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Posted to commits@jena.apache.org by an...@apache.org on 2018/05/04 09:03:14 UTC

[13/24] jena git commit: JENA-1537: Remove dependency on Xerces. Import needed code

http://git-wip-us.apache.org/repos/asf/jena/blob/c9a7e646/jena-core/src/main/java/org/apache/jena/ext/xerces/impl/xpath/regex/RegularExpression.java
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diff --git a/jena-core/src/main/java/org/apache/jena/ext/xerces/impl/xpath/regex/RegularExpression.java b/jena-core/src/main/java/org/apache/jena/ext/xerces/impl/xpath/regex/RegularExpression.java
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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.jena.ext.xerces.impl.xpath.regex;
+
+import java.text.CharacterIterator;
+import java.util.Locale;
+import java.util.Stack;
+
+import org.apache.jena.ext.xerces.util.IntStack;
+
+/**
+ * A regular expression matching engine using Non-deterministic Finite Automaton (NFA).
+ * This engine does not conform to the POSIX regular expression.
+ *
+ * <hr width="50%">
+ * <h3>How to use</h3>
+ *
+ * <dl>
+ *   <dt>A. Standard way
+ *   <dd>
+ * <pre>
+ * RegularExpression re = new RegularExpression(<var>regex</var>);
+ * if (re.matches(text)) { ... }
+ * </pre>
+ *
+ *   <dt>B. Capturing groups
+ *   <dd>
+ * <pre>
+ * RegularExpression re = new RegularExpression(<var>regex</var>);
+ * Match match = new Match();
+ * if (re.matches(text, match)) {
+ *     ... // You can refer captured texts with methods of the <code>Match</code> class.
+ * }
+ * </pre>
+ *
+ * </dl>
+ *
+ * <h4>Case-insensitive matching</h4>
+ * <pre>
+ * RegularExpression re = new RegularExpression(<var>regex</var>, "i");
+ * if (re.matches(text) >= 0) { ...}
+ * </pre>
+ *
+ * <h4>Options</h4>
+ * <p>You can specify options to <a href="#RegularExpression(java.lang.String, java.lang.String)"><code>RegularExpression(</code><var>regex</var><code>, </code><var>options</var><code>)</code></a>
+ *    or <a href="#setPattern(java.lang.String, java.lang.String)"><code>setPattern(</code><var>regex</var><code>, </code><var>options</var><code>)</code></a>.
+ *    This <var>options</var> parameter consists of the following characters.
+ * </p>
+ * <dl>
+ *   <dt><a name="I_OPTION"><code>"i"</code></a>
+ *   <dd>This option indicates case-insensitive matching.
+ *   <dt><a name="M_OPTION"><code>"m"</code></a>
+ *   <dd class="REGEX"><kbd>^</kbd> and <kbd>$</kbd> consider the EOL characters within the text.
+ *   <dt><a name="S_OPTION"><code>"s"</code></a>
+ *   <dd class="REGEX"><kbd>.</kbd> matches any one character.
+ *   <dt><a name="U_OPTION"><code>"u"</code></a>
+ *   <dd class="REGEX">Redefines <Kbd>\d \D \w \W \s \S \b \B \&lt; \></kbd> as becoming to Unicode.
+ *   <dt><a name="W_OPTION"><code>"w"</code></a>
+ *   <dd class="REGEX">By this option, <kbd>\b \B \&lt; \></kbd> are processed with the method of
+ *      'Unicode Regular Expression Guidelines' Revision 4.
+ *      When "w" and "u" are specified at the same time,
+ *      <kbd>\b \B \&lt; \></kbd> are processed for the "w" option.
+ *   <dt><a name="COMMA_OPTION"><code>","</code></a>
+ *   <dd>The parser treats a comma in a character class as a range separator.
+ *      <kbd class="REGEX">[a,b]</kbd> matches <kbd>a</kbd> or <kbd>,</kbd> or <kbd>b</kbd> without this option.
+ *      <kbd class="REGEX">[a,b]</kbd> matches <kbd>a</kbd> or <kbd>b</kbd> with this option.
+ *
+ *   <dt><a name="X_OPTION"><code>"X"</code></a>
+ *   <dd class="REGEX">
+ *       By this option, the engine confoms to <a href="http://www.w3.org/TR/2000/WD-xmlschema-2-20000407/#regexs">XML Schema: Regular Expression</a>.
+ *       The <code>match()</code> method does not do subsring matching
+ *       but entire string matching.
+ *
+ * </dl>
+ * 
+ * <hr width="50%">
+ * <h3>Syntax</h3>
+ * <table border="1" bgcolor="#ddeeff">
+ *   <tr>
+ *    <td>
+ *     <h4>Differences from the Perl 5 regular expression</h4>
+ *     <ul>
+ *      <li>There is 6-digit hexadecimal character representation  (<kbd>\u005cv</kbd><var>HHHHHH</var>.)
+ *      <li>Supports subtraction, union, and intersection operations for character classes.
+ *      <li>Not supported: <kbd>\</kbd><var>ooo</var> (Octal character representations),
+ *          <Kbd>\G</kbd>, <kbd>\C</kbd>, <kbd>\l</kbd><var>c</var>,
+ *          <kbd>\u005c u</kbd><var>c</var>, <kbd>\L</kbd>, <kbd>\U</kbd>,
+ *          <kbd>\E</kbd>, <kbd>\Q</kbd>, <kbd>\N{</kbd><var>name</var><kbd>}</kbd>,
+ *          <Kbd>(?{<kbd><var>code</var><kbd>})</kbd>, <Kbd>(??{<kbd><var>code</var><kbd>})</kbd>
+ *     </ul>
+ *    </td>
+ *   </tr>
+ * </table>
+ *
+ * <P>Meta characters are `<KBD>. * + ? { [ ( ) | \ ^ $</KBD>'.</P>
+ * <ul>
+ *   <li>Character
+ *     <dl>
+ *       <dt class="REGEX"><kbd>.</kbd> (A period)
+ *       <dd>Matches any one character except the following characters.
+ *       <dd>LINE FEED (U+000A), CARRIAGE RETURN (U+000D),
+ *           PARAGRAPH SEPARATOR (U+2029), LINE SEPARATOR (U+2028)
+ *       <dd>This expression matches one code point in Unicode. It can match a pair of surrogates.
+ *       <dd>When <a href="#S_OPTION">the "s" option</a> is specified,
+ *           it matches any character including the above four characters.
+ *
+ *       <dt class="REGEX"><Kbd>\e \f \n \r \t</kbd>
+ *       <dd>Matches ESCAPE (U+001B), FORM FEED (U+000C), LINE FEED (U+000A),
+ *           CARRIAGE RETURN (U+000D), HORIZONTAL TABULATION (U+0009)
+ *
+ *       <dt class="REGEX"><kbd>\c</kbd><var>C</var>
+ *       <dd>Matches a control character.
+ *           The <var>C</var> must be one of '<kbd>@</kbd>', '<kbd>A</kbd>'-'<kbd>Z</kbd>',
+ *           '<kbd>[</kbd>', '<kbd>\u005c</kbd>', '<kbd>]</kbd>', '<kbd>^</kbd>', '<kbd>_</kbd>'.
+ *           It matches a control character of which the character code is less than
+ *           the character code of the <var>C</var> by 0x0040.
+ *       <dd class="REGEX">For example, a <kbd>\cJ</kbd> matches a LINE FEED (U+000A),
+ *           and a <kbd>\c[</kbd> matches an ESCAPE (U+001B).
+ *
+ *       <dt class="REGEX">a non-meta character
+ *       <dd>Matches the character.
+ *
+ *       <dt class="REGEX"><KBD>\</KBD> + a meta character
+ *       <dd>Matches the meta character.
+ *
+ *       <dt class="REGEX"><kbd>\u005cx</kbd><var>HH</var> <kbd>\u005cx{</kbd><var>HHHH</var><kbd>}</kbd>
+ *       <dd>Matches a character of which code point is <var>HH</var> (Hexadecimal) in Unicode.
+ *           You can write just 2 digits for <kbd>\u005cx</kbd><var>HH</var>, and
+ *           variable length digits for <kbd>\u005cx{</kbd><var>HHHH</var><kbd>}</kbd>.
+ *
+ *       <!--
+ *       <dt class="REGEX"><kbd>\u005c u</kbd><var>HHHH</var>
+ *       <dd>Matches a character of which code point is <var>HHHH</var> (Hexadecimal) in Unicode.
+ *       -->
+ *
+ *       <dt class="REGEX"><kbd>\u005cv</kbd><var>HHHHHH</var>
+ *       <dd>Matches a character of which code point is <var>HHHHHH</var> (Hexadecimal) in Unicode.
+ *
+ *       <dt class="REGEX"><kbd>\g</kbd>
+ *       <dd>Matches a grapheme.
+ *       <dd class="REGEX">It is equivalent to <kbd>(?[\p{ASSIGNED}]-[\p{M}\p{C}])?(?:\p{M}|[\x{094D}\x{09CD}\x{0A4D}\x{0ACD}\x{0B3D}\x{0BCD}\x{0C4D}\x{0CCD}\x{0D4D}\x{0E3A}\x{0F84}]\p{L}|[\x{1160}-\x{11A7}]|[\x{11A8}-\x{11FF}]|[\x{FF9E}\x{FF9F}])*</kbd>
+ *
+ *       <dt class="REGEX"><kbd>\X</kbd>
+ *       <dd class="REGEX">Matches a combining character sequence.
+ *       It is equivalent to <kbd>(?:\PM\pM*)</kbd>
+ *     </dl>
+ *   </li>
+ *
+ *   <li>Character class
+ *     <dl>
++ *       <dt class="REGEX"><kbd>[</kbd><var>R<sub>1</sub></var><var>R<sub>2</sub></var><var>...</var><var>R<sub>n</sub></var><kbd>]</kbd> (without <a href="#COMMA_OPTION">"," option</a>)
++ *       <dt class="REGEX"><kbd>[</kbd><var>R<sub>1</sub></var><kbd>,</kbd><var>R<sub>2</sub></var><kbd>,</kbd><var>...</var><kbd>,</kbd><var>R<sub>n</sub></var><kbd>]</kbd> (with <a href="#COMMA_OPTION">"," option</a>)
+ *       <dd>Positive character class.  It matches a character in ranges.
+ *       <dd><var>R<sub>n</sub></var>:
+ *       <ul>
+ *         <li class="REGEX">A character (including <Kbd>\e \f \n \r \t</kbd> <kbd>\u005cx</kbd><var>HH</var> <kbd>\u005cx{</kbd><var>HHHH</var><kbd>}</kbd> <!--kbd>\u005c u</kbd><var>HHHH</var--> <kbd>\u005cv</kbd><var>HHHHHH</var>)
+ *             <p>This range matches the character.
+ *         <li class="REGEX"><var>C<sub>1</sub></var><kbd>-</kbd><var>C<sub>2</sub></var>
+ *             <p>This range matches a character which has a code point that is >= <var>C<sub>1</sub></var>'s code point and &lt;= <var>C<sub>2</sub></var>'s code point.
++ *         <li class="REGEX">A POSIX character class: <Kbd>[:alpha:] [:alnum:] [:ascii:] [:cntrl:] [:digit:] [:graph:] [:lower:] [:print:] [:punct:] [:space:] [:upper:] [:xdigit:]</kbd>,
++ *             and negative POSIX character classes in Perl like <kbd>[:^alpha:]</kbd>
+ *             <p>...
+ *         <li class="REGEX"><kbd>\d \D \s \S \w \W \p{</kbd><var>name</var><kbd>} \P{</kbd><var>name</var><kbd>}</kbd>
+ *             <p>These expressions specifies the same ranges as the following expressions.
+ *       </ul>
+ *       <p class="REGEX">Enumerated ranges are merged (union operation).
+ *          <kbd>[a-ec-z]</kbd> is equivalent to <kbd>[a-z]</kbd>
+ *
+ *       <dt class="REGEX"><kbd>[^</kbd><var>R<sub>1</sub></var><var>R<sub>2</sub></var><var>...</var><var>R<sub>n</sub></var><kbd>]</kbd> (without a <a href="#COMMA_OPTION">"," option</a>)
+ *       <dt class="REGEX"><kbd>[^</kbd><var>R<sub>1</sub></var><kbd>,</kbd><var>R<sub>2</sub></var><kbd>,</kbd><var>...</var><kbd>,</kbd><var>R<sub>n</sub></var><kbd>]</kbd> (with a <a href="#COMMA_OPTION">"," option</a>)
+ *       <dd>Negative character class.  It matches a character not in ranges.
+ *
+ *       <dt class="REGEX"><kbd>(?[</kbd><var>ranges</var><kbd>]</kbd><var>op</var><kbd>[</kbd><var>ranges</var><kbd>]</kbd><var>op</var><kbd>[</kbd><var>ranges</var><kbd>]</kbd> ... <Kbd>)</kbd>
+ *       (<var>op</var> is <kbd>-</kbd> or <kbd>+</kbd> or <kbd>&</kbd>.)
+ *       <dd>Subtraction or union or intersection for character classes.
+ *       <dd class="REGEX">For exmaple, <kbd>(?[A-Z]-[CF])</kbd> is equivalent to <kbd>[A-BD-EG-Z]</kbd>, and <kbd>(?[0x00-0x7f]-[K]&[\p{Lu}])</kbd> is equivalent to <kbd>[A-JL-Z]</kbd>.
+ *       <dd>The result of this operations is a <u>positive character class</u>
+ *           even if an expression includes any negative character classes.
+ *           You have to take care on this in case-insensitive matching.
+ *           For instance, <kbd>(?[^b])</kbd> is equivalent to <kbd>[\x00-ac-\x{10ffff}]</kbd>,
+ *           which is equivalent to <kbd>[^b]</kbd> in case-sensitive matching.
+ *           But, in case-insensitive matching, <kbd>(?[^b])</kbd> matches any character because
+ *           it includes '<kbd>B</kbd>' and '<kbd>B</kbd>' matches '<kbd>b</kbd>'
+ *           though <kbd>[^b]</kbd> is processed as <kbd>[^Bb]</kbd>.
+ *
+ *       <dt class="REGEX"><kbd>[</kbd><var>R<sub>1</sub>R<sub>2</sub>...</var><kbd>-[</kbd><var>R<sub>n</sub>R<sub>n+1</sub>...</var><kbd>]]</kbd> (with an <a href="#X_OPTION">"X" option</a>)</dt>
+ *       <dd>Character class subtraction for the XML Schema.
+ *           You can use this syntax when you specify an <a href="#X_OPTION">"X" option</a>.
+ *           
+ *       <dt class="REGEX"><kbd>\d</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[0-9]</kbd>.
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>\p{Nd}</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\D</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[^0-9]</kbd>
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>\P{Nd}</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\s</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[ \f\n\r\t]</kbd>
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>[ \f\n\r\t\p{Z}]</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\S</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[^ \f\n\r\t]</kbd>
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>[^ \f\n\r\t\p{Z}]</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\w</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[a-zA-Z0-9_]</kbd>
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>[\p{Lu}\p{Ll}\p{Lo}\p{Nd}_]</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\W</kbd>
+ *       <dd class="REGEX">Equivalent to <kbd>[^a-zA-Z0-9_]</kbd>
+ *       <dd>When <a href="#U_OPTION">a "u" option</a> is set, it is equivalent to
+ *           <span class="REGEX"><kbd>[^\p{Lu}\p{Ll}\p{Lo}\p{Nd}_]</kbd></span>.
+ *
+ *       <dt class="REGEX"><kbd>\p{</kbd><var>name</var><kbd>}</kbd>
+ *       <dd>Matches one character in the specified General Category (the second field in <a href="ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData.txt"><kbd>UnicodeData.txt</kbd></a>) or the specified <a href="ftp://ftp.unicode.org/Public/UNIDATA/Blocks.txt">Block</a>.
+ *       The following names are available:
+ *       <dl>
+ *         <dt>Unicode General Categories:
+ *         <dd><kbd>
+ *       L, M, N, Z, C, P, S, Lu, Ll, Lt, Lm, Lo, Mn, Me, Mc, Nd, Nl, No, Zs, Zl, Zp,
+ *       Cc, Cf, Cn, Co, Cs, Pd, Ps, Pe, Pc, Po, Sm, Sc, Sk, So,
+ *         </kbd>
+ *         <dd>(Currently the Cn category includes U+10000-U+10FFFF characters)
+ *         <dt>Unicode Blocks:
+ *         <dd><kbd>
+ *       Basic Latin, Latin-1 Supplement, Latin Extended-A, Latin Extended-B,
+ *       IPA Extensions, Spacing Modifier Letters, Combining Diacritical Marks, Greek,
+ *       Cyrillic, Armenian, Hebrew, Arabic, Devanagari, Bengali, Gurmukhi, Gujarati,
+ *       Oriya, Tamil, Telugu, Kannada, Malayalam, Thai, Lao, Tibetan, Georgian,
+ *       Hangul Jamo, Latin Extended Additional, Greek Extended, General Punctuation,
+ *       Superscripts and Subscripts, Currency Symbols, Combining Marks for Symbols,
+ *       Letterlike Symbols, Number Forms, Arrows, Mathematical Operators,
+ *       Miscellaneous Technical, Control Pictures, Optical Character Recognition,
+ *       Enclosed Alphanumerics, Box Drawing, Block Elements, Geometric Shapes,
+ *       Miscellaneous Symbols, Dingbats, CJK Symbols and Punctuation, Hiragana,
+ *       Katakana, Bopomofo, Hangul Compatibility Jamo, Kanbun,
+ *       Enclosed CJK Letters and Months, CJK Compatibility, CJK Unified Ideographs,
+ *       Hangul Syllables, High Surrogates, High Private Use Surrogates, Low Surrogates,
+ *       Private Use, CJK Compatibility Ideographs, Alphabetic Presentation Forms,
+ *       Arabic Presentation Forms-A, Combining Half Marks, CJK Compatibility Forms,
+ *       Small Form Variants, Arabic Presentation Forms-B, Specials,
+ *       Halfwidth and Fullwidth Forms
+ *         </kbd>
+ *         <dt>Others:
+ *         <dd><kbd>ALL</kbd> (Equivalent to <kbd>[\u005cu0000-\u005cv10FFFF]</kbd>)
+ *         <dd><kbd>ASSGINED</kbd> (<kbd>\p{ASSIGNED}</kbd> is equivalent to <kbd>\P{Cn}</kbd>)
+ *         <dd><kbd>UNASSGINED</kbd>
+ *             (<kbd>\p{UNASSIGNED}</kbd> is equivalent to <kbd>\p{Cn}</kbd>)
+ *       </dl>
+ *
+ *       <dt class="REGEX"><kbd>\P{</kbd><var>name</var><kbd>}</kbd>
+ *       <dd>Matches one character not in the specified General Category or the specified Block.
+ *     </dl>
+ *   </li>
+ *
+ *   <li>Selection and Quantifier
+ *     <dl>
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>|</kbd><VAR>Y</VAR>
+ *       <dd>...
+ *
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>*</KBD>
+ *       <dd>Matches 0 or more <var>X</var>.
+ *
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>+</KBD>
+ *       <dd>Matches 1 or more <var>X</var>.
+ *
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>?</KBD>
+ *       <dd>Matches 0 or 1 <var>X</var>.
+ *
+ *       <dt class="REGEX"><var>X</var><kbd>{</kbd><var>number</var><kbd>}</kbd>
+ *       <dd>Matches <var>number</var> times.
+ *
+ *       <dt class="REGEX"><var>X</var><kbd>{</kbd><var>min</var><kbd>,}</kbd>
+ *       <dd>...
+ *
+ *       <dt class="REGEX"><var>X</var><kbd>{</kbd><var>min</var><kbd>,</kbd><var>max</var><kbd>}</kbd>
+ *       <dd>...
+ *
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>*?</kbd>
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>+?</kbd>
+ *       <dt class="REGEX"><VAR>X</VAR><kbd>??</kbd>
+ *       <dt class="REGEX"><var>X</var><kbd>{</kbd><var>min</var><kbd>,}?</kbd>
+ *       <dt class="REGEX"><var>X</var><kbd>{</kbd><var>min</var><kbd>,</kbd><var>max</var><kbd>}?</kbd>
+ *       <dd>Non-greedy matching.
+ *     </dl>
+ *   </li>
+ *
+ *   <li>Grouping, Capturing, and Back-reference
+ *     <dl>
+ *       <dt class="REGEX"><KBD>(?:</kbd><VAR>X</VAR><kbd>)</KBD>
+ *       <dd>Grouping. "<KBD>foo+</KBD>" matches "<KBD>foo</KBD>" or "<KBD>foooo</KBD>".
+ *       If you want it matches "<KBD>foofoo</KBD>" or "<KBD>foofoofoo</KBD>",
+ *       you have to write "<KBD>(?:foo)+</KBD>".
+ *
+ *       <dt class="REGEX"><KBD>(</kbd><VAR>X</VAR><kbd>)</KBD>
+ *       <dd>Grouping with capturing.
+ * It make a group and applications can know
+ * where in target text a group matched with methods of a <code>Match</code> instance
+ * after <code><a href="#matches(java.lang.String, org.apache.xerces.utils.regex.Match)">matches(String,Match)</a></code>.
+ * The 0th group means whole of this regular expression.
+ * The <VAR>N</VAR>th gorup is the inside of the <VAR>N</VAR>th left parenthesis.
+ * 
+ *   <p>For instance, a regular expression is
+ *   "<FONT color=blue><KBD> *([^&lt;:]*) +&lt;([^&gt;]*)&gt; *</KBD></FONT>"
+ *   and target text is
+ *   "<FONT color=red><KBD>From: TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;</KBD></FONT>":
+ *   <ul>
+ *     <li><code>Match.getCapturedText(0)</code>:
+ *     "<FONT color=red><KBD> TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;</KBD></FONT>"
+ *     <li><code>Match.getCapturedText(1)</code>: "<FONT color=red><KBD>TAMURA Kent</KBD></FONT>"
+ *     <li><code>Match.getCapturedText(2)</code>: "<FONT color=red><KBD>kent@trl.ibm.co.jp</KBD></FONT>"
+ *   </ul>
+ *
+ *       <dt class="REGEX"><kbd>\1 \2 \3 \4 \5 \6 \7 \8 \9</kbd>
+ *       <dd>
+ *
+ *       <dt class="REGEX"><kbd>(?></kbd><var>X</var><kbd>)</kbd>
+ *       <dd>Independent expression group. ................
+ *
+ *       <dt class="REGEX"><kbd>(?</kbd><var>options</var><kbd>:</kbd><var>X</var><kbd>)</kbd>
+ *       <dt class="REGEX"><kbd>(?</kbd><var>options</var><kbd>-</kbd><var>options2</var><kbd>:</kbd><var>X</var><kbd>)</kbd>
+ *       <dd>............................
+ *       <dd>The <var>options</var> or the <var>options2</var> consists of 'i' 'm' 's' 'w'.
+ *           Note that it can not contain 'u'.
+ *
+ *       <dt class="REGEX"><kbd>(?</kbd><var>options</var><kbd>)</kbd>
+ *       <dt class="REGEX"><kbd>(?</kbd><var>options</var><kbd>-</kbd><var>options2</var><kbd>)</kbd>
+ *       <dd>......
+ *       <dd>These expressions must be at the beginning of a group.
+ *     </dl>
+ *   </li>
+ *
+ *   <li>Anchor
+ *     <dl>
+ *       <dt class="REGEX"><kbd>\A</kbd>
+ *       <dd>Matches the beginnig of the text.
+ *
+ *       <dt class="REGEX"><kbd>\Z</kbd>
+ *       <dd>Matches the end of the text, or before an EOL character at the end of the text,
+ *           or CARRIAGE RETURN + LINE FEED at the end of the text.
+ *
+ *       <dt class="REGEX"><kbd>\z</kbd>
+ *       <dd>Matches the end of the text.
+ *
+ *       <dt class="REGEX"><kbd>^</kbd>
+ *       <dd>Matches the beginning of the text.  It is equivalent to <span class="REGEX"><Kbd>\A</kbd></span>.
+ *       <dd>When <a href="#M_OPTION">a "m" option</a> is set,
+ *           it matches the beginning of the text, or after one of EOL characters (
+ *           LINE FEED (U+000A), CARRIAGE RETURN (U+000D), LINE SEPARATOR (U+2028),
+ *           PARAGRAPH SEPARATOR (U+2029).)
+ *
+ *       <dt class="REGEX"><kbd>$</kbd>
+ *       <dd>Matches the end of the text, or before an EOL character at the end of the text,
+ *           or CARRIAGE RETURN + LINE FEED at the end of the text.
+ *       <dd>When <a href="#M_OPTION">a "m" option</a> is set,
+ *           it matches the end of the text, or before an EOL character.
+ *
+ *       <dt class="REGEX"><kbd>\b</kbd>
+ *       <dd>Matches word boundary.
+ *           (See <a href="#W_OPTION">a "w" option</a>)
+ *
+ *       <dt class="REGEX"><kbd>\B</kbd>
+ *       <dd>Matches non word boundary.
+ *           (See <a href="#W_OPTION">a "w" option</a>)
+ *
+ *       <dt class="REGEX"><kbd>\&lt;</kbd>
+ *       <dd>Matches the beginning of a word.
+ *           (See <a href="#W_OPTION">a "w" option</a>)
+ *
+ *       <dt class="REGEX"><kbd>\&gt;</kbd>
+ *       <dd>Matches the end of a word.
+ *           (See <a href="#W_OPTION">a "w" option</a>)
+ *     </dl>
+ *   </li>
+ *   <li>Lookahead and lookbehind
+ *     <dl>
+ *       <dt class="REGEX"><kbd>(?=</kbd><var>X</var><kbd>)</kbd>
+ *       <dd>Lookahead.
+ *
+ *       <dt class="REGEX"><kbd>(?!</kbd><var>X</var><kbd>)</kbd>
+ *       <dd>Negative lookahead.
+ *
+ *       <dt class="REGEX"><kbd>(?&lt;=</kbd><var>X</var><kbd>)</kbd>
+ *       <dd>Lookbehind.
+ *       <dd>(Note for text capturing......)
+ *
+ *       <dt class="REGEX"><kbd>(?&lt;!</kbd><var>X</var><kbd>)</kbd>
+ *       <dd>Negative lookbehind.
+ *     </dl>
+ *   </li>
+ *
+ *   <li>Misc.
+ *     <dl>
+ *       <dt class="REGEX"><kbd>(?(</Kbd><var>condition</var><Kbd>)</kbd><var>yes-pattern</var><kbd>|</kbd><var>no-pattern</var><kbd>)</kbd>,
+ *       <dt class="REGEX"><kbd>(?(</kbd><var>condition</var><kbd>)</kbd><var>yes-pattern</var><kbd>)</kbd>
+ *       <dd>......
+ *       <dt class="REGEX"><kbd>(?#</kbd><var>comment</var><kbd>)</kbd>
+ *       <dd>Comment.  A comment string consists of characters except '<kbd>)</kbd>'.
+ *           You can not write comments in character classes and before quantifiers.
+ *     </dl>
+ *   </li>
+ * </ul>
+ *
+ *
+ * <hr width="50%">
+ * <h3>BNF for the regular expression</h3>
+ * <pre>
+ * regex ::= ('(?' options ')')? term ('|' term)*
+ * term ::= factor+
+ * factor ::= anchors | atom (('*' | '+' | '?' | minmax ) '?'? )?
+ *            | '(?#' [^)]* ')'
+ * minmax ::= '{' ([0-9]+ | [0-9]+ ',' | ',' [0-9]+ | [0-9]+ ',' [0-9]+) '}'
+ * atom ::= char | '.' | char-class | '(' regex ')' | '(?:' regex ')' | '\' [0-9]
+ *          | '\w' | '\W' | '\d' | '\D' | '\s' | '\S' | category-block | '\X'
+ *          | '(?>' regex ')' | '(?' options ':' regex ')'
+ *          | '(?' ('(' [0-9] ')' | '(' anchors ')' | looks) term ('|' term)? ')'
+ * options ::= [imsw]* ('-' [imsw]+)?
+ * anchors ::= '^' | '$' | '\A' | '\Z' | '\z' | '\b' | '\B' | '\&lt;' | '\>'
+ * looks ::= '(?=' regex ')'  | '(?!' regex ')'
+ *           | '(?&lt;=' regex ')' | '(?&lt;!' regex ')'
+ * char ::= '\\' | '\' [efnrtv] | '\c' [@-_] | code-point | character-1
+ * category-block ::= '\' [pP] category-symbol-1
+ *                    | ('\p{' | '\P{') (category-symbol | block-name
+ *                                       | other-properties) '}'
+ * category-symbol-1 ::= 'L' | 'M' | 'N' | 'Z' | 'C' | 'P' | 'S'
+ * category-symbol ::= category-symbol-1 | 'Lu' | 'Ll' | 'Lt' | 'Lm' | Lo'
+ *                     | 'Mn' | 'Me' | 'Mc' | 'Nd' | 'Nl' | 'No'
+ *                     | 'Zs' | 'Zl' | 'Zp' | 'Cc' | 'Cf' | 'Cn' | 'Co' | 'Cs'
+ *                     | 'Pd' | 'Ps' | 'Pe' | 'Pc' | 'Po'
+ *                     | 'Sm' | 'Sc' | 'Sk' | 'So'
+ * block-name ::= (See above)
+ * other-properties ::= 'ALL' | 'ASSIGNED' | 'UNASSIGNED'
+ * character-1 ::= (any character except meta-characters)
+ *
+ * char-class ::= '[' ranges ']'
+ *                | '(?[' ranges ']' ([-+&] '[' ranges ']')? ')'
+ * ranges ::= '^'? (range <a href="#COMMA_OPTION">','?</a>)+
+ * range ::= '\d' | '\w' | '\s' | '\D' | '\W' | '\S' | category-block
+ *           | range-char | range-char '-' range-char
+ * range-char ::= '\[' | '\]' | '\\' | '\' [,-efnrtv] | code-point | character-2
+ * code-point ::= '\x' hex-char hex-char
+ *                | '\x{' hex-char+ '}'
+ * <!--               | '\u005c u' hex-char hex-char hex-char hex-char
+ * -->               | '\v' hex-char hex-char hex-char hex-char hex-char hex-char
+ * hex-char ::= [0-9a-fA-F]
+ * character-2 ::= (any character except \[]-,)
+ * </pre>
+ *
+ * <hr width="50%">
+ * <h3>TODO</h3>
+ * <ul>
+ *   <li><a href="http://www.unicode.org/unicode/reports/tr18/">Unicode Regular Expression Guidelines</a>
+ *     <ul>
+ *       <li>2.4 Canonical Equivalents
+ *       <li>Level 3
+ *     </ul>
+ *   <li>Parsing performance
+ * </ul>
+ *
+ * <hr width="50%">
+ * 
+ * @xerces.internal
+ *
+ * @author TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;
+ * @version $Id: RegularExpression.java 961928 2010-07-08 20:43:46Z knoaman $
+ */
+@SuppressWarnings("all")
+public class RegularExpression implements java.io.Serializable {
+    
+    private static final long serialVersionUID = 6242499334195006401L;
+
+    static final boolean DEBUG = false;
+
+    /**
+     * Compiles a token tree into an operation flow.
+     */
+    private synchronized void compile(Token tok) {
+        if (this.operations != null)
+            return;
+        this.numberOfClosures = 0;
+        this.operations = this.compile(tok, null, false);
+    }
+
+    /**
+     * Converts a token to an operation.
+     */
+    private Op compile(Token tok, Op next, boolean reverse) {
+        Op ret;
+        switch (tok.type) {
+        case Token.DOT:
+            ret = Op.createDot();
+            ret.next = next;
+            break;
+
+        case Token.CHAR:
+            ret = Op.createChar(tok.getChar());
+            ret.next = next;
+            break;
+
+        case Token.ANCHOR:
+            ret = Op.createAnchor(tok.getChar());
+            ret.next = next;
+            break;
+
+        case Token.RANGE:
+        case Token.NRANGE:
+            ret = Op.createRange(tok);
+            ret.next = next;
+            break;
+
+        case Token.CONCAT:
+            ret = next;
+            if (!reverse) {
+                for (int i = tok.size()-1;  i >= 0;  i --) {
+                    ret = compile(tok.getChild(i), ret, false);
+                }
+            } else {
+                for (int i = 0;  i < tok.size();  i ++) {
+                    ret = compile(tok.getChild(i), ret, true);
+                }
+            }
+            break;
+
+        case Token.UNION:
+            Op.UnionOp uni = Op.createUnion(tok.size());
+            for (int i = 0;  i < tok.size();  i ++) {
+                uni.addElement(compile(tok.getChild(i), next, reverse));
+            }
+            ret = uni;                          // ret.next is null.
+            break;
+
+        case Token.CLOSURE:
+        case Token.NONGREEDYCLOSURE:
+            Token child = tok.getChild(0);
+            int min = tok.getMin();
+            int max = tok.getMax();
+            if (min >= 0 && min == max) { // {n}
+                ret = next;
+                for (int i = 0; i < min;  i ++) {
+                    ret = compile(child, ret, reverse);
+                }
+                break;
+            }
+            if (min > 0 && max > 0)
+                max -= min;
+            if (max > 0) {
+                // X{2,6} -> XX(X(X(XX?)?)?)?
+                ret = next;
+                for (int i = 0;  i < max;  i ++) {
+                    Op.ChildOp q = Op.createQuestion(tok.type == Token.NONGREEDYCLOSURE);
+                    q.next = next;
+                    q.setChild(compile(child, ret, reverse));
+                    ret = q;
+                }
+            } else {
+                Op.ChildOp op;
+                if (tok.type == Token.NONGREEDYCLOSURE) {
+                    op = Op.createNonGreedyClosure();
+                } else {                        // Token.CLOSURE
+                    op = Op.createClosure(this.numberOfClosures++);
+                }
+                op.next = next;
+                op.setChild(compile(child, op, reverse));
+                ret = op;
+            }
+            if (min > 0) {
+                for (int i = 0;  i < min;  i ++) {
+                    ret = compile(child, ret, reverse);
+                }
+            }
+            break;
+
+        case Token.EMPTY:
+            ret = next;
+            break;
+
+        case Token.STRING:
+            ret = Op.createString(tok.getString());
+            ret.next = next;
+            break;
+
+        case Token.BACKREFERENCE:
+            ret = Op.createBackReference(tok.getReferenceNumber());
+            ret.next = next;
+            break;
+
+        case Token.PAREN:
+            if (tok.getParenNumber() == 0) {
+                ret = compile(tok.getChild(0), next, reverse);
+            } else if (reverse) {
+                next = Op.createCapture(tok.getParenNumber(), next);
+                next = compile(tok.getChild(0), next, reverse);
+                ret = Op.createCapture(-tok.getParenNumber(), next);
+            } else {
+                next = Op.createCapture(-tok.getParenNumber(), next);
+                next = compile(tok.getChild(0), next, reverse);
+                ret = Op.createCapture(tok.getParenNumber(), next);
+            }
+            break;
+
+        case Token.LOOKAHEAD:
+            ret = Op.createLook(Op.LOOKAHEAD, next, compile(tok.getChild(0), null, false));
+            break;
+        case Token.NEGATIVELOOKAHEAD:
+            ret = Op.createLook(Op.NEGATIVELOOKAHEAD, next, compile(tok.getChild(0), null, false));
+            break;
+        case Token.LOOKBEHIND:
+            ret = Op.createLook(Op.LOOKBEHIND, next, compile(tok.getChild(0), null, true));
+            break;
+        case Token.NEGATIVELOOKBEHIND:
+            ret = Op.createLook(Op.NEGATIVELOOKBEHIND, next, compile(tok.getChild(0), null, true));
+            break;
+
+        case Token.INDEPENDENT:
+            ret = Op.createIndependent(next, compile(tok.getChild(0), null, reverse));
+            break;
+
+        case Token.MODIFIERGROUP:
+            ret = Op.createModifier(next, compile(tok.getChild(0), null, reverse),
+                                    ((Token.ModifierToken)tok).getOptions(),
+                                    ((Token.ModifierToken)tok).getOptionsMask());
+            break;
+
+        case Token.CONDITION:
+            Token.ConditionToken ctok = (Token.ConditionToken)tok;
+            int ref = ctok.refNumber;
+            Op condition = ctok.condition == null ? null : compile(ctok.condition, null, reverse);
+            Op yes = compile(ctok.yes, next, reverse);
+            Op no = ctok.no == null ? null : compile(ctok.no, next, reverse);
+            ret = Op.createCondition(next, ref, condition, yes, no);
+            break;
+
+        default:
+            throw new RuntimeException("Unknown token type: "+tok.type);
+        } // switch (tok.type)
+        return ret;
+    }
+
+
+//Public
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @return true if the target is matched to this regular expression.
+     */
+    public boolean matches(char[]  target) {
+        return this.matches(target, 0,  target .length , (Match)null);
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern
+     * in specified range or not.
+     *
+     * @param start Start offset of the range.
+     * @param end  End offset +1 of the range.
+     * @return true if the target is matched to this regular expression.
+     */
+    public boolean matches(char[]  target, int start, int end) {
+        return this.matches(target, start, end, (Match)null);
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @param match A Match instance for storing matching result.
+     * @return Offset of the start position in <VAR>target</VAR>; or -1 if not match.
+     */
+    public boolean matches(char[]  target, Match match) {
+        return this.matches(target, 0,  target .length , match);
+    }
+
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern
+     * in specified range or not.
+     *
+     * @param start Start offset of the range.
+     * @param end  End offset +1 of the range.
+     * @param match A Match instance for storing matching result.
+     * @return Offset of the start position in <VAR>target</VAR>; or -1 if not match.
+     */
+    public boolean matches(char[] target, int start, int end, Match match) {
+
+        synchronized (this) {
+            if (this.operations == null)
+                this.prepare();
+            if (this.context == null)
+                this.context = new Context();
+        }
+        Context con = null;
+        synchronized (this.context) {
+            con = this.context.inuse ? new Context() : this.context;
+            con.reset(target, start, end, this.numberOfClosures);
+        }
+        if (match != null) {
+            match.setNumberOfGroups(this.nofparen);
+            match.setSource(target);
+        } else if (this.hasBackReferences) {
+            match = new Match();
+            match.setNumberOfGroups(this.nofparen);
+            // Need not to call setSource() because
+            // a caller can not access this match instance.
+        }
+        con.match = match;
+
+        if (RegularExpression.isSet(this.options, XMLSCHEMA_MODE)) {
+            int matchEnd = this. match(con, this.operations, con.start, 1, this.options);
+            //System.err.println("DEBUG: matchEnd="+matchEnd);
+            if (matchEnd == con.limit) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, con.start);
+                    con.match.setEnd(0, matchEnd);
+                }
+                con.setInUse(false);
+                return true;
+            }
+            return false;
+        }
+
+        /*
+         * The pattern has only fixed string.
+         * The engine uses Boyer-Moore.
+         */
+        if (this.fixedStringOnly) {
+            //System.err.println("DEBUG: fixed-only: "+this.fixedString);
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o >= 0) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, o);
+                    con.match.setEnd(0, o+this.fixedString.length());
+                }
+                con.setInUse(false);
+                return true;
+            }
+            con.setInUse(false);
+            return false;
+        }
+
+        /*
+         * The pattern contains a fixed string.
+         * The engine checks with Boyer-Moore whether the text contains the fixed string or not.
+         * If not, it return with false.
+         */
+        if (this.fixedString != null) {
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o < 0) {
+                //System.err.println("Non-match in fixed-string search.");
+                con.setInUse(false);
+                return false;
+            }
+        }
+
+        int limit = con.limit-this.minlength;
+        int matchStart;
+        int matchEnd = -1;
+
+        /*
+         * Checks whether the expression starts with ".*".
+         */
+        if (this.operations != null
+            && this.operations.type == Op.CLOSURE && this.operations.getChild().type == Op.DOT) {
+            if (isSet(this.options, SINGLE_LINE)) {
+                matchStart = con.start;
+                matchEnd = this. match(con, this.operations, con.start, 1, this.options);
+            } else {
+                boolean previousIsEOL = true;
+                for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                    int ch =  target [  matchStart ] ;
+                    if (isEOLChar(ch)) {
+                        previousIsEOL = true;
+                    } else {
+                        if (previousIsEOL) {
+                            if (0 <= (matchEnd = this. match(con, this.operations,
+                                                             matchStart, 1, this.options)))
+                                break;
+                        }
+                        previousIsEOL = false;
+                    }
+                }
+            }
+        }
+
+        /*
+         * Optimization against the first character.
+         */
+        else if (this.firstChar != null) {
+            //System.err.println("DEBUG: with firstchar-matching: "+this.firstChar);
+            RangeToken range = this.firstChar;
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                int ch =  target [matchStart] ;
+                if (REUtil.isHighSurrogate(ch) && matchStart+1 < con.limit) {
+                    ch = REUtil.composeFromSurrogates(ch, target[matchStart+1]);
+                }
+                if (!range.match(ch))  {
+                    continue;
+                }
+                if (0 <= (matchEnd = this. match(con, this.operations,
+                                                 matchStart, 1, this.options))) {
+                        break;
+                }
+            }
+        }
+
+        /*
+         * Straightforward matching.
+         */
+        else {
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                if (0 <= (matchEnd = this. match(con, this.operations, matchStart, 1, this.options)))
+                    break;
+            }
+        }
+
+        if (matchEnd >= 0) {
+            if (con.match != null) {
+                con.match.setBeginning(0, matchStart);
+                con.match.setEnd(0, matchEnd);
+            }
+            con.setInUse(false);
+            return true;
+        } else {
+            con.setInUse(false);
+            return false;
+        }
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @return true if the target is matched to this regular expression.
+     */
+    public boolean matches(String  target) {
+        return this.matches(target, 0,  target .length() , (Match)null);
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern
+     * in specified range or not.
+     *
+     * @param start Start offset of the range.
+     * @param end  End offset +1 of the range.
+     * @return true if the target is matched to this regular expression.
+     */
+    public boolean matches(String  target, int start, int end) {
+        return this.matches(target, start, end, (Match)null);
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @param match A Match instance for storing matching result.
+     * @return Offset of the start position in <VAR>target</VAR>; or -1 if not match.
+     */
+    public boolean matches(String  target, Match match) {
+        return this.matches(target, 0,  target .length() , match);
+    }
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern
+     * in specified range or not.
+     *
+     * @param start Start offset of the range.
+     * @param end  End offset +1 of the range.
+     * @param match A Match instance for storing matching result.
+     * @return Offset of the start position in <VAR>target</VAR>; or -1 if not match.
+     */
+    public boolean matches(String  target, int start, int end, Match match) {
+
+        synchronized (this) {
+            if (this.operations == null)
+                this.prepare();
+            if (this.context == null)
+                this.context = new Context();
+        }
+        Context con = null;
+        synchronized (this.context) {
+            con = this.context.inuse ? new Context() : this.context;
+            con.reset(target, start, end, this.numberOfClosures);
+        }
+        if (match != null) {
+            match.setNumberOfGroups(this.nofparen);
+            match.setSource(target);
+        } else if (this.hasBackReferences) {
+            match = new Match();
+            match.setNumberOfGroups(this.nofparen);
+            // Need not to call setSource() because
+            // a caller can not access this match instance.
+        }
+        con.match = match;
+
+        if (RegularExpression.isSet(this.options, XMLSCHEMA_MODE)) {
+            if (DEBUG) {
+                System.err.println("target string="+target);
+            }
+            int matchEnd = this. match(con, this.operations, con.start, 1, this.options);
+            if (DEBUG) {
+                System.err.println("matchEnd="+matchEnd);
+                System.err.println("con.limit="+con.limit);
+            }
+            if (matchEnd == con.limit) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, con.start);
+                    con.match.setEnd(0, matchEnd);
+                }
+                con.setInUse(false);
+                return true;
+            }
+            return false;
+        }
+
+        /*
+         * The pattern has only fixed string.
+         * The engine uses Boyer-Moore.
+         */
+        if (this.fixedStringOnly) {
+            //System.err.println("DEBUG: fixed-only: "+this.fixedString);
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o >= 0) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, o);
+                    con.match.setEnd(0, o+this.fixedString.length());
+                }
+                con.setInUse(false);
+                return true;
+            }
+            con.setInUse(false);
+            return false;
+        }
+
+        /*
+         * The pattern contains a fixed string.
+         * The engine checks with Boyer-Moore whether the text contains the fixed string or not.
+         * If not, it return with false.
+         */
+        if (this.fixedString != null) {
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o < 0) {
+                //System.err.println("Non-match in fixed-string search.");
+                con.setInUse(false);
+                return false;
+            }
+        }
+
+        int limit = con.limit-this.minlength;
+        int matchStart;
+        int matchEnd = -1;
+
+        /*
+         * Checks whether the expression starts with ".*".
+         */
+        if (this.operations != null
+            && this.operations.type == Op.CLOSURE && this.operations.getChild().type == Op.DOT) {
+            if (isSet(this.options, SINGLE_LINE)) {
+                matchStart = con.start;
+                matchEnd = this.match(con, this.operations, con.start, 1, this.options);
+            } else {
+                boolean previousIsEOL = true;
+                for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                    int ch =  target .charAt(  matchStart ) ;
+                    if (isEOLChar(ch)) {
+                        previousIsEOL = true;
+                    } else {
+                        if (previousIsEOL) {
+                            if (0 <= (matchEnd = this.match(con, this.operations,
+                                                            matchStart, 1, this.options)))
+                                break;
+                        }
+                        previousIsEOL = false;
+                    }
+                }
+            }
+        }
+
+        /*
+         * Optimization against the first character.
+         */
+        else if (this.firstChar != null) {
+            //System.err.println("DEBUG: with firstchar-matching: "+this.firstChar);
+            RangeToken range = this.firstChar;
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                int ch =  target .charAt(  matchStart ) ;
+                if (REUtil.isHighSurrogate(ch) && matchStart+1 < con.limit) {
+                    ch = REUtil.composeFromSurrogates(ch, target.charAt(matchStart+1));
+                }
+                if (!range.match(ch)) {
+                    continue;
+                }
+                if (0 <= (matchEnd = this.match(con, this.operations,
+                                                matchStart, 1, this.options))) {
+                        break;
+                }                
+            }
+        }
+
+        /*
+         * Straightforward matching.
+         */
+        else {
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                if (0 <= (matchEnd = this.match(con, this.operations, matchStart, 1, this.options)))
+                    break;
+            }
+        }
+
+        if (matchEnd >= 0) {
+            if (con.match != null) {
+                con.match.setBeginning(0, matchStart);
+                con.match.setEnd(0, matchEnd);
+            }
+            con.setInUse(false);
+            return true;
+        } else {
+            con.setInUse(false);
+            return false;
+        }
+    }
+
+    /**
+     * @return -1 when not match; offset of the end of matched string when match.
+     */
+    private int match(Context con, Op op, int offset, int dx, int opts) {
+        final ExpressionTarget target = con.target;
+        final Stack opStack = new Stack();
+        final IntStack dataStack = new IntStack();
+        final boolean isSetIgnoreCase = isSet(opts, IGNORE_CASE);
+        int retValue = -1;
+        boolean returned = false;
+
+        for (;;) {
+            if (op == null || offset > con.limit || offset < con.start) {
+                if (op == null) {
+                    retValue = isSet(opts, XMLSCHEMA_MODE) && offset != con.limit ? -1 : offset;
+                }
+                else {
+                   retValue = -1; 
+                }
+                returned = true;
+            }
+            else  {
+                retValue = -1;
+                // dx value is either 1 or -1
+                switch (op.type) {
+                case Op.CHAR:
+                    {
+                        final int o1 = (dx > 0) ? offset : offset -1;
+                        if (o1 >= con.limit || o1 < 0 || !matchChar(op.getData(), target.charAt(o1), isSetIgnoreCase)) {
+                            returned = true;
+                            break;
+                        }
+                        offset += dx;
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.DOT:
+                    {
+                        int o1 = (dx > 0) ? offset : offset - 1;
+                        if (o1 >= con.limit || o1 < 0) {
+                            returned = true;
+                            break;
+                        }
+                        if (isSet(opts, SINGLE_LINE)) {
+                            if (REUtil.isHighSurrogate(target.charAt(o1)) && o1+dx >= 0 && o1+dx < con.limit) {
+                                o1 += dx;
+                            }
+                        }
+                        else {
+                            int ch = target.charAt(o1);
+                            if (REUtil.isHighSurrogate(ch) && o1+dx >= 0 && o1+dx < con.limit) {
+                                o1 += dx;
+                                ch = REUtil.composeFromSurrogates(ch, target.charAt(o1));
+                            }
+                            if (isEOLChar(ch)) {
+                                returned = true;
+                                break;
+                            }
+                        }
+                        offset = (dx > 0) ? o1 + 1 : o1;
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.RANGE:
+                case Op.NRANGE:
+                    {
+                        int o1 = (dx > 0) ? offset : offset -1;
+                        if (o1 >= con.limit || o1 < 0) {
+                            returned = true;
+                            break;
+                        }
+                        int ch = target.charAt(offset);
+                        if (REUtil.isHighSurrogate(ch) && o1+dx < con.limit && o1+dx >=0) {
+                            o1 += dx;
+                            ch = REUtil.composeFromSurrogates(ch, target.charAt(o1));
+                        }
+                        final RangeToken tok = op.getToken();
+                        if (!tok.match(ch)) {
+                            returned = true;
+                            break;
+                        }
+                        offset = (dx > 0) ? o1+1 : o1;
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.ANCHOR:
+                    {
+                        if (!matchAnchor(target, op, con, offset, opts)) {
+                            returned = true;
+                            break;
+                        }
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.BACKREFERENCE:
+                    {
+                        int refno = op.getData();
+                        if (refno <= 0 || refno >= this.nofparen) {
+                            throw new RuntimeException("Internal Error: Reference number must be more than zero: "+refno);
+                        }
+                        if (con.match.getBeginning(refno) < 0 || con.match.getEnd(refno) < 0) {
+                            returned = true;
+                            break;
+                        }
+                        int o2 = con.match.getBeginning(refno);
+                        int literallen = con.match.getEnd(refno)-o2;
+                        if (dx > 0) {
+                            if (!target.regionMatches(isSetIgnoreCase, offset, con.limit, o2, literallen)) {
+                                returned = true;
+                                break;
+                            }
+                            offset += literallen;
+                        }
+                        else {
+                            if (!target.regionMatches(isSetIgnoreCase, offset-literallen, con.limit, o2, literallen)) {
+                                returned = true;
+                                break;
+                            }
+                            offset -= literallen;
+                        }
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.STRING:
+                    {
+                        String literal = op.getString();
+                        int literallen = literal.length();
+                        if (dx > 0) {
+                            if (!target.regionMatches(isSetIgnoreCase, offset, con.limit, literal, literallen)) {
+                                returned = true;
+                                break;
+                            }
+                            offset += literallen;
+                        }
+                        else {
+                            if (!target.regionMatches(isSetIgnoreCase, offset-literallen, con.limit, literal, literallen)) {
+                                returned = true;
+                                break;
+                            }
+                            offset -= literallen;
+                        }
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.CLOSURE:
+                    {
+                        // Saves current position to avoid zero-width repeats.
+                        final int id = op.getData();
+                        if (con.closureContexts[id].contains(offset)) {
+                            returned = true;
+                            break;
+                        }
+                        
+                        con.closureContexts[id].addOffset(offset);
+                    }
+                    // fall through
+
+                case Op.QUESTION:
+                    {
+                        opStack.push(op);
+                        dataStack.push(offset);
+                        op = op.getChild();
+                    }
+                    break;
+
+                case Op.NONGREEDYCLOSURE:
+                case Op.NONGREEDYQUESTION:
+                    {
+                        opStack.push(op);
+                        dataStack.push(offset);
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.UNION:
+                    if (op.size() == 0) {
+                        returned = true;
+                    }
+                    else {
+                        opStack.push(op);
+                        dataStack.push(0);
+                        dataStack.push(offset);
+                        op = op.elementAt(0);
+                    }
+                    break;
+
+                case Op.CAPTURE:
+                    {
+                        final int refno = op.getData();
+                        if (con.match != null) {
+                            if (refno > 0) {
+                                dataStack.push(con.match.getBeginning(refno));
+                                con.match.setBeginning(refno, offset);
+                            }
+                            else {
+                                final int index = -refno;
+                                dataStack.push(con.match.getEnd(index));
+                                con.match.setEnd(index, offset);
+                            }
+                            opStack.push(op);
+                            dataStack.push(offset);
+                        }
+                        op = op.next;
+                    }
+                    break;
+
+                case Op.LOOKAHEAD:
+                case Op.NEGATIVELOOKAHEAD:
+                case Op.LOOKBEHIND:
+                case Op.NEGATIVELOOKBEHIND:
+                    {
+                        opStack.push(op);
+                        dataStack.push(dx);
+                        dataStack.push(offset);
+                        dx = (op.type == Op.LOOKAHEAD || op.type == Op.NEGATIVELOOKAHEAD) ? 1 : -1;
+                        op = op.getChild();
+                    }
+                    break;
+
+                case Op.INDEPENDENT:
+                    {
+                        opStack.push(op);
+                        dataStack.push(offset);
+                        op = op.getChild();
+                    }
+                    break;
+
+                case Op.MODIFIER:
+                    {
+                        int localopts = opts;
+                        localopts |= op.getData();
+                        localopts &= ~op.getData2();
+                        opStack.push(op);
+                        dataStack.push(opts);
+                        dataStack.push(offset);
+                        opts = localopts;
+                        op = op.getChild();
+                    }
+                    break;
+
+                case Op.CONDITION:
+                    {
+                        Op.ConditionOp cop = (Op.ConditionOp)op;
+                        if (cop.refNumber > 0) {
+                            if (cop.refNumber >= this.nofparen) {
+                                throw new RuntimeException("Internal Error: Reference number must be more than zero: "+cop.refNumber);
+                            }
+                            if (con.match.getBeginning(cop.refNumber) >= 0
+                                    && con.match.getEnd(cop.refNumber) >= 0) {
+                                op = cop.yes;
+                            }
+                            else if (cop.no != null) {
+                                op = cop.no;
+                            }
+                            else {
+                                op = cop.next;
+                            }
+                        }
+                        else {
+                            opStack.push(op);
+                            dataStack.push(offset);
+                            op = cop.condition;
+                        }
+                    }
+                    break;
+
+                default:
+                    throw new RuntimeException("Unknown operation type: " + op.type);
+                }
+            }
+
+            // handle recursive operations
+            while (returned) {
+                // exhausted all the operations
+                if (opStack.isEmpty()) {
+                    return retValue;
+                }
+
+                op = (Op) opStack.pop();
+                offset = dataStack.pop();
+
+                switch (op.type) {
+                case Op.CLOSURE:
+                case Op.QUESTION:
+                    if (retValue < 0) {
+                        op = op.next;
+                        returned = false;
+                    }
+                    break;
+
+                case Op.NONGREEDYCLOSURE:
+                case Op.NONGREEDYQUESTION:
+                    if (retValue < 0) {
+                        op = op.getChild();
+                        returned = false;
+                    }
+                    break;
+
+                case Op.UNION:
+                    {
+                        int unionIndex = dataStack.pop();
+                        if (DEBUG) {
+                            System.err.println("UNION: "+unionIndex+", ret="+retValue);
+                        }
+
+                        if (retValue < 0) {
+                            if (++unionIndex < op.size()) {
+                                opStack.push(op);
+                                dataStack.push(unionIndex);
+                                dataStack.push(offset);
+                                op = op.elementAt(unionIndex);
+                                returned = false;
+                            }
+                            else {
+                                retValue = -1;
+                            }
+                        }
+                    }
+                    break;
+
+                case Op.CAPTURE:
+                    final int refno = op.getData();
+                    final int saved = dataStack.pop();
+                    if (retValue < 0) {
+                        if (refno > 0) {
+                            con.match.setBeginning(refno, saved);
+                        }
+                        else {
+                            con.match.setEnd(-refno, saved);
+                        }
+                    }
+                    break;
+                    
+                case Op.LOOKAHEAD:
+                case Op.LOOKBEHIND:
+                    {
+                        dx = dataStack.pop();
+                        if (0 <= retValue) {
+                            op = op.next;
+                            returned = false;
+                        }
+                        retValue = -1;
+                    }
+                    break;
+
+                case Op.NEGATIVELOOKAHEAD:
+                case Op.NEGATIVELOOKBEHIND:
+                    {
+                        dx = dataStack.pop();
+                        if (0 > retValue)  {
+                            op = op.next;
+                            returned = false;
+                        }
+                        retValue = -1;
+                    }
+                    break;
+
+                case Op.MODIFIER:
+                    opts = dataStack.pop();
+                    // fall through
+
+                case Op.INDEPENDENT:
+                    if (retValue >= 0)  {
+                        offset = retValue;
+                        op = op.next;
+                        returned = false;
+                    }
+                    break;
+
+                case Op.CONDITION:
+                    {
+                        final Op.ConditionOp cop = (Op.ConditionOp)op;
+                        if (0 <= retValue) {
+                            op = cop.yes;
+                        }
+                        else if (cop.no != null) {
+                            op = cop.no;
+                        }
+                        else {
+                            op = cop.next;
+                        }
+                    }
+                    returned = false;
+                    break;
+
+                default:
+                    break;
+                }
+            }
+        }
+    }
+
+    private boolean matchChar(int ch, int other, boolean ignoreCase) {
+        return (ignoreCase) ? matchIgnoreCase(ch, other) : ch == other;
+    }
+
+    boolean matchAnchor(ExpressionTarget target, Op op, Context con, int offset, int opts) {
+        boolean go = false;
+        switch (op.getData()) {
+        case '^':
+            if (isSet(opts, MULTIPLE_LINES)) {
+                if (!(offset == con.start
+                      || offset > con.start && offset < con.limit && isEOLChar(target.charAt(offset-1))))
+                    return false;
+            } else {
+                if (offset != con.start)
+                    return false;
+            }
+            break;
+
+        case '@':                         // Internal use only.
+            // The @ always matches line beginnings.
+            if (!(offset == con.start
+                  || offset > con.start && isEOLChar(target.charAt(offset-1))))
+                return false;
+            break;
+
+        case '$':
+            if (isSet(opts, MULTIPLE_LINES)) {
+                if (!(offset == con.limit
+                      || offset < con.limit && isEOLChar(target.charAt(offset))))
+                    return false;
+            } else {
+                if (!(offset == con.limit
+                      || offset+1 == con.limit && isEOLChar(target.charAt(offset))
+                      || offset+2 == con.limit &&  target.charAt(offset) == CARRIAGE_RETURN
+                      &&  target.charAt(offset+1) == LINE_FEED))
+                    return false;
+            }
+            break;
+
+        case 'A':
+            if (offset != con.start)  return false;
+            break;
+
+        case 'Z':
+            if (!(offset == con.limit
+                  || offset+1 == con.limit && isEOLChar(target.charAt(offset))
+                  || offset+2 == con.limit &&  target.charAt(offset) == CARRIAGE_RETURN
+                  &&  target.charAt(offset+1) == LINE_FEED))
+                return false;
+            break;
+
+        case 'z':
+            if (offset != con.limit)  return false;
+            break;
+
+        case 'b':
+            if (con.length == 0) 
+                return false;
+            {
+                int after = getWordType(target, con.start, con.limit, offset, opts);
+                if (after == WT_IGNORE)  return false;
+                int before = getPreviousWordType(target, con.start, con.limit, offset, opts);
+                if (after == before)  return false;
+            }
+            break;
+
+        case 'B':
+            if (con.length == 0)
+                go = true;
+            else {
+                int after = getWordType(target, con.start, con.limit, offset, opts);
+                go = after == WT_IGNORE
+                     || after == getPreviousWordType(target, con.start, con.limit, offset, opts);
+            }
+            if (!go)  return false;
+            break;
+
+        case '<':
+            if (con.length == 0 || offset == con.limit)  return false;
+            if (getWordType(target, con.start, con.limit, offset, opts) != WT_LETTER
+                || getPreviousWordType(target, con.start, con.limit, offset, opts) != WT_OTHER)
+                return false;
+            break;
+
+        case '>':
+            if (con.length == 0 || offset == con.start)  return false;
+            if (getWordType(target, con.start, con.limit, offset, opts) != WT_OTHER
+                || getPreviousWordType(target, con.start, con.limit, offset, opts) != WT_LETTER)
+                return false;
+            break;
+        } // switch anchor type
+        
+        return true;
+    }
+
+    private static final int getPreviousWordType(ExpressionTarget target, int begin, int end,
+                                                 int offset, int opts) {
+        int ret = getWordType(target, begin, end, --offset, opts);
+        while (ret == WT_IGNORE)
+            ret = getWordType(target, begin, end, --offset, opts);
+        return ret;
+    }
+
+    private static final int getWordType(ExpressionTarget target, int begin, int end,
+                                         int offset, int opts) {
+        if (offset < begin || offset >= end)  return WT_OTHER;
+        return getWordType0(target.charAt(offset) , opts);
+    }
+
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @return true if the target is matched to this regular expression.
+     */
+    public boolean matches(CharacterIterator target) {
+        return this.matches(target, (Match)null);
+    }
+
+
+    /**
+     * Checks whether the <var>target</var> text <strong>contains</strong> this pattern or not.
+     *
+     * @param match A Match instance for storing matching result.
+     * @return Offset of the start position in <VAR>target</VAR>; or -1 if not match.
+     */
+    public boolean matches(CharacterIterator  target, Match match) {
+        int start = target.getBeginIndex();
+        int end = target.getEndIndex();
+
+
+
+        synchronized (this) {
+            if (this.operations == null)
+                this.prepare();
+            if (this.context == null)
+                this.context = new Context();
+        }
+        Context con = null;
+        synchronized (this.context) {
+            con = this.context.inuse ? new Context() : this.context;
+            con.reset(target, start, end, this.numberOfClosures);
+        }
+        if (match != null) {
+            match.setNumberOfGroups(this.nofparen);
+            match.setSource(target);
+        } else if (this.hasBackReferences) {
+            match = new Match();
+            match.setNumberOfGroups(this.nofparen);
+            // Need not to call setSource() because
+            // a caller can not access this match instance.
+        }
+        con.match = match;
+
+        if (RegularExpression.isSet(this.options, XMLSCHEMA_MODE)) {
+            int matchEnd = this.match(con, this.operations, con.start, 1, this.options);
+            //System.err.println("DEBUG: matchEnd="+matchEnd);
+            if (matchEnd == con.limit) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, con.start);
+                    con.match.setEnd(0, matchEnd);
+                }
+                con.setInUse(false);
+                return true;
+            }
+            return false;
+        }
+
+        /*
+         * The pattern has only fixed string.
+         * The engine uses Boyer-Moore.
+         */
+        if (this.fixedStringOnly) {
+            //System.err.println("DEBUG: fixed-only: "+this.fixedString);
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o >= 0) {
+                if (con.match != null) {
+                    con.match.setBeginning(0, o);
+                    con.match.setEnd(0, o+this.fixedString.length());
+                }
+                con.setInUse(false);
+                return true;
+            }
+            con.setInUse(false);
+            return false;
+        }
+
+        /*
+         * The pattern contains a fixed string.
+         * The engine checks with Boyer-Moore whether the text contains the fixed string or not.
+         * If not, it return with false.
+         */
+        if (this.fixedString != null) {
+            int o = this.fixedStringTable.matches(target, con.start, con.limit);
+            if (o < 0) {
+                //System.err.println("Non-match in fixed-string search.");
+                con.setInUse(false);
+                return false;
+            }
+        }
+
+        int limit = con.limit-this.minlength;
+        int matchStart;
+        int matchEnd = -1;
+
+        /*
+         * Checks whether the expression starts with ".*".
+         */
+        if (this.operations != null
+            && this.operations.type == Op.CLOSURE && this.operations.getChild().type == Op.DOT) {
+            if (isSet(this.options, SINGLE_LINE)) {
+                matchStart = con.start;
+                matchEnd = this.match(con, this.operations, con.start, 1, this.options);
+            } else {
+                boolean previousIsEOL = true;
+                for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                    int ch =  target .setIndex(  matchStart ) ;
+                    if (isEOLChar(ch)) {
+                        previousIsEOL = true;
+                    } else {
+                        if (previousIsEOL) {
+                            if (0 <= (matchEnd = this.match(con, this.operations,
+                                                            matchStart, 1, this.options)))
+                                break;
+                        }
+                        previousIsEOL = false;
+                    }
+                }
+            }
+        }
+
+        /*
+         * Optimization against the first character.
+         */
+        else if (this.firstChar != null) {
+            //System.err.println("DEBUG: with firstchar-matching: "+this.firstChar);
+            RangeToken range = this.firstChar;
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                int ch =  target .setIndex(  matchStart ) ;
+                if (REUtil.isHighSurrogate(ch) && matchStart+1 < con.limit) {
+                    ch = REUtil.composeFromSurrogates(ch, target.setIndex(matchStart+1));
+                }
+                if (!range.match(ch)) {
+                    continue;
+                }
+                if (0 <= (matchEnd = this.match(con, this.operations,
+                                                matchStart, 1, this.options))) {
+                    break;
+                }
+            }
+        }
+
+        /*
+         * Straightforward matching.
+         */
+        else {
+            for (matchStart = con.start;  matchStart <= limit;  matchStart ++) {
+                if (0 <= (matchEnd = this. match(con, this.operations, matchStart, 1, this.options)))
+                    break;
+            }
+        }
+
+        if (matchEnd >= 0) {
+            if (con.match != null) {
+                con.match.setBeginning(0, matchStart);
+                con.match.setEnd(0, matchEnd);
+            }
+            con.setInUse(false);
+            return true;
+        } else {
+            con.setInUse(false);
+            return false;
+        }
+    }
+
+    // ================================================================
+
+    /**
+     * A regular expression.
+     * @serial
+     */
+    String regex;
+    /**
+     * @serial
+     */
+    int options;
+
+    /**
+     * The number of parenthesis in the regular expression.
+     * @serial
+     */
+    int nofparen;
+    /**
+     * Internal representation of the regular expression.
+     * @serial
+     */
+    Token tokentree;
+
+    boolean hasBackReferences = false;
+
+    transient int minlength;
+    transient Op operations = null;
+    transient int numberOfClosures;
+    transient Context context = null;
+    transient RangeToken firstChar = null;
+
+    transient String fixedString = null;
+    transient int fixedStringOptions;
+    transient BMPattern fixedStringTable = null;
+    transient boolean fixedStringOnly = false;
+
+    static abstract class ExpressionTarget {
+        abstract char charAt(int index);
+        abstract boolean regionMatches(boolean ignoreCase, int offset, int limit, String part, int partlen);
+        abstract boolean regionMatches(boolean ignoreCase, int offset, int limit, int offset2, int partlen);
+    }
+    
+    static final class StringTarget extends ExpressionTarget {
+        
+        private String target;
+        
+        StringTarget(String target) {
+            this.target = target;
+        }
+        
+        final void resetTarget(String target) {
+            this.target = target;
+        }
+        
+        @Override
+        final char charAt(int index) {
+            return target.charAt(index);
+        }
+        
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit,
+                              String part, int partlen) {
+            if (limit-offset < partlen) {
+                return false;
+            }
+            return (ignoreCase) ? target.regionMatches(true, offset, part, 0, partlen) : target.regionMatches(offset, part, 0, partlen);
+        }
+
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit,
+                                    int offset2, int partlen) {
+            if (limit-offset < partlen) {
+                return false;
+            }
+            return (ignoreCase) ? target.regionMatches(true, offset, target, offset2, partlen)
+                                : target.regionMatches(offset, target, offset2, partlen);
+        }
+    }
+    
+    static final class CharArrayTarget extends ExpressionTarget {
+        
+        char[] target;
+        
+        CharArrayTarget(char[] target) {
+            this.target = target; 
+        }
+
+        final void resetTarget(char[] target) {
+            this.target = target;
+        }
+
+        @Override
+        char charAt(int index) {
+            return target[index];
+        }
+        
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit,
+                String part, int partlen) {
+            if (offset < 0 || limit-offset < partlen)  {
+                return false;
+            }
+            return (ignoreCase) ? regionMatchesIgnoreCase(offset, limit, part, partlen)
+                                : regionMatches(offset, limit, part, partlen);
+        }
+
+        private final boolean regionMatches(int offset, int limit, String part, int partlen) {
+            int i = 0;
+            while (partlen-- > 0) {
+                if (target[offset++] != part.charAt(i++)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        private final boolean regionMatchesIgnoreCase(int offset, int limit, String part, int partlen) {
+            int i = 0;
+            while (partlen-- > 0) {
+                final char ch1 = target[offset++] ;
+                final char ch2 = part.charAt(i++);
+                if (ch1 == ch2) {
+                    continue;
+                }
+                final char uch1 = Character.toUpperCase(ch1);
+                final char uch2 = Character.toUpperCase(ch2);
+                if (uch1 == uch2) {
+                    continue;
+                }
+                if (Character.toLowerCase(uch1) != Character.toLowerCase(uch2)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit, int offset2, int partlen) {
+            if (offset < 0 || limit-offset < partlen) {
+                return false;
+            }
+            return (ignoreCase) ? regionMatchesIgnoreCase(offset, limit, offset2, partlen)
+                                : regionMatches(offset, limit, offset2, partlen);
+        }
+
+        private final boolean regionMatches(int offset, int limit, int offset2, int partlen) {
+            int i = offset2;
+            while (partlen-- > 0) {
+                if ( target [  offset++ ]  !=  target [  i++ ] )
+                    return false;
+            }
+            return true;
+        }
+
+        private final boolean regionMatchesIgnoreCase(int offset, int limit, int offset2, int partlen) {
+            int i = offset2;
+            while (partlen-- > 0) {
+                final char ch1 =  target[offset++] ;
+                final char ch2 =  target[i++] ;
+                if (ch1 == ch2) {
+                    continue;
+                }
+                final char uch1 = Character.toUpperCase(ch1);
+                final char uch2 = Character.toUpperCase(ch2);
+                if (uch1 == uch2) {
+                    continue;
+                }
+                if (Character.toLowerCase(uch1) != Character.toLowerCase(uch2)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+
+    static final class CharacterIteratorTarget extends ExpressionTarget {
+        CharacterIterator target;
+        
+        CharacterIteratorTarget(CharacterIterator target) {
+            this.target = target; 
+        }
+
+        final void resetTarget(CharacterIterator target) {
+            this.target = target;
+        }
+
+        @Override
+        final char charAt(int index) {
+            return target.setIndex(index);
+        }
+
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit,
+                String part, int partlen) {
+            if (offset < 0 || limit-offset < partlen)  {
+                return false;
+            }
+            return (ignoreCase) ? regionMatchesIgnoreCase(offset, limit, part, partlen)
+                                : regionMatches(offset, limit, part, partlen);
+        }
+        
+        private final boolean regionMatches(int offset, int limit, String part, int partlen) {
+            int i = 0;
+            while (partlen-- > 0) {
+                if (target.setIndex(offset++) != part.charAt(i++)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+        
+        private final boolean regionMatchesIgnoreCase(int offset, int limit, String part, int partlen) {
+            int i = 0;
+            while (partlen-- > 0) {
+                final char ch1 = target.setIndex(offset++) ;
+                final char ch2 = part.charAt(i++);
+                if (ch1 == ch2) {
+                    continue;
+                }
+                final char uch1 = Character.toUpperCase(ch1);
+                final char uch2 = Character.toUpperCase(ch2);
+                if (uch1 == uch2) {
+                    continue;
+                }
+                if (Character.toLowerCase(uch1) != Character.toLowerCase(uch2)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        @Override
+        final boolean regionMatches(boolean ignoreCase, int offset, int limit, int offset2, int partlen) {
+            if (offset < 0 || limit-offset < partlen) {
+                return false;
+            }
+            return (ignoreCase) ? regionMatchesIgnoreCase(offset, limit, offset2, partlen)
+                                : regionMatches(offset, limit, offset2, partlen);
+        }
+
+        private final boolean regionMatches(int offset, int limit, int offset2, int partlen) {
+            int i = offset2;
+            while (partlen-- > 0) {
+                if (target.setIndex(offset++) != target.setIndex(i++)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        private final boolean regionMatchesIgnoreCase(int offset, int limit, int offset2, int partlen) {
+            int i = offset2;
+            while (partlen-- > 0) {
+                final char ch1 = target.setIndex(offset++) ;
+                final char ch2 = target.setIndex(i++) ;
+                if (ch1 == ch2) {
+                    continue;
+                }
+                final char uch1 = Character.toUpperCase(ch1);
+                final char uch2 = Character.toUpperCase(ch2);
+                if (uch1 == uch2) {
+                    continue;
+                }
+                if (Character.toLowerCase(uch1) != Character.toLowerCase(uch2)) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+
+    static final class ClosureContext {
+        
+        int[] offsets = new int[4];
+        int currentIndex = 0;
+        
+        boolean contains(int offset) {
+            for (int i=0; i<currentIndex;++i) {
+                if (offsets[i] == offset) {
+                    return true;
+                }
+            }
+            return false;
+        }
+        
+        void reset() {
+            currentIndex = 0;
+        }
+
+        void addOffset(int offset) {
+            // We do not check for duplicates, caller is responsible for that
+            if (currentIndex == offsets.length) {
+                offsets = expandOffsets();
+            }
+            offsets[currentIndex++] = offset;
+        }
+        
+        private int[] expandOffsets() {
+            final int len = offsets.length;
+            final int newLen = len << 1;
+            int[] newOffsets = new int[newLen];
+            
+            System.arraycopy(offsets, 0, newOffsets, 0, currentIndex);
+            return newOffsets;
+        }
+    }
+    
+    static final class Context {
+        int start;
+        int limit;
+        int length;
+        Match match;
+        boolean inuse = false;
+        ClosureContext[] closureContexts;
+        
+        private StringTarget stringTarget; 
+        private CharArrayTarget charArrayTarget;
+        private CharacterIteratorTarget characterIteratorTarget;
+
+        ExpressionTarget target;
+
+        Context() {
+        }
+
+        private void resetCommon(int nofclosures) {
+            this.length = this.limit-this.start;
+            setInUse(true);
+            this.match = null;
+            if (this.closureContexts == null || this.closureContexts.length != nofclosures) {
+                this.closureContexts = new ClosureContext[nofclosures];
+            }
+            for (int i = 0;  i < nofclosures;  i ++)  {
+                if (this.closureContexts[i] == null) {
+                    this.closureContexts[i] = new ClosureContext();
+                }
+                else {
+                    this.closureContexts[i].reset();
+                }
+            }
+        }
+
+        void reset(CharacterIterator target, int start, int limit, int nofclosures) {
+            if (characterIteratorTarget == null) {
+                characterIteratorTarget = new CharacterIteratorTarget(target);
+            }
+            else {
+                characterIteratorTarget.resetTarget(target);
+            }
+            this.target = characterIteratorTarget;
+            this.start = start;
+            this.limit = limit;
+            this.resetCommon(nofclosures);
+        }
+
+        void reset(String target, int start, int limit, int nofclosures) {
+            if (stringTarget == null) {
+                stringTarget = new StringTarget(target);
+            }
+            else {
+                stringTarget.resetTarget(target);
+            }
+            this.target = stringTarget;
+            this.start = start;
+            this.limit = limit;
+            this.resetCommon(nofclosures);
+        }
+
+        void reset(char[] target, int start, int limit, int nofclosures) {
+            if (charArrayTarget == null) {
+                charArrayTarget = new CharArrayTarget(target);
+            }
+            else {
+                charArrayTarget.resetTarget(target);
+            }
+            this.target = charArrayTarget;
+            this.start = start;
+            this.limit = limit;
+            this.resetCommon(nofclosures);
+        }
+        synchronized void setInUse(boolean inUse) {
+            this.inuse = inUse;
+        }
+    }
+
+    /**
+     * Prepares for matching.  This method is called just before starting matching.
+     */
+    void prepare() {
+        if (Op.COUNT)  Op.nofinstances = 0;
+        this.compile(this.tokentree);
+        /*
+        if  (this.operations.type == Op.CLOSURE && this.operations.getChild().type == Op.DOT) { // .*
+            Op anchor = Op.createAnchor(isSet(this.options, SINGLE_LINE) ? 'A' : '@');
+            anchor.next = this.operations;
+            this.operations = anchor;
+        }
+        */
+        if (Op.COUNT)  System.err.println("DEBUG: The number of operations: "+Op.nofinstances);
+
+        this.minlength = this.tokentree.getMinLength();
+
+        this.firstChar = null;
+        if (!isSet(this.options, PROHIBIT_HEAD_CHARACTER_OPTIMIZATION)
+            && !isSet(this.options, XMLSCHEMA_MODE)) {
+            RangeToken firstChar = Token.createRange();
+            int fresult = this.tokentree.analyzeFirstCharacter(firstChar, this.options);
+            if (fresult == Token.FC_TERMINAL) {
+                firstChar.compactRanges();
+                this.firstChar = firstChar;
+                if (DEBUG)
+                    System.err.println("DEBUG: Use the first character optimization: "+firstChar);
+            }
+        }
+
+        if (this.operations != null
+            && (this.operations.type == Op.STRING || this.operations.type == Op.CHAR)
+            && this.operations.next == null) {
+            if (DEBUG)
+                System.err.print(" *** Only fixed string! *** ");
+            this.fixedStringOnly = true;
+            if (this.operations.type == Op.STRING)
+                this.fixedString = this.operations.getString();
+            else if (this.operations.getData() >= 0x10000) { // Op.CHAR
+                this.fixedString = REUtil.decomposeToSurrogates(this.operations.getData());
+            } else {
+                char[] ac = new char[1];
+                ac[0] = (char)this.operations.getData();
+                this.fixedString = new String(ac);
+            }
+            this.fixedStringOptions = this.options;
+            this.fixedStringTable = new BMPattern(this.fixedString, 256,
+                                                  isSet(this.fixedStringOptions, IGNORE_CASE));
+        } else if (!isSet(this.options, PROHIBIT_FIXED_STRING_OPTIMIZATION)
+                   && !isSet(this.options, XMLSCHEMA_MODE)) {
+            Token.FixedStringContainer container = new Token.FixedStringContainer();
+            this.tokentree.findFixedString(container, this.options);
+            this.fixedString = container.token == null ? null : container.token.getString();
+            this.fixedStringOptions = container.options;
+            if (this.fixedString != null && this.fixedString.length() < 2)
+                this.fixedString = null;
+            // This pattern has a fixed string of which length is more than one.
+            if (this.fixedString != null) {
+                this.fixedStringTable = new BMPattern(this.fixedString, 256,
+                                                      isSet(this.fixedStringOptions, IGNORE_CASE));
+                if (DEBUG) {
+                    System.err.println("DEBUG: The longest fixed string: "+this.fixedString.length()
+                                       +"/" //+this.fixedString
+                                       +"/"+REUtil.createOptionString(this.fixedStringOptions));
+                    System.err.print("String: ");
+                    REUtil.dumpString(this.fixedString);
+                }
+            }
+        }
+    }
+
+    /**
+     * An option.
+     * If you specify this option, <span class="REGEX"><kbd>(</kbd><var>X</var><kbd>)</kbd></span>
+     * captures matched text, and <span class="REGEX"><kbd>(:?</kbd><var>X</var><kbd>)</kbd></span>
+     * does not capture.
+     *
+     * @see #RegularExpression(java.

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