</i><tt>}</tt>
 
*
    
for a Unicode character by its name.
 
*
    
</p></li>
 
*
 
*
    
<li><p> The conditional constructs
 
*
    
<tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>)</tt> and
 
*
    
<tt>(?(</tt><i>condition</i><tt>)</tt><i>X</i><tt>|</tt><i>Y</i><tt>)</tt>,
 
*
    
</p></li>
 
*
 
*
    
<li><p> The embedded code constructs <tt>(?{</tt><i>code</i><tt>})</tt>
 
*
    
and <tt>(??{</tt><i>code</i><tt>})</tt>,</p></li>
 
*
 
*
    
<li><p> The embedded comment syntax <tt>(?#comment)</tt>, and </p></li>
 
*
 
*
    
<li><p> The preprocessing operations <tt>\l</tt> <tt>&#92;u</tt>,
 
*
    
<tt>\L</tt>, and <tt>\U</tt>.
  
</p></li>
 
*
 
* </ul>
 
*
 
* <p> Constructs supported by this class but not by Perl: </p>
 
*
 
* <ul>
 
*
 
*
    
<li><p> Character-class union and intersection as described
 
*
    
<a href="#cc">above</a>.</p></li>
 
*
 
* </ul>
 
*
 
* <p> Notable differences from Perl: </p>
 
*
 
* <ul>
 
*
 
*
    
<li><p> In Perl, <tt>\1</tt> through <tt>\9</tt> are always interpreted
 
*
    
as back references; a backslash-escaped number greater than <tt>9</tt> is
 
*
    
treated as a back reference if at least that many subexpressions exist,
 
*
    
otherwise it is interpreted, if possible, as an octal escape.
  
In this
 
*
    
class octal escapes must always begin with a zero. In this class,
 
*
    
<tt>\1</tt> through <tt>\9</tt> are always interpreted as back
 
*
    
references, and a larger number is accepted as a back reference if at
 
*
    
least that many subexpressions exist at that point in the regular
 
*
    
expression, otherwise the parser will drop digits until the number is
 
*
    
smaller or equal to the existing number of groups or it is one digit.
 
*
    
</p></li>
 
*
 
*
    
<li><p> Perl uses the <tt>g</tt> flag to request a match that resumes
 
*
    
where the last match left off.
  
This functionality is provided implicitly
 
*
    
by the {@link Matcher} class: Repeated invocations of the {@link
 
*
    
Matcher#find find} method will resume where the last match left off,
 
*
    
unless the matcher is reset.
  
</p></li>
 
*
 
*
    
<li><p> In Perl, embedded flags at the top level of an expression affect
 
*
    
the whole expression.
  
In this class, embedded flags always take effect
 
*
    
at the point at which they appear, whether they are at the top level or
 
*
    
within a group; in the latter case, flags are restored at the end of the
 
*
    
group just as in Perl.
  
</p></li>
 
*
 
* </ul>
 
*
 
*
 
* <p> For a more precise description of the behavior of regular expression
 
* constructs, please see <a href=" http://www.oreilly.com/catalog/regex3/">
 
* <i>Mastering Regular Expressions, 3nd Edition</i>, Jeffrey E. F. Friedl,
 
* O'Reilly and Associates, 2006.</a>
 
* </p>
 
*
 
* @see java.lang.String#split(String, int)
 
* @see java.lang.String#split(String)
 
*
 
* @author
      
Mike McCloskey
 
* @author
      
Mark Reinhold
 
* @author
      
JSR-51 Expert Group
 
* @since
       
1.4
 
* @spec
        
JSR-51
 
*/


public final class Pattern
    
implements java.io.Serializable
{

    
/**
     
* Regular expression modifier values.
  
Instead of being passed as
     
* arguments, they can also be passed as inline modifiers.
     
* For example, the following statements have the same effect.
     
* <pre>
     
* RegExp r1 = RegExp.compile("abc", Pattern.I|Pattern.M);
     
* RegExp r2 = RegExp.compile("(?im)abc", 0);
     
* </pre>
     
*
     
* The flags are duplicated so that the familiar Perl match flag
     
* names are available.
     
*/


    
/**
     
* Enables Unix lines mode.
     
*
     
* <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
     
* in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
     
*
     
* <p> Unix lines mode can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?d)</tt>.
     
*/

    
public static final int UNIX_LINES = 0x01;

    
/**
     
* Enables case-insensitive matching.
     
*
     
* <p> By default, case-insensitive matching assumes that only characters
     
* in the US-ASCII charset are being matched.
  
Unicode-aware
     
* case-insensitive matching can be enabled by specifying the {@link
     
* #UNICODE_CASE} flag in conjunction with this flag.
     
*
     
* <p> Case-insensitive matching can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?i)</tt>.
     
*
     
* <p> Specifying this flag may impose a slight performance penalty.
  
</p>
     
*/

    
public static final int CASE_INSENSITIVE = 0x02;

    
/**
     
* Permits whitespace and comments in pattern.
     
*
     
* <p> In this mode, whitespace is ignored, and embedded comments starting
     
* with <tt>#</tt> are ignored until the end of a line.
     
*
     
* <p> Comments mode can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?x)</tt>.
     
*/

    
public static final int COMMENTS = 0x04;

    
/**
     
* Enables multiline mode.
     
*
     
* <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
     
* just after or just before, respectively, a line terminator or the end of
     
* the input sequence.
  
By default these expressions only match at the
     
* beginning and the end of the entire input sequence.
     
*
     
* <p> Multiline mode can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?m)</tt>.
  
</p>
     
*/

    
public static final int MULTILINE = 0x08;

    
/**
     
* Enables literal parsing of the pattern.
     
*
     
* <p> When this flag is specified then the input string that specifies
     
* the pattern is treated as a sequence of literal characters.
     
* Metacharacters or escape sequences in the input sequence will be
     
* given no special meaning.
     
*
     
* <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
     
* matching when used in conjunction with this flag. The other flags
     
* become superfluous.
     
*
     
* <p> There is no embedded flag character for enabling literal parsing.
     
* @since 1.5
     
*/

    
public static final int LITERAL = 0x10;

    
/**
     
* Enables dotall mode.
     
*
     
* <p> In dotall mode, the expression <tt>.</tt> matches any character,
     
* including a line terminator.
  
By default this expression does not match
     
* line terminators.
     
*
     
* <p> Dotall mode can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?s)</tt>.
  
(The <tt>s</tt> is a mnemonic for
     
* "single-line" mode, which is what this is called in Perl.)
  
</p>
     
*/

    
public static final int DOTALL = 0x20;

    
/**
     
* Enables Unicode-aware case folding.
     
*
     
* <p> When this flag is specified then case-insensitive matching, when
     
* enabled by the
 
 
flag, is done in a manner
     
* consistent with the Unicode Standard.
  
By default, case-insensitive
     
* matching assumes that only characters in the US-ASCII charset are being
     
* matched.
     
*
     
* <p> Unicode-aware case folding can also be enabled via the embedded flag
     
* expression&nbsp;<tt>(?u)</tt>.
     
*
     
* <p> Specifying this flag may impose a performance penalty.
  
</p>
     
*/

    
public static final int UNICODE_CASE = 0x40;

    
/**
     
* Enables canonical equivalence.
     
*
     
* <p> When this flag is specified then two characters will be considered
     
* to match if, and only if, their full canonical decompositions match.
     
* The expression <tt>"a&#92;u030A"</tt>, for example, will match the
     
* string <tt>"&#92;u00E5"</tt> when this flag is specified.
  
By default,
     
* matching does not take canonical equivalence into account.
     
*
     
* <p> There is no embedded flag character for enabling canonical
     
* equivalence.
     
*
     
* <p> Specifying this flag may impose a performance penalty.
  
</p>
     
*/

    
public static final int CANON_EQ = 0x80;

    
/**
     
* Enables the Unicode version of <i>Predefined character classes</i> and
     
* <i>POSIX character classes</i>.
     
*
     
* <p> When this flag is specified then the (US-ASCII only)
     
* <i>Predefined character classes</i> and <i>POSIX character classes</i>
     
* are in conformance with
     
* <a href=" http://www.unicode.org/reports/tr18/"><i>Unicode
 
Technical
     
* Standard #18: Unicode Regular Expression</i></a>
     
* <i>Annex C: Compatibility Properties</i>.
     
* <p>
     
* The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
     
* flag expression&nbsp;<tt>(?U)</tt>.
     
* <p>
     
* The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
     
* folding.
     
* <p>
     
* Specifying this flag may impose a performance penalty.
  
</p>
     
* @since 1.7
     
*/

    
public static final int UNICODE_CHARACTER_CLASS = 0x100;

    
/* Pattern has only two serialized components: The pattern string
     
* and the flags, which are all that is needed to recompile the pattern
     
* when it is deserialized.
     
*/


    
/** use serialVersionUID from Merlin b59 for interoperability */
    
private static final long serialVersionUID = 5073258162644648461L;

    
/**
     
* The original regular-expression pattern string.
     
*
     
* @serial
     
*/

    
private String pattern;

    
/**
     
* The original pattern flags.
     
*
     
* @serial
     
*/
    
private int flags;

    
/**
     
* Boolean indicating this Pattern is compiled; this is necessary in order
     
* to lazily compile deserialized Patterns.
     
*/

    
private transient volatile boolean compiled = false;

    
/**
     
* The normalized pattern string.
     
*/
    
private transient String normalizedPattern;

    
/**
     
* The starting point of state machine for the find operation.
  
This allows
     
* a match to start anywhere in the input.
     
*/

    
transient Node root;

    
/**
     
* The root of object tree for a match operation.
  
The pattern is matched
     
* at the beginning.
  
This may include a find that uses BnM or a First
     
* node.
     
*/

    
transient Node matchRoot;

    
/**
     
* Temporary storage used by parsing pattern slice.
     
*/

    
transient int[] buffer;

    
/**
     
* Map the "name" of the "named capturing group" to its group id
     
* node.
     
*/

    
transient volatile Map<String, Integer> namedGroups;

    
/**
     
* Temporary storage used while parsing group references.
     
*/

    
transient GroupHead[] groupNodes;

    
/**
     
* Temporary null terminated code point array used by pattern compiling.
     
*/

    
private transient int[] temp;

    
/**
     
* The number of capturing groups in this Pattern. Used by matchers to
     
* allocate storage needed to perform a match.
     
*/

    
transient int capturingGroupCount;

    
/**
     
* The local variable count used by parsing tree. Used by matchers to
     
* allocate storage needed to perform a match.
     
*/

    
transient int localCount;

    
/**
     
* Index into the pattern string that keeps track of how much has been
     
* parsed.
     
*/

    
private transient int cursor;

    
/**
     
* Holds the length of the pattern string.
     
*/
    
private transient int patternLength;

    
/**
     
* If the Start node might possibly match supplementary characters.
     
* It is set to true during compiling if
     
* (1) There is supplementary char in pattern, or
     
* (2) There is complement node of Category or Block
     
*/

    
private transient boolean hasSupplementary;

    
/**
     
* Compiles the given regular expression into a pattern.
     
*
     
* @param
  
regex
     
*
         
The expression to be compiled
     
* @return the given regular expression compiled into a pattern
     
* @throws
  
PatternSyntaxException
     
*
          
If the expression's syntax is invalid
     
*/

    
public static Pattern compile(String regex) {
        
return new Pattern(regex, 0);
    
}

    
/**
     
* Compiles the given regular expression into a pattern with the given
     
* flags.
     
*
     
* @param
  
regex
     
*
         
The expression to be compiled
     
*
     
* @param
  
flags
     
*
         
Match flags, a bit mask that may include
     
*
         
, {@link #MULTILINE}, {@link #DOTALL},
     
*
         
, {@link #CANON_EQ}, {@link #UNIX_LINES},
     
*
         
, {@link #UNICODE_CHARACTER_CLASS}
     
*
         
and
 

     
*
     
* @return the given regular expression compiled into a pattern with the given flags
     
* @throws
  
IllegalArgumentException
     
*
          
If bit values other than those corresponding to the defined
     
*
          
match flags are set in <tt>flags</tt>
     
*
     
* @throws
  
PatternSyntaxException
     
*
          
If the expression's syntax is invalid
     
*/

    
public static Pattern compile(String regex, int flags) {
        
return new Pattern(regex, flags);
    
}

    
/**
     
* Returns the regular expression from which this pattern was compiled.
     
*
     
* @return
  
The source of this pattern
     
*/

    
public String pattern() {
        
return pattern;
    
}

    
/**
     
* <p>Returns the string representation of this pattern. This
     
* is the regular expression from which this pattern was
     
* compiled.</p>
     
*
     
* @return
  
The string representation of this pattern
     
* @since 1.5
     
*/

    
public String toString() {
        
return pattern;
    
}

    
/**
     
* Creates a matcher that will match the given input against this pattern.
     
*
     
* @param
  
input
     
*
         
The character sequence to be matched
     
*
     
* @return
  
A new matcher for this pattern
     
*/

    
public Matcher matcher(CharSequence input) {
        
if (!compiled) {
            
synchronized(this) {
                
if (!compiled)
                    
compile();
            
}
        
}
        
Matcher m = new Matcher(this, input);
        
return m;
    
}

    
/**
     
* Returns this pattern's match flags.
     
*
     
* @return
  
The match flags specified when this pattern was compiled
     
*/

    
public int flags() {
        
return flags;
    
}

    
/**
     
* Compiles the given regular expression and attempts to match the given
     
* input against it.
     
*
     
* <p> An invocation of this convenience method of the form
     
*
     
* <blockquote><pre>
     
* Pattern.matches(regex, input);</pre></blockquote>
     
*
     
* behaves in exactly the same way as the expression
     
*
     
* <blockquote><pre>
     
* Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
     
*
     
* <p> If a pattern is to be used multiple times, compiling it once and reusing
     
* it will be more efficient than invoking this method each time.
  
</p>
     
*
     
* @param
  
regex
     
*
         
The expression to be compiled
     
*
     
* @param
  
input
     
*
         
The character sequence to be matched
     
* @return whether or not the regular expression matches on the input
     
* @throws
  
PatternSyntaxException
     
*
          
If the expression's syntax is invalid
     
*/

    
public static boolean matches(String regex, CharSequence input) {
        
Pattern p = Pattern.compile(regex);
        
Matcher m = p.matcher(input);
        
return m.matches();
    
}

    
/**
     
* Splits the given input sequence around matches of this pattern.
     
*
     
* <p> The array returned by this method contains each substring of the
     
* input sequence that is terminated by another subsequence that matches
     
* this pattern or is terminated by the end of the input sequence.
  
The
     
* substrings in the array are in the order in which they occur in the
     
* input. If this pattern does not match any subsequence of the input then
     
* the resulting array has just one element, namely the input sequence in
     
* string form.
     
*
     
* <p> When there is a positive-width match at the beginning of the input
     
* sequence then an empty leading substring is included at the beginning
     
* of the resulting array. A zero-width match at the beginning however
     
* never produces such empty leading substring.
     
*
     
* <p> The <tt>limit</tt> parameter controls the number of times the
     
* pattern is applied and therefore affects the length of the resulting
     
* array.
  
If the limit <i>n</i> is greater than zero then the pattern
     
* will be applied at most <i>n</i>&nbsp;-&nbsp;1 times, the array's
     
* length will be no greater than <i>n</i>, and the array's last entry
     
* will contain all input beyond the last matched delimiter.
  
If <i>n</i>
     
* is non-positive then the pattern will be applied as many times as
     
* possible and the array can have any length.
  
If <i>n</i> is zero then
     
* the pattern will be applied as many times as possible, the array can
     
* have any length, and trailing empty strings will be discarded.
     
*
     
* <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
     
* results with these parameters:
     
*
     
* <blockquote><table cellpadding=1 cellspacing=0
     
*
              
summary="Split examples showing regex, limit, and result">
     
* <tr><th align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
     
*<th align="left"><i>Limit&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
     
*<th align="left"><i>Result&nbsp;&nbsp;&nbsp;&nbsp;</i></th></tr>
     
* <tr><td align=center>:</td>
     
*<td align=center>2</td>
     
*<td><tt>{ "boo", "and:foo" }</tt></td></tr>
     
* <tr><td align=center>:</td>
     
*<td align=center>5</td>
     
*<td><tt>{ "boo", "and", "foo" }</tt></td></tr>
     
* <tr><td align=center>:</td>
     
*<td align=center>-2</td>
     
*<td><tt>{ "boo", "and", "foo" }</tt></td></tr>
     
* <tr><td align=center>o</td>
     
*<td align=center>5</td>
     
*<td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
     
* <tr><td align=center>o</td>
     
*<td align=center>-2</td>
     
*<td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
     
* <tr><td align=center>o</td>
     
*<td align=center>0</td>
     
*<td><tt>{ "b", "", ":and:f" }</tt></td></tr>
     
* </table></blockquote>
     
*
     
* @param
  
input
     
*
         
The character sequence to be split
     
*
     
* @param
  
limit
     
*
         
The result threshold, as described above
     
*
     
* @return
  
The array of strings computed by splitting the input
     
*
          
around matches of this pattern
     
*/

    
public String[] split(CharSequence input, int limit) {
        
int index = 0;
        
boolean matchLimited = limit > 0;
        
ArrayList<String> matchList = new ArrayList<>();
        
Matcher m = matcher(input);

        
// Add segments before each match found
        
while(m.find()) {
            
if (!matchLimited || matchList.size() < limit - 1) {
                
if (index == 0 && index == m.start() && m.start() == m.end()) {
                    
// no empty leading substring included for zero-width match
                    
// at the beginning of the input char sequence.
                    
continue;
                
}
                
String match = input.subSequence(index, m.start()).toString();
                
matchList.add(match);
                
index = m.end();
            
} else if (matchList.size() == limit - 1) { // last one
                
String match = input.subSequence(index,
                                                 
input.length()).toString();
                
matchList.add(match);
                
index = m.end();
            
}
        
}

        
// If no match was found, return this
        
if (index == 0)
            
return new String[] {input.toString()};

        
// Add remaining segment
        
if (!matchLimited || matchList.size() < limit)
            
matchList.add(input.subSequence(index, input.length()).toString());

        
// Construct result
        
int resultSize = matchList.size();
        
if (limit == 0)
            
while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
                
resultSize--;
        
String[] result = new String[resultSize];
        
return matchList.subList(0, resultSize).toArray(result);
    
}

    
/**
     
* Splits the given input sequence around matches of this pattern.
     
*
     
* <p> This method works as if by invoking the two-argument {@link
     
* #split(java.lang.CharSequence, int) split} method with the given input
     
* sequence and a limit argument of zero.
  
Trailing empty strings are
     
* therefore not included in the resulting array. </p>
     
*
     
* <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
     
* results with these expressions:
     
*
     
* <blockquote><table cellpadding=1 cellspacing=0
     
*
              
summary="Split examples showing regex and result">
     
* <tr><th align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
     
*<th align="left"><i>Result</i></th></tr>
     
* <tr><td align=center>:</td>
     
*<td><tt>{ "boo", "and", "foo" }</tt></td></tr>
     
* <tr><td align=center>o</td>
     
*<td><tt>{ "b", "", ":and:f" }</tt></td></tr>
     
* </table></blockquote>
     
*
     
*
     
* @param
  
input
     
*
         
The character sequence to be split
     
*
     
* @return
  
The array of strings computed by splitting the input
     
*
          
around matches of this pattern
     
*/

    
public String[] split(CharSequence input) {
        
return split(input, 0);
    
}

    
/**
     
* Returns a literal pattern <code>String</code> for the specified
     
* <code>String</code>.
     
*
     
* <p>This method produces a <code>String</code> that can be used to
     
* create a <code>Pattern</code> that would match the string
     
* <code>s</code> as if it were a literal pattern.</p> Metacharacters
     
* or escape sequences in the input sequence will be given no special
     
* meaning.
     
*
     
* @param
  
s The string to be literalized
     
* @return
  
A literal string replacement
     
* @since 1.5
     
*/

    
public static String quote(String s) {
        
int slashEIndex = s.indexOf("\\E");
        
if (slashEIndex == -1)
            
return "\\Q" + s + "\\E";

        
StringBuilder sb = new StringBuilder(s.length() * 2);
        
sb.append("\\Q");
        
slashEIndex = 0;
        
int current = 0;
        
while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
            
sb.append(s.substring(current, slashEIndex));
            
current = slashEIndex + 2;
            
sb.append("\\E\\\\E\\Q");
        
}
        
sb.append(s.substring(current, s.length()));
        
sb.append("\\E");
        
return sb.toString();
    
}

    
/**
     
* Recompile the Pattern instance from a stream.
  
The original pattern
     
* string is read in and the object tree is recompiled from it.
     
*/

    
private void readObject(java.io.ObjectInputStream s)
        
throws java.io.IOException, ClassNotFoundException {

        
// Read in all fields
        
s.defaultReadObject();

        
// Initialize counts
        
capturingGroupCount = 1;
        
localCount = 0;

        
// if length > 0, the Pattern is lazily compiled
        
compiled = false;
        
if (pattern.length() == 0) {
            
root = new Start(lastAccept);
            
matchRoot = lastAccept;
            
compiled = true;
        
}
    
}

    
/**
     
* This private constructor is used to create all Patterns. The pattern
     
* string and match flags are all that is needed to completely describe
     
* a Pattern. An empty pattern string results in an object tree with
     
* only a Start node and a LastNode node.
     
*/

    
private Pattern(String p, int f) {
        
pattern = p;
        
flags = f;

        
// to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
        
if ((flags & UNICODE_CHARACTER_CLASS) != 0)
            
flags |= UNICODE_CASE;

        
// Reset group index count
        
capturingGroupCount = 1;
        
localCount = 0;

        
if (pattern.length() > 0) {
            
compile();
        
} else {
            
root = new Start(lastAccept);
            
matchRoot = lastAccept;
        
}
    
}

    
/**
     
* The pattern is converted to normalizedD form and then a pure group
     
* is constructed to match canonical equivalences of the characters.
     
*/

    
private void normalize() {
        
boolean inCharClass = false;
        
int lastCodePoint = -1;

        
// Convert pattern into normalizedD form
        
normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
        
patternLength = normalizedPattern.length();

        
// Modify pattern to match canonical equivalences
        
StringBuilder newPattern = new StringBuilder(patternLength);
        
for(int i=0; i<patternLength; ) {
            
int c = normalizedPattern.codePointAt(i);
            
StringBuilder sequenceBuffer;
            
if ((Character.getType(c) == Character.NON_SPACING_MARK)
                
&& (lastCodePoint != -1)) {
                
sequenceBuffer = new StringBuilder();
                
sequenceBuffer.appendCodePoint(lastCodePoint);
                
sequenceBuffer.appendCodePoint(c);
                
while(Character.getType(c) == Character.NON_SPACING_MARK) {
                    
i += Character.charCount(c);
                    
if (i >= patternLength)
                        
break;
                    
c = normalizedPattern.codePointAt(i);
                    
sequenceBuffer.appendCodePoint(c);
                
}
                
String ea = produceEquivalentAlternation(
                                               
sequenceBuffer.toString());
                
newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
                
newPattern.append("(?:").append(ea).append(")");
            
} else if (c == '[' && lastCodePoint != '\\') {
                
i = normalizeCharClass(newPattern, i);
            
} else {
                
newPattern.appendCodePoint(c);
            
}
            
lastCodePoint = c;
            
i += Character.charCount(c);
        
}
        
normalizedPattern = newPattern.toString();
    
}

    
/**
     
* Complete the character class being parsed and add a set
     
* of alternations to it that will match the canonical equivalences
     
* of the characters within the class.
     
*/

    
private int normalizeCharClass(StringBuilder newPattern, int i) {
        
StringBuilder charClass = new StringBuilder();
        
StringBuilder eq = null;
        
int lastCodePoint = -1;
        
String result;

        
i++;
        
if (i == normalizedPattern.length())
            
throw error("Unclosed character class");
        
charClass.append("[");
        
while(true) {
            
int c = normalizedPattern.codePointAt(i);
            
StringBuilder sequenceBuffer;

            
if (c == ']' && lastCodePoint != '\\') {
                
charClass.append((char)c);
                
break;
            
} else if (Character.getType(c) == Character.NON_SPACING_MARK) {
                
sequenceBuffer = new StringBuilder();
                
sequenceBuffer.appendCodePoint(lastCodePoint);
                
while(Character.getType(c) == Character.NON_SPACING_MARK) {
                    
sequenceBuffer.appendCodePoint(c);
                    
i += Character.charCount(c);
                    
if (i >= normalizedPattern.length())
                        
break;
                    
c = normalizedPattern.codePointAt(i);
                
}
                
String ea = produceEquivalentAlternation(
                                                  
sequenceBuffer.toString());

                
charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
                
if (eq == null)
                    
eq = new StringBuilder();
                
eq.append('|');
                
eq.append(ea);
            
} else {
                
charClass.appendCodePoint(c);
                
i++;
            
}
            
if (i == normalizedPattern.length())
                
throw error("Unclosed character class");
            
lastCodePoint = c;
        
}

        
if (eq != null) {
            
result = "(?:"+charClass.toString()+eq.toString()+")";
        
} else {
            
result = charClass.toString();
        
}

        
newPattern.append(result);
        
return i;
    
}

    
/**
     
* Given a specific sequence composed of a regular character and
     
* combining marks that follow it, produce the alternation that will
     
* match all canonical equivalences of that sequence.
     
*/

    
private String produceEquivalentAlternation(String source) {
        
int len = countChars(source, 0, 1);
        
if (source.length() == len)
            
// source has one character.
            
return source;

        
String base = source.substring(0,len);
        
String combiningMarks = source.substring(len);

        
String[] perms = producePermutations(combiningMarks);
        
StringBuilder result = new StringBuilder(source);

        
// Add combined permutations
        
for(int x=0; x<perms.length; x++) {
            
String next = base + perms[x];
            
if (x>0)
                
result.append("|"+next);
            
next = composeOneStep(next);
            
if (next != null)
                
result.append("|"+produceEquivalentAlternation(next));
        
}
        
return result.toString();
    
}

    
/**
     
* Returns an array of strings that have all the possible
     
* permutations of the characters in the input string.
     
* This is used to get a list of all possible orderings
     
* of a set of combining marks. Note that some of the permutations
     
* are invalid because of combining class collisions, and these
     
* possibilities must be removed because they are not canonically
     
* equivalent.
     
*/

    
private String[] producePermutations(String input) {
        
if (input.length() == countChars(input, 0, 1))
            
return new String[] {input};

        
if (input.length() == countChars(input, 0, 2)) {
            
int c0 = Character.codePointAt(input, 0);
            
int c1 = Character.codePointAt(input, Character.charCount(c0));
            
if (getClass(c1) == getClass(c0)) {
                
return new String[] {input};
            
}
            
String[] result = new String[2];
            
result[0] = input;
            
StringBuilder sb = new StringBuilder(2);
            
sb.appendCodePoint(c1);
            
sb.appendCodePoint(c0);
            
result[1] = sb.toString();
            
return result;
        
}

        
int length = 1;
        
int nCodePoints = countCodePoints(input);
        
for(int x=1; x<nCodePoints; x++)
            
length = length * (x+1);

        
String[] temp = new String[length];

        
int combClass[] = new int[nCodePoints];
        
for(int x=0, i=0; x<nCodePoints; x++) {
            
int c = Character.codePointAt(input, i);
            
combClass[x] = getClass(c);
            
i +=
  
Character.charCount(c);
        
}

        
// For each char, take it out and add the permutations
        
// of the remaining chars
        
int index = 0;
        
int len;
        
// offset maintains the index in code units.
loop:
   
for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
            
len = countChars(input, offset, 1);
            
boolean skip = false;
            
for(int y=x-1; y>=0; y--) {
                
if (combClass[y] == combClass[x]) {
                    
continue loop;
                
}
            
}
            
StringBuilder sb = new StringBuilder(input);
            
String otherChars = sb.delete(offset, offset+len).toString();
            
String[] subResult = producePermutations(otherChars);

            
String prefix = input.substring(offset, offset+len);
            
for(int y=0; y<subResult.length; y++)
                
temp[index++] =
  
prefix + subResult[y];
        
}
        
String[] result = new String[index];
        
for (int x=0; x<index; x++)
            
result[x] = temp[x];
        
return result;
    
}

    
private int getClass(int c) {
        
return sun.text.Normalizer.getCombiningClass(c);
    
}

    
/**
     
* Attempts to compose input by combining the first character
     
* with the first combining mark following it. Returns a String
     
* that is the composition of the leading character with its first
     
* combining mark followed by the remaining combining marks. Returns
     
* null if the first two characters cannot be further composed.
     
*/

    
private String composeOneStep(String input) {
        
int len = countChars(input, 0, 2);
        
String firstTwoCharacters = input.substring(0, len);
        
String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);

        
if (result.equals(firstTwoCharacters))
            
return null;
        
else {
            
String remainder = input.substring(len);
            
return result + remainder;
        
}
    
}

    
/**
     
* Preprocess any \Q...\E sequences in `temp', meta-quoting them.
     
* See the description of `quotemeta' in perlfunc(1).
     
*/

    
private void RemoveQEQuoting() {
        
final int pLen = patternLength;
        
int i = 0;
        
while (i < pLen-1) {
            
if (temp[i] != '\\')
                
i += 1;
            
else if (temp[i + 1] != 'Q')
                
i += 2;
            
else
                
break
;
        
}
        
if (i >= pLen - 1)
    
// No \Q sequence found
            
return;
        
int j = i;
        
i += 2;
        
int[] newtemp = new int[j + 3*(pLen-i) + 2];
        
System.arraycopy(temp, 0, newtemp, 0, j);

        
boolean inQuote = true;
        
boolean beginQuote = true;
        
while (i < pLen) {
            
int c = temp[i++];
            
if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
                
newtemp[j++] = c;
            
} else if (ASCII.isDigit(c)) {
                
if (beginQuote) {
                    
/*
                     
* A unicode escape \[0xu] could be before this quote,
                     
* and we don't want this numeric char to processed as
                     
* part of the escape.
                     
*/

                    
newtemp[j++] = '\\';
                    
newtemp[j++] = 'x';
                    
newtemp[j++] = '3';
                
}
                
newtemp[j++] = c;
            
} else if (c != '\\') {
                
if (inQuote) newtemp[j++] = '\\';
                
newtemp[j++] = c;
            
} else if (inQuote) {
                
if (temp[i] == 'E') {
                    
i++;
                    
inQuote = false;
                
} else {
                    
newtemp[j++] = '\\';
                    
newtemp[j++] = '\\';
                
}
            
} else {
                
if (temp[i] == 'Q') {
                    
i++;
                    
inQuote = true;
                    
beginQuote = true;
                    
continue;
                
} else {
                    
newtemp[j++] = c;
                    
if (i != pLen)
                        
newtemp[j++] = temp[i++];
                
}
            
}

            
beginQuote = false;
        
}

        
patternLength = j;
        
temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
    
}

    
/**
     
* Copies regular expression to an int array and invokes the parsing
     
* of the expression which will create the object tree.
     
*/

    
private void compile() {
        
// Handle canonical equivalences
        
if (has(CANON_EQ) && !has(LITERAL)) {
            
normalize();
        
} else {
            
normalizedPattern = pattern;
        
}
        
patternLength = normalizedPattern.length();

        
// Copy pattern to int array for convenience
        
// Use double zero to terminate pattern
        
temp = new int[patternLength + 2];

        
hasSupplementary = false;
        
int c, count = 0;
        
// Convert all chars into code points
        
for (int x = 0; x < patternLength; x += Character.charCount(c)) {
            
c = normalizedPattern.codePointAt(x);
            
if (isSupplementary(c)) {
                
hasSupplementary = true;
            
}
            
temp[count++] = c;
        
}

        
patternLength = count;
   
// patternLength now in code points

        
if (! has(LITERAL))
            
RemoveQEQuoting();

        
// Allocate all temporary objects here.
        
buffer = new int[32];
        
groupNodes = new GroupHead[10];
        
namedGroups = null;

        
if (has(LITERAL)) {
            
// Literal pattern handling
            
matchRoot = newSlice(temp, patternLength, hasSupplementary);
            
matchRoot.next = lastAccept;
        
} else {
            
// Start recursive descent parsing
            
matchRoot = expr(lastAccept);
            
// Check extra pattern characters
            
if (patternLength != cursor) {
                
if (peek() == ')') {
                    
throw error("Unmatched closing ')'");
                
} else {
                    
throw error("Unexpected internal error");
                
}
            
}
        
}

        
// Peephole optimization
        
if (matchRoot instanceof Slice) {
            
root = BnM.optimize(matchRoot);
            
if (root == matchRoot) {
                
root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
            
}
        
} else if (matchRoot instanceof Begin || matchRoot instanceof First) {
            
root = matchRoot;
        
} else {
            
root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
        
}

        
// Release temporary storage
        
temp = null;
        
buffer = null;
        
groupNodes = null;
        
patternLength = 0;
        
compiled = true;
    
}

    
Map<String, Integer> namedGroups() {
        
if (namedGroups == null)
            
namedGroups = new HashMap<>(2);
        
return namedGroups;
    
}

    
/**
     
* Used to print out a subtree of the Pattern to help with debugging.
     
*/
    
private static void printObjectTree(Node node) {
        
while(node != null) {
            
if (node instanceof Prolog) {
                
System.out.println(node);
                
printObjectTree(((Prolog)node).loop);
                
System.out.println("**** end contents prolog loop");
            
} else if (node instanceof Loop) {
                
System.out.println(node);
                
printObjectTree(((Loop)node).body);
                
System.out.println("**** end contents Loop body");
            
} else if (node instanceof Curly) {
                
System.out.println(node);
                
printObjectTree(((Curly)node).atom);
                
System.out.println("**** end contents Curly body");
            
} else if (node instanceof GroupCurly) {
                
System.out.println(node);
                
printObjectTree(((GroupCurly)node).atom);
                
System.out.println("**** end contents GroupCurly body");
            
} else if (node instanceof GroupTail) {
                
System.out.println(node);
                
System.out.println("Tail next is "+node.next);
                
return;
            
} else {
                
System.out.println(node);
            
}
            
node = node.next;
            
if (node != null)
                
System.out.println("->next:");
            
if (node == Pattern.accept) {
                
System.out.println("Accept Node");
                
node = null;
            
}
       
}
    
}

    
/**
     
* Used to accumulate information about a subtree of the object graph
     
* so that optimizations can be applied to the subtree.
     
*/

    
static final class TreeInfo {
        
int minLength;
        
int maxLength;
        
boolean maxValid;
        
boolean deterministic;

        
TreeInfo() {
            
reset();
        
}
        
void reset() {
            
minLength = 0;
            
maxLength = 0;
            
maxValid = true;
            
deterministic = true;
        
}
    
}

    
/*
     
* The following private methods are mainly used to improve the
     
* readability of the code. In order to let the Java compiler easily
     
* inline them, we should not put many assertions or error checks in them.
     
*/


    
/**
     
* Indicates whether a particular flag is set or not.
     
*/
    
private boolean has(int f) {
        
return (flags & f) != 0;
    
}

    
/**
     
* Match next character, signal error if failed.
     
*/

    
private void accept(int ch, String s) {
        
int testChar = temp[cursor++];
        
if (has(COMMENTS))
            
testChar = parsePastWhitespace(testChar);
        
if (ch != testChar) {
            
throw error(s);
        
}
    
}

    
/**
     
* Mark the end of pattern with a specific character.
     
*/
    
private void mark(int c) {
        
temp[patternLength] = c;
    
}

    
/**
     
* Peek the next character, and do not advance the cursor.
     
*/
    
private int peek() {
        
int ch = temp[cursor];
        
if (has(COMMENTS))
            
ch = peekPastWhitespace(ch);
        
return ch;
    
}

    
/**
     
* Read the next character, and advance the cursor by one.
     
*/
    
private int read() {
        
int ch = temp[cursor++];
        
if (has(COMMENTS))
            
ch = parsePastWhitespace(ch);
        
return ch;
    
}

    
/**
     
* Read the next character, and advance the cursor by one,
     
* ignoring the COMMENTS setting
     
*/

    
private int readEscaped() {
        
int ch = temp[cursor++];
        
return ch;
    
}

    
/**
     
* Advance the cursor by one, and peek the next character.
     
*/
    
private int next() {
        
int ch = temp[++cursor];
        
if (has(COMMENTS))
            
ch = peekPastWhitespace(ch);
        
return ch;
    
}

    
/**
     
* Advance the cursor by one, and peek the next character,
     
* ignoring the COMMENTS setting
     
*/

    
private int nextEscaped() {
        
int ch = temp[++cursor];
        
return ch;
    
}

    
/**
     
* If in xmode peek past whitespace and comments.
     
*/
    
private int peekPastWhitespace(int ch) {
        
while (ASCII.isSpace(ch) || ch == '#') {
            
while (ASCII.isSpace(ch))
                
ch = temp[++cursor];
            
if (ch == '#') {
                
ch = peekPastLine();
            
}
        
}
        
return ch;
    
}

    
/**
     
* If in xmode parse past whitespace and comments.
     
*/
    
private int parsePastWhitespace(int ch) {
        
while (ASCII.isSpace(ch) || ch == '#') {
            
while (ASCII.isSpace(ch))
                
ch = temp[cursor++];
            
if (ch == '#')
                
ch = parsePastLine();
        
}
        
return ch;
    
}

    
/**
     
* xmode parse past comment to end of line.
     
*/
    
private int parsePastLine() {
        
int ch = temp[cursor++];
        
while (ch != 0 && !isLineSeparator(ch))
            
ch = temp[cursor++];
        
return ch;
    
}

    
/**
     
* xmode peek past comment to end of line.
     
*/
    
private int peekPastLine() {
        
int ch = temp[++cursor];
        
while (ch != 0 && !isLineSeparator(ch))
            
ch = temp[++cursor];
        
return ch;
    
}

    
/**
     
* Determines if character is a line separator in the current mode
     
*/
    
private boolean isLineSeparator(int ch) {
        
if (has(UNIX_LINES)) {
            
return ch == '\n';
        
} else {
            
return (ch == '\n' ||
                    
ch == '\r' ||
                    
(ch|1) == '\u2029' ||
                    
ch == '\u0085');
        
}
    
}

    
/**
     
* Read the character after the next one, and advance the cursor by two.
     
*/
    
private int skip() {
        
int i = cursor;
        
int ch = temp[i+1];
        
cursor = i + 2;
        
return ch;
    
}

    
/**
     
* Unread one next character, and retreat cursor by one.
     
*/
    
private void unread() {
        
cursor--;
    
}

    
/**
     
* Internal method used for handling all syntax errors. The pattern is
     
* displayed with a pointer to aid in locating the syntax error.
     
*/

    
private PatternSyntaxException error(String s) {
        
return new PatternSyntaxException(s, normalizedPattern,
  
cursor - 1);
    
}

    
/**
     
* Determines if there is any supplementary character or unpaired
     
* surrogate in the specified range.
     
*/

    
private boolean findSupplementary(int start, int end) {
        
for (int i = start; i < end; i++) {
            
if (isSupplementary(temp[i]))
                
return true;
        
}
        
return false;
    
}

    
/**
     
* Determines if the specified code point is a supplementary
     
* character or unpaired surrogate.
     
*/

    
private static final boolean isSupplementary(int ch) {
        
return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
               
Character.isSurrogate((char)ch);
    
}

    
/**
     
*
  
The following methods handle the main parsing. They are sorted
     
*
  
according to their precedence order, the lowest one first.
     
*/


    
/**
     
* The expression is parsed with branch nodes added for alternations.
     
* This may be called recursively to parse sub expressions that may
     
* contain alternations.
     
*/

    
private Node expr(Node end) {
        
Node prev = null;
        
Node firstTail = null;
        
Branch branch = null;
        
Node branchConn = null;

        
for (;;) {
            
Node node = sequence(end);
            
Node nodeTail = root;
      
//double return
            
if (prev == null) {
                
prev = node;
                
firstTail = nodeTail;
            
} else {
                
// Branch
                
if (branchConn == null) {
                    
branchConn = new BranchConn();
                    
branchConn.next = end;
                
}
                
if (node == end) {
                    
// if the node returned from sequence() is "end"
                    
// we have an empty expr, set a null atom into
                    
// the branch to indicate to go "next" directly.
                    
node = null;
                
} else {
                    
// the "tail.next" of each atom goes to branchConn
                    
nodeTail.next = branchConn;
                
}
                
if (prev == branch) {
                    
branch.add(node);
                
} else {
                    
if (prev == end) {
                        
prev = null;
                    
} else {
                        
// replace the "end" with "branchConn" at its tail.next
                        
// when put the "prev" into the branch as the first atom.
                        
firstTail.next = branchConn;
                    
}
                    
prev = branch = new Branch(prev, node, branchConn);
                
}
            
}
            
if (peek() != '|') {
                
return prev;
            
}
            
next();
        
}
    
}

    
@SuppressWarnings("fallthrough")
    
/**
     
* Parsing of sequences between alternations.
     
*/
    
private Node sequence(Node end) {
        
Node head = null;
        
Node tail = null;
        
Node node = null;
    
LOOP:
        
for (;;) {
            
int ch = peek();
            
switch (ch) {
            
case '(':
                
// Because group handles its own closure,
                
// we need to treat it differently
                
node = group0();
                
// Check for comment or flag group
                
if (node == null)
                    
continue;
                
if (head == null)
                    
head = node;
                
else
                    
tail.next = node;
                
// Double return: Tail was returned in root
                
tail = root;
                
continue;
            
case '[':
                
node = clazz(true);
                
break;
            
case '\\':
                
ch = nextEscaped();
                
if (ch == 'p' || ch == 'P') {
                    
boolean oneLetter = true;
                    
boolean comp = (ch == 'P');
                    
ch = next(); // Consume { if present
                    
if (ch != '{') {
                        
unread();
                    
} else {
                        
oneLetter = false;
                    
}
                    
node = family(oneLetter, comp);
                
} else {
                    
unread();
                    
node = atom();
                
}
                
break;
            
case '^':
                
next();
                
if (has(MULTILINE)) {
                    
if (has(UNIX_LINES))
                        
node = new UnixCaret();
                    
else
                        
node = new Caret();
                
} else {
                    
node = new Begin();
                
}
                
break;
            
case '$':
                
next();
                
if (has(UNIX_LINES))
                    
node = new UnixDollar(has(MULTILINE));
                
else
                    
node = new Dollar(has(MULTILINE));
                
break;
            
case '.':
                
next();
                
if (has(DOTALL)) {
                    
node = new All();
                
} else {
                    
if (has(UNIX_LINES))
                        
node = new UnixDot();
                    
else {
                        
node = new Dot();
                    
}
                
}
                
break;
            
case '|':
            
case ')':
                
break LOOP;
            
case ']': // Now interpreting dangling ] and } as literals
            
case '}':
                
node = atom();
                
break;
            
case '?':
            
case '*':
            
case '+':
                
next();
                
throw error("Dangling meta character '" + ((char)ch) + "'");
            
case 0:
                
if (cursor >= patternLength) {
                    
break LOOP;
                
}
                
// Fall through
            
default:
                
node = atom();
                
break;
            
}

            
node = closure(node);

            
if (head == null) {
                
head = tail = node;
            
} else {
                
tail.next = node;
                
tail = node;
            
}
        
}
        
if (head == null) {
            
return end;
        
}
        
tail.next = end;
        
root = tail;
      
//double return
        
return head;
    
}

    
@SuppressWarnings("fallthrough")
    
/**
     
* Parse and add a new Single or Slice.
     
*/
    
private Node atom() {
        
int first = 0;
        
int prev = -1;
        
boolean hasSupplementary = false;
        
int ch = peek();
        
for (;;) {
            
switch (ch) {
            
case '*':
            
case '+':
            
case '?':
            
case '{':
                
if (first > 1) {
                    
cursor = prev;
    
// Unwind one character
                    
first--;
                
}
                
break;
            
case '$':
            
case '.':
            
case '^':
            
case '(':
            
case '[':
            
case '|':
            
case ')':
                
break;
            
case '\\':
                
ch = nextEscaped();
                
if (ch == 'p' || ch == 'P') { // Property
                    
if (first > 0) { // Slice is waiting; handle it first
                        
unread();
                        
break;
                    
} else { // No slice; just return the family node
                        
boolean comp = (ch == 'P');
                        
boolean oneLetter = true;
                        
ch = next(); // Consume { if present
                        
if (ch != '{')
                            
unread();
                        
else
                            
oneLetter = false;
                        
return family(oneLetter, comp);
                    
}
                
}
                
unread();
                
prev = cursor;
                
ch = escape(false, first == 0, false);
                
if (ch >= 0) {
                    
append(ch, first);
                    
first++;
                    
if (isSupplementary(ch)) {
                        
hasSupplementary = true;
                    
}
                    
ch = peek();
                    
continue;
                
} else if (first == 0) {
                    
return root;
                
}
                
// Unwind meta escape sequence
                
cursor = prev;
                
break;
            
case 0:
                
if (cursor >= patternLength) {
                    
break;
                
}
                
// Fall through
            
default:
                
prev = cursor;
                
append(ch, first);
                
first++;
                
if (isSupplementary(ch)) {
                    
hasSupplementary = true;
                
}
                
ch = next();
                
continue;
            
}
            
break;
        
}
        
if (first == 1) {
            
return newSingle(buffer[0]);
        
} else {
            
return newSlice(buffer, first, hasSupplementary);
        
}
    
}

    
private void append(int ch, int len) {
        
if (len >= buffer.length) {
            
int[] tmp = new int[len+len];
            
System.arraycopy(buffer, 0, tmp, 0, len);
            
buffer = tmp;
        
}
        
buffer[len] = ch;
    
}

    
/**
     
* Parses a backref greedily, taking as many numbers as it
     
* can. The first digit is always treated as a backref, but
     
* multi digit numbers are only treated as a backref if at
     
* least that many backrefs exist at this point in the regex.
     
*/

    
private Node ref(int refNum) {
        
boolean done = false;
        
while(!done) {
            
int ch = peek();
            
switch(ch) {
            
case '0':
            
case '1':
            
case '2':
            
case '3':
            
case '4':
            
case '5':
            
case '6':
            
case '7':
            
case '8':
            
case '9':
                
int newRefNum = (refNum * 10) + (ch - '0');
                
// Add another number if it doesn't make a group
                
// that doesn't exist
                
if (capturingGroupCount - 1 < newRefNum) {
                    
done = true;
                    
break;
                
}
                
refNum = newRefNum;
                
read();
                
break;
            
default:
                
done = true;
                
break;
            
}
        
}
        
if (has(CASE_INSENSITIVE))
            
return new CIBackRef(refNum, has(UNICODE_CASE));
        
else
            
return new
BackRef(refNum);
    
}

    
/**
     
* Parses an escape sequence to determine the actual value that needs
     
* to be matched.
     
* If -1 is returned and create was true a new object was added to the tree
     
* to handle the escape sequence.
     
* If the returned value is greater than zero, it is the value that
     
* matches the escape sequence.
     
*/

    
private int escape(boolean inclass, boolean create, boolean isrange) {
        
int ch = skip();
        
switch (ch) {
        
case '0':
            
return o();
        
case '1':
        
case '2':
        
case '3':
        
case '4':
        
case '5':
        
case '6':
        
case '7':
        
case '8':
        
case '9':
            
if (inclass) break;
            
if (create) {
                
root = ref((ch - '0'));
            
}
            
return -1;
        
case 'A':
            
if (inclass) break;
            
if (create) root = new Begin();
            
return -1;
        
case 'B':
            
if (inclass) break;
            
if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
            
return -1;
        
case 'C':
            
break;
        
case 'D':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.DIGIT).complement()
                               
: new Ctype(ASCII.DIGIT).complement();
            
return -1;
        
case 'E':
        
case 'F':
            
break;
        
case 'G':
            
if (inclass) break;
            
if (create) root = new LastMatch();
            
return -1;
        
case 'H':
            
if (create) root = new HorizWS().complement();
            
return -1;
        
case 'I':
        
case 'J':
        
case 'K':
        
case 'L':
        
case 'M':
        
case 'N':
        
case 'O':
        
case 'P':
        
case 'Q':
            
break;
        
case 'R':
            
if (inclass) break;
            
if (create) root = new LineEnding();
            
return -1;
        
case 'S':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.WHITE_SPACE).complement()
                               
: new Ctype(ASCII.SPACE).complement();
            
return -1;
        
case 'T':
        
case 'U':
            
break;
        
case 'V':
            
if (create) root = new VertWS().complement();
            
return -1;
        
case 'W':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.WORD).complement()
                               
: new Ctype(ASCII.WORD).complement();
            
return -1;
        
case 'X':
        
case 'Y':
            
break;
        
case 'Z':
            
if (inclass) break;
            
if (create) {
                
if (has(UNIX_LINES))
                    
root = new UnixDollar(false);
                
else
                    
root = new Dollar(false);
            
}
            
return -1;
        
case 'a':
            
return '\007';
        
case 'b':
            
if (inclass) break;
            
if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
            
return -1;
        
case 'c':
            
return c();
        
case 'd':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.DIGIT)
                               
: new Ctype(ASCII.DIGIT);
            
return -1;
        
case 'e':
            
return '\033';
        
case 'f':
            
return '\f';
        
case 'g':
            
break;
        
case 'h':
            
if (create) root = new HorizWS();
            
return -1;
        
case 'i':
        
case 'j':
            
break;
        
case 'k':
            
if (inclass)
                
break;
            
if (read() != '<')
                
throw error("\\k is not followed by '<' for named capturing group");
            
String name = groupname(read());
            
if (!namedGroups().containsKey(name))
                
throw error("(named capturing group <"+ name+"> does not exit");
            
if (create) {
                
if (has(CASE_INSENSITIVE))
                    
root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
                
else
                    
root = new BackRef(namedGroups().get(name));
            
}
            
return -1;
        
case 'l':
        
case 'm':
            
break;
        
case 'n':
            
return '\n';
        
case 'o':
        
case 'p':
        
case 'q':
            
break;
        
case 'r':
            
return '\r';
        
case 's':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.WHITE_SPACE)
                               
: new Ctype(ASCII.SPACE);
            
return -1;
        
case 't':
            
return '\t';
        
case 'u':
            
return u();
        
case 'v':
            
// '\v' was implemented as VT/0x0B in releases < 1.8 (though
            
// undocumented). In JDK8 '\v' is specified as a predefined
            
// character class for all vertical whitespace characters.
            
// So [-1, root=VertWS node] pair is returned (instead of a
            
// single 0x0B). This breaks the range if '\v' is used as
            
// the start or end value, such as [\v-...] or [...-\v], in
            
// which a single definite value (0x0B) is expected. For
            
// compatibility concern '\013'/0x0B is returned if isrange.
            
if (isrange)
                
return '\013';
            
if (create) root = new VertWS();
            
return -1;
        
case 'w':
            
if (create) root = has(UNICODE_CHARACTER_CLASS)
                               
? new Utype(UnicodeProp.WORD)
                               
: new Ctype(ASCII.WORD);
            
return -1;
        
case 'x':
            
return x();
        
case 'y':
            
break;
        
case 'z':
            
if (inclass) break;
            
if (create) root = new End();
            
return -1;
        
default:
            
return ch;
        
}
        
throw error("Illegal/unsupported escape sequence");
    
}

    
/**
     
* Parse a character class, and return the node that matches it.
     
*
     
* Consumes a ] on the way out if consume is true. Usually consume
     
* is true except for the case of [abc&&def] where def is a separate
     
* right hand node with "understood" brackets.
     
*/

    
private CharProperty clazz(boolean consume) {
        
CharProperty prev = null;
        
CharProperty node = null;
        
BitClass bits = new BitClass();
        
boolean include = true;
        
boolean firstInClass = true;
        
int ch = next();
        
for (;;) {
            
switch (ch) {
                
case '^':
                    
// Negates if first char in a class, otherwise literal
                    
if (firstInClass) {
                        
if (temp[cursor-1] != '[')
                            
break;
                        
ch = next();
                        
include = !include;
                        
continue;
                    
} else {
                        
// ^ not first in class, treat as literal
                        
break;
                    
}
                
case '[':
                    
firstInClass = false;
                    
node = clazz(true);
                    
if (prev == null)
                        
prev = node;
                    
else
                        
prev = union(prev, node);
                    
ch = peek();
                    
continue;
                
case '&':
                    
firstInClass = false;
                    
ch = next();
                    
if (ch == '&') {
                        
ch = next();
                        
CharProperty rightNode = null;
                        
while (ch != ']' && ch != '&') {
                            
if (ch == '[') {
                                
if (rightNode == null)
                                    
rightNode = clazz(true);
                                
else
                                    
rightNode = union(rightNode, clazz(true));
                            
} else { // abc&&def
                                
unread();
                                
rightNode = clazz(false);
                            
}
                            
ch = peek();
                        
}
                        
if (rightNode != null)
                            
node = rightNode;
                        
if (prev == null) {
                            
if (rightNode == null)
                                
throw error("Bad class syntax");
                            
else
                                
prev = rightNode;
                        
} else {
                            
prev = intersection(prev, node);
                        
}
                    
} else {
                        
// treat as a literal &
                        
unread();
                        
break;
                    
}
                    
continue;
                
case 0:
                    
firstInClass = false;
                    
if (cursor >= patternLength)
                        
throw error("Unclosed character class");
                    
break;
                
case ']':
                    
firstInClass = false;
                    
if (prev != null) {
                        
if (consume)
                            
next();
                        
return prev;
                    
}
                    
break;
                
default:
                    
firstInClass = false;
                    
break;
            
}
            
node = range(bits);
            
if (include) {
                
if (prev == null) {
                    
prev = node;
                
} else {
                    
if (prev != node)
                        
prev = union(prev, node);
                
}
            
} else {
                
if (prev == null) {
                    
prev = node.complement();
                
} else {
                    
if (prev != node)
                        
prev = setDifference(prev, node);
                
}
            
}
            
ch = peek();
        
}
    
}

    
private CharProperty bitsOrSingle(BitClass bits, int ch) {
        
/* Bits can only handle codepoints in [u+0000-u+00ff] range.
           
Use "single" node instead of bits when dealing with unicode
           
case folding for codepoints listed below.
           
(1)Uppercase out of range: u+00ff, u+00b5
              
toUpperCase(u+00ff) -> u+0178
              
toUpperCase(u+00b5) -> u+039c
           
(2)LatinSmallLetterLongS u+17f
              
toUpperCase(u+017f) -> u+0053
           
(3)LatinSmallLetterDotlessI u+131
              
toUpperCase(u+0131) -> u+0049
           
(4)LatinCapitalLetterIWithDotAbove u+0130
              
toLowerCase(u+0130) -> u+0069
           
(5)KelvinSign u+212a
              
toLowerCase(u+212a) ==> u+006B
           
(6)AngstromSign u+212b
              
toLowerCase(u+212b) ==> u+00e5
        
*/

        
int d;
        
if (ch < 256 &&
            
!(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
              
(ch == 0xff || ch == 0xb5 ||
               
ch == 0x49 || ch == 0x69 ||
  
//I and i
               
ch == 0x53 || ch == 0x73 ||
  
//S and s
               
ch == 0x4b || ch == 0x6b ||
  
//K and k
               
ch == 0xc5 || ch == 0xe5)))
  
//A+ring
            
return bits.add(ch, flags());
        
return newSingle(ch);
    
}

    
/**
     
* Parse a single character or a character range in a character class
     
* and return its representative node.
     
*/

    
private CharProperty range(BitClass bits) {
        
int ch = peek();
        
if (ch == '\\') {
            
ch = nextEscaped();
            
if (ch == 'p' || ch == 'P') { // A property
                
boolean comp = (ch == 'P');
                
boolean oneLetter = true;
                
// Consume { if present
                
ch = next();
                
if (ch != '{')
                    
unread();
                
else
                    
oneLetter = false;
                
return family(oneLetter, comp);
            
} else { // ordinary escape
                
boolean isrange = temp[cursor+1] == '-';
                
unread();
                
ch = escape(true, true, isrange);
                
if (ch == -1)
                    
return (CharProperty) root;
            
}
        
} else {
            
next();
        
}
        
if (ch >= 0) {
            
if (peek() == '-') {
                
int endRange = temp[cursor+1];
                
if (endRange == '[') {
                    
return bitsOrSingle(bits, ch);
                
}
                
if (endRange != ']') {
                    
next();
                    
int m = peek();
                    
if (m == '\\') {
                        
m = escape(true, false, true);
                    
} else {
                        
next();
                    
}
                    
if (m < ch) {
                        
throw error("Illegal character range");
                    
}
                    
if (has(CASE_INSENSITIVE))
                        
return caseInsensitiveRangeFor(ch, m);
                    
else
                        
return
rangeFor(ch, m);
                
}
            
}
            
return bitsOrSingle(bits, ch);
        
}
        
throw error("Unexpected character '"+((char)ch)+"'");
    
}

    
/**
     
* Parses a Unicode character family and returns its representative node.
     
*/

    
private CharProperty family(boolean singleLetter,
                                
boolean maybeComplement)
    
{
        
next();
        
String name;
        
CharProperty node = null;

        
if (singleLetter) {
            
int c = temp[cursor];
            
if (!Character.isSupplementaryCodePoint(c)) {
                
name = String.valueOf((char)c);
            
} else {
                
name = new String(temp, cursor, 1);
            
}
            
read();
        
} else {
            
int i = cursor;
            
mark('}');
            
while(read() != '}') {
            
}
            
mark('\000');
            
int j = cursor;
            
if (j > patternLength)
                
throw error("Unclosed character family");
            
if (i + 1 >= j)
                
throw error("Empty character family");
            
name = new String(temp, i, j-i-1);
        
}

        
int i = name.indexOf('=');
        
if (i != -1) {
            
// property construct \p{name=value}
            
String value = name.substring(i + 1);
            
name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
            
if ("sc".equals(name) || "script".equals(name)) {
                
node = unicodeScriptPropertyFor(value);
            
} else if ("blk".equals(name) || "block".equals(name)) {
                
node = unicodeBlockPropertyFor(value);
            
} else if ("gc".equals(name) || "general_category".equals(name)) {
                
node = charPropertyNodeFor(value);
            
} else {
                
throw error("Unknown Unicode property {name=<" + name + ">, "
                             
+ "value=<" + value + ">}");
            
}
        
} else {
            
if (name.startsWith("In")) {
                
// \p{inBlockName}
                
node = unicodeBlockPropertyFor(name.substring(2));
            
} else if (name.startsWith("Is")) {
                
// \p{isGeneralCategory} and \p{isScriptName}
                
name = name.substring(2);
                
UnicodeProp uprop = UnicodeProp.forName(name);
                
if (uprop != null)
                    
node = new Utype(uprop);
                
if (node == null)
                    
node = CharPropertyNames.charPropertyFor(name);
                
if (node == null)
                    
node = unicodeScriptPropertyFor(name);
            
} else {
                
if (has(UNICODE_CHARACTER_CLASS)) {
                    
UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
                    
if (uprop != null)
                        
node = new Utype(uprop);
                
}
                
if (node == null)
                    
node = charPropertyNodeFor(name);
            
}
        
}
        
if (maybeComplement) {
            
if (node instanceof Category || node instanceof Block)
                
hasSupplementary = true;
            
node = node.complement();
        
}
        
return node;
    
}


    
/**
     
* Returns a CharProperty matching all characters belong to
     
* a UnicodeScript.
     
*/

    
private CharProperty unicodeScriptPropertyFor(String name) {
        
final Character.UnicodeScript script;
        
try {
            
script = Character.UnicodeScript.forName(name);
        
} catch (IllegalArgumentException iae) {
            
throw error("Unknown character script name {" + name + "}");
        
}
        
return new Script(script);
    
}

    
/**
     
* Returns a CharProperty matching all characters in a UnicodeBlock.
     
*/

    
private CharProperty unicodeBlockPropertyFor(String name) {
        
final Character.UnicodeBlock block;
        
try {
            
block = Character.UnicodeBlock.forName(name);
        
} catch (IllegalArgumentException iae) {
            
throw error("Unknown character block name {" + name + "}");
        
}
        
return new Block(block);
    
}

    
/**
     
* Returns a CharProperty matching all characters in a named property.
     
*/

    
private CharProperty charPropertyNodeFor(String name) {
        
CharProperty p = CharPropertyNames.charPropertyFor(name);
        
if (p == null)
            
throw error("Unknown character property name {" + name + "}");
        
return p;
    
}

    
/**
     
* Parses and returns the name of a "named capturing group", the trailing
     
* ">" is consumed after parsing.
     
*/

    
private String groupname(int ch) {
        
StringBuilder sb = new StringBuilder();
        
sb.append(Character.toChars(ch));
        
while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
               
ASCII.isDigit(ch)) {
            
sb.append(Character.toChars(ch));
        
}
        
if (sb.length() == 0)
            
throw error("named capturing group has 0 length name");
        
if (ch != '>')
            
throw error("named capturing group is missing trailing '>'");
        
return sb.toString();
    
}

    
/**
     
* Parses a group and returns the head node of a set of nodes that process
     
* the group. Sometimes a double return system is used where the tail is
     
* returned in root.
     
*/

    
private Node group0() {
        
boolean capturingGroup = false;
        
Node head = null;
        
Node tail = null;
        
int save = flags;
        
root = null;
        
int ch = next();
        
if (ch == '?') {
            
ch = skip();
            
switch (ch) {
            
case ':':
   
//
  
(?:xxx) pure group
                
head = createGroup(true);
                
tail = root;
                
head.next = expr(tail);
                
break;
            
case '=':
   
// (?=xxx) and (?!xxx) lookahead
            
case '!':
                
head = createGroup(true);
                
tail = root;
                
head.next = expr(tail);
                
if (ch == '=') {
                    
head = tail = new Pos(head);
                
} else {
                    
head = tail = new Neg(head);
                
}
                
break;
            
case '>':
   
// (?>xxx)
  
independent group
                
head = createGroup(true);
                
tail = root;
                
head.next = expr(tail);
                
head = tail = new Ques(head, INDEPENDENT);
                
break;
            
case '<':
   
// (?<xxx)
  
look behind
                
ch = read();
                
if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
                    
// named captured group
                    
String name = groupname(ch);
                    
if (namedGroups().containsKey(name))
                        
throw error("Named capturing group <" + name
                                    
+ "> is already defined");
                    
capturingGroup = true;
                    
head = createGroup(false);
                    
tail = root;
                    
namedGroups().put(name, capturingGroupCount-1);
                    
head.next = expr(tail);
                    
break;
                
}
                
int start = cursor;
                
head = createGroup(true);
                
tail = root;
                
head.next = expr(tail);
                
tail.next = lookbehindEnd;
                
TreeInfo info = new TreeInfo();
                
head.study(info);
                
if (info.maxValid == false) {
                    
throw error("Look-behind group does not have "
                                
+ "an obvious maximum length");
                
}
                
boolean hasSupplementary = findSupplementary(start, patternLength);
                
if (ch == '=') {
                    
head = tail = (hasSupplementary ?
                                   
new BehindS(head, info.maxLength,
                                               
info.minLength) :
                                   
new Behind(head, info.maxLength,
                                              
info.minLength));
                
} else if (ch == '!') {
                    
head = tail = (hasSupplementary ?
                                   
new NotBehindS(head, info.maxLength,
                                                  
info.minLength) :
                                   
new NotBehind(head, info.maxLength,
                                                 
info.minLength));
                
} else {
                    
throw error("Unknown look-behind group");
                
}
                
break;
            
case '$':
            
case '@':
                
throw error("Unknown group type");
            
default:
    
// (?xxx:) inlined match flags
                
unread();
                
addFlag();
                
ch = read();
                
if (ch == ')') {
                    
return null;
    
// Inline modifier only
                
}
                
if (ch != ':') {
                    
throw error("Unknown inline modifier");
                
}
                
head = createGroup(true);
                
tail = root;
                
head.next = expr(tail);
                
break;
            
}
        
} else { // (xxx) a regular group
            
capturingGroup = true;
            
head = createGroup(false);
            
tail = root;
            
head.next = expr(tail);
        
}

        
accept(')', "Unclosed group");
        
flags = save;

        
// Check for quantifiers
        
Node node = closure(head);
        
if (node == head) { // No closure
            
root = tail;
            
return node;
    
// Dual return
        
}
        
if (head == tail) { // Zero length assertion
            
root = node;
            
return node;
    
// Dual return
        
}

        
if (node instanceof Ques) {
            
Ques ques = (Ques) node;
            
if (ques.type == POSSESSIVE) {
                
root = node;
                
return node;
            
}
            
tail.next = new BranchConn();
            
tail = tail.next;
            
if (ques.type == GREEDY) {
                
head = new Branch(head, null, tail);
            
} else { // Reluctant quantifier
                
head = new Branch(null, head, tail);
            
}
            
root = tail;
            
return head;
        
} else if (node instanceof Curly) {
            
Curly curly = (Curly) node;
            
if (curly.type == POSSESSIVE) {
                
root = node;
                
return node;
            
}
            
// Discover if the group is deterministic
            
TreeInfo info = new TreeInfo();
            
if (head.study(info)) { // Deterministic
                
GroupTail temp = (GroupTail) tail;
                
head = root = new GroupCurly(head.next, curly.cmin,
                                   
curly.cmax, curly.type,
                                   
((GroupTail)tail).localIndex,
                                   
((GroupTail)tail).groupIndex,
                                             
capturingGroup);
                
return head;
            
} else { // Non-deterministic
                
int temp = ((GroupHead) head).localIndex;
                
Loop loop;
                
if (curly.type == GREEDY)
                    
loop = new Loop(this.localCount, temp);
                
else
  
// Reluctant Curly
                    
loop = new LazyLoop(this.localCount, temp);
                
Prolog prolog = new Prolog(loop);
                
this.localCount += 1;
                
loop.cmin = curly.cmin;
                
loop.cmax = curly.cmax;
                
loop.body = head;
                
tail.next = loop;
                
root = loop;
                
return prolog; // Dual return
            
}
        
}
        
throw error("Internal logic error");
    
}

    
/**
     
* Create group head and tail nodes using double return. If the group is
     
* created with anonymous true then it is a pure group and should not
     
* affect group counting.
     
*/

    
private Node createGroup(boolean anonymous) {
        
int localIndex = localCount++;
        
int groupIndex = 0;
        
if (!anonymous)
            
groupIndex = capturingGroupCount++;
        
GroupHead head = new GroupHead(localIndex);
        
root = new GroupTail(localIndex, groupIndex);
        
if (!anonymous && groupIndex < 10)
            
groupNodes[groupIndex] = head;
        
return head;
    
}

    
@SuppressWarnings("fallthrough")
    
/**
     
* Parses inlined match flags and set them appropriately.
     
*/

    
private void addFlag() {
        
int ch = peek();
        
for (;;) {
            
switch (ch) {
            
case 'i':
                
flags |= CASE_INSENSITIVE;
                
break;
            
case 'm':
                
flags |= MULTILINE;
                
break;
            
case 's':
                
flags |= DOTALL;
                
break;
            
case 'd':
                
flags |= UNIX_LINES;
                
break;
            
case 'u':
                
flags |= UNICODE_CASE;
                
break;
            
case 'c':
                
flags |= CANON_EQ;
                
break;
            
case 'x':
                
flags |= COMMENTS;
                
break;
            
case 'U':
                
flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
                
break;
            
case '-': // subFlag then fall through
                
ch = next();
                
subFlag();
            
default:
                
return;
            
}
            
ch = next();
        
}
    
}

    
@SuppressWarnings("fallthrough")
    
/**
     
* Parses the second part of inlined match flags and turns off
     
* flags appropriately.
     
*/

    
private void subFlag() {
        
int ch = peek();
        
for (;;) {
            
switch (ch) {
            
case 'i':
                
flags &= ~CASE_INSENSITIVE;
                
break;
            
case 'm':
                
flags &= ~MULTILINE;
                
break;
            
case 's':
                
flags &= ~DOTALL;
                
break;
            
case 'd':
                
flags &= ~UNIX_LINES;
                
break;
            
case 'u':
                
flags &= ~UNICODE_CASE;
                
break;
            
case 'c':
                
flags &= ~CANON_EQ;
                
break;
            
case 'x':
                
flags &= ~COMMENTS;
                
break;
            
case 'U':
                
flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
            
default:
                
return;
            
}
            
ch = next();
        
}
    
}

    
static final int MAX_REPS
   
= 0x7FFFFFFF;

    
static final int GREEDY
     
= 0;

    
static final int LAZY
       
= 1;

    
static final int POSSESSIVE = 2;

    
static final int INDEPENDENT = 3;

    
/**
     
* Processes repetition. If the next character peeked is a quantifier
     
* then new nodes must be appended to handle the repetition.
     
* Prev could be a single or a group, so it could be a chain of nodes.
     
*/

    
private Node closure(Node prev) {
        
Node atom;
        
int ch = peek();
        
switch (ch) {
        
case '?':
            
ch = next();
            
if (ch == '?') {
                
next();
                
return new Ques(prev, LAZY);
            
} else if (ch == '+') {
                
next();
                
return new Ques(prev, POSSESSIVE);
            
}
            
return new Ques(prev, GREEDY);
        
case '*':
            
ch = next();
            
if (ch == '?') {
                
next();
                
return new Curly(prev, 0, MAX_REPS, LAZY);
            
} else if (ch == '+') {
                
next();
                
return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
            
}
            
return new Curly(prev, 0, MAX_REPS, GREEDY);
        
case '+':
            
ch = next();
            
if (ch == '?') {
                
next();
                
return new Curly(prev, 1, MAX_REPS, LAZY);
            
} else if (ch == '+') {
                
next();
                
return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
            
}
            
return new Curly(prev, 1, MAX_REPS, GREEDY);
        
case '{':
            
ch = temp[cursor+1];
            
if (ASCII.isDigit(ch)) {
                
skip();
                
int cmin = 0;
                
do {
                    
cmin = cmin * 10 + (ch - '0');
                
} while (ASCII.isDigit(ch = read()));
                
int cmax = cmin;
                
if (ch == ',') {
                    
ch = read();
                    
cmax = MAX_REPS;
                    
if (ch != '}') {
                        
cmax = 0;
                        
while (ASCII.isDigit(ch)) {
                            
cmax = cmax * 10 + (ch - '0');
                            
ch = read();
                        
}
                    
}
                
}
                
if (ch != '}')
                    
throw error("Unclosed counted closure");
                
if (((cmin) | (cmax) | (cmax - cmin)) < 0)
                    
throw error("Illegal repetition range");
                
Curly curly;
                
ch = peek();
                
if (ch == '?') {
                    
next();
                    
curly = new Curly(prev, cmin, cmax, LAZY);
                
} else if (ch == '+') {
                    
next();
                    
curly = new Curly(prev, cmin, cmax, POSSESSIVE);
                
} else {
                    
curly = new Curly(prev, cmin, cmax, GREEDY);
                
}
                
return curly;
            
} else {
                
throw error("Illegal repetition");
            
}
        
default:
            
return prev;
        
}
    
}

    
/**
     
*
  
Utility method for parsing control escape sequences.
     
*/

    
private int c() {
        
if (cursor < patternLength) {
            
return read() ^ 64;
        
}
        
throw error("Illegal control escape sequence");
    
}

    
/**
     
*
  
Utility method for parsing octal escape sequences.
     
*/

    
private int o() {
        
int n = read();
        
if (((n-'0')|('7'-n)) >= 0) {
            
int m = read();
            
if (((m-'0')|('7'-m)) >= 0) {
                
int o = read();
                
if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
                    
return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
                
}
                
unread();
                
return (n - '0') * 8 + (m - '0');
            
}
            
unread();
            
return (n - '0');
        
}
        
throw error("Illegal octal escape sequence");
    
}

    
/**
     
*
  
Utility method for parsing hexadecimal escape sequences.
     
*/

    
private int x() {
        
int n = read();
        
if (ASCII.isHexDigit(n)) {
            
int m = read();
            
if (ASCII.isHexDigit(m)) {
                
return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
            
}
        
} else if (n == '{' && ASCII.isHexDigit(peek())) {
            
int ch = 0;
            
while (ASCII.isHexDigit(n = read())) {
                
ch = (ch << 4) + ASCII.toDigit(n);
                
if (ch > Character.MAX_CODE_POINT)
                    
throw error("Hexadecimal codepoint is too big");
            
}
            
if (n != '}')
                
throw error("Unclosed hexadecimal escape sequence");
            
return ch;
        
}
        
throw error("Illegal hexadecimal escape sequence");
    
}

    
/**
     
*
  
Utility method for parsing unicode escape sequences.
     
*/

    
private int cursor() {
        
return cursor;
    
}

    
private void setcursor(int pos) {
        
cursor = pos;
    
}

    
private int uxxxx() {
        
int n = 0;
        
for (int i = 0; i < 4; i++) {
            
int ch = read();
            
if (!ASCII.isHexDigit(ch)) {
                
throw error("Illegal Unicode escape sequence");
            
}
            
n = n * 16 + ASCII.toDigit(ch);
        
}
        
return n;
    
}

    
private int u() {
        
int n = uxxxx();
        
if (Character.isHighSurrogate((char)n)) {
            
int cur = cursor();
            
if (read() == '\\' && read() == 'u') {
                
int n2 = uxxxx();
                
if (Character.isLowSurrogate((char)n2))
                    
return Character.toCodePoint((char)n, (char)n2);
            
}
            
setcursor(cur);
        
}
        
return n;
    
}

    
//
    
// Utility methods for code point support
    
//

    
private static final int countChars(CharSequence seq, int index,
                                        
int lengthInCodePoints) {
        
// optimization
        
if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
            
assert (index >= 0 && index < seq.length());
            
return 1;
        
}
        
int length = seq.length();
        
int x = index;
        
if (lengthInCodePoints >= 0) {
            
assert (index >= 0 && index < length);
            
for (int i = 0; x < length && i < lengthInCodePoints; i++) {
                
if (Character.isHighSurrogate(seq.charAt(x++))) {
                    
if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
                        
x++;
                    
}
                
}
            
}
            
return x - index;
        
}

        
assert (index >= 0 && index <= length);
        
if (index == 0) {
            
return 0;
        
}
        
int len = -lengthInCodePoints;
        
for (int i = 0; x > 0 && i < len; i++) {
            
if (Character.isLowSurrogate(seq.charAt(--x))) {
                
if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
                    
x--;
                
}
            
}
        
}
        
return index - x;
    
}

    
private static final int countCodePoints(CharSequence seq) {
        
int length = seq.length();
        
int n = 0;
        
for (int i = 0; i < length; ) {
            
n++;
            
if (Character.isHighSurrogate(seq.charAt(i++))) {
                
if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
                    
i++;
                
}
            
}
        
}
        
return n;
    
}

    
/**
     
*
  
Creates a bit vector for matching Latin-1 values. A normal BitClass
     
*
  
never matches values above Latin-1, and a complemented BitClass always
     
*
  
matches values above Latin-1.
     
*/

    
private static final class BitClass extends BmpCharProperty {
        
final boolean[] bits;
        
BitClass() { bits = new boolean[256]; }
        
private BitClass(boolean[] bits) { this.bits = bits; }
        
BitClass add(int c, int flags) {
            
assert c >= 0 && c <= 255;
            
if ((flags & CASE_INSENSITIVE) != 0) {
                
if (ASCII.isAscii(c)) {
                    
bits[ASCII.toUpper(c)] = true;
                    
bits[ASCII.toLower(c)] = true;
                
} else if ((flags & UNICODE_CASE) != 0) {
                    
bits[Character.toLowerCase(c)] = true;
                    
bits[Character.toUpperCase(c)] = true;
                
}
            
}
            
bits[c] = true;
            
return this;
        
}
        
boolean isSatisfiedBy(int ch) {
            
return ch < 256 && bits[ch];
        
}
    
}

    
/**
     
*
  
Returns a suitably optimized, single character matcher.
     
*/

    
private CharProperty newSingle(final int ch) {
        
if (has(CASE_INSENSITIVE)) {
            
int lower, upper;
            
if (has(UNICODE_CASE)) {
                
upper = Character.toUpperCase(ch);
                
lower = Character.toLowerCase(upper);
                
if (upper != lower)
                    
return new SingleU(lower);
            
} else if (ASCII.isAscii(ch)) {
                
lower = ASCII.toLower(ch);
                
upper = ASCII.toUpper(ch);
                
if (lower != upper)
                    
return new SingleI(lower, upper);
            
}
        
}
        
if (isSupplementary(ch))
            
return new SingleS(ch);
    
// Match a given Unicode character
        
return new Single(ch);
         
// Match a given BMP character
    
}

    
/**
     
*
  
Utility method for creating a string slice matcher.
     
*/

    
private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
        
int[] tmp = new int[count];
        
if (has(CASE_INSENSITIVE)) {
            
if (has(UNICODE_CASE)) {
                
for (int i = 0; i < count; i++) {
                    
tmp[i] = Character.toLowerCase(
                                 
Character.toUpperCase(buf[i]));
                
}
                
return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
            
}
            
for (int i = 0; i < count; i++) {
                
tmp[i] = ASCII.toLower(buf[i]);
            
}
            
return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
        
}
        
for (int i = 0; i < count; i++) {
            
tmp[i] = buf[i];
        
}
        
return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
    
}

    
/**
     
* The following classes are the building components of the object
     
* tree that represents a compiled regular expression. The object tree
     
* is made of individual elements that handle constructs in the Pattern.
     
* Each type of object knows how to match its equivalent construct with
     
* the match() method.
     
*/


    
/**
     
* Base class for all node classes. Subclasses should override the match()
     
* method as appropriate. This class is an accepting node, so its match()
     
* always returns true.
     
*/

    
static class Node extends Object {
        
Node next;
        
Node() {
            
next = Pattern.accept;
        
}
        
/**
         
* This method implements the classic accept node.
         
*/

        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
matcher.last = i;
            
matcher.groups[0] = matcher.first;
            
matcher.groups[1] = matcher.last;
            
return true;
        
}
        
/**
         
* This method is good for all zero length assertions.
         
*/
        
boolean study(TreeInfo info) {
            
if (next != null) {
                
return next.study(info);
            
} else {
                
return info.deterministic;
            
}
        
}
    
}

    
static class LastNode extends Node {
        
/**
         
* This method implements the classic accept node with
         
* the addition of a check to see if the match occurred
         
* using all of the input.
         
*/

        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (matcher.acceptMode == Matcher.ENDANCHOR && i != matcher.to)
                
return false;
            
matcher.last = i;
            
matcher.groups[0] = matcher.first;
            
matcher.groups[1] = matcher.last;
            
return true;
        
}
    
}

    
/**
     
* Used for REs that can start anywhere within the input string.
     
* This basically tries to match repeatedly at each spot in the
     
* input string, moving forward after each try. An anchored search
     
* or a BnM will bypass this node completely.
     
*/

    
static class Start extends Node {
        
int minLength;
        
Start(Node node) {
            
this.next = node;
            
TreeInfo info = new TreeInfo();
            
next.study(info);
            
minLength = info.minLength;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (i > matcher.to - minLength) {
                
matcher.hitEnd = true;
                
return false;
            
}
            
int guard = matcher.to - minLength;
            
for (; i <= guard; i++) {
                
if (next.match(matcher, i, seq)) {
                    
matcher.first = i;
                    
matcher.groups[0] = matcher.first;
                    
matcher.groups[1] = matcher.last;
                    
return true;
                
}
            
}
            
matcher.hitEnd = true;
            
return false;
        
}
        
boolean study(TreeInfo info) {
            
next.study(info);
            
info.maxValid = false;
            
info.deterministic = false;
            
return false;
        
}
    
}

    
/*
     
* StartS supports supplementary characters, including unpaired surrogates.
     
*/

    
static final class StartS extends Start {
        
StartS(Node node) {
            
super(node);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (i > matcher.to - minLength) {
                
matcher.hitEnd = true;
                
return false;
            
}
            
int guard = matcher.to - minLength;
            
while (i <= guard) {
                
//if ((ret = next.match(matcher, i, seq)) || i == guard)
                
if (next.match(matcher, i, seq)) {
                    
matcher.first = i;
                    
matcher.groups[0] = matcher.first;
                    
matcher.groups[1] = matcher.last;
                    
return true;
                
}
                
if (i == guard)
                    
break;
                
// Optimization to move to the next character. This is
                
// faster than countChars(seq, i, 1).
                
if (Character.isHighSurrogate(seq.charAt(i++))) {
                    
if (i < seq.length() &&
                        
Character.isLowSurrogate(seq.charAt(i))) {
                        
i++;
                    
}
                
}
            
}
            
matcher.hitEnd = true;
            
return false;
        
}
    
}

    
/**
     
* Node to anchor at the beginning of input. This object implements the
     
* match for a \A sequence, and the caret anchor will use this if not in
     
* multiline mode.
     
*/

    
static final class Begin extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int fromIndex = (matcher.anchoringBounds) ?
                
matcher.from : 0;
            
if (i == fromIndex && next.match(matcher, i, seq)) {
                
matcher.first = i;
                
matcher.groups[0] = i;
                
matcher.groups[1] = matcher.last;
                
return true;
            
} else {
                
return false;
            
}
        
}
    
}

    
/**
     
* Node to anchor at the end of input. This is the absolute end, so this
     
* should not match at the last newline before the end as $ will.
     
*/

    
static final class End extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int endIndex = (matcher.anchoringBounds) ?
                
matcher.to : matcher.getTextLength();
            
if (i == endIndex) {
                
matcher.hitEnd = true;
                
return next.match(matcher, i, seq);
            
}
            
return false;
        
}
    
}

    
/**
     
* Node to anchor at the beginning of a line. This is essentially the
     
* object to match for the multiline ^.
     
*/

    
static final class Caret extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int startIndex = matcher.from;
            
int endIndex = matcher.to;
            
if (!matcher.anchoringBounds) {
                
startIndex = 0;
                
endIndex = matcher.getTextLength();
            
}
            
// Perl does not match ^ at end of input even after newline
            
if (i == endIndex) {
                
matcher.hitEnd = true;
                
return false;
            
}
            
if (i > startIndex) {
                
char ch = seq.charAt(i-1);
                
if (ch != '\n' && ch != '\r'
                    
&& (ch|1) != '\u2029'
                    
&& ch != '\u0085' ) {
                    
return false;
                
}
                
// Should treat /r/n as one newline
                
if (ch == '\r' && seq.charAt(i) == '\n')
                    
return false;
            
}
            
return next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Node to anchor at the beginning of a line when in unixdot mode.
     
*/
    
static final class UnixCaret extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int startIndex = matcher.from;
            
int endIndex = matcher.to;
            
if (!matcher.anchoringBounds) {
                
startIndex = 0;
                
endIndex = matcher.getTextLength();
            
}
            
// Perl does not match ^ at end of input even after newline
            
if (i == endIndex) {
                
matcher.hitEnd = true;
                
return false;
            
}
            
if (i > startIndex) {
                
char ch = seq.charAt(i-1);
                
if (ch != '\n') {
                    
return false;
                
}
            
}
            
return next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Node to match the location where the last match ended.
     
* This is used for the \G construct.
     
*/

    
static final class LastMatch extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (i != matcher.oldLast)
                
return false;
            
return next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Node to anchor at the end of a line or the end of input based on the
     
* multiline mode.
     
*
     
* When not in multiline mode, the $ can only match at the very end
     
* of the input, unless the input ends in a line terminator in which
     
* it matches right before the last line terminator.
     
*
     
* Note that \r\n is considered an atomic line terminator.
     
*
     
* Like ^ the $ operator matches at a position, it does not match the
     
* line terminators themselves.
     
*/

    
static final class Dollar extends Node {
        
boolean multiline;
        
Dollar(boolean mul) {
            
multiline = mul;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int endIndex = (matcher.anchoringBounds) ?
                
matcher.to : matcher.getTextLength();
            
if (!multiline) {
                
if (i < endIndex - 2)
                    
return false;
                
if (i == endIndex - 2) {
                    
char ch = seq.charAt(i);
                    
if (ch != '\r')
                        
return false;
                    
ch = seq.charAt(i + 1);
                    
if (ch != '\n')
                        
return false;
                
}
            
}
            
// Matches before any line terminator; also matches at the
            
// end of input
            
// Before line terminator:
            
// If multiline, we match here no matter what
            
// If not multiline, fall through so that the end
            
// is marked as hit; this must be a /r/n or a /n
            
// at the very end so the end was hit; more input
            
// could make this not match here
            
if (i < endIndex) {
                
char ch = seq.charAt(i);
                 
if (ch == '\n') {
                     
// No match between \r\n
                     
if (i > 0 && seq.charAt(i-1) == '\r')
                         
return false;
                     
if (multiline)
                         
return next.match(matcher, i, seq);
                 
} else if (ch == '\r' || ch == '\u0085' ||
                            
(ch|1) == '\u2029') {
                     
if (multiline)
                         
return next.match(matcher, i, seq);
                 
} else { // No line terminator, no match
                     
return false;
                 
}
            
}
            
// Matched at current end so hit end
            
matcher.hitEnd = true;
            
// If a $ matches because of end of input, then more input
            
// could cause it to fail!
            
matcher.requireEnd = true;
            
return next.match(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
next.study(info);
            
return info.deterministic;
        
}
    
}

    
/**
     
* Node to anchor at the end of a line or the end of input based on the
     
* multiline mode when in unix lines mode.
     
*/

    
static final class UnixDollar extends Node {
        
boolean multiline;
        
UnixDollar(boolean mul) {
            
multiline = mul;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int endIndex = (matcher.anchoringBounds) ?
                
matcher.to : matcher.getTextLength();
            
if (i < endIndex) {
                
char ch = seq.charAt(i);
                
if (ch == '\n') {
                    
// If not multiline, then only possible to
                    
// match at very end or one before end
                    
if (multiline == false && i != endIndex - 1)
                        
return false;
                    
// If multiline return next.match without setting
                    
// matcher.hitEnd
                    
if (multiline)
                        
return next.match(matcher, i, seq);
                
} else {
                    
return false;
                
}
            
}
            
// Matching because at the end or 1 before the end;
            
// more input could change this so set hitEnd
            
matcher.hitEnd = true;
            
// If a $ matches because of end of input, then more input
            
// could cause it to fail!
            
matcher.requireEnd = true;
            
return next.match(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
next.study(info);
            
return info.deterministic;
        
}
    
}

    
/**
     
* Node class that matches a Unicode line ending '\R'
     
*/
    
static final class LineEnding extends Node {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
// (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
            
if (i < matcher.to) {
                
int ch = seq.charAt(i);
                
if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
                    
ch == 0x85 || ch == 0x2028 || ch == 0x2029)
                    
return next.match(matcher, i + 1, seq);
                
if (ch == 0x0D) {
                    
i++;
                    
if (i < matcher.to && seq.charAt(i) == 0x0A)
                        
i++;
                    
return next.match(matcher, i, seq);
                
}
            
} else {
                
matcher.hitEnd = true;
            
}
            
return false;
        
}
        
boolean study(TreeInfo info) {
            
info.minLength++;
            
info.maxLength += 2;
            
return next.study(info);
        
}
    
}

    
/**
     
* Abstract node class to match one character satisfying some
     
* boolean property.
     
*/

    
private static abstract class CharProperty extends Node {
        
abstract boolean isSatisfiedBy(int ch);
        
CharProperty complement() {
            
return new CharProperty() {
                    
boolean isSatisfiedBy(int ch) {
                        
return ! CharProperty.this.isSatisfiedBy(ch);}};
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (i < matcher.to) {
                
int ch = Character.codePointAt(seq, i);
                
return isSatisfiedBy(ch)
                    
&& next.match(matcher, i+Character.charCount(ch), seq);
            
} else {
                
matcher.hitEnd = true;
                
return false;
            
}
        
}
        
boolean study(TreeInfo info) {
            
info.minLength++;
            
info.maxLength++;
            
return next.study(info);
        
}
    
}

    
/**
     
* Optimized version of CharProperty that works only for
     
* properties never satisfied by Supplementary characters.
     
*/

    
private static abstract class BmpCharProperty extends CharProperty {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (i < matcher.to) {
                
return isSatisfiedBy(seq.charAt(i))
                    
&& next.match(matcher, i+1, seq);
            
} else {
                
matcher.hitEnd = true;
                
return false;
            
}
        
}
    
}

    
/**
     
* Node class that matches a Supplementary Unicode character
     
*/

    
static final class SingleS extends CharProperty {
        
final int c;
        
SingleS(int c) { this.c = c; }
        
boolean isSatisfiedBy(int ch) {
            
return ch == c;
        
}
    
}

    
/**
     
* Optimization -- matches a given BMP character
     
*/
    
static final class Single extends BmpCharProperty {
        
final int c;
        
Single(int c) { this.c = c; }
        
boolean isSatisfiedBy(int ch) {
            
return ch == c;
        
}
    
}

    
/**
     
* Case insensitive matches a given BMP character
     
*/
    
static final class SingleI extends BmpCharProperty {
        
final int lower;
        
final int upper;
        
SingleI(int lower, int upper) {
            
this.lower = lower;
            
this.upper = upper;
        
}
        
boolean isSatisfiedBy(int ch) {
            
return ch == lower || ch == upper;
        
}
    
}

    
/**
     
* Unicode case insensitive matches a given Unicode character
     
*/

    
static final class SingleU extends CharProperty {
        
final int lower;
        
SingleU(int lower) {
            
this.lower = lower;
        
}
        
boolean isSatisfiedBy(int ch) {
            
return lower == ch ||
                
lower == Character.toLowerCase(Character.toUpperCase(ch));
        
}
    
}

    
/**
     
* Node class that matches a Unicode block.
     
*/
    
static final class Block extends CharProperty {
        
final Character.UnicodeBlock block;
        
Block(Character.UnicodeBlock block) {
            
this.block = block;
        
}
        
boolean isSatisfiedBy(int ch) {
            
return block == Character.UnicodeBlock.of(ch);
        
}
    
}

    
/**
     
* Node class that matches a Unicode script
     
*/
    
static final class Script extends CharProperty {
        
final Character.UnicodeScript script;
        
Script(Character.UnicodeScript script) {
            
this.script = script;
        
}
        
boolean isSatisfiedBy(int ch) {
            
return script == Character.UnicodeScript.of(ch);
        
}
    
}

    
/**
     
* Node class that matches a Unicode category.
     
*/
    
static final class Category extends CharProperty {
        
final int typeMask;
        
Category(int typeMask) { this.typeMask = typeMask; }
        
boolean isSatisfiedBy(int ch) {
            
return (typeMask & (1 << Character.getType(ch))) != 0;
        
}
    
}

    
/**
     
* Node class that matches a Unicode "type"
     
*/
    
static final class Utype extends CharProperty {
        
final UnicodeProp uprop;
        
Utype(UnicodeProp uprop) { this.uprop = uprop; }
        
boolean isSatisfiedBy(int ch) {
            
return uprop.is(ch);
        
}
    
}

    
/**
     
* Node class that matches a POSIX type.
     
*/
    
static final class Ctype extends BmpCharProperty {
        
final int ctype;
        
Ctype(int ctype) { this.ctype = ctype; }
        
boolean isSatisfiedBy(int ch) {
            
return ch < 128 && ASCII.isType(ch, ctype);
        
}
    
}

    
/**
     
* Node class that matches a Perl vertical whitespace
     
*/
    
static final class VertWS extends BmpCharProperty {
        
boolean isSatisfiedBy(int cp) {
            
return (cp >= 0x0A && cp <= 0x0D) ||
                   
cp == 0x85 || cp == 0x2028 || cp == 0x2029;
        
}
    
}

    
/**
     
* Node class that matches a Perl horizontal whitespace
     
*/
    
static final class HorizWS extends BmpCharProperty {
        
boolean isSatisfiedBy(int cp) {
            
return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
                   
cp == 0x1680 || cp == 0x180e ||
                   
cp >= 0x2000 && cp <= 0x200a ||
                   
cp == 0x202f || cp == 0x205f || cp == 0x3000;
        
}
    
}

    
/**
     
* Base class for all Slice nodes
     
*/
    
static class SliceNode extends Node {
        
int[] buffer;
        
SliceNode(int[] buf) {
            
buffer = buf;
        
}
        
boolean study(TreeInfo info) {
            
info.minLength += buffer.length;
            
info.maxLength += buffer.length;
            
return next.study(info);
        
}
    
}

    
/**
     
* Node class for a case sensitive/BMP-only sequence of literal
     
* characters.
     
*/

    
static final class Slice extends SliceNode {
        
Slice(int[] buf) {
            
super(buf);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] buf = buffer;
            
int len = buf.length;
            
for (int j=0; j<len; j++) {
                
if ((i+j) >= matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
if (buf[j] != seq.charAt(i+j))
                    
return false;
            
}
            
return next.match(matcher, i+len, seq);
        
}
    
}

    
/**
     
* Node class for a case_insensitive/BMP-only sequence of literal
     
* characters.
     
*/

    
static class SliceI extends SliceNode {
        
SliceI(int[] buf) {
            
super(buf);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] buf = buffer;
            
int len = buf.length;
            
for (int j=0; j<len; j++) {
                
if ((i+j) >= matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
int c = seq.charAt(i+j);
                
if (buf[j] != c &&
                    
buf[j] != ASCII.toLower(c))
                    
return false;
            
}
            
return next.match(matcher, i+len, seq);
        
}
    
}

    
/**
     
* Node class for a unicode_case_insensitive/BMP-only sequence of
     
* literal characters. Uses unicode case folding.
     
*/

    
static final class SliceU extends SliceNode {
        
SliceU(int[] buf) {
            
super(buf);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] buf = buffer;
            
int len = buf.length;
            
for (int j=0; j<len; j++) {
                
if ((i+j) >= matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
int c = seq.charAt(i+j);
                
if (buf[j] != c &&
                    
buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
                    
return false;
            
}
            
return next.match(matcher, i+len, seq);
        
}
    
}

    
/**
     
* Node class for a case sensitive sequence of literal characters
     
* including supplementary characters.
     
*/

    
static final class SliceS extends SliceNode {
        
SliceS(int[] buf) {
            
super(buf);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] buf = buffer;
            
int x = i;
            
for (int j = 0; j < buf.length; j++) {
                
if (x >= matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
int c = Character.codePointAt(seq, x);
                
if (buf[j] != c)
                    
return false;
                
x += Character.charCount(c);
                
if (x > matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
            
}
            
return next.match(matcher, x, seq);
        
}
    
}

    
/**
     
* Node class for a case insensitive sequence of literal characters
     
* including supplementary characters.
     
*/

    
static class SliceIS extends SliceNode {
        
SliceIS(int[] buf) {
            
super(buf);
        
}
        
int toLower(int c) {
            
return ASCII.toLower(c);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] buf = buffer;
            
int x = i;
            
for (int j = 0; j < buf.length; j++) {
                
if (x >= matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
int c = Character.codePointAt(seq, x);
                
if (buf[j] != c && buf[j] != toLower(c))
                    
return false;
                
x += Character.charCount(c);
                
if (x > matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
            
}
            
return next.match(matcher, x, seq);
        
}
    
}

    
/**
     
* Node class for a case insensitive sequence of literal characters.
     
* Uses unicode case folding.
     
*/

    
static final class SliceUS extends SliceIS {
        
SliceUS(int[] buf) {
            
super(buf);
        
}
        
int toLower(int c) {
            
return Character.toLowerCase(Character.toUpperCase(c));
        
}
    
}

    
private static boolean inRange(int lower, int ch, int upper) {
        
return lower <= ch && ch <= upper;
    
}

    
/**
     
* Returns node for matching characters within an explicit value range.
     
*/

    
private static CharProperty rangeFor(final int lower,
                                         
final int upper) {
        
return new CharProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return inRange(lower, ch, upper);}};
    
}

    
/**
     
* Returns node for matching characters within an explicit value
     
* range in a case insensitive manner.
     
*/

    
private CharProperty caseInsensitiveRangeFor(final int lower,
                                                 
final int upper) {
        
if (has(UNICODE_CASE))
            
return new CharProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
if (inRange(lower, ch, upper))
                        
return true;
                    
int up = Character.toUpperCase(ch);
                    
return inRange(lower, up, upper) ||
                           
inRange(lower, Character.toLowerCase(up), upper);}};
        
return new CharProperty() {
            
boolean isSatisfiedBy(int ch) {
                
return inRange(lower, ch, upper) ||
                    
ASCII.isAscii(ch) &&
                        
(inRange(lower, ASCII.toUpper(ch), upper) ||
                         
inRange(lower, ASCII.toLower(ch), upper));
            
}};
    
}

    
/**
     
* Implements the Unicode category ALL and the dot metacharacter when
     
* in dotall mode.
     
*/

    
static final class All extends CharProperty {
        
boolean isSatisfiedBy(int ch) {
            
return true;
        
}
    
}

    
/**
     
* Node class for the dot metacharacter when dotall is not enabled.
     
*/
    
static final class Dot extends CharProperty {
        
boolean isSatisfiedBy(int ch) {
            
return (ch != '\n' && ch != '\r'
                    
&& (ch|1) != '\u2029'
                    
&& ch != '\u0085');
        
}
    
}

    
/**
     
* Node class for the dot metacharacter when dotall is not enabled
     
* but UNIX_LINES is enabled.
     
*/

    
static final class UnixDot extends CharProperty {
        
boolean isSatisfiedBy(int ch) {
            
return ch != '\n';
        
}
    
}

    
/**
     
* The 0 or 1 quantifier. This one class implements all three types.
     
*/

    
static final class Ques extends Node {
        
Node atom;
        
int type;
        
Ques(Node node, int type) {
            
this.atom = node;
            
this.type = type;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
switch (type) {
            
case GREEDY:
                
return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
                    
|| next.match(matcher, i, seq);
            
case LAZY:
                
return next.match(matcher, i, seq)
                    
|| (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
            
case POSSESSIVE:
                
if (atom.match(matcher, i, seq)) i = matcher.last;
                
return next.match(matcher, i, seq);
            
default:
                
return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
            
}
        
}
        
boolean study(TreeInfo info) {
            
if (type != INDEPENDENT) {
                
int minL = info.minLength;
                
atom.study(info);
                
info.minLength = minL;
                
info.deterministic = false;
                
return next.study(info);
            
} else {
                
atom.study(info);
                
return next.study(info);
            
}
        
}
    
}

    
/**
     
* Handles the curly-brace style repetition with a specified minimum and
     
* maximum occurrences. The * quantifier is handled as a special case.
     
* This class handles the three types.
     
*/

    
static final class Curly extends Node {
        
Node atom;
        
int type;
        
int cmin;
        
int cmax;

        
Curly(Node node, int cmin, int cmax, int type) {
            
this.atom = node;
            
this.type = type;
            
this.cmin = cmin;
            
this.cmax = cmax;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int j;
            
for (j = 0; j < cmin; j++) {
                
if (atom.match(matcher, i, seq)) {
                    
i = matcher.last;
                    
continue;
                
}
                
return false;
            
}
            
if (type == GREEDY)
                
return match0(matcher, i, j, seq);
            
else if (type == LAZY)
                
return match1(matcher, i, j, seq);
            
else
                
return
match2(matcher, i, j, seq);
        
}
        
// Greedy match.
        
// i is the index to start matching at
        
// j is the number of atoms that have matched
        
boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
            
if (j >= cmax) {
                
// We have matched the maximum... continue with the rest of
                
// the regular expression
                
return next.match(matcher, i, seq);
            
}
            
int backLimit = j;
            
while (atom.match(matcher, i, seq)) {
                
// k is the length of this match
                
int k = matcher.last - i;
                
if (k == 0) // Zero length match
                    
break;
                
// Move up index and number matched
                
i = matcher.last;
                
j++;
                
// We are greedy so match as many as we can
                
while (j < cmax) {
                    
if (!atom.match(matcher, i, seq))
                        
break;
                    
if (i + k != matcher.last) {
                        
if (match0(matcher, matcher.last, j+1, seq))
                            
return true;
                        
break;
                    
}
                    
i += k;
                    
j++;
                
}
                
// Handle backing off if match fails
                
while (j >= backLimit) {
                   
if (next.match(matcher, i, seq))
                        
return true;
                    
i -= k;
                    
j--;
                
}
                
return false;
            
}
            
return next.match(matcher, i, seq);
        
}
        
// Reluctant match. At this point, the minimum has been satisfied.
        
// i is the index to start matching at
        
// j is the number of atoms that have matched
        
boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
            
for (;;) {
                
// Try finishing match without consuming any more
                
if (next.match(matcher, i, seq))
                    
return true;
                
// At the maximum, no match found
                
if (j >= cmax)
                    
return false;
                
// Okay, must try one more atom
                
if (!atom.match(matcher, i, seq))
                    
return false;
                
// If we haven't moved forward then must break out
                
if (i == matcher.last)
                    
return false;
                
// Move up index and number matched
                
i = matcher.last;
                
j++;
            
}
        
}
        
boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
            
for (; j < cmax; j++) {
                
if (!atom.match(matcher, i, seq))
                    
break;
                
if (i == matcher.last)
                    
break;
                
i = matcher.last;
            
}
            
return next.match(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
// Save original info
            
int minL = info.minLength;
            
int maxL = info.maxLength;
            
boolean maxV = info.maxValid;
            
boolean detm = info.deterministic;
            
info.reset();

            
atom.study(info);

            
int temp = info.minLength * cmin + minL;
            
if (temp < minL) {
                
temp = 0xFFFFFFF; // arbitrary large number
            
}
            
info.minLength = temp;

            
if (maxV & info.maxValid) {
                
temp = info.maxLength * cmax + maxL;
                
info.maxLength = temp;
                
if (temp < maxL) {
                    
info.maxValid = false;
                
}
            
} else {
                
info.maxValid = false;
            
}

            
if (info.deterministic && cmin == cmax)
                
info.deterministic = detm;
            
else
                
info.deterministic = false;
            
return next.study(info);
        
}
    
}

    
/**
     
* Handles the curly-brace style repetition with a specified minimum and
     
* maximum occurrences in deterministic cases. This is an iterative
     
* optimization over the Prolog and Loop system which would handle this
     
* in a recursive way. The * quantifier is handled as a special case.
     
* If capture is true then this class saves group settings and ensures
     
* that groups are unset when backing off of a group match.
     
*/

    
static final class GroupCurly extends Node {
        
Node atom;
        
int type;
        
int cmin;
        
int cmax;
        
int localIndex;
        
int groupIndex;
        
boolean capture;

        
GroupCurly(Node node, int cmin, int cmax, int type, int local,
                   
int group, boolean capture) {
            
this.atom = node;
            
this.type = type;
            
this.cmin = cmin;
            
this.cmax = cmax;
            
this.localIndex = local;
            
this.groupIndex = group;
            
this.capture = capture;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] groups = matcher.groups;
            
int[] locals = matcher.locals;
            
int save0 = locals[localIndex];
            
int save1 = 0;
            
int save2 = 0;

            
if (capture) {
                
save1 = groups[groupIndex];
                
save2 = groups[groupIndex+1];
            
}

            
// Notify GroupTail there is no need to setup group info
            
// because it will be set here
            
locals[localIndex] = -1;

            
boolean ret = true;
            
for (int j = 0; j < cmin; j++) {
                
if (atom.match(matcher, i, seq)) {
                    
if (capture) {
                        
groups[groupIndex] = i;
                        
groups[groupIndex+1] = matcher.last;
                    
}
                    
i = matcher.last;
                
} else {
                    
ret = false;
                    
break;
                
}
            
}
            
if (ret) {
                
if (type == GREEDY) {
                    
ret = match0(matcher, i, cmin, seq);
                
} else if (type == LAZY) {
                    
ret = match1(matcher, i, cmin, seq);
                
} else {
                    
ret = match2(matcher, i, cmin, seq);
                
}
            
}
            
if (!ret) {
                
locals[localIndex] = save0;
                
if (capture) {
                    
groups[groupIndex] = save1;
                    
groups[groupIndex+1] = save2;
                
}
            
}
            
return ret;
        
}
        
// Aggressive group match
        
boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
            
// don't back off passing the starting "j"
            
int min = j;
            
int[] groups = matcher.groups;
            
int save0 = 0;
            
int save1 = 0;
            
if (capture) {
                
save0 = groups[groupIndex];
                
save1 = groups[groupIndex+1];
            
}
            
for (;;) {
                
if (j >= cmax)
                    
break;
                
if (!atom.match(matcher, i, seq))
                    
break;
                
int k = matcher.last - i;
                
if (k <= 0) {
                    
if (capture) {
                        
groups[groupIndex] = i;
                        
groups[groupIndex+1] = i + k;
                    
}
                    
i = i + k;
                    
break;
                
}
                
for (;;) {
                    
if (capture) {
                        
groups[groupIndex] = i;
                        
groups[groupIndex+1] = i + k;
                    
}
                    
i = i + k;
                    
if (++j >= cmax)
                        
break;
                    
if (!atom.match(matcher, i, seq))
                        
break;
                    
if (i + k != matcher.last) {
                        
if (match0(matcher, i, j, seq))
                            
return true;
                        
break;
                    
}
                
}
                
while (j > min) {
                    
if (next.match(matcher, i, seq)) {
                        
if (capture) {
                            
groups[groupIndex+1] = i;
                            
groups[groupIndex] = i - k;
                        
}
                        
return true;
                    
}
                    
// backing off
                    
i = i - k;
                    
if (capture) {
                        
groups[groupIndex+1] = i;
                        
groups[groupIndex] = i - k;
                    
}
                    
j--;

                
}
                
break;
            
}
            
if (capture) {
                
groups[groupIndex] = save0;
                
groups[groupIndex+1] = save1;
            
}
            
return next.match(matcher, i, seq);
        
}
        
// Reluctant matching
        
boolean match1(Matcher matcher, int i, int j, CharSequence seq) {
            
for (;;) {
                
if (next.match(matcher, i, seq))
                    
return true;
                
if (j >= cmax)
                    
return false;
                
if (!atom.match(matcher, i, seq))
                    
return false;
                
if (i == matcher.last)
                    
return false;
                
if (capture) {
                    
matcher.groups[groupIndex] = i;
                    
matcher.groups[groupIndex+1] = matcher.last;
                
}
                
i = matcher.last;
                
j++;
            
}
        
}
        
// Possessive matching
        
boolean match2(Matcher matcher, int i, int j, CharSequence seq) {
            
for (; j < cmax; j++) {
                
if (!atom.match(matcher, i, seq)) {
                    
break;
                
}
                
if (capture) {
                    
matcher.groups[groupIndex] = i;
                    
matcher.groups[groupIndex+1] = matcher.last;
                
}
                
if (i == matcher.last) {
                    
break;
                
}
                
i = matcher.last;
            
}
            
return next.match(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
// Save original info
            
int minL = info.minLength;
            
int maxL = info.maxLength;
            
boolean maxV = info.maxValid;
            
boolean detm = info.deterministic;
            
info.reset();

            
atom.study(info);

            
int temp = info.minLength * cmin + minL;
            
if (temp < minL) {
                
temp = 0xFFFFFFF; // Arbitrary large number
            
}
            
info.minLength = temp;

            
if (maxV & info.maxValid) {
                
temp = info.maxLength * cmax + maxL;
                
info.maxLength = temp;
                
if (temp < maxL) {
                    
info.maxValid = false;
                
}
            
} else {
                
info.maxValid = false;
            
}

            
if (info.deterministic && cmin == cmax) {
                
info.deterministic = detm;
            
} else {
                
info.deterministic = false;
            
}
            
return next.study(info);
        
}
    
}

    
/**
     
* A Guard node at the end of each atom node in a Branch. It
     
* serves the purpose of chaining the "match" operation to
     
* "next" but not the "study", so we can collect the TreeInfo
     
* of each atom node without including the TreeInfo of the
     
* "next".
     
*/

    
static final class BranchConn extends Node {
        
BranchConn() {};
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
return next.match(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
return info.deterministic;
        
}
    
}

    
/**
     
* Handles the branching of alternations. Note this is also used for
     
* the ? quantifier to branch between the case where it matches once
     
* and where it does not occur.
     
*/

    
static final class Branch extends Node {
        
Node[] atoms = new Node[2];
        
int size = 2;
        
Node conn;
        
Branch(Node first, Node second, Node branchConn) {
            
conn = branchConn;
            
atoms[0] = first;
            
atoms[1] = second;
        
}

        
void add(Node node) {
            
if (size >= atoms.length) {
                
Node[] tmp = new Node[atoms.length*2];
                
System.arraycopy(atoms, 0, tmp, 0, atoms.length);
                
atoms = tmp;
            
}
            
atoms[size++] = node;
        
}

        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
for (int n = 0; n < size; n++) {
                
if (atoms[n] == null) {
                    
if (conn.next.match(matcher, i, seq))
                        
return true;
                
} else if (atoms[n].match(matcher, i, seq)) {
                    
return true;
                
}
            
}
            
return false;
        
}

        
boolean study(TreeInfo info) {
            
int minL = info.minLength;
            
int maxL = info.maxLength;
            
boolean maxV = info.maxValid;

            
int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
            
int maxL2 = -1;
            
for (int n = 0; n < size; n++) {
                
info.reset();
                
if (atoms[n] != null)
                    
atoms[n].study(info);
                
minL2 = Math.min(minL2, info.minLength);
                
maxL2 = Math.max(maxL2, info.maxLength);
                
maxV = (maxV & info.maxValid);
            
}

            
minL += minL2;
            
maxL += maxL2;

            
info.reset();
            
conn.next.study(info);

            
info.minLength += minL;
            
info.maxLength += maxL;
            
info.maxValid &= maxV;
            
info.deterministic = false;
            
return false;
        
}
    
}

    
/**
     
* The GroupHead saves the location where the group begins in the locals
     
* and restores them when the match is done.
     
*
     
* The matchRef is used when a reference to this group is accessed later
     
* in the expression. The locals will have a negative value in them to
     
* indicate that we do not want to unset the group if the reference
     
* doesn't match.
     
*/

    
static final class GroupHead extends Node {
        
int localIndex;
        
GroupHead(int localCount) {
            
localIndex = localCount;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int save = matcher.locals[localIndex];
            
matcher.locals[localIndex] = i;
            
boolean ret = next.match(matcher, i, seq);
            
matcher.locals[localIndex] = save;
            
return ret;
        
}
        
boolean matchRef(Matcher matcher, int i, CharSequence seq) {
            
int save = matcher.locals[localIndex];
            
matcher.locals[localIndex] = ~i; // HACK
            
boolean ret = next.match(matcher, i, seq);
            
matcher.locals[localIndex] = save;
            
return ret;
        
}
    
}

    
/**
     
* Recursive reference to a group in the regular expression. It calls
     
* matchRef because if the reference fails to match we would not unset
     
* the group.
     
*/

    
static final class GroupRef extends Node {
        
GroupHead head;
        
GroupRef(GroupHead head) {
            
this.head = head;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
return head.matchRef(matcher, i, seq)
                
&& next.match(matcher, matcher.last, seq);
        
}
        
boolean study(TreeInfo info) {
            
info.maxValid = false;
            
info.deterministic = false;
            
return next.study(info);
        
}
    
}

    
/**
     
* The GroupTail handles the setting of group beginning and ending
     
* locations when groups are successfully matched. It must also be able to
     
* unset groups that have to be backed off of.
     
*
     
* The GroupTail node is also used when a previous group is referenced,
     
* and in that case no group information needs to be set.
     
*/

    
static final class GroupTail extends Node {
        
int localIndex;
        
int groupIndex;
        
GroupTail(int localCount, int groupCount) {
            
localIndex = localCount;
            
groupIndex = groupCount + groupCount;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int tmp = matcher.locals[localIndex];
            
if (tmp >= 0) { // This is the normal group case.
                
// Save the group so we can unset it if it
                
// backs off of a match.
                
int groupStart = matcher.groups[groupIndex];
                
int groupEnd = matcher.groups[groupIndex+1];

                
matcher.groups[groupIndex] = tmp;
                
matcher.groups[groupIndex+1] = i;
                
if (next.match(matcher, i, seq)) {
                    
return true;
                
}
                
matcher.groups[groupIndex] = groupStart;
                
matcher.groups[groupIndex+1] = groupEnd;
                
return false;
            
} else {
                
// This is a group reference case. We don't need to save any
                
// group info because it isn't really a group.
                
matcher.last = i;
                
return true;
            
}
        
}
    
}

    
/**
     
* This sets up a loop to handle a recursive quantifier structure.
     
*/
    
static final class Prolog extends Node {
        
Loop loop;
        
Prolog(Loop loop) {
            
this.loop = loop;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
return loop.matchInit(matcher, i, seq);
        
}
        
boolean study(TreeInfo info) {
            
return loop.study(info);
        
}
    
}

    
/**
     
* Handles the repetition count for a greedy Curly. The matchInit
     
* is called from the Prolog to save the index of where the group
     
* beginning is stored. A zero length group check occurs in the
     
* normal match but is skipped in the matchInit.
     
*/

    
static class Loop extends Node {
        
Node body;
        
int countIndex; // local count index in matcher locals
        
int beginIndex; // group beginning index
        
int cmin, cmax;
        
Loop(int countIndex, int beginIndex) {
            
this.countIndex = countIndex;
            
this.beginIndex = beginIndex;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
// Avoid infinite loop in zero-length case.
            
if (i > matcher.locals[beginIndex]) {
                
int count = matcher.locals[countIndex];

                
// This block is for before we reach the minimum
                
// iterations required for the loop to match
                
if (count < cmin) {
                    
matcher.locals[countIndex] = count + 1;
                    
boolean b = body.match(matcher, i, seq);
                    
// If match failed we must backtrack, so
                    
// the loop count should NOT be incremented
                    
if (!b)
                        
matcher.locals[countIndex] = count;
                    
// Return success or failure since we are under
                    
// minimum
                    
return b;
                
}
                
// This block is for after we have the minimum
                
// iterations required for the loop to match
                
if (count < cmax) {
                    
matcher.locals[countIndex] = count + 1;
                    
boolean b = body.match(matcher, i, seq);
                    
// If match failed we must backtrack, so
                    
// the loop count should NOT be incremented
                    
if (!b)
                        
matcher.locals[countIndex] = count;
                    
else
                        
return true
;
                
}
            
}
            
return next.match(matcher, i, seq);
        
}
        
boolean matchInit(Matcher matcher, int i, CharSequence seq) {
            
int save = matcher.locals[countIndex];
            
boolean ret = false;
            
if (0 < cmin) {
                
matcher.locals[countIndex] = 1;
                
ret = body.match(matcher, i, seq);
            
} else if (0 < cmax) {
                
matcher.locals[countIndex] = 1;
                
ret = body.match(matcher, i, seq);
                
if (ret == false)
                    
ret = next.match(matcher, i, seq);
            
} else {
                
ret = next.match(matcher, i, seq);
            
}
            
matcher.locals[countIndex] = save;
            
return ret;
        
}
        
boolean study(TreeInfo info) {
            
info.maxValid = false;
            
info.deterministic = false;
            
return false;
        
}
    
}

    
/**
     
* Handles the repetition count for a reluctant Curly. The matchInit
     
* is called from the Prolog to save the index of where the group
     
* beginning is stored. A zero length group check occurs in the
     
* normal match but is skipped in the matchInit.
     
*/

    
static final class LazyLoop extends Loop {
        
LazyLoop(int countIndex, int beginIndex) {
            
super(countIndex, beginIndex);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
// Check for zero length group
            
if (i > matcher.locals[beginIndex]) {
                
int count = matcher.locals[countIndex];
                
if (count < cmin) {
                    
matcher.locals[countIndex] = count + 1;
                    
boolean result = body.match(matcher, i, seq);
                    
// If match failed we must backtrack, so
                    
// the loop count should NOT be incremented
                    
if (!result)
                        
matcher.locals[countIndex] = count;
                    
return result;
                
}
                
if (next.match(matcher, i, seq))
                    
return true;
                
if (count < cmax) {
                    
matcher.locals[countIndex] = count + 1;
                    
boolean result = body.match(matcher, i, seq);
                    
// If match failed we must backtrack, so
                    
// the loop count should NOT be incremented
                    
if (!result)
                        
matcher.locals[countIndex] = count;
                    
return result;
                
}
                
return false;
            
}
            
return next.match(matcher, i, seq);
        
}
        
boolean matchInit(Matcher matcher, int i, CharSequence seq) {
            
int save = matcher.locals[countIndex];
            
boolean ret = false;
            
if (0 < cmin) {
                
matcher.locals[countIndex] = 1;
                
ret = body.match(matcher, i, seq);
            
} else if (next.match(matcher, i, seq)) {
                
ret = true;
            
} else if (0 < cmax) {
                
matcher.locals[countIndex] = 1;
                
ret = body.match(matcher, i, seq);
            
}
            
matcher.locals[countIndex] = save;
            
return ret;
        
}
        
boolean study(TreeInfo info) {
            
info.maxValid = false;
            
info.deterministic = false;
            
return false;
        
}
    
}

    
/**
     
* Refers to a group in the regular expression. Attempts to match
     
* whatever the group referred to last matched.
     
*/

    
static class BackRef extends Node {
        
int groupIndex;
        
BackRef(int groupCount) {
            
super();
            
groupIndex = groupCount + groupCount;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int j = matcher.groups[groupIndex];
            
int k = matcher.groups[groupIndex+1];

            
int groupSize = k - j;
            
// If the referenced group didn't match, neither can this
            
if (j < 0)
                
return false;

            
// If there isn't enough input left no match
            
if (i + groupSize > matcher.to) {
                
matcher.hitEnd = true;
                
return false;
            
}
            
// Check each new char to make sure it matches what the group
            
// referenced matched last time around
            
for (int index=0; index<groupSize; index++)
                
if (seq.charAt(i+index) != seq.charAt(j+index))
                    
return false;

            
return next.match(matcher, i+groupSize, seq);
        
}
        
boolean study(TreeInfo info) {
            
info.maxValid = false;
            
return next.study(info);
        
}
    
}

    
static class CIBackRef extends Node {
        
int groupIndex;
        
boolean doUnicodeCase;
        
CIBackRef(int groupCount, boolean doUnicodeCase) {
            
super();
            
groupIndex = groupCount + groupCount;
            
this.doUnicodeCase = doUnicodeCase;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int j = matcher.groups[groupIndex];
            
int k = matcher.groups[groupIndex+1];

            
int groupSize = k - j;

            
// If the referenced group didn't match, neither can this
            
if (j < 0)
                
return false;

            
// If there isn't enough input left no match
            
if (i + groupSize > matcher.to) {
                
matcher.hitEnd = true;
                
return false;
            
}

            
// Check each new char to make sure it matches what the group
            
// referenced matched last time around
            
int x = i;
            
for (int index=0; index<groupSize; index++) {
                
int c1 = Character.codePointAt(seq, x);
                
int c2 = Character.codePointAt(seq, j);
                
if (c1 != c2) {
                    
if (doUnicodeCase) {
                        
int cc1 = Character.toUpperCase(c1);
                        
int cc2 = Character.toUpperCase(c2);
                        
if (cc1 != cc2 &&
                            
Character.toLowerCase(cc1) !=
                            
Character.toLowerCase(cc2))
                            
return false;
                    
} else {
                        
if (ASCII.toLower(c1) != ASCII.toLower(c2))
                            
return false;
                    
}
                
}
                
x += Character.charCount(c1);
                
j += Character.charCount(c2);
            
}

            
return next.match(matcher, i+groupSize, seq);
        
}
        
boolean study(TreeInfo info) {
            
info.maxValid = false;
            
return next.study(info);
        
}
    
}

    
/**
     
* Searches until the next instance of its atom. This is useful for
     
* finding the atom efficiently without passing an instance of it
     
* (greedy problem) and without a lot of wasted search time (reluctant
     
* problem).
     
*/

    
static final class First extends Node {
        
Node atom;
        
First(Node node) {
            
this.atom = BnM.optimize(node);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (atom instanceof BnM) {
                
return atom.match(matcher, i, seq)
                    
&& next.match(matcher, matcher.last, seq);
            
}
            
for (;;) {
                
if (i > matcher.to) {
                    
matcher.hitEnd = true;
                    
return false;
                
}
                
if (atom.match(matcher, i, seq)) {
                    
return next.match(matcher, matcher.last, seq);
                
}
                
i += countChars(seq, i, 1);
                
matcher.first++;
            
}
        
}
        
boolean study(TreeInfo info) {
            
atom.study(info);
            
info.maxValid = false;
            
info.deterministic = false;
            
return next.study(info);
        
}
    
}

    
static final class Conditional extends Node {
        
Node cond, yes, not;
        
Conditional(Node cond, Node yes, Node not) {
            
this.cond = cond;
            
this.yes = yes;
            
this.not = not;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
if (cond.match(matcher, i, seq)) {
                
return yes.match(matcher, i, seq);
            
} else {
                
return not.match(matcher, i, seq);
            
}
        
}
        
boolean study(TreeInfo info) {
            
int minL = info.minLength;
            
int maxL = info.maxLength;
            
boolean maxV = info.maxValid;
            
info.reset();
            
yes.study(info);

            
int minL2 = info.minLength;
            
int maxL2 = info.maxLength;
            
boolean maxV2 = info.maxValid;
            
info.reset();
            
not.study(info);

            
info.minLength = minL + Math.min(minL2, info.minLength);
            
info.maxLength = maxL + Math.max(maxL2, info.maxLength);
            
info.maxValid = (maxV & maxV2 & info.maxValid);
            
info.deterministic = false;
            
return next.study(info);
        
}
    
}

    
/**
     
* Zero width positive lookahead.
     
*/
    
static final class Pos extends Node {
        
Node cond;
        
Pos(Node cond) {
            
this.cond = cond;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int savedTo = matcher.to;
            
boolean conditionMatched = false;

            
// Relax transparent region boundaries for lookahead
            
if (matcher.transparentBounds)
                
matcher.to = matcher.getTextLength();
            
try {
                
conditionMatched = cond.match(matcher, i, seq);
            
} finally {
                
// Reinstate region boundaries
                
matcher.to = savedTo;
            
}
            
return conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Zero width negative lookahead.
     
*/
    
static final class Neg extends Node {
        
Node cond;
        
Neg(Node cond) {
            
this.cond = cond;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int savedTo = matcher.to;
            
boolean conditionMatched = false;

            
// Relax transparent region boundaries for lookahead
            
if (matcher.transparentBounds)
                
matcher.to = matcher.getTextLength();
            
try {
                
if (i < matcher.to) {
                    
conditionMatched = !cond.match(matcher, i, seq);
                
} else {
                    
// If a negative lookahead succeeds then more input
                    
// could cause it to fail!
                    
matcher.requireEnd = true;
                    
conditionMatched = !cond.match(matcher, i, seq);
                
}
            
} finally {
                
// Reinstate region boundaries
                
matcher.to = savedTo;
            
}
            
return conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* For use with lookbehinds; matches the position where the lookbehind
     
* was encountered.
     
*/

    
static Node lookbehindEnd = new Node() {
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
return i == matcher.lookbehindTo;
        
}
    
};

    
/**
     
* Zero width positive lookbehind.
     
*/
    
static class Behind extends Node {
        
Node cond;
        
int rmax, rmin;
        
Behind(Node cond, int rmax, int rmin) {
            
this.cond = cond;
            
this.rmax = rmax;
            
this.rmin = rmin;
        
}

        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int savedFrom = matcher.from;
            
boolean conditionMatched = false;
            
int startIndex = (!matcher.transparentBounds) ?
                             
matcher.from : 0;
            
int from = Math.max(i - rmax, startIndex);
            
// Set end boundary
            
int savedLBT = matcher.lookbehindTo;
            
matcher.lookbehindTo = i;
            
// Relax transparent region boundaries for lookbehind
            
if (matcher.transparentBounds)
                
matcher.from = 0;
            
for (int j = i - rmin; !conditionMatched && j >= from; j--) {
                
conditionMatched = cond.match(matcher, j, seq);
            
}
            
matcher.from = savedFrom;
            
matcher.lookbehindTo = savedLBT;
            
return conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Zero width positive lookbehind, including supplementary
     
* characters or unpaired surrogates.
     
*/

    
static final class BehindS extends Behind {
        
BehindS(Node cond, int rmax, int rmin) {
            
super(cond, rmax, rmin);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int rmaxChars = countChars(seq, i, -rmax);
            
int rminChars = countChars(seq, i, -rmin);
            
int savedFrom = matcher.from;
            
int startIndex = (!matcher.transparentBounds) ?
                             
matcher.from : 0;
            
boolean conditionMatched = false;
            
int from = Math.max(i - rmaxChars, startIndex);
            
// Set end boundary
            
int savedLBT = matcher.lookbehindTo;
            
matcher.lookbehindTo = i;
            
// Relax transparent region boundaries for lookbehind
            
if (matcher.transparentBounds)
                
matcher.from = 0;

            
for (int j = i - rminChars;
                 
!conditionMatched && j >= from;
                 
j -= j>from ? countChars(seq, j, -1) : 1) {
                
conditionMatched = cond.match(matcher, j, seq);
            
}
            
matcher.from = savedFrom;
            
matcher.lookbehindTo = savedLBT;
            
return conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Zero width negative lookbehind.
     
*/
    
static class NotBehind extends Node {
        
Node cond;
        
int rmax, rmin;
        
NotBehind(Node cond, int rmax, int rmin) {
            
this.cond = cond;
            
this.rmax = rmax;
            
this.rmin = rmin;
        
}

        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int savedLBT = matcher.lookbehindTo;
            
int savedFrom = matcher.from;
            
boolean conditionMatched = false;
            
int startIndex = (!matcher.transparentBounds) ?
                             
matcher.from : 0;
            
int from = Math.max(i - rmax, startIndex);
            
matcher.lookbehindTo = i;
            
// Relax transparent region boundaries for lookbehind
            
if (matcher.transparentBounds)
                
matcher.from = 0;
            
for (int j = i - rmin; !conditionMatched && j >= from; j--) {
                
conditionMatched = cond.match(matcher, j, seq);
            
}
            
// Reinstate region boundaries
            
matcher.from = savedFrom;
            
matcher.lookbehindTo = savedLBT;
            
return !conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Zero width negative lookbehind, including supplementary
     
* characters or unpaired surrogates.
     
*/

    
static final class NotBehindS extends NotBehind {
        
NotBehindS(Node cond, int rmax, int rmin) {
            
super(cond, rmax, rmin);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int rmaxChars = countChars(seq, i, -rmax);
            
int rminChars = countChars(seq, i, -rmin);
            
int savedFrom = matcher.from;
            
int savedLBT = matcher.lookbehindTo;
            
boolean conditionMatched = false;
            
int startIndex = (!matcher.transparentBounds) ?
                             
matcher.from : 0;
            
int from = Math.max(i - rmaxChars, startIndex);
            
matcher.lookbehindTo = i;
            
// Relax transparent region boundaries for lookbehind
            
if (matcher.transparentBounds)
                
matcher.from = 0;
            
for (int j = i - rminChars;
                 
!conditionMatched && j >= from;
                 
j -= j>from ? countChars(seq, j, -1) : 1) {
                
conditionMatched = cond.match(matcher, j, seq);
            
}
            
//Reinstate region boundaries
            
matcher.from = savedFrom;
            
matcher.lookbehindTo = savedLBT;
            
return !conditionMatched && next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Returns the set union of two CharProperty nodes.
     
*/
    
private static CharProperty union(final CharProperty lhs,
                                      
final CharProperty rhs) {
        
return new CharProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
    
}

    
/**
     
* Returns the set intersection of two CharProperty nodes.
     
*/
    
private static CharProperty intersection(final CharProperty lhs,
                                             
final CharProperty rhs) {
        
return new CharProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
    
}

    
/**
     
* Returns the set difference of two CharProperty nodes.
     
*/
    
private static CharProperty setDifference(final CharProperty lhs,
                                              
final CharProperty rhs) {
        
return new CharProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
    
}

    
/**
     
* Handles word boundaries. Includes a field to allow this one class to
     
* deal with the different types of word boundaries we can match. The word
     
* characters include underscores, letters, and digits. Non spacing marks
     
* can are also part of a word if they have a base character, otherwise
     
* they are ignored for purposes of finding word boundaries.
     
*/

    
static final class Bound extends Node {
        
static int LEFT = 0x1;
        
static int RIGHT= 0x2;
        
static int BOTH = 0x3;
        
static int NONE = 0x4;
        
int type;
        
boolean useUWORD;
        
Bound(int n, boolean useUWORD) {
            
type = n;
            
this.useUWORD = useUWORD;
        
}

        
boolean isWord(int ch) {
            
return useUWORD ? UnicodeProp.WORD.is(ch)
                            
: (ch == '_' || Character.isLetterOrDigit(ch));
        
}

        
int check(Matcher matcher, int i, CharSequence seq) {
            
int ch;
            
boolean left = false;
            
int startIndex = matcher.from;
            
int endIndex = matcher.to;
            
if (matcher.transparentBounds) {
                
startIndex = 0;
                
endIndex = matcher.getTextLength();
            
}
            
if (i > startIndex) {
                
ch = Character.codePointBefore(seq, i);
                
left = (isWord(ch) ||
                    
((Character.getType(ch) == Character.NON_SPACING_MARK)
                     
&& hasBaseCharacter(matcher, i-1, seq)));
            
}
            
boolean right = false;
            
if (i < endIndex) {
                
ch = Character.codePointAt(seq, i);
                
right = (isWord(ch) ||
                    
((Character.getType(ch) == Character.NON_SPACING_MARK)
                     
&& hasBaseCharacter(matcher, i, seq)));
            
} else {
                
// Tried to access char past the end
                
matcher.hitEnd = true;
                
// The addition of another char could wreck a boundary
                
matcher.requireEnd = true;
            
}
            
return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
return (check(matcher, i, seq) & type) > 0
                
&& next.match(matcher, i, seq);
        
}
    
}

    
/**
     
* Non spacing marks only count as word characters in bounds calculations
     
* if they have a base character.
     
*/

    
private static boolean hasBaseCharacter(Matcher matcher, int i,
                                            
CharSequence seq)
    
{
        
int start = (!matcher.transparentBounds) ?
            
matcher.from : 0;
        
for (int x=i; x >= start; x--) {
            
int ch = Character.codePointAt(seq, x);
            
if (Character.isLetterOrDigit(ch))
                
return true;
            
if (Character.getType(ch) == Character.NON_SPACING_MARK)
                
continue;
            
return false;
        
}
        
return false;
    
}

    
/**
     
* Attempts to match a slice in the input using the Boyer-Moore string
     
* matching algorithm. The algorithm is based on the idea that the
     
* pattern can be shifted farther ahead in the search text if it is
     
* matched right to left.
     
* <p>
     
* The pattern is compared to the input one character at a time, from
     
* the rightmost character in the pattern to the left. If the characters
     
* all match the pattern has been found. If a character does not match,
     
* the pattern is shifted right a distance that is the maximum of two
     
* functions, the bad character shift and the good suffix shift. This
     
* shift moves the attempted match position through the input more
     
* quickly than a naive one position at a time check.
     
* <p>
     
* The bad character shift is based on the character from the text that
     
* did not match. If the character does not appear in the pattern, the
     
* pattern can be shifted completely beyond the bad character. If the
     
* character does occur in the pattern, the pattern can be shifted to
     
* line the pattern up with the next occurrence of that character.
     
* <p>
     
* The good suffix shift is based on the idea that some subset on the right
     
* side of the pattern has matched. When a bad character is found, the
     
* pattern can be shifted right by the pattern length if the subset does
     
* not occur again in pattern, or by the amount of distance to the
     
* next occurrence of the subset in the pattern.
     
*
     
* Boyer-Moore search methods adapted from code by Amy Yu.
     
*/

    
static class BnM extends Node {
        
int[] buffer;
        
int[] lastOcc;
        
int[] optoSft;

        
/**
         
* Pre calculates arrays needed to generate the bad character
         
* shift and the good suffix shift. Only the last seven bits
         
* are used to see if chars match; This keeps the tables small
         
* and covers the heavily used ASCII range, but occasionally
         
* results in an aliased match for the bad character shift.
         
*/

        
static Node optimize(Node node) {
            
if (!(node instanceof Slice)) {
                
return node;
            
}

            
int[] src = ((Slice) node).buffer;
            
int patternLength = src.length;
            
// The BM algorithm requires a bit of overhead;
            
// If the pattern is short don't use it, since
            
// a shift larger than the pattern length cannot
            
// be used anyway.
            
if (patternLength < 4) {
                
return node;
            
}
            
int i, j, k;
            
int[] lastOcc = new int[128];
            
int[] optoSft = new int[patternLength];
            
// Precalculate part of the bad character shift
            
// It is a table for where in the pattern each
            
// lower 7-bit value occurs
            
for (i = 0; i < patternLength; i++) {
                
lastOcc[src[i]&0x7F] = i + 1;
            
}
            
// Precalculate the good suffix shift
            
// i is the shift amount being considered
NEXT:
       
for (i = patternLength; i > 0; i--) {
                
// j is the beginning index of suffix being considered
                
for (j = patternLength - 1; j >= i; j--) {
                    
// Testing for good suffix
                    
if (src[j] == src[j-i]) {
                        
// src[j..len] is a good suffix
                        
optoSft[j-1] = i;
                    
} else {
                        
// No match. The array has already been
                        
// filled up with correct values before.
                        
continue NEXT;
                    
}
                
}
                
// This fills up the remaining of optoSft
                
// any suffix can not have larger shift amount
                
// then its sub-suffix. Why???
                
while (j > 0) {
                    
optoSft[--j] = i;
                
}
            
}
            
// Set the guard value because of unicode compression
            
optoSft[patternLength-1] = 1;
            
if (node instanceof SliceS)
                
return new BnMS(src, lastOcc, optoSft, node.next);
            
return new BnM(src, lastOcc, optoSft, node.next);
        
}
        
BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
            
this.buffer = src;
            
this.lastOcc = lastOcc;
            
this.optoSft = optoSft;
            
this.next = next;
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] src = buffer;
            
int patternLength = src.length;
            
int last = matcher.to - patternLength;

            
// Loop over all possible match positions in text
NEXT:
       
while (i <= last) {
                
// Loop over pattern from right to left
                
for (int j = patternLength - 1; j >= 0; j--) {
                    
int ch = seq.charAt(i+j);
                    
if (ch != src[j]) {
                        
// Shift search to the right by the maximum of the
                        
// bad character shift and the good suffix shift
                        
i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
                        
continue NEXT;
                    
}
                
}
                
// Entire pattern matched starting at i
                
matcher.first = i;
                
boolean ret = next.match(matcher, i + patternLength, seq);
                
if (ret) {
                    
matcher.first = i;
                    
matcher.groups[0] = matcher.first;
                    
matcher.groups[1] = matcher.last;
                    
return true;
                
}
                
i++;
            
}
            
// BnM is only used as the leading node in the unanchored case,
            
// and it replaced its Start() which always searches to the end
            
// if it doesn't find what it's looking for, so hitEnd is true.
            
matcher.hitEnd = true;
            
return false;
        
}
        
boolean study(TreeInfo info) {
            
info.minLength += buffer.length;
            
info.maxValid = false;
            
return next.study(info);
        
}
    
}

    
/**
     
* Supplementary support version of BnM(). Unpaired surrogates are
     
* also handled by this class.
     
*/

    
static final class BnMS extends BnM {
        
int lengthInChars;

        
BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
            
super(src, lastOcc, optoSft, next);
            
for (int x = 0; x < buffer.length; x++) {
                
lengthInChars += Character.charCount(buffer[x]);
            
}
        
}
        
boolean match(Matcher matcher, int i, CharSequence seq) {
            
int[] src = buffer;
            
int patternLength = src.length;
            
int last = matcher.to - lengthInChars;

            
// Loop over all possible match positions in text
NEXT:
       
while (i <= last) {
                
// Loop over pattern from right to left
                
int ch;
                
for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
                     
j > 0; j -= Character.charCount(ch), x--) {
                    
ch = Character.codePointBefore(seq, i+j);
                    
if (ch != src[x]) {
                        
// Shift search to the right by the maximum of the
                        
// bad character shift and the good suffix shift
                        
int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
                        
i += countChars(seq, i, n);
                        
continue NEXT;
                    
}
                
}
                
// Entire pattern matched starting at i
                
matcher.first = i;
                
boolean ret = next.match(matcher, i + lengthInChars, seq);
                
if (ret) {
                    
matcher.first = i;
                    
matcher.groups[0] = matcher.first;
                    
matcher.groups[1] = matcher.last;
                    
return true;
                
}
                
i += countChars(seq, i, 1);
            
}
            
matcher.hitEnd = true;
            
return false;
        
}
    
}

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

    
/**
     
*
  
This must be the very first initializer.
     
*/
    
static Node accept = new Node();

    
static Node lastAccept = new LastNode();

    
private static class CharPropertyNames {

        
static CharProperty charPropertyFor(String name) {
            
CharPropertyFactory m = map.get(name);
            
return m == null ? null : m.make();
        
}

        
private static abstract class CharPropertyFactory {
            
abstract CharProperty make();
        
}

        
private static void defCategory(String name,
                                        
final int typeMask) {
            
map.put(name, new CharPropertyFactory() {
                    
CharProperty make() { return new Category(typeMask);}});
        
}

        
private static void defRange(String name,
                                     
final int lower, final int upper) {
            
map.put(name, new CharPropertyFactory() {
                    
CharProperty make() { return rangeFor(lower, upper);}});
        
}

        
private static void defCtype(String name,
                                     
final int ctype) {
            
map.put(name, new CharPropertyFactory() {
                    
CharProperty make() { return new Ctype(ctype);}});
        
}

        
private static abstract class CloneableProperty
            
extends CharProperty implements Cloneable
        
{
            
public CloneableProperty clone() {
                
try {
                    
return (CloneableProperty) super.clone();
                
} catch (CloneNotSupportedException e) {
                    
throw new AssertionError(e);
                
}
            
}
        
}

        
private static void defClone(String name,
                                     
final CloneableProperty p) {
            
map.put(name, new CharPropertyFactory() {
                    
CharProperty make() { return p.clone();}});
        
}

        
private static final HashMap<String, CharPropertyFactory> map
            
= new HashMap<>();

        
static {
            
// Unicode character property aliases, defined in
            
//
 
http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
            
defCategory("Cn", 1<<Character.UNASSIGNED);
            
defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
            
defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
            
defCategory("Lt", 1<<Character.TITLECASE_LETTER);
            
defCategory("Lm", 1<<Character.MODIFIER_LETTER);
            
defCategory("Lo", 1<<Character.OTHER_LETTER);
            
defCategory("Mn", 1<<Character.NON_SPACING_MARK);
            
defCategory("Me", 1<<Character.ENCLOSING_MARK);
            
defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
            
defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
            
defCategory("Nl", 1<<Character.LETTER_NUMBER);
            
defCategory("No", 1<<Character.OTHER_NUMBER);
            
defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
            
defCategory("Zl", 1<<Character.LINE_SEPARATOR);
            
defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
            
defCategory("Cc", 1<<Character.CONTROL);
            
defCategory("Cf", 1<<Character.FORMAT);
            
defCategory("Co", 1<<Character.PRIVATE_USE);
            
defCategory("Cs", 1<<Character.SURROGATE);
            
defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
            
defCategory("Ps", 1<<Character.START_PUNCTUATION);
            
defCategory("Pe", 1<<Character.END_PUNCTUATION);
            
defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
            
defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
            
defCategory("Sm", 1<<Character.MATH_SYMBOL);
            
defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
            
defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
            
defCategory("So", 1<<Character.OTHER_SYMBOL);
            
defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
            
defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
            
defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
                              
(1<<Character.LOWERCASE_LETTER) |
                              
(1<<Character.TITLECASE_LETTER) |
                              
(1<<Character.MODIFIER_LETTER)
  
|
                              
(1<<Character.OTHER_LETTER)));
            
defCategory("M", ((1<<Character.NON_SPACING_MARK) |
                              
(1<<Character.ENCLOSING_MARK)
   
|
                              
(1<<Character.COMBINING_SPACING_MARK)));
            
defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
                              
(1<<Character.LETTER_NUMBER)
        
|
                              
(1<<Character.OTHER_NUMBER)));
            
defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
                              
(1<<Character.LINE_SEPARATOR)
  
|
                              
(1<<Character.PARAGRAPH_SEPARATOR)));
            
defCategory("C", ((1<<Character.CONTROL)
     
|
                              
(1<<Character.FORMAT)
      
|
                              
(1<<Character.PRIVATE_USE) |
                              
(1<<Character.SURROGATE))); // Other
            
defCategory("P", ((1<<Character.DASH_PUNCTUATION)
      
|
                              
(1<<Character.START_PUNCTUATION)
     
|
                              
(1<<Character.END_PUNCTUATION)
       
|
                              
(1<<Character.CONNECTOR_PUNCTUATION) |
                              
(1<<Character.OTHER_PUNCTUATION)
     
|
                              
(1<<Character.INITIAL_QUOTE_PUNCTUATION) |
                              
(1<<Character.FINAL_QUOTE_PUNCTUATION)));
            
defCategory("S", ((1<<Character.MATH_SYMBOL)
     
|
                              
(1<<Character.CURRENCY_SYMBOL) |
                              
(1<<Character.MODIFIER_SYMBOL) |
                              
(1<<Character.OTHER_SYMBOL)));
            
defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
                               
(1<<Character.LOWERCASE_LETTER) |
                               
(1<<Character.TITLECASE_LETTER)));
            
defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
                               
(1<<Character.LOWERCASE_LETTER) |
                               
(1<<Character.TITLECASE_LETTER) |
                               
(1<<Character.MODIFIER_LETTER)
  
|
                               
(1<<Character.OTHER_LETTER)
     
|
                               
(1<<Character.DECIMAL_DIGIT_NUMBER)));
            
defRange("L1", 0x00, 0xFF); // Latin-1
            
map.put("all", new CharPropertyFactory() {
                    
CharProperty make() { return new All(); }});

            
// Posix regular expression character classes, defined in
            
//
 
http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
            
defRange("ASCII", 0x00, 0x7F);
   
// ASCII
            
defCtype("Alnum", ASCII.ALNUM);
  
// Alphanumeric characters
            
defCtype("Alpha", ASCII.ALPHA);
  
// Alphabetic characters
            
defCtype("Blank", ASCII.BLANK);
  
// Space and tab characters
            
defCtype("Cntrl", ASCII.CNTRL);
  
// Control characters
            
defRange("Digit", '0', '9');
     
// Numeric characters
            
defCtype("Graph", ASCII.GRAPH);
  
// printable and visible
            
defRange("Lower", 'a', 'z');
     
// Lower-case alphabetic
            
defRange("Print", 0x20, 0x7E);
   
// Printable characters
            
defCtype("Punct", ASCII.PUNCT);
  
// Punctuation characters
            
defCtype("Space", ASCII.SPACE);
  
// Space characters
            
defRange("Upper", 'A', 'Z');
     
// Upper-case alphabetic
            
defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits

            
// Java character properties, defined by methods in Character.java
            
defClone("javaLowerCase", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isLowerCase(ch);}});
            
defClone("javaUpperCase", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isUpperCase(ch);}});
            
defClone("javaAlphabetic", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isAlphabetic(ch);}});
            
defClone("javaIdeographic", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isIdeographic(ch);}});
            
defClone("javaTitleCase", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isTitleCase(ch);}});
            
defClone("javaDigit", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isDigit(ch);}});
            
defClone("javaDefined", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isDefined(ch);}});
            
defClone("javaLetter", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isLetter(ch);}});
            
defClone("javaLetterOrDigit", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isLetterOrDigit(ch);}});
            
defClone("javaJavaIdentifierStart", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isJavaIdentifierStart(ch);}});
            
defClone("javaJavaIdentifierPart", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isJavaIdentifierPart(ch);}});
            
defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isUnicodeIdentifierStart(ch);}});
            
defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isUnicodeIdentifierPart(ch);}});
            
defClone("javaIdentifierIgnorable", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isIdentifierIgnorable(ch);}});
            
defClone("javaSpaceChar", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isSpaceChar(ch);}});
            
defClone("javaWhitespace", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isWhitespace(ch);}});
            
defClone("javaISOControl", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isISOControl(ch);}});
            
defClone("javaMirrored", new CloneableProperty() {
                
boolean isSatisfiedBy(int ch) {
                    
return Character.isMirrored(ch);}});
        
}
    
}

    
/**
     
* Creates a predicate which can be used to match a string.
     
*
     
* @return
  
The predicate which can be used for matching on a string
     
* @since
   
1.8
     
*/

    
public Predicate<String> asPredicate() {
        
return s -> matcher(s).find();
    
}

    
/**
     
* Creates a stream from the given input sequence around matches of this
     
* pattern.
     
*
     
* <p> The stream returned by this method contains each substring of the
     
* input sequence that is terminated by another subsequence that matches
     
* this pattern or is terminated by the end of the input sequence.
  
The
     
* substrings in the stream are in the order in which they occur in the
     
* input. Trailing empty strings will be discarded and not encountered in
     
* the stream.
     
*
     
* <p> If this pattern does not match any subsequence of the input then
     
* the resulting stream has just one element, namely the input sequence in
     
* string form.
     
*
     
* <p> When there is a positive-width match at the beginning of the input
     
* sequence then an empty leading substring is included at the beginning
     
* of the stream. A zero-width match at the beginning however never produces
     
* such empty leading substring.
     
*
     
* <p> If the input sequence is mutable, it must remain constant during the
     
* execution of the terminal stream operation.
  
Otherwise, the result of the
     
* terminal stream operation is undefined.
     
*
     
* @param
   
input
     
*
          
The character sequence to be split
     
*
     
* @return
  
The stream of strings computed by splitting the input
     
*
          
around matches of this pattern
     
* @see#split(CharSequence)
     
* @since
   
1.8
     
*/

    
public Stream<String> splitAsStream(final CharSequence input) {
        
class MatcherIterator implements Iterator<String> {
            
private final Matcher matcher;
            
// The start position of the next sub-sequence of input
            
// when current == input.length there are no more elements
            
private int current;
            
// null if the next element, if any, needs to obtained
            
private String nextElement;
            
// > 0 if there are N next empty elements
            
private int emptyElementCount;

            
MatcherIterator() {
                
this.matcher = matcher(input);
            
}

            
public String next() {
                
if (!hasNext())
                    
throw new NoSuchElementException();

                
if (emptyElementCount == 0) {
                    
String n = nextElement;
                    
nextElement = null;
                    
return n;
                
} else {
                    
emptyElementCount--;
                    
return "";
                
}
            
}

            
public boolean hasNext() {
                
if (nextElement != null || emptyElementCount > 0)
                    
return true;

                
if (current == input.length())
                    
return false;

                
// Consume the next matching element
                
// Count sequence of matching empty elements
                
while (matcher.find()) {
                    
nextElement = input.subSequence(current, matcher.start()).toString();
                    
current = matcher.end();
                    
if (!nextElement.isEmpty()) {
                        
return true;
                    
} else if (current > 0) { // no empty leading substring for zero-width
                                              
// match at the beginning of the input
                        
emptyElementCount++;
                    
}
                
}

                
// Consume last matching element
                
nextElement = input.subSequence(current, input.length()).toString();
                
current = input.length();
                
if (!nextElement.isEmpty()) {
                    
return true;
                
} else {
                    
// Ignore a terminal sequence of matching empty elements
                    
emptyElementCount = 0;
                    
nextElement = null;
                    
return false;
                
}
            
}
        
}
        
return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
                
new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
    
}
}