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	/*
	* 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> </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 <tt><=</tt> <i>n</i> <tt><=</tt> 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 <tt><=</tt> <i>n</i> <tt><=</tt> 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 <tt><=</tt> <i>m</i> <tt><=</tt> 3,
	* 0 <tt><=</tt> <i>n</i> <tt><=</tt> 7)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>hh</i></td>
	* <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hh</i></td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\u</tt><i>hhhh</i></td>
	* <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>hhhh</i></td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\x</tt><i>{h...h}</i></td>
	* <td headers="matches">The character with hexadecimal value <tt>0x</tt><i>h...h</i>
	* ({@link java.lang.Character#MIN_CODE_POINT Character.MIN_CODE_POINT}
	*  <= <tt>0x</tt><i>h...h</i> <=
	* {@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>'\u0009'</tt>)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\n</tt></td>
	* <td headers="matches">The newline (line feed) character (<tt>'\u000A'</tt>)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\r</tt></td>
	* <td headers="matches">The carriage-return character (<tt>'\u000D'</tt>)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\f</tt></td>
	* <td headers="matches">The form-feed character (<tt>'\u000C'</tt>)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\a</tt></td>
	* <td headers="matches">The alert (bell) character (<tt>'\u0007'</tt>)</td></tr>
	* <tr><td valign="top" headers="construct characters"><tt>\e</tt></td>
	* <td headers="matches">The escape character (<tt>'\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> </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> </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\u1680\u180e\u2000-\u200a\u202f\u205f\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\u2028\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> </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> </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> </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 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 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> </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 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> </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>\u000D\u000A\|[\u000A\u000B\u000C\u000D\u0085\u2028\u2029]
	* </tt></td></tr>
	*
	* <tr><th> </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> </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> </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> </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> </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><<i>name</i>></td>
	* <td valign="bottom" headers="matches">Whatever the
	* <a href="#groupname">named-capturing group</a> "name" matched</td></tr>
	*
	* <tr><th> </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> </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>(?<<a href="#groupname">name</a>></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) </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>  </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>(?<=</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>(?<!</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>(?></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™ 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>"\b"</tt>, for example, matches a single backspace character when
	* interpreted as a regular expression, while <tt>"\\b"</tt> matches a
	* word boundary. The string literal <tt>"$hello$"</tt> is illegal
	* and leads to a compile-time error; in order to match the string
	* <tt>(hello)</tt> the string literal <tt>"\$hello\$"</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>&&</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    </th>
	* <td>Literal escape    </td>
	* <td><tt>\x</tt></td></tr>
	* <tr><th>2    </th>
	* <td>Grouping</td>
	* <td><tt>[...]</tt></td></tr>
	* <tr><th>3    </th>
	* <td>Range</td>
	* <td><tt>a-z</tt></td></tr>
	* <tr><th>4    </th>
	* <td>Union</td>
	* <td><tt>[a-e][i-u]</tt></td></tr>
	* <tr><th>5    </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 (<tt>'\n'</tt>),
	*
	* <li> A carriage-return character followed immediately by a newline
	* character (<tt>"\r\n"</tt>),
	*
	* <li> A standalone carriage-return character (<tt>'\r'</tt>),
	*
	* <li> A next-line character (<tt>'\u0085'</tt>),
	*
	* <li> A line-separator character (<tt>'\u2028'</tt>), or
	*
	* <li> A paragraph-separator character (<tt>'\u2029</tt>).
	*
	* </ul>
	* <p>If {@link #UNIX_LINES} 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 {@link #DOTALL} flag is specified.
	*
	* <p> By default, the regular expressions <tt>^</tt> and <tt>$</tt> ignore
	* line terminators and only match at the beginning and the end, respectively,
	* of the entire input sequence. If {@link #MULTILINE} mode is activated then
	* <tt>^</tt> matches at the beginning of input and after any line terminator
	* except at the end of input. When in {@link #MULTILINE} mode <tt>$</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    </th>
	* <td><tt>((A)(B(C)))</tt></td></tr>
	* <tr><th>2    </th>
	* <td><tt>(A)</tt></td></tr>
	* <tr><th>3    </th>
	* <td><tt>(B(C))</tt></td></tr>
	* <tr><th>4    </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>'\u0041'</tt> through <tt>'\u005a'</tt>),
	* <li> The lowercase letters <tt>'a'</tt> through <tt>'z'</tt>
	* (<tt>'\u0061'</tt> through <tt>'\u007a'</tt>),
	* <li> The digits <tt>'0'</tt> through <tt>'9'</tt>
	* (<tt>'\u0030'</tt> through <tt>'\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>\u2014</tt> in Java source code
	* are processed as described in section 3.3 of
	* <cite>The Java™ 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>"\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>\x{...}</tt>, for example a supplementary character U+2011F
	* can be specified as <tt>\x{2011F}</tt>, instead of two consecutive
	* Unicode escape sequences of the surrogate pair
	* <tt>\uD840</tt><tt>\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 {@link #UNICODE_CHARACTER_CLASS} 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    </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>\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 <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 <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 <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 <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 <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 {@link #CASE_INSENSITIVE} 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 <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\u030A"</tt>, for example, will match the
	* string <tt>"\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 <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 #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
	* {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
	* {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
	* and {@link #COMMENTS}
	*
	* @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> - 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    </i></th>
	* <th align="left"><i>Limit    </i></th>
	* <th align="left"><i>Result    </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    </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) {
	try {
	compile();
	} catch (StackOverflowError soe) {
	throw error("Stack overflow during pattern compilation");
	}
	} 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++];
	if (ch == 0 && cursor > patternLength) {
	cursor = patternLength;
	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];
	if (ch == 0 && cursor > patternLength) {
	cursor = patternLength;
	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);
	}
	}

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