/**
 * Copyright (c) 2017 Eclipse contributors and others.
 * All rights reserved.   This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v20.html
 *
 * Contributors:
 *   See notice below.
 *
 * ---------------------------------------------------------------------
 *
 * 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.
 *
 * ---------------------------------------------------------------------
 *
 *  =========================================================================
 * ==  NOTICE file corresponding to section 4(d) of the Apache License,   ==
 * ==  Version 2.0, in this case for the Apache Xerces Java distribution. ==
 * =========================================================================
 *
 * Apache Xerces Java
 * Copyright 1999-2010 The Apache Software Foundation
 *
 * This product includes software developed at
 * The Apache Software Foundation (http://www.apache.org/).
 *
 * Portions of this software were originally based on the following:
 *   - software copyright (c) 1999, IBM Corporation., http://www.ibm.com.
 *   - software copyright (c) 1999, Sun Microsystems., http://www.sun.com.
 *   - voluntary contributions made by Paul Eng on behalf of the 
 *     Apache Software Foundation that were originally developed at iClick, Inc.,
 *     software copyright (c) 1999.
 */
package org.eclipse.emf.ecore.xml.type.internal;


import java.text.CharacterIterator;
import java.util.Hashtable;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.Stack;
import java.util.Vector;

import org.eclipse.emf.ecore.plugin.EcorePlugin;

/**
 * NOTE: this class is for internal use only.
 */
@SuppressWarnings("all")
public final class RegEx
{

/**
 * A simple integer based stack.
 *
 * moved to org.apache.xerces.util by neilg to support the
 * XPathMatcher.
 * @author  Andy Clark, IBM
 *
 * @version $Id: IntStack.java 447241 2006-09-18 05:12:57Z mrglavas $
 */
final static class IntStack {

    //
    // Data
    //

    /** Stack depth. */
    private int fDepth;

    /** Stack data. */
    private int[] fData;

    //
    // Public methods
    //

    /** Returns the size of the stack. */
    public int size() {
        return fDepth;
    }

    /** Pushes a value onto the stack. */
    public void push(int value) {
        ensureCapacity(fDepth + 1);
        fData[fDepth++] = value;
    }

    /** Peeks at the top of the stack. */
    public int peek() {
        return fData[fDepth - 1];
    }

    /** Returns the element at the specified depth in the stack. */
    public int elementAt(int depth) {
        return fData[depth];
    }

    /** Pops a value off of the stack. */
    public int pop() {
        return fData[--fDepth];
    }

    /** Clears the stack. */
    public void clear() {
        fDepth = 0;
    }

    // debugging

    /** Prints the stack. */
    public void print() {
        System.out.print('(');
        System.out.print(fDepth);
        System.out.print(") {");
        for (int i = 0; i < fDepth; i++) {
            if (i == 3) {
                System.out.print(" ...");
                break;
            }
            System.out.print(' ');
            System.out.print(fData[i]);
            if (i < fDepth - 1) {
                System.out.print(',');
            }
        }
        System.out.print(" }");
        System.out.println();
    }

    //
    // Private methods
    //

    /** Ensures capacity. */
    private void ensureCapacity(int size) {
        if (fData == null) {
            fData = new int[32];
        }
        else if (fData.length <= size) {
            int[] newdata = new int[fData.length * 2];
            System.arraycopy(fData, 0, newdata, 0, fData.length);
            fData = newdata;
        }
    }

} // class IntStack



/**
 * Boyer-Moore searcher.
 * 
 * @xerces.internal
 *
 * @version $Id: BMPattern.java 572108 2007-09-02 18:48:31Z mrglavas $
 */
static class BMPattern {
    final char[] pattern;
    final int[] shiftTable;
    final boolean ignoreCase;

    public BMPattern(String pat, boolean ignoreCase) {
        this(pat, 256, ignoreCase);
    }

    public BMPattern(String pat, int tableSize, boolean ignoreCase) {
        this.pattern = pat.toCharArray();
        this.shiftTable = new int[tableSize];
        this.ignoreCase = ignoreCase;

        int length = pattern.length;
        for (int i = 0;  i < this.shiftTable.length;  i ++)
            this.shiftTable[i] = length;

        for (int i = 0;  i < length;  i ++) {
            char ch = this.pattern[i];
            int diff = length-i-1;
            int index = ch % this.shiftTable.length;
            if (diff < this.shiftTable[index])
                this.shiftTable[index] = diff;
            if (this.ignoreCase) {
                ch = Character.toUpperCase(ch);
                index = ch % this.shiftTable.length;
                if (diff < this.shiftTable[index])
                    this.shiftTable[index] = diff;
                ch = Character.toLowerCase(ch);
                index = ch % this.shiftTable.length;
                if (diff < this.shiftTable[index])
                    this.shiftTable[index] = diff;
            }
        }
    }

    /**
     *
     * @return -1 if <var>iterator</var> does not contain this pattern.
     */
    public int matches(CharacterIterator iterator, int start, int limit) {
        if (this.ignoreCase)  return this.matchesIgnoreCase(iterator, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = iterator.setIndex(--index)) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }

    /**
     *
     * @return -1 if <var>str</var> does not contain this pattern.
     */
    public int matches(String str, int start, int limit) {
        if (this.ignoreCase)  return this.matchesIgnoreCase(str, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            //System.err.println("Starts at "+index);
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = str.charAt(--index)) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }
    /**
     *
     * @return -1 if <var>chars</char> does not contain this pattern.
     */
    public int matches(char[] chars, int start, int limit) {
        if (this.ignoreCase)  return this.matchesIgnoreCase(chars, start, limit);
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            //System.err.println("Starts at "+index);
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                if ((ch = chars[--index]) != this.pattern[--pindex])
                    break;
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }

    int matchesIgnoreCase(CharacterIterator iterator, int start, int limit) {
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = iterator.setIndex(--index);
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }
    
    int matchesIgnoreCase(String text, int start, int limit) {
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = text.charAt(--index);
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }
    int matchesIgnoreCase(char[] chars, int start, int limit) {
        int plength = this.pattern.length;
        if (plength == 0)  return start;
        int index = start+plength;
        while (index <= limit) {
            int pindex = plength;
            int nindex = index+1;
            char ch;
            do {
                char ch1 = ch = chars[--index];
                char ch2 = this.pattern[--pindex];
                if (ch1 != ch2) {
                    ch1 = Character.toUpperCase(ch1);
                    ch2 = Character.toUpperCase(ch2);
                    if (ch1 != ch2 && Character.toLowerCase(ch1) != Character.toLowerCase(ch2))
                        break;
                }
                if (pindex == 0)
                    return index;
            } while (pindex > 0);
            index += this.shiftTable[ch % this.shiftTable.length]+1;
            if (index < nindex)  index = nindex;
        }
        return -1;
    }

    /*
    public static void main(String[] argv) {
        try {
            int[] shiftTable = new int[256];
            initializeBoyerMoore(argv[0], shiftTable, true);
            int o = -1;
            CharacterIterator ite = new java.text.StringCharacterIterator(argv[1]);
            long start = System.currentTimeMillis();
            //for (int i = 0;  i < 10000;  i ++)
                o = searchIgnoreCasesWithBoyerMoore(ite, 0, argv[0], shiftTable);
            start = System.currentTimeMillis()-start;
            System.out.println("Result: "+o+", Elapsed: "+start);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }*/
}


/**
 * @xerces.internal
 * 
 * @version $Id: CaseInsensitiveMap.java 834653 2009-11-10 20:32:39Z mrglavas $
 */
final static class CaseInsensitiveMap {

    private static int CHUNK_SHIFT = 10;           /* 2^10 = 1k */
    private static int CHUNK_SIZE = (1<<CHUNK_SHIFT);
    private static int CHUNK_MASK = (CHUNK_SIZE-1);
    private static int INITIAL_CHUNK_COUNT = 64;   /* up to 0xFFFF */

    private static int[][][] caseInsensitiveMap;
    
    private static int LOWER_CASE_MATCH = 1;
    private static int UPPER_CASE_MATCH = 2;
    
    static {
        buildCaseInsensitiveMap();
    }

    /**
     *  Return a list of code point characters (not including the input value)
     *  that can be substituted in a case insensitive match
     */
    static public int[] get(int codePoint) {
        return (codePoint < 0x10000) ? getMapping(codePoint) : null;
    }

    private static int[] getMapping(int codePoint) {
        int chunk = codePoint >>> CHUNK_SHIFT;
        int offset = codePoint & CHUNK_MASK;
        
        return caseInsensitiveMap[chunk][offset];
    }
    
    private static void buildCaseInsensitiveMap() {
        caseInsensitiveMap = new int[INITIAL_CHUNK_COUNT][CHUNK_SIZE][];
        int lc, uc;
        for (int i=0; i<0x10000; i++) {
            lc = Character.toLowerCase((char) i);
            uc = Character.toUpperCase((char) i);

            // lower/upper case value is not the same as code point
            if (lc != uc || lc != i) {
                int[] map = new int[2];
                int index = 0;

                if (lc != i) {
                    map[index++] = lc;
                    map[index++] = LOWER_CASE_MATCH;
                    int[] lcMap = getMapping(lc);
                    if (lcMap != null) {
                        map = updateMap(i, map, lc, lcMap, LOWER_CASE_MATCH);
                    }
                }
                
                if (uc != i) {
                    if (index == map.length) {
                        map = expandMap(map, 2);
                    }
                    map[index++] = uc;
                    map[index++] = UPPER_CASE_MATCH;
                    int[] ucMap = getMapping(uc);
                    if (ucMap != null) {
                        map = updateMap(i, map, uc, ucMap, UPPER_CASE_MATCH);
                    }
                }
                
                set(i, map);
            }
        }
    }
    
    private static int[] expandMap(int[] srcMap, int expandBy) {
        final int oldLen = srcMap.length;
        int[] newMap = new int[oldLen + expandBy];
        
        System.arraycopy(srcMap, 0, newMap, 0, oldLen);
        return newMap;
    }
    
    private static void set(int codePoint, int[] map) {
        int chunk = codePoint >>> CHUNK_SHIFT;
        int offset = codePoint & CHUNK_MASK;
        
        caseInsensitiveMap[chunk][offset] = map;
    }

    private static int[] updateMap(int codePoint, int[] codePointMap,
            int ciCodePoint, int[] ciCodePointMap, int matchType) {
        for (int i=0; i<ciCodePointMap.length; i+=2) {
            int c = ciCodePointMap[i];
            int[] cMap = getMapping(c);
            if (cMap != null) {
                if (contains(cMap, ciCodePoint, matchType)) {
                    if (!contains(cMap, codePoint)) {
                        cMap = expandAndAdd(cMap, codePoint, matchType);
                        set(c, cMap);
                    }
                    if (!contains(codePointMap, c)) {
                        codePointMap = expandAndAdd(codePointMap, c,matchType);
                    }
                }
            }
        }
        
        if (!contains(ciCodePointMap, codePoint)) {
            ciCodePointMap = expandAndAdd(ciCodePointMap, codePoint, matchType);
            set(ciCodePoint, ciCodePointMap);
        }

        return codePointMap;
    }
    
    private static boolean contains(int[] map, int codePoint) {
        for (int i=0; i<map.length; i += 2) {
            if (map[i] == codePoint) {
                return true;
            }
        }
        return false;
    }

    private static boolean contains(int[] map, int codePoint, int matchType) {
        for (int i=0; i<map.length; i += 2) {
            if (map[i] == codePoint && map[i+1] == matchType) {
                return true;
            }
        }
        return false;
    }
    
    private static int[] expandAndAdd(int[] srcMap, int codePoint, int matchType) {
        final int oldLen = srcMap.length;
        int[] newMap = new int[oldLen + 2];
        
        System.arraycopy(srcMap, 0, newMap, 0, oldLen);
        newMap[oldLen] = codePoint;
        newMap[oldLen+1] = matchType;
        return newMap;
    }
}


/**
 * An instance of this class has ranges captured in matching.
 * 
 * @xerces.internal
 *
 * @see RegularExpression#matches(char[], int, int, Match)
 * @see RegularExpression#matches(char[], Match)
 * @see RegularExpression#matches(java.text.CharacterIterator, Match)
 * @see RegularExpression#matches(java.lang.String, int, int, Match)
 * @see RegularExpression#matches(java.lang.String, Match)
 * @author TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;
 * @version $Id: Match.java 446721 2006-09-15 20:35:34Z mrglavas $
 */
static class Match implements Cloneable {
    int[] beginpos = null;
    int[] endpos = null;
    int nofgroups = 0;

    CharacterIterator ciSource = null;
    String strSource = null;
    char[] charSource = null;

    /**
     * Creates an instance.
     */
    public Match() {
    }

    /**
     *
     */
    public synchronized Object clone() {
        Match ma = new Match();
        if (this.nofgroups > 0) {
            ma.setNumberOfGroups(this.nofgroups);
            if (this.ciSource != null)  ma.setSource(this.ciSource);
            if (this.strSource != null)  ma.setSource(this.strSource);
            for (int i = 0;  i < this.nofgroups;  i ++) {
                ma.setBeginning(i, this.getBeginning(i));
                ma.setEnd(i, this.getEnd(i));
            }
        }
        return ma;
    }

    /**
     *
     */
    protected void setNumberOfGroups(int n) {
        int oldn = this.nofgroups;
        this.nofgroups = n;
        if (oldn <= 0
            || oldn < n || n*2 < oldn) {
            this.beginpos = new int[n];
            this.endpos = new int[n];
        }
        for (int i = 0;  i < n;  i ++) {
            this.beginpos[i] = -1;
            this.endpos[i] = -1;
        }
    }

    /**
     *
     */
    protected void setSource(CharacterIterator ci) {
        this.ciSource = ci;
        this.strSource = null;
        this.charSource = null;
    }
    /**
     *
     */
    protected void setSource(String str) {
        this.ciSource = null;
        this.strSource = str;
        this.charSource = null;
    }
    /**
     *
     */
    protected void setSource(char[] chars) {
        this.ciSource = null;
        this.strSource = null;
        this.charSource = chars;
    }

    /**
     *
     */
    protected void setBeginning(int index, int v) {
        this.beginpos[index] = v;
    }

    /**
     *
     */
    protected void setEnd(int index, int v) {
        this.endpos[index] = v;
    }

    /**
     * Return the number of regular expression groups.
     * This method returns 1 when the regular expression has no capturing-parenthesis.
     */
    public int getNumberOfGroups() {
        if (this.nofgroups <= 0)
            throw new IllegalStateException("A result is not set.");
        return this.nofgroups;
    }

    /**
     * Return a start position in the target text matched to specified regular expression group.
     *
     * @param index Less than <code>getNumberOfGroups()</code>.
     */
    public int getBeginning(int index) {
        if (this.beginpos == null)
            throw new IllegalStateException("A result is not set.");
        if (index < 0 || this.nofgroups <= index)
            throw new IllegalArgumentException("The parameter must be less than "
                                               +this.nofgroups+": "+index);
        return this.beginpos[index];
    }

    /**
     * Return an end position in the target text matched to specified regular expression group.
     *
     * @param index Less than <code>getNumberOfGroups()</code>.
     */
    public int getEnd(int index) {
        if (this.endpos == null)
            throw new IllegalStateException("A result is not set.");
        if (index < 0 || this.nofgroups <= index)
            throw new IllegalArgumentException("The parameter must be less than "
                                               +this.nofgroups+": "+index);
        return this.endpos[index];
    }

    /**
     * Return an substring of the target text matched to specified regular expression group.
     *
     * @param index Less than <code>getNumberOfGroups()</code>.
     */
    public String getCapturedText(int index) {
        if (this.beginpos == null)
            throw new IllegalStateException("match() has never been called.");
        if (index < 0 || this.nofgroups <= index)
            throw new IllegalArgumentException("The parameter must be less than "
                                               +this.nofgroups+": "+index);
        String ret;
        int begin = this.beginpos[index], end = this.endpos[index];
        if (begin < 0 || end < 0)  return null;
        if (this.ciSource != null) {
            ret = REUtil.substring(this.ciSource, begin, end);
        } else if (this.strSource != null) {
            ret = this.strSource.substring(begin, end);
        } else {
            ret = new String(this.charSource, begin, end-begin);
        }
        return ret;
    }
}


/**
 * @xerces.internal
 * 
 * @version $Id: Op.java 572108 2007-09-02 18:48:31Z mrglavas $
 */
static class Op {
    static final int DOT = 0;
    static final int CHAR = 1;                  // Single character
    static final int RANGE = 3;                 // [a-zA-Z]
    static final int NRANGE = 4;                // [^a-zA-Z]
    static final int ANCHOR = 5;                // ^ $ ...
    static final int STRING = 6;                // literal String 
    static final int CLOSURE = 7;               // X*
    static final int NONGREEDYCLOSURE = 8;      // X*?
    static final int QUESTION = 9;              // X?
    static final int NONGREEDYQUESTION = 10;    // X??
    static final int UNION = 11;                // X|Y
    static final int CAPTURE = 15;              // ( and )
    static final int BACKREFERENCE = 16;        // \1 \2 ...
    static final int LOOKAHEAD = 20;            // (?=...)
    static final int NEGATIVELOOKAHEAD = 21;    // (?!...)
    static final int LOOKBEHIND = 22;           // (?<=...)
    static final int NEGATIVELOOKBEHIND = 23;   // (?<!...)
    static final int INDEPENDENT = 24;          // (?>...)
    static final int MODIFIER = 25;             // (?ims-ims:...)
    static final int CONDITION = 26;            // (?(..)yes|no)

    static int nofinstances = 0;
    static final boolean COUNT = false;

    static Op createDot() {
        if (Op.COUNT)  Op.nofinstances ++;
        return new Op(Op.DOT);
    }
    static CharOp createChar(int data) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.CHAR, data);
    }
    static CharOp createAnchor(int data) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.ANCHOR, data);
    }
    static CharOp createCapture(int number, Op next) {
        if (Op.COUNT)  Op.nofinstances ++;
        CharOp op = new CharOp(Op.CAPTURE, number);
        op.next = next;
        return op;
    }
    static UnionOp createUnion(int size) {
        if (Op.COUNT)  Op.nofinstances ++;
        //System.err.println("Creates UnionOp");
        return new UnionOp(Op.UNION, size);
    }
    static ChildOp createClosure(int id) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new ModifierOp(Op.CLOSURE, id, -1);
    }
    static ChildOp createNonGreedyClosure() {
        if (Op.COUNT)  Op.nofinstances ++;
        return new ChildOp(Op.NONGREEDYCLOSURE);
    }
    static ChildOp createQuestion(boolean nongreedy) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new ChildOp(nongreedy ? Op.NONGREEDYQUESTION : Op.QUESTION);
    }
    static RangeOp createRange(Token tok) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new RangeOp(Op.RANGE, tok);
    }
    static ChildOp createLook(int type, Op next, Op branch) {
        if (Op.COUNT)  Op.nofinstances ++;
        ChildOp op = new ChildOp(type);
        op.setChild(branch);
        op.next = next;
        return op;
    }
    static CharOp createBackReference(int refno) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new CharOp(Op.BACKREFERENCE, refno);
    }
    static StringOp createString(String literal) {
        if (Op.COUNT)  Op.nofinstances ++;
        return new StringOp(Op.STRING, literal);
    }
    static ChildOp createIndependent(Op next, Op branch) {
        if (Op.COUNT)  Op.nofinstances ++;
        ChildOp op = new ChildOp(Op.INDEPENDENT);
        op.setChild(branch);
        op.next = next;
        return op;
    }
    static ModifierOp createModifier(Op next, Op branch, int add, int mask) {
        if (Op.COUNT)  Op.nofinstances ++;
        ModifierOp op = new ModifierOp(Op.MODIFIER, add, mask);
        op.setChild(branch);
        op.next = next;
        return op;
    }
    static ConditionOp createCondition(Op next, int ref, Op conditionflow, Op yesflow, Op noflow) {
        if (Op.COUNT)  Op.nofinstances ++;
        ConditionOp op = new ConditionOp(Op.CONDITION, ref, conditionflow, yesflow, noflow);
        op.next = next;
        return op;
    }

    final int type;
    Op next = null;

    protected Op(int type) {
        this.type = type;
    }

    int size() {                                // for UNION
        return 0;
    }
    Op elementAt(int index) {                   // for UNIoN
        throw new RuntimeException("Internal Error: type="+this.type);
    }
    Op getChild() {                             // for CLOSURE, QUESTION
        throw new RuntimeException("Internal Error: type="+this.type);
    }
                                                // ModifierOp
    int getData() {                             // CharOp  for CHAR, BACKREFERENCE, CAPTURE, ANCHOR, 
        throw new RuntimeException("Internal Error: type="+this.type);
    }
    int getData2() {                            // ModifierOp
        throw new RuntimeException("Internal Error: type="+this.type);
    }
    RangeToken getToken() {                     // RANGE, NRANGE
        throw new RuntimeException("Internal Error: type="+this.type);
    }
    String getString() {                        // STRING
        throw new RuntimeException("Internal Error: type="+this.type);
    }

    // ================================================================
    static class CharOp extends Op {
        final int charData;
        CharOp(int type, int data) {
            super(type);
            this.charData = data;
        }
        int getData() {
            return this.charData;
        }
    }

    // ================================================================
    static class UnionOp extends Op {
        final Vector branches;
        UnionOp(int type, int size) {
            super(type);
            this.branches = new Vector(size);
        }
        void addElement(Op op) {
            this.branches.addElement(op);
        }
        int size() {
            return this.branches.size();
        }
        Op elementAt(int index) {
            return (Op)this.branches.elementAt(index);
        }
    }

    // ================================================================
    static class ChildOp extends Op {
        Op child;
        ChildOp(int type) {
            super(type);
        }
        void setChild(Op child) {
            this.child = child;
        }
        Op getChild() {
            return this.child;
        }
    }
    // ================================================================
    static class ModifierOp extends ChildOp {
        final int v1;
        final int v2;
        ModifierOp(int type, int v1, int v2) {
            super(type);
            this.v1 = v1;
            this.v2 = v2;
        }
        int getData() {
            return this.v1;
        }
        int getData2() {
            return this.v2;
        }
    }
    // ================================================================
    static class RangeOp extends Op {
        final Token tok;
        RangeOp(int type, Token tok) {
            super(type);
            this.tok = tok;
        }
        RangeToken getToken() {
            return (RangeToken)this.tok;
        }
    }
    // ================================================================
    static class StringOp extends Op {
        final String string;
        StringOp(int type, String literal) {
            super(type);
            this.string = literal;
        }
        String getString() {
            return this.string;
        }
    }
    // ================================================================
    static class ConditionOp extends Op {
        final int refNumber;
        final Op condition;
        final Op yes;
        final Op no;
        ConditionOp(int type, int refno, Op conditionflow, Op yesflow, Op noflow) {
            super(type);
            this.refNumber = refno;
            this.condition = conditionflow;
            this.yes = yesflow;
            this.no = noflow;
        }
    }
}


/**
 * @xerces.internal
 *
 * @author TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;
 * @version $Id: ParseException.java 572108 2007-09-02 18:48:31Z mrglavas $
 */
public static class ParseException extends RuntimeException {
    
    /** Serialization version. */
    static final long serialVersionUID = -7012400318097691370L;
    
    final int location;

    /*
    public ParseException(String mes) {
        this(mes, -1);
    }
    */
    /**
     *
     */
    public ParseException(String mes, int location) {
        super(mes);
        this.location = location;
    }

    /**
     *
     * @return -1 if location information is not available.
     */
    public int getLocation() {
        return this.location;
    }
}


/**
 * A regular expression parser for the XML Schema.
 * 
 * @xerces.internal
 *
 * @author TAMURA Kent &lt;kent@trl.ibm.co.jp&gt;
 * @version $Id: ParserForXMLSchema.java 831926 2009-11-02 15:38:53Z knoaman $
 */
static class ParserForXMLSchema extends RegexParser {

    public ParserForXMLSchema() {
        //this.setLocale(Locale.getDefault());
    }
    public ParserForXMLSchema(Locale locale) {
        super(locale);
    }

    Token processCaret() throws ParseException {
        this.next();
        return Token.createChar('^');
    }
    Token processDollar() throws ParseException {
        this.next();
        return Token.createChar('$');
     }
    Token processLookahead() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processNegativelookahead() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processLookbehind() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processNegativelookbehind() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_A() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_Z() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_z() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_b() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_B() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_lt() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_gt() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processStar(Token tok) throws ParseException {
        this.next();
        return Token.createClosure(tok);
    }
    Token processPlus(Token tok) throws ParseException {
        // X+ -> XX*
        this.next();
        return Token.createConcat(tok, Token.createClosure(tok));
    }
    Token processQuestion(Token tok) throws ParseException {
        // X? -> X|
        this.next();
        Token par = Token.createUnion();
        par.addChild(tok);
        par.addChild(Token.createEmpty());
        return par;
    }
    boolean checkQuestion(int off) {
        return false;
    }
    Token processParen() throws ParseException {
        this.next();
        Token tok = Token.createParen(this.parseRegex(), 0);
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processParen2() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processCondition() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processModifiers() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processIndependent() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_c() throws ParseException {
        this.next();
        return this.getTokenForShorthand('c');
    }
    Token processBacksolidus_C() throws ParseException {
        this.next();
        return this.getTokenForShorthand('C');
    }
    Token processBacksolidus_i() throws ParseException {
        this.next();
        return this.getTokenForShorthand('i');
    }
    Token processBacksolidus_I() throws ParseException {
        this.next();
        return this.getTokenForShorthand('I');
    }
    Token processBacksolidus_g() throws ParseException {
        throw this.ex("parser.process.1", this.offset-2);
    }
    Token processBacksolidus_X() throws ParseException {
        throw ex("parser.process.1", this.offset-2);
    }
    Token processBackreference() throws ParseException {
        throw ex("parser.process.1", this.offset-4);
    }

    int processCIinCharacterClass(RangeToken tok, int c) {
        tok.mergeRanges(this.getTokenForShorthand(c));
        return -1;
    }


    /**
     * Parses a character-class-expression, not a character-class-escape.
     *
     * c-c-expression   ::= '[' c-group ']'
     * c-group          ::= positive-c-group | negative-c-group | c-c-subtraction
     * positive-c-group ::= (c-range | c-c-escape)+
     * negative-c-group ::= '^' positive-c-group
     * c-c-subtraction  ::= (positive-c-group | negative-c-group) subtraction
     * subtraction      ::= '-' c-c-expression
     * c-range          ::= single-range | from-to-range
     * single-range     ::= multi-c-escape | category-c-escape | block-c-escape | &lt;any XML char&gt;
     * cc-normal-c      ::= &lt;any character except [, ], \&gt;
     * from-to-range    ::= cc-normal-c '-' cc-normal-c
     *
     * @param useNrage Ignored.
     * @return This returns no NrageToken.
     */
    protected RangeToken parseCharacterClass(boolean useNrange) throws ParseException {
        this.setContext(S_INBRACKETS);
        this.next();                            // '['
        boolean nrange = false;
        @SuppressWarnings("unused")
        boolean wasDecoded = false;             // used to detect if the last - was escaped.
        RangeToken base = null;
        RangeToken tok;
        if (this.read() == T_CHAR && this.chardata == '^') {
            nrange = true;
            this.next();                        // '^'
            base = Token.createRange();
            base.addRange(0, Token.UTF16_MAX);
            tok = Token.createRange();
        } else {
            tok = Token.createRange();
        }
        int type;
        boolean firstloop = true;
        while ((type = this.read()) != T_EOF) { // Don't use 'cotinue' for this loop.
            
            wasDecoded = false;
            // single-range | from-to-range | subtraction
            if (type == T_CHAR && this.chardata == ']' && !firstloop) {
                if (nrange) {
                    base.subtractRanges(tok);
                    tok = base;
                }
                break;
            }
            int c = this.chardata;
            boolean end = false;
            if (type == T_BACKSOLIDUS) {
                switch (c) {
                  case 'd':  case 'D':
                  case 'w':  case 'W':
                  case 's':  case 'S':
                    tok.mergeRanges(this.getTokenForShorthand(c));
                    end = true;
                    break;

                  case 'i':  case 'I':
                  case 'c':  case 'C':
                    c = this.processCIinCharacterClass(tok, c);
                    if (c < 0)  end = true;
                    break;
                    
                  case 'p':
                  case 'P':
                    int pstart = this.offset;
                    RangeToken tok2 = this.processBacksolidus_pP(c);
                    if (tok2 == null)  throw this.ex("parser.atom.5", pstart);
                    tok.mergeRanges(tok2);
                    end = true;
                    break;
                   
                 case '-':
                    c = this.decodeEscaped();
                    wasDecoded = true;
                    break;

                  default:
                    c = this.decodeEscaped();
                } // \ + c
            } // backsolidus
            else if (type == T_XMLSCHEMA_CC_SUBTRACTION && !firstloop) {
                                                // Subraction
                if (nrange) {
                    base.subtractRanges(tok);
                    tok = base;
                }
                RangeToken range2 = this.parseCharacterClass(false);
                tok.subtractRanges(range2);
                if (this.read() != T_CHAR || this.chardata != ']')
                    throw this.ex("parser.cc.5", this.offset);
                break;                          // Exit this loop
            }
            this.next();
            if (!end) {                         // if not shorthands...
                if (type == T_CHAR) {
                    if (c == '[')  throw this.ex("parser.cc.6", this.offset-2);
                    if (c == ']')  throw this.ex("parser.cc.7", this.offset-2);
                    if (c == '-' && this.chardata != ']' && !firstloop)  throw this.ex("parser.cc.8", this.offset-2);   // if regex = '[-]' then invalid
                }
                if (this.read() != T_CHAR || this.chardata != '-' || c == '-' && firstloop) { // Here is no '-'.
                    if (!this.isSet(RegularExpression.IGNORE_CASE) || c > 0xffff) {
                        tok.addRange(c, c);
                    }
                    else {
                        addCaseInsensitiveChar(tok, c);
                    }
                } else {                        // Found '-'
                                                // Is this '-' is a from-to token??
                    this.next(); // Skips '-'
                    if ((type = this.read()) == T_EOF)  throw this.ex("parser.cc.2", this.offset);
                                                // c '-' ']' -> '-' is a single-range.
                    if(type == T_CHAR && this.chardata == ']') {                // if - is at the last position of the group
                        if (!this.isSet(RegularExpression.IGNORE_CASE) || c > 0xffff) {
                            tok.addRange(c, c);
                        }
                        else {
                            addCaseInsensitiveChar(tok, c);
                        }
                        tok.addRange('-', '-');
                    }
                    else if (type == T_XMLSCHEMA_CC_SUBTRACTION) {
                        throw this.ex("parser.cc.8", this.offset-1);
                    } else {
                        
                        int rangeend = this.chardata;
                        if (type == T_CHAR) {
                            if (rangeend == '[')  throw this.ex("parser.cc.6", this.offset-1);
                            if (rangeend == ']')  throw this.ex("parser.cc.7", this.offset-1);
                            if (rangeend == '-')  throw this.ex("parser.cc.8", this.offset-2);
                        }
                        else if (type == T_BACKSOLIDUS)
                            rangeend = this.decodeEscaped();
                        this.next();

                        if (c > rangeend)  throw this.ex("parser.ope.3", this.offset-1);
                        if (!this.isSet(RegularExpression.IGNORE_CASE) ||
                                (c > 0xffff && rangeend > 0xffff)) {
                            tok.addRange(c, rangeend);
                        }
                        else {
                            addCaseInsensitiveCharRange(tok, c, rangeend);
                        }
                    }
                }
            }
            firstloop = false;
        }
        if (this.read() == T_EOF)
            throw this.ex("parser.cc.2", this.offset);
        tok.sortRanges();
        tok.compactRanges();
        //tok.dumpRanges();
        this.setContext(S_NORMAL);
        this.next();                    // Skips ']'

        return tok;
    }

    protected RangeToken parseSetOperations() throws ParseException {
        throw this.ex("parser.process.1", this.offset);
    }
 
    Token getTokenForShorthand(int ch) {
        switch (ch) {
          case 'd':
            return ParserForXMLSchema.getRange("xml:isDigit", true);
          case 'D':
            return ParserForXMLSchema.getRange("xml:isDigit", false);
          case 'w':
            return ParserForXMLSchema.getRange("xml:isWord", true);
          case 'W':
            return ParserForXMLSchema.getRange("xml:isWord", false);
          case 's':
            return ParserForXMLSchema.getRange("xml:isSpace", true);
          case 'S':
            return ParserForXMLSchema.getRange("xml:isSpace", false);
          case 'c':
            return ParserForXMLSchema.getRange("xml:isNameChar", true);
          case 'C':
            return ParserForXMLSchema.getRange("xml:isNameChar", false);
          case 'i':
            return ParserForXMLSchema.getRange("xml:isInitialNameChar", true);
          case 'I':
            return ParserForXMLSchema.getRange("xml:isInitialNameChar", false);
          default:
            throw new RuntimeException("Internal Error: shorthands: \\u"+Integer.toString(ch, 16));
        }
    }
    int decodeEscaped() throws ParseException {
        if (this.read() != T_BACKSOLIDUS)  throw ex("parser.next.1", this.offset-1);
        int c = this.chardata;
        switch (c) {
          case 'n':  c = '\n';  break; // LINE FEED U+000A
          case 'r':  c = '\r';  break; // CRRIAGE RETURN U+000D
          case 't':  c = '\t';  break; // HORIZONTAL TABULATION U+0009
          case '\\':
          case '|':
          case '.':
          case '^':
          case '-':
          case '?':
          case '*':
          case '+':
          case '{':
          case '}':
          case '(':
          case ')':
          case '[':
          case ']':
            break; // return actucal char
          default:
            throw ex("parser.process.1", this.offset-2);
        }
        return c;
    }

    static private Hashtable ranges = null;
    static private Hashtable ranges2 = null;
    static synchronized protected RangeToken getRange(String name, boolean positive) {
        if (ranges == null) {
            ranges = new Hashtable();
            ranges2 = new Hashtable();

            Token tok = Token.createRange();
            setupRange(tok, SPACES);
            ranges.put("xml:isSpace", tok);
            ranges2.put("xml:isSpace", Token.complementRanges(tok));

            tok = Token.createRange();
            setupRange(tok, DIGITS);
            ranges.put("xml:isDigit", tok);
            ranges2.put("xml:isDigit", Token.complementRanges(tok));

            tok = Token.createRange();
            setupRange(tok, DIGITS);
            ranges.put("xml:isDigit", tok);
            ranges2.put("xml:isDigit", Token.complementRanges(tok));

            tok = Token.createRange();
            setupRange(tok, LETTERS);
            tok.mergeRanges((Token)ranges.get("xml:isDigit"));
            ranges.put("xml:isWord", tok);
            ranges2.put("xml:isWord", Token.complementRanges(tok));

            tok = Token.createRange();
            setupRange(tok, NAMECHARS);
            ranges.put("xml:isNameChar", tok);
            ranges2.put("xml:isNameChar", Token.complementRanges(tok));

            tok = Token.createRange();
            setupRange(tok, LETTERS);
            tok.addRange('_', '_');
            tok.addRange(':', ':');
            ranges.put("xml:isInitialNameChar", tok);
            ranges2.put("xml:isInitialNameChar", Token.complementRanges(tok));
        }
        RangeToken tok = positive ? (RangeToken)ranges.get(name)
            : (RangeToken)ranges2.get(name);
        return tok;
    }

    static void setupRange(Token range, String src) {
        int len = src.length();
        for (int i = 0;  i < len;  i += 2)
            range.addRange(src.charAt(i), src.charAt(i+1));
    }

    private static final String SPACES = "\t\n\r\r  ";
    private static final String NAMECHARS =
        "\u002d\u002e\u0030\u003a\u0041\u005a\u005f\u005f\u0061\u007a\u00b7\u00b7\u00c0\u00d6"
        +"\u00d8\u00f6\u00f8\u0131\u0134\u013e\u0141\u0148\u014a\u017e\u0180\u01c3\u01cd\u01f0"
        +"\u01f4\u01f5\u01fa\u0217\u0250\u02a8\u02bb\u02c1\u02d0\u02d1\u0300\u0345\u0360\u0361"
        +"\u0386\u038a\u038c\u038c\u038e\u03a1\u03a3\u03ce\u03d0\u03d6\u03da\u03da\u03dc\u03dc"
        +"\u03de\u03de\u03e0\u03e0\u03e2\u03f3\u0401\u040c\u040e\u044f\u0451\u045c\u045e\u0481"
        +"\u0483\u0486\u0490\u04c4\u04c7\u04c8\u04cb\u04cc\u04d0\u04eb\u04ee\u04f5\u04f8\u04f9"
        +"\u0531\u0556\u0559\u0559\u0561\u0586\u0591\u05a1\u05a3\u05b9\u05bb\u05bd\u05bf\u05bf"
        +"\u05c1\u05c2\u05c4\u05c4\u05d0\u05ea\u05f0\u05f2\u0621\u063a\u0640\u0652\u0660\u0669"
        +"\u0670\u06b7\u06ba\u06be\u06c0\u06ce\u06d0\u06d3\u06d5\u06e8\u06ea\u06ed\u06f0\u06f9"
        +"\u0901\u0903\u0905\u0939\u093c\u094d\u0951\u0954\u0958\u0963\u0966\u096f\u0981\u0983"
        +"\u0985\u098c\u098f\u0990\u0993\u09a8\u09aa\u09b0\u09b2\u09b2\u09b6\u09b9\u09bc\u09bc"
        +"\u09be\u09c4\u09c7\u09c8\u09cb\u09cd\u09d7\u09d7\u09dc\u09dd\u09df\u09e3\u09e6\u09f1"
        +"\u0a02\u0a02\u0a05\u0a0a\u0a0f\u0a10\u0a13\u0a28\u0a2a\u0a30\u0a32\u0a33\u0a35\u0a36"
        +"\u0a38\u0a39\u0a3c\u0a3c\u0a3e\u0a42\u0a47\u0a48\u0a4b\u0a4d\u0a59\u0a5c\u0a5e\u0a5e"
        +"\u0a66\u0a74\u0a81\u0a83\u0a85\u0a8b\u0a8d\u0a8d\u0a8f\u0a91\u0a93\u0aa8\u0aaa\u0ab0"
        +"\u0ab2\u0ab3\u0ab5\u0ab9\u0abc\u0ac5\u0ac7\u0ac9\u0acb\u0acd\u0ae0\u0ae0\u0ae6\u0aef"
        +"\u0b01\u0b03\u0b05\u0b0c\u0b0f\u0b10\u0b13\u0b28\u0b2a\u0b30\u0b32\u0b33\u0b36\u0b39"
        +"\u0b3c\u0b43\u0b47\u0b48\u0b4b\u0b4d\u0b56\u0b57\u0b5c\u0b5d\u0b5f\u0b61\u0b66\u0b6f"
        +"\u0b82\u0b83\u0b85\u0b8a\u0b8e\u0b90\u0b92\u0b95\u0b99\u0b9a\u0b9c\u0b9c\u0b9e\u0b9f"
        +"\u0ba3\u0ba4\u0ba8\u0baa\u0bae\u0bb5\u0bb7\u0bb9\u0bbe\u0bc2\u0bc6\u0bc8\u0bca\u0bcd"
        +"\u0bd7\u0bd7\u0be7\u0bef\u0c01\u0c03\u0c05\u0c0c\u0c0e\u0c10\u0c12\u0c28\u0c2a\u0c33"
        +"\u0c35\u0c39\u0c3e\u0c44\u0c46\u0c48\u0c4a\u0c4d\u0c55\u0c56\u0c60\u0c61\u0c66\u0c6f"
        +"\u0c82\u0c83\u0c85\u0c8c\u0c8e\u0c90\u0c92\u0ca8\u0caa\u0cb3\u0cb5\u0cb9\u0cbe\u0cc4"
        +"\u0cc6\u0cc8\u0cca\u0ccd\u0cd5\u0cd6\u0cde\u0cde\u0ce0\u0ce1\u0ce6\u0cef\u0d02\u0d03"
        +"\u0d05\u0d0c\u0d0e\u0d10\u0d12\u0d28\u0d2a\u0d39\u0d3e\u0d43\u0d46\u0d48\u0d4a\u0d4d"
        +"\u0d57\u0d57\u0d60\u0d61\u0d66\u0d6f\u0e01\u0e2e\u0e30\u0e3a\u0e40\u0e4e\u0e50\u0e59"
        +"\u0e81\u0e82\u0e84\u0e84\u0e87\u0e88\u0e8a\u0e8a\u0e8d\u0e8d\u0e94\u0e97\u0e99\u0e9f"
        +"\u0ea1\u0ea3\u0ea5\u0ea5\u0ea7\u0ea7\u0eaa\u0eab\u0ead\u0eae\u0eb0\u0eb9\u0ebb\u0ebd"
        +"\u0ec0\u0ec4\u0ec6\u0ec6\u0ec8\u0ecd\u0ed0\u0ed9\u0f18\u0f19\u0f20\u0f29\u0f35\u0f35"
        +"\u0f37\u0f37\u0f39\u0f39\u0f3e\u0f47\u0f49\u0f69\u0f71\u0f84\u0f86\u0f8b\u0f90\u0f95"
        +"\u0f97\u0f97\u0f99\u0fad\u0fb1\u0fb7\u0fb9\u0fb9\u10a0\u10c5\u10d0\u10f6\u1100\u1100"
        +"\u1102\u1103\u1105\u1107\u1109\u1109\u110b\u110c\u110e\u1112\u113c\u113c\u113e\u113e"
        +"\u1140\u1140\u114c\u114c\u114e\u114e\u1150\u1150\u1154\u1155\u1159\u1159\u115f\u1161"
        +"\u1163\u1163\u1165\u1165\u1167\u1167\u1169\u1169\u116d\u116e\u1172\u1173\u1175\u1175"
        +"\u119e\u119e\u11a8\u11a8\u11ab\u11ab\u11ae\u11af\u11b7\u11b8\u11ba\u11ba\u11bc\u11c2"
        +"\u11eb\u11eb\u11f0\u11f0\u11f9\u11f9\u1e00\u1e9b\u1ea0\u1ef9\u1f00\u1f15\u1f18\u1f1d"
        +"\u1f20\u1f45\u1f48\u1f4d\u1f50\u1f57\u1f59\u1f59\u1f5b\u1f5b\u1f5d\u1f5d\u1f5f\u1f7d"
        +"\u1f80\u1fb4\u1fb6\u1fbc\u1fbe\u1fbe\u1fc2\u1fc4\u1fc6\u1fcc\u1fd0\u1fd3\u1fd6\u1fdb"
        +"\u1fe0\u1fec\u1ff2\u1ff4\u1ff6\u1ffc\u20d0\u20dc\u20e1\u20e1\u2126\u2126\u212a\u212b"
        +"\u212e\u212e\u2180\u2182\u3005\u3005\u3007\u3007\u3021\u302f\u3031\u3035\u3041\u3094"
        +"\u3099\u309a\u309d\u309e\u30a1\u30fa\u30fc\u30fe\u3105\u312c\u4e00\u9fa5\uac00\ud7a3"
        +"";
    private static final String LETTERS =
        "\u0041\u005a\u0061\u007a\u00c0\u00d6\u00d8\u00f6\u00f8\u0131\u0134\u013e\u0141\u0148"
        +"\u014a\u017e\u0180\u01c3\u01cd\u01f0\u01f4\u01f5\u01fa\u0217\u0250\u02a8\u02bb\u02c1"
        +"\u0386\u0386\u0388\u038a\u038c\u038c\u038e\u03a1\u03a3\u03ce\u03d0\u03d6\u03da\u03da"
        +"\u03dc\u03dc\u03de\u03de\u03e0\u03e0\u03e2\u03f3\u0401\u040c\u040e\u044f\u0451\u045c"
        +"\u045e\u0481\u0490\u04c4\u04c7\u04c8\u04cb\u04cc\u04d0\u04eb\u04ee\u04f5\u04f8\u04f9"
        +"\u0531\u0556\u0559\u0559\u0561\u0586\u05d0\u05ea\u05f0\u05f2\u0621\u063a\u0641\u064a"
        +"\u0671\u06b7\u06ba\u06be\u06c0\u06ce\u06d0\u06d3\u06d5\u06d5\u06e5\u06e6\u0905\u0939"
        +"\u093d\u093d\u0958\u0961\u0985\u098c\u098f\u0990\u0993\u09a8\u09aa\u09b0\u09b2\u09b2"
        +"\u09b6\u09b9\u09dc\u09dd\u09df\u09e1\u09f0\u09f1\u0a05\u0a0a\u0a0f\u0a10\u0a13\u0a28"
        +"\u0a2a\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59\u0a5c\u0a5e\u0a5e\u0a72\u0a74"
        +"\u0a85\u0a8b\u0a8d\u0a8d\u0a8f\u0a91\u0a93\u0aa8\u0aaa\u0ab0\u0ab2\u0ab3\u0ab5\u0ab9"
        +"\u0abd\u0abd\u0ae0\u0ae0\u0b05\u0b0c\u0b0f\u0b10\u0b13\u0b28\u0b2a\u0b30\u0b32\u0b33"
        +"\u0b36\u0b39\u0b3d\u0b3d\u0b5c\u0b5d\u0b5f\u0b61\u0b85\u0b8a\u0b8e\u0b90\u0b92\u0b95"
        +"\u0b99\u0b9a\u0b9c\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8\u0baa\u0bae\u0bb5\u0bb7\u0bb9"
        +"\u0c05\u0c0c\u0c0e\u0c10\u0c12\u0c28\u0c2a\u0c33\u0c35\u0c39\u0c60\u0c61\u0c85\u0c8c"
        +"\u0c8e\u0c90\u0c92\u0ca8\u0caa\u0cb3\u0cb5\u0cb9\u0cde\u0cde\u0ce0\u0ce1\u0d05\u0d0c"
        +"\u0d0e\u0d10\u0d12\u0d28\u0d2a\u0d39\u0d60\u0d61\u0e01\u0e2e\u0e30\u0e30\u0e32\u0e33"
        +"\u0e40\u0e45\u0e81\u0e82\u0e84\u0e84\u0e87\u0e88\u0e8a\u0e8a\u0e8d\u0e8d\u0e94\u0e97"
        +"\u0e99\u0e9f\u0ea1\u0ea3\u0ea5\u0ea5\u0ea7\u0ea7\u0eaa\u0eab\u0ead\u0eae\u0eb0\u0eb0"
        +"\u0eb2\u0eb3\u0ebd\u0ebd\u0ec0\u0ec4\u0f40\u0f47\u0f49\u0f69\u10a0\u10c5\u10d0\u10f6"
        +"\u1100\u1100\u1102\u1103\u1105\u1107\u1109\u1109\u110b\u110c\u110e\u1112\u113c\u113c"
        +"\u113e\u113e\u1140\u1140\u114c\u114c\u114e\u114e\u1150\u1150\u1154\u1155\u1159\u1159"
        +"\u115f\u1161\u1163\u1163\u1165\u1165\u1167\u1167\u1169\u1169\u116d\u116e\u1172\u1173"
        +"\u1175\u1175\u119e\u119e\u11a8\u11a8\u11ab\u11ab\u11ae\u11af\u11b7\u11b8\u11ba\u11ba"
        +"\u11bc\u11c2\u11eb\u11eb\u11f0\u11f0\u11f9\u11f9\u1e00\u1e9b\u1ea0\u1ef9\u1f00\u1f15"
        +"\u1f18\u1f1d\u1f20\u1f45\u1f48\u1f4d\u1f50\u1f57\u1f59\u1f59\u1f5b\u1f5b\u1f5d\u1f5d"
        +"\u1f5f\u1f7d\u1f80\u1fb4\u1fb6\u1fbc\u1fbe\u1fbe\u1fc2\u1fc4\u1fc6\u1fcc\u1fd0\u1fd3"
        +"\u1fd6\u1fdb\u1fe0\u1fec\u1ff2\u1ff4\u1ff6\u1ffc\u2126\u2126\u212a\u212b\u212e\u212e"
        +"\u2180\u2182\u3007\u3007\u3021\u3029\u3041\u3094\u30a1\u30fa\u3105\u312c\u4e00\u9fa5"
        +"\uac00\ud7a3";
    private static final String DIGITS =
        "\u0030\u0039\u0660\u0669\u06F0\u06F9\u0966\u096F\u09E6\u09EF\u0A66\u0A6F\u0AE6\u0AEF"
        +"\u0B66\u0B6F\u0BE7\u0BEF\u0C66\u0C6F\u0CE6\u0CEF\u0D66\u0D6F\u0E50\u0E59\u0ED0\u0ED9"
        +"\u0F20\u0F29";
}


/**
 * This class represents a character class such as [a-z] or a period.
 * 
 * @xerces.internal
 *
 * @version $Id: RangeToken.java 965250 2010-07-18 16:04:58Z mrglavas $
 */
final static class RangeToken extends Token implements java.io.Serializable {

    private static final long serialVersionUID = -553983121197679934L;
    
    int[] ranges;
    boolean sorted;
    boolean compacted;
    RangeToken icaseCache = null;
    int[] map = null;
    int nonMapIndex;

    RangeToken(int type) {
        super(type);
        this.setSorted(false);
    }

                                                // for RANGE or NRANGE
    protected void addRange(int start, int end) {
        this.icaseCache = null;
        //System.err.println("Token#addRange(): "+start+" "+end);
        int r1, r2;
        if (start <= end) {
            r1 = start;
            r2 = end;
        } else {
            r1 = end;
            r2 = start;
        }

        int pos = 0;
        if (this.ranges == null) {
            this.ranges = new int[2];
            this.ranges[0] = r1;
            this.ranges[1] = r2;
            this.setSorted(true);
        } else {
            pos = this.ranges.length;
            if (this.ranges[pos-1]+1 == r1) {
                this.ranges[pos-1] = r2;
                return;
            }
            int[] temp = new int[pos+2];
            System.arraycopy(this.ranges, 0, temp, 0, pos);
            this.ranges = temp;
            if (this.ranges[pos-1] >= r1)
                this.setSorted(false);
            this.ranges[pos++] = r1;
            this.ranges[pos] = r2;
            if (!this.sorted)
                this.sortRanges();
        }
    }

    private final boolean isSorted() {
        return this.sorted;
    }
    private final void setSorted(boolean sort) {
        this.sorted = sort;
        if (!sort)  this.compacted = false;
    }
    private final boolean isCompacted() {
        return this.compacted;
    }
    private final void setCompacted() {
        this.compacted = true;
    }

    protected void sortRanges() {
        if (this.isSorted())
            return;
        if (this.ranges == null)
            return;
        //System.err.println("Do sorting: "+this.ranges.length);

                                                // Bubble sort
                                                // Why? -- In many cases,
                                                //         this.ranges has few elements.
        for (int i = this.ranges.length-4;  i >= 0;  i -= 2) {
            for (int j = 0;  j <= i;  j += 2) {
                if (this.ranges[j] > this.ranges[j+2]
                    || this.ranges[j] == this.ranges[j+2] && this.ranges[j+1] > this.ranges[j+3]) {
                    int tmp;
                    tmp = this.ranges[j+2];
                    this.ranges[j+2] = this.ranges[j];
                    this.ranges[j] = tmp;
                    tmp = this.ranges[j+3];
                    this.ranges[j+3] = this.ranges[j+1];
                    this.ranges[j+1] = tmp;
                }
            }
        }
        this.setSorted(true);
    }

    /**
     * this.ranges is sorted.
     */
    protected void compactRanges() {
        boolean DEBUG = false;
        if (this.ranges == null || this.ranges.length <= 2)
            return;
        if (this.isCompacted())
            return;
        int base = 0;                           // Index of writing point
        int target = 0;                         // Index of processing point

        while (target < this.ranges.length) {
            if (base != target) {
                this.ranges[base] = this.ranges[target++];
                this.ranges[base+1] = this.ranges[target++];
            } else
                target += 2;
            int baseend = this.ranges[base+1];
            while (target < this.ranges.length) {
                if (baseend+1 < this.ranges[target])
                    break;
                if (baseend+1 == this.ranges[target]) {
                    if (DEBUG)
                        System.err.println("Token#compactRanges(): Compaction: ["+this.ranges[base]
                                           +", "+this.ranges[base+1]
                                           +"], ["+this.ranges[target]
                                           +", "+this.ranges[target+1]
                                           +"] -> ["+this.ranges[base]
                                           +", "+this.ranges[target+1]
                                           +"]");
                    this.ranges[base+1] = this.ranges[target+1];
                    baseend = this.ranges[base+1];
                    target += 2;
                } else if (baseend >= this.ranges[target+1]) {
                    if (DEBUG)
                        System.err.println("Token#compactRanges(): Compaction: ["+this.ranges[base]
                                           +", "+this.ranges[base+1]
                                           +"], ["+this.ranges[target]
                                           +", "+this.ranges[target+1]
                                           +"] -> ["+this.ranges[base]
                                           +", "+this.ranges[base+1]
                                           +"]");
                    target += 2;
                } else if (baseend < this.ranges[target+1]) {
                    if (DEBUG)
                        System.err.println("Token#compactRanges(): Compaction: ["+this.ranges[base]
                                           +", "+this.ranges[base+1]
                                           +"], ["+this.ranges[target]
                                           +", "+this.ranges[target+1]
                                           +"] -> ["+this.ranges[base]
                                           +", "+this.ranges[target+1]
                                           +"]");
                    this.ranges[base+1] = this.ranges[target+1];
                    baseend = this.ranges[base+1];
                    target += 2;
                } else {
                    throw new RuntimeException("Token#compactRanges(): Internel Error: ["
                                               +this.ranges[base]
                                               +","+this.ranges[base+1]
                                               +"] ["+this.ranges[target]
                                               +","+this.ranges[target+1]+"]");
                }
            } // while
            base += 2;
        }

        if (base != this.ranges.length) {
            int[] result = new int[base];
            System.arraycopy(this.ranges, 0, result, 0, base);
            this.ranges = result;
        }
        this.setCompacted();
    }

    protected void mergeRanges(Token token) {
        RangeToken tok = (RangeToken)token;
        this.sortRanges();
        tok.sortRanges();
        if (tok.ranges == null)
            return;
        this.icaseCache = null;
        this.setSorted(true);
        if (this.ranges == null) {
            this.ranges = new int[tok.ranges.length];
            System.arraycopy(tok.ranges, 0, this.ranges, 0, tok.ranges.length);
            return;
        }
        int[] result = new int[this.ranges.length+tok.ranges.length];
        for (int i = 0, j = 0, k = 0;  i < this.ranges.length || j < tok.ranges.length;) {
            if (i >= this.ranges.length) {
                result[k++] = tok.ranges[j++];
                result[k++] = tok.ranges[j++];
            } else if (j >= tok.ranges.length) {
                result[k++] = this.ranges[i++];
                result[k++] = this.ranges[i++];
            } else if (tok.ranges[j] < this.ranges[i]
                       || tok.ranges[j] == this.ranges[i] && tok.ranges[j+1] < this.ranges[i+1]) {
                result[k++] = tok.ranges[j++];
                result[k++] = tok.ranges[j++];
            } else {
                result[k++] = this.ranges[i++];
                result[k++] = this.ranges[i++];
            }
        }
        this.ranges = result;
    }

    protected void subtractRanges(Token token) {
        if (token.type == NRANGE) {
            this.intersectRanges(token);
            return;
        }
        RangeToken tok = (RangeToken)token;
        if (tok.ranges == null || this.ranges == null)
            return;
        this.icaseCache = null;
        this.sortRanges();
        this.compactRanges();
        tok.sortRanges();
        tok.compactRanges();

        //System.err.println("Token#substractRanges(): Entry: "+this.ranges.length+", "+tok.ranges.length);

        int[] result = new int[this.ranges.length+tok.ranges.length];
        int wp = 0, src = 0, sub = 0;
        while (src < this.ranges.length && sub < tok.ranges.length) {
            int srcbegin = this.ranges[src];
            int srcend = this.ranges[src+1];
            int subbegin = tok.ranges[sub];
            int subend = tok.ranges[sub+1];
            if (srcend < subbegin) {            // Not overlapped
                                                // src: o-----o
                                                // sub:         o-----o
                                                // res: o-----o
                                                // Reuse sub
                result[wp++] = this.ranges[src++];
                result[wp++] = this.ranges[src++];
            } else if (srcend >= subbegin
                       && srcbegin <= subend) { // Overlapped
                                                // src:    o--------o
                                                // sub:  o----o
                                                // sub:      o----o
                                                // sub:          o----o
                                                // sub:  o------------o
                if (subbegin <= srcbegin && srcend <= subend) {
                                                // src:    o--------o
                                                // sub:  o------------o
                                                // res: empty
                                                // Reuse sub
                    src += 2;
                } else if (subbegin <= srcbegin) {
                                                // src:    o--------o
                                                // sub:  o----o
                                                // res:       o-----o
                                                // Reuse src(=res)
                    this.ranges[src] = subend+1;
                    sub += 2;
                } else if (srcend <= subend) {
                                                // src:    o--------o
                                                // sub:          o----o
                                                // res:    o-----o
                                                // Reuse sub
                    result[wp++] = srcbegin;
                    result[wp++] = subbegin-1;
                    src += 2;
                } else {
                                                // src:    o--------o
                                                // sub:      o----o
                                                // res:    o-o    o-o
                                                // Reuse src(=right res)
                    result[wp++] = srcbegin;
                    result[wp++] = subbegin-1;
                    this.ranges[src] = subend+1;
                    sub += 2;
                }
            } else if (subend < srcbegin) {
                                                // Not overlapped
                                                // src:          o-----o
                                                // sub: o----o
                sub += 2;
            } else {
                throw new RuntimeException("Token#subtractRanges(): Internal Error: ["+this.ranges[src]
                                           +","+this.ranges[src+1]
                                           +"] - ["+tok.ranges[sub]
                                           +","+tok.ranges[sub+1]
                                           +"]");
            }
        }
        while (src < this.ranges.length) {
            result[wp++] = this.ranges[src++];
            result[wp++] = this.ranges[src++];
        }
        this.ranges = new int[wp];
        System.arraycopy(result, 0, this.ranges, 0, wp);
                                                // this.ranges is sorted and compacted.
    }

    /**
     * @param tok Ignore whether it is NRANGE or not.
     */
    protected void intersectRanges(Token token) {
        RangeToken tok = (RangeToken)token;
        if (tok.ranges == null || this.ranges == null)
            return;
        this.icaseCache = null;
        this.sortRanges();
        this.compactRanges();
        tok.sortRanges();
        tok.compactRanges();

        int[] result = new int[this.ranges.length+tok.ranges.length];
        int wp = 0, src1 = 0, src2 = 0;
        while (src1 < this.ranges.length && src2 < tok.ranges.length) {
            int src1begin = this.ranges[src1];
            int src1end = this.ranges[src1+1];
            int src2begin = tok.ranges[src2];
            int src2end = tok.ranges[src2+1];
            if (src1end < src2begin) {          // Not overlapped
                                                // src1: o-----o
                                                // src2:         o-----o
                                                // res:  empty
                                                // Reuse src2
                src1 += 2;
            } else if (src1end >= src2begin
                       && src1begin <= src2end) { // Overlapped
                                                // src1:    o--------o
                                                // src2:  o----o
                                                // src2:      o----o
                                                // src2:          o----o
                                                // src2:  o------------o
                if (src2begin <= src1begin && src1end <= src2end) {
                                                // src1:    o--------o
                                                // src2:  o------------o
                                                // res:     o--------o
                                                // Reuse src2
                    result[wp++] = src1begin;
                    result[wp++] = src1end;
                    src1 += 2;
                } else if (src2begin <= src1begin) {
                                                // src1:    o--------o
                                                // src2:  o----o
                                                // res:     o--o
                                                // Reuse the rest of src1
                    result[wp++] = src1begin;
                    result[wp++] = src2end;
                    this.ranges[src1] = src2end+1;
                    src2 += 2;
                } else if (src1end <= src2end) {
                                                // src1:    o--------o
                                                // src2:          o----o
                                                // res:           o--o
                                                // Reuse src2
                    result[wp++] = src2begin;
                    result[wp++] = src1end;
                    src1 += 2;
                } else {
                                                // src1:    o--------o
                                                // src2:      o----o
                                                // res:       o----o
                                                // Reuse the rest of src1
                    result[wp++] = src2begin;
                    result[wp++] = src2end;
                    this.ranges[src1] = src2end+1;
                }
            } else if (src2end < src1begin) {
                                                // Not overlapped
                                                // src1:          o-----o
                                                // src2: o----o
                src2 += 2;
            } else {
                throw new RuntimeException("Token#intersectRanges(): Internal Error: ["
                                           +this.ranges[src1]
                                           +","+this.ranges[src1+1]
                                           +"] & ["+tok.ranges[src2]
                                           +","+tok.ranges[src2+1]
                                           +"]");
            }
        }
        while (src1 < this.ranges.length) {
            result[wp++] = this.ranges[src1++];
            result[wp++] = this.ranges[src1++];
        }
        this.ranges = new int[wp];
        System.arraycopy(result, 0, this.ranges, 0, wp);
                                                // this.ranges is sorted and compacted.
    }

    /**
     * for RANGE: Creates complement.
     * for NRANGE: Creates the same meaning RANGE.
     */
    static Token complementRanges(Token token) {
        if (token.type != RANGE && token.type != NRANGE)
            throw new IllegalArgumentException("Token#complementRanges(): must be RANGE: "+token.type);
        RangeToken tok = (RangeToken)token;
        tok.sortRanges();
        tok.compactRanges();
        int len = tok.ranges.length+2;
        if (tok.ranges[0] == 0)
            len -= 2;
        int last = tok.ranges[tok.ranges.length-1];
        if (last == UTF16_MAX)
            len -= 2;
        RangeToken ret = Token.createRange();
        ret.ranges = new int[len];
        int wp = 0;
        if (tok.ranges[0] > 0) {
            ret.ranges[wp++] = 0;
            ret.ranges[wp++] = tok.ranges[0]-1;
        }
        for (int i = 1;  i < tok.ranges.length-2;  i += 2) {
            ret.ranges[wp++] = tok.ranges[i]+1;
            ret.ranges[wp++] = tok.ranges[i+1]-1;
        }
        if (last != UTF16_MAX) {
            ret.ranges[wp++] = last+1;
            ret.ranges[wp] = UTF16_MAX;
        }
        ret.setCompacted();
        return ret;
    }

    synchronized RangeToken getCaseInsensitiveToken() {
        if (this.icaseCache != null)
            return this.icaseCache;
            
        RangeToken uppers = this.type == Token.RANGE ? Token.createRange() : Token.createNRange();
        for (int i = 0;  i < this.ranges.length;  i += 2) {
            for (int ch = this.ranges[i];  ch <= this.ranges[i+1];  ch ++) {
                if (ch > 0xffff)
                    uppers.addRange(ch, ch);
                else {
                    char uch = Character.toUpperCase((char)ch);
                    uppers.addRange(uch, uch);
                }
            }
        }
        RangeToken lowers = this.type == Token.RANGE ? Token.createRange() : Token.createNRange();
        for (int i = 0;  i < uppers.ranges.length;  i += 2) {
            for (int ch = uppers.ranges[i];  ch <= uppers.ranges[i+1];  ch ++) {
                if (ch > 0xffff)
                    lowers.addRange(ch, ch);
                else {
                    char uch = Character.toLowerCase((char)ch);
                    lowers.addRange(uch, uch);
                }
            }
        }
        lowers.mergeRanges(uppers);
        lowers.mergeRanges(this);
        lowers.compactRanges();

        this.icaseCache = lowers;
        return lowers;
    }

    void dumpRanges() {
        System.err.print("RANGE: ");
        if (this.ranges == null) {
            System.err.println(" NULL");
            return;
        }
        for (int i = 0;  i < this.ranges.length;  i += 2) {
            System.err.print("["+this.ranges[i]+","+this.ranges[i+1]+"] ");
        }
        System.err.println("");
    }

    boolean match(int ch) {
        if (this.map == null)  this.createMap();
        boolean ret;
        if (this.type == RANGE) {
            if (ch < MAPSIZE)
                return (this.map[ch/32] & (1<<(ch&0x1f))) != 0;
            ret = false;
            for (int i = this.nonMapIndex;  i < this.ranges.length;  i += 2) {
                if (this.ranges[i] <= ch && ch <= this.ranges[i+1])
                    return true;
            }
        } else {
            if (ch < MAPSIZE)
                return (this.map[ch/32] & (1<<(ch&0x1f))) == 0;
            ret = true;
            for (int i = this.nonMapIndex;  i < this.ranges.length;  i += 2) {
                if (this.ranges[i] <= ch && ch <= this.ranges[i+1])
                    return false;
            }
        }
        return ret;
    }

    private static final int MAPSIZE = 256;
    private void createMap() {
        int asize = MAPSIZE/32;                 // 32 is the number of bits in `int'.
        int [] map = new int[asize];
        int nonMapIndex = this.ranges.length;
        for (int i = 0; i < asize; ++i) {
            map[i] = 0;
        }
        for (int i = 0; i < this.ranges.length;  i += 2) {
            int s = this.ranges[i];
            int e = this.ranges[i+1];
            if (s < MAPSIZE) {
                for (int j = s; j <= e && j < MAPSIZE; j++) {
                    map[j/32] |= 1<<(j&0x1f); // s&0x1f : 0-31
                }
            } 
            else {
                nonMapIndex = i;
                break;
            }
            if (e >= MAPSIZE) {
                nonMapIndex = i;
                break;
            }
        }
        this.map = map;
        this.nonMapIndex = nonMapIndex;
        //for (int i = 0;  i < asize;  i ++)  System.err.println("Map: "+Integer.toString(this.map[i], 16));
    }

    public String toString(int options) {
        String ret;
        if (this.type == RANGE) {
            if (this == Token.token_dot)
                ret = ".";
            else if (this == Token.token_0to9)
                ret = "\\d";
            else if (this == Token.token_wordchars)
                ret = "\\w";
            else if (this == Token.token_spaces)
                ret = "\\s";
            else {
                StringBuilder sb = new StringBuilder();
                sb.append('[');
                for (int i = 0;  i < this.ranges.length;  i += 2) {
                    if ((options & RegularExpression.SPECIAL_COMMA) != 0 && i > 0)  sb.append(',');
                    if (this.ranges[i] == this.ranges[i+1]) {
                        sb.append(escapeCharInCharClass(this.ranges[i]));
                    } else {
                        sb.append(escapeCharInCharClass(this.ranges[i]));
                        sb.append((char)'-');
                        sb.append(escapeCharInCharClass(this.ranges[i+1]));
                    }
                }
                sb.append(']');
                ret = sb.toString();
            }
        } else {
            if (this == Token.token_not_0to9)
                ret = "\\D";
            else if (this == Token.token_not_wordchars)
                ret = "\\W";
            else if (this == Token.token_not_spaces)
                ret = "\\S";
            else {
                StringBuilder sb = new StringBuilder();
                sb.append("[^");
                for (int i = 0;  i < this.ranges.length;  i += 2) {
                    if ((options & RegularExpression.SPECIAL_COMMA) != 0 && i > 0)  sb.append(',');
                    if (this.ranges[i] == this.ranges[i+1]) {
                        sb.append(escapeCharInCharClass(this.ranges[i]));
                    } else {
                        sb.append(escapeCharInCharClass(this.ranges[i]));
                        sb.append('-');
                        sb.append(escapeCharInCharClass(this.ranges[i+1]));
                    }
                }
                sb.append(']');
                ret = sb.toString();
            }
        }
        return ret;
    }

    private static String escapeCharInCharClass(int ch) {
        String ret;
        switch (ch) {
          case '[':  case ']':  case '-':  case '^':
          case ',':  case '\\':
            ret = "\\"+(char)ch;
            break;
          case '\f':  ret = "\\f";  break;
          case '\n':  ret = "\\n";  break;
          case '\r':  ret = "\\r";  break;
          case '\t':  ret = "\\t";  break;
          case 0x1b:  ret = "\\e";  break;
          //case 0x0b:  ret = "\\v";  break;
          default:
            if (ch < 0x20) {
                String pre = "0"+Integer.toHexString(ch);
                ret = "\\x"+pre.substring(pre.length()-2, pre.length());
            } else if (ch >= 0x10000) {
                String pre = "0"+Integer.toHexString(ch);
                ret = "\\v"+pre.substring(pre.length()-6, pre.length());
            } else
                ret = ""+(char)ch;
        }
        return ret;
    }

}


/**
 * A Regular Expression Parser.
 * 
 * @xerces.internal
 *
 * @version $Id: RegexParser.java 1033661 2010-11-10 19:31:44Z knoaman $
 */
static class RegexParser {
    static final int T_CHAR = 0;
    static final int T_EOF = 1;
    static final int T_OR = 2;                  // '|'
    static final int T_STAR = 3;                // '*'
    static final int T_PLUS = 4;                // '+'
    static final int T_QUESTION = 5;            // '?'
    static final int T_LPAREN = 6;              // '('
    static final int T_RPAREN = 7;              // ')'
    static final int T_DOT = 8;                 // '.'
    static final int T_LBRACKET = 9;            // '['
    static final int T_BACKSOLIDUS = 10;        // '\'
    static final int T_CARET = 11;              // '^'
    static final int T_DOLLAR = 12;             // '$'
    static final int T_LPAREN2 = 13;            // '(?:'
    static final int T_LOOKAHEAD = 14;          // '(?='
    static final int T_NEGATIVELOOKAHEAD = 15;  // '(?!'
    static final int T_LOOKBEHIND = 16;         // '(?<='
    static final int T_NEGATIVELOOKBEHIND = 17; // '(?<!'
    static final int T_INDEPENDENT = 18;        // '(?>'
    static final int T_SET_OPERATIONS = 19;     // '(?['
    static final int T_POSIX_CHARCLASS_START = 20; // '[:' in a character class
    static final int T_COMMENT = 21;            // '(?#'
    static final int T_MODIFIERS = 22;          // '(?' [\-,a-z,A-Z]
    static final int T_CONDITION = 23;          // '(?('
    static final int T_XMLSCHEMA_CC_SUBTRACTION = 24; // '-[' in a character class

    static class ReferencePosition {
        int refNumber;
        int position;
        ReferencePosition(int n, int pos) {
            this.refNumber = n;
            this.position = pos;
        }
    }

    int offset;
    String regex;
    int regexlen;
    int options;
    ResourceBundle resources;
    int chardata;
    int nexttoken;
    static protected final int S_NORMAL = 0;
    static protected final int S_INBRACKETS = 1;
    static protected final int S_INXBRACKETS = 2;
    int context = S_NORMAL;
    int parenOpened = 1;
    int parennumber = 1;
    boolean hasBackReferences;
    Vector references = null;

    public RegexParser() {
        this.setLocale(Locale.getDefault());
    }
    public RegexParser(Locale locale) {
        this.setLocale(locale);
    }

    public void setLocale(Locale locale) {
      /*
        try {
            if (locale != null) {
                this.resources = ResourceBundle.getBundle("org.apache.xerces.impl.xpath.regex.message", locale);
            }
            else {
                this.resources = ResourceBundle.getBundle("org.apache.xerces.impl.xpath.regex.message");
            }
        } 
        catch (MissingResourceException mre) {
            throw new RuntimeException("Installation Problem???  Couldn't load messages: "
                                       + mre.getMessage());
        }
        */
    }

    final ParseException ex(String key, int loc) {
        return new ParseException(EcorePlugin.INSTANCE.getString(key), loc);
    }

    protected final boolean isSet(int flag) {
        return (this.options & flag) == flag;
    }

    synchronized Token parse(String regex, int options) throws ParseException {
        this.options = options;
        this.offset = 0;
        this.setContext(S_NORMAL);
        this.parennumber = 1;
        this.parenOpened = 1;
        this.hasBackReferences = false;
        this.regex = regex;
        if (this.isSet(RegularExpression.EXTENDED_COMMENT))
            this.regex = REUtil.stripExtendedComment(this.regex);
        this.regexlen = this.regex.length();


        this.next();
        Token ret = this.parseRegex();
        if (this.offset != this.regexlen)
            throw ex("parser.parse.1", this.offset);
        if (this.references != null) {
            for (int i = 0;  i < this.references.size();  i ++) {
                ReferencePosition position = (ReferencePosition)this.references.elementAt(i);
                if (this.parennumber <= position.refNumber)
                    throw ex("parser.parse.2", position.position);
            }
            this.references.removeAllElements();
        }
        return ret;
    }

    /*
    public RegularExpression createRegex(String regex, int options) throws ParseException {
        Token tok = this.parse(regex, options);
        return new RegularExpression(regex, tok, this.parennumber, this.hasBackReferences, options);
    }
    */

    protected final void setContext(int con) {
        this.context = con;
    }

    final int read() {
        return this.nexttoken;
    }

    final void next() {
        if (this.offset >= this.regexlen) {
            this.chardata = -1;
            this.nexttoken = T_EOF;
            return;
        }

        int ret;
        int ch = this.regex.charAt(this.offset++);
        this.chardata = ch;

        if (this.context == S_INBRACKETS) {
            // In a character class, this.chardata has one character, that is to say,
            // a pair of surrogates is composed and stored to this.chardata.
            switch (ch) {
              case '\\':
                ret = T_BACKSOLIDUS;
                if (this.offset >= this.regexlen)
                    throw ex("parser.next.1", this.offset-1);
                this.chardata = this.regex.charAt(this.offset++);
                break;

              case '-':
                // Allow character class subtraction (regardless of whether we are in
                // XML Schema mode or not)
                if (this.offset < this.regexlen && this.regex.charAt(this.offset) == '[') {
                    this.offset++;
                    ret = T_XMLSCHEMA_CC_SUBTRACTION;
                } else
                    ret = T_CHAR;
                break;

              case '[':
                if (!this.isSet(RegularExpression.XMLSCHEMA_MODE)
                    && this.offset < this.regexlen && this.regex.charAt(this.offset) == ':') {
                    this.offset++;
                    ret = T_POSIX_CHARCLASS_START;
                    break;
                } // Through down
              default:
                if (REUtil.isHighSurrogate(ch) && this.offset < this.regexlen) {
                    int low = this.regex.charAt(this.offset);
                    if (REUtil.isLowSurrogate(low)) {
                        this.chardata = REUtil.composeFromSurrogates(ch, low);
                        this.offset ++;
                    }
                }
                ret = T_CHAR;
            }
            this.nexttoken = ret;
            return;
        }

        switch (ch) {
          case '|': ret = T_OR;             break;
          case '*': ret = T_STAR;           break;
          case '+': ret = T_PLUS;           break;
          case '?': ret = T_QUESTION;       break;
          case ')': ret = T_RPAREN;         break;
          case '.': ret = T_DOT;            break;
          case '[': ret = T_LBRACKET;       break;
          case '^':
              if (this.isSet(RegularExpression.XMLSCHEMA_MODE)) {
                  ret = T_CHAR;
              }
              else {
                  ret = T_CARET;
              }
              break;
          case '$': 
              if (this.isSet(RegularExpression.XMLSCHEMA_MODE)) {
                  ret = T_CHAR;
              }
              else {
                  ret = T_DOLLAR;
              }
              break;
          case '(':
            ret = T_LPAREN;
            if (this.offset >= this.regexlen)
                break;
            if (this.regex.charAt(this.offset) != '?')
                break;
            if (++this.offset >= this.regexlen)
                throw ex("parser.next.2", this.offset-1);
            ch = this.regex.charAt(this.offset++);
            switch (ch) {
              case ':':  ret = T_LPAREN2;            break;
              case '=':  ret = T_LOOKAHEAD;          break;
              case '!':  ret = T_NEGATIVELOOKAHEAD;  break;
              case '[':  ret = T_SET_OPERATIONS;     break;
              case '>':  ret = T_INDEPENDENT;        break;
              case '<':
                if (this.offset >= this.regexlen)
                    throw ex("parser.next.2", this.offset-3);
                ch = this.regex.charAt(this.offset++);
                if (ch == '=') {
                    ret = T_LOOKBEHIND;
                } else if (ch == '!') {
                    ret = T_NEGATIVELOOKBEHIND;
                } else
                    throw ex("parser.next.3", this.offset-3);
                break;
              case '#':
                while (this.offset < this.regexlen) {
                    ch = this.regex.charAt(this.offset++);
                    if (ch == ')')  break;
                }
                if (ch != ')')
                    throw ex("parser.next.4", this.offset-1);
                ret = T_COMMENT;
                break;
              default:
                if (ch == '-' || 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z') {// Options
                    this.offset --;
                    ret = T_MODIFIERS;
                    break;
                } else if (ch == '(') {         // conditional
                    ret = T_CONDITION;          // this.offsets points the next of '('.
                    break;
                }
                throw ex("parser.next.2", this.offset-2);
            }
            break;
            
          case '\\':
            ret = T_BACKSOLIDUS;
            if (this.offset >= this.regexlen)
                throw ex("parser.next.1", this.offset-1);
            this.chardata = this.regex.charAt(this.offset++);
            break;

          default:
            ret = T_CHAR;
        }
        this.nexttoken = ret;
    }

    /**
     * regex ::= term (`|` term)*
     * term ::= factor+
     * factor ::= ('^' | '$' | '\A' | '\Z' | '\z' | '\b' | '\B' | '\<' | '\>'
     *            | atom (('*' | '+' | '?' | minmax ) '?'? )?)
     *            | '(?=' regex ')'  | '(?!' regex ')'  | '(?&lt;=' regex ')'  | '(?&lt;!' regex ')'
     * atom ::= char | '.' | range | '(' regex ')' | '(?:' regex ')' | '\' [0-9]
     *          | '\w' | '\W' | '\d' | '\D' | '\s' | '\S' | category-block 
     */
    Token parseRegex() throws ParseException {
        Token tok = this.parseTerm();
        Token parent = null;
        while (this.read() == T_OR) {
            this.next();                    // '|'
            if (parent == null) {
                parent = Token.createUnion();
                parent.addChild(tok);
                tok = parent;
            }
            tok.addChild(this.parseTerm());
        }
        return tok;
    }

    /**
     * term ::= factor+
     */
    Token parseTerm() throws ParseException {
        int ch = this.read();
        if (ch == T_OR || ch == T_RPAREN || ch == T_EOF) {
            return Token.createEmpty();
        } else {
            Token tok = this.parseFactor();
            Token concat = null;
            while ((ch = this.read()) != T_OR && ch != T_RPAREN && ch != T_EOF) {
                if (concat == null) {
                    concat = Token.createConcat();
                    concat.addChild(tok);
                    tok = concat;
                }
                concat.addChild(this.parseFactor());
                //tok = Token.createConcat(tok, this.parseFactor());
            }
            return tok;
        }
    }

    // ----------------------------------------------------------------

    Token processCaret() throws ParseException {
        this.next();
        return Token.token_linebeginning;
    }
    Token processDollar() throws ParseException {
        this.next();
        return Token.token_lineend;
    }
    Token processLookahead() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.LOOKAHEAD, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // ')'
        return tok;
    }
    Token processNegativelookahead() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.NEGATIVELOOKAHEAD, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // ')'
        return tok;
    }
    Token processLookbehind() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.LOOKBEHIND, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // ')'
        return tok;
    }
    Token processNegativelookbehind() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.NEGATIVELOOKBEHIND, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                    // ')'
        return tok;
    }
    Token processBacksolidus_A() throws ParseException {
        this.next();
        return Token.token_stringbeginning;
    }
    Token processBacksolidus_Z() throws ParseException {
        this.next();
        return Token.token_stringend2;
    }
    Token processBacksolidus_z() throws ParseException {
        this.next();
        return Token.token_stringend;
    }
    Token processBacksolidus_b() throws ParseException {
        this.next();
        return Token.token_wordedge;
    }
    Token processBacksolidus_B() throws ParseException {
        this.next();
        return Token.token_not_wordedge;
    }
    Token processBacksolidus_lt() throws ParseException {
        this.next();
        return Token.token_wordbeginning;
    }
    Token processBacksolidus_gt() throws ParseException {
        this.next();
        return Token.token_wordend;
    }
    Token processStar(Token tok) throws ParseException {
        this.next();
        if (this.read() == T_QUESTION) {
            this.next();
            return Token.createNGClosure(tok);
        } else
            return Token.createClosure(tok);
    }
    Token processPlus(Token tok) throws ParseException {
        // X+ -> XX*
        this.next();
        if (this.read() == T_QUESTION) {
            this.next();
            return Token.createConcat(tok, Token.createNGClosure(tok));
        } else
            return Token.createConcat(tok, Token.createClosure(tok));
    }
    Token processQuestion(Token tok) throws ParseException {
        // X? -> X|
        this.next();
        Token par = Token.createUnion();
        if (this.read() == T_QUESTION) {
            this.next();
            par.addChild(Token.createEmpty());
            par.addChild(tok);
        } else {
            par.addChild(tok);
            par.addChild(Token.createEmpty());
        }
        return par;
    }
    boolean checkQuestion(int off) {
        return off < this.regexlen && this.regex.charAt(off) == '?';
    }
    Token processParen() throws ParseException {
        this.next();
        int p = this.parenOpened++;
        Token tok = Token.createParen(this.parseRegex(), p);
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.parennumber++;
        this.next();                            // Skips ')'
        return tok;
    }
    Token processParen2() throws ParseException {
        this.next();
        Token tok = Token.createParen(this.parseRegex(), 0);
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processCondition() throws ParseException {
                                                // this.offset points the next of '('
        if (this.offset+1 >= this.regexlen)  throw ex("parser.factor.4", this.offset);
                                                // Parses a condition.
        int refno = -1;
        Token condition = null;
        int ch = this.regex.charAt(this.offset);
        if ('1' <= ch && ch <= '9') {
            refno = ch-'0';
            int finalRefno = refno;
            
            if (this.parennumber <= refno)
                throw ex("parser.parse.2", this.offset);

            while (this.offset + 1 < this.regexlen) {
                ch = this.regex.charAt(this.offset + 1);
                if ('0' <= ch && ch <= '9') {
                    refno = (refno * 10) + (ch - '0');
                    if (refno < this.parennumber) {
                        finalRefno= refno;
                        ++this.offset;
                    }
                    else {
                        break;
                    }
                }
                else {
                    break;
                }
            }

            this.hasBackReferences = true;
            if (this.references == null)  this.references = new Vector();
            this.references.addElement(new ReferencePosition(finalRefno, this.offset));
            this.offset ++;
            if (this.regex.charAt(this.offset) != ')')  throw ex("parser.factor.1", this.offset);
            this.offset ++;
        } else {
            if (ch == '?')  this.offset --; // Points '('.
            this.next();
            condition = this.parseFactor();
            switch (condition.type) {
              case Token.LOOKAHEAD:
              case Token.NEGATIVELOOKAHEAD:
              case Token.LOOKBEHIND:
              case Token.NEGATIVELOOKBEHIND:
                break;
              case Token.ANCHOR:
                if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
                break;
              default:
                throw ex("parser.factor.5", this.offset);
            }
        }
                                                // Parses yes/no-patterns.
        this.next();
        Token yesPattern = this.parseRegex();
        Token noPattern = null;
        if (yesPattern.type == Token.UNION) {
            if (yesPattern.size() != 2)  throw ex("parser.factor.6", this.offset);
            noPattern = yesPattern.getChild(1);
            yesPattern = yesPattern.getChild(0);
        }
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();
        return Token.createCondition(refno, condition, yesPattern, noPattern);
    }
    Token processModifiers() throws ParseException {
                                                // this.offset points the next of '?'.
                                                // modifiers ::= [imsw]* ('-' [imsw]*)? ':'
        int add = 0, mask = 0, ch = -1;
        while (this.offset < this.regexlen) {
            ch = this.regex.charAt(this.offset);
            int v = REUtil.getOptionValue(ch);
            if (v == 0)  break;                 // '-' or ':'?
            add |= v;
            this.offset ++;
        }
        if (this.offset >= this.regexlen)  throw ex("parser.factor.2", this.offset-1);
        if (ch == '-') {
            this.offset ++;
            while (this.offset < this.regexlen) {
                ch = this.regex.charAt(this.offset);
                int v = REUtil.getOptionValue(ch);
                if (v == 0)  break;             // ':'?
                mask |= v;
                this.offset ++;
            }
            if (this.offset >= this.regexlen)  throw ex("parser.factor.2", this.offset-1);
        }
        Token tok;
        if (ch == ':') {
            this.offset ++;
            this.next();
            tok = Token.createModifierGroup(this.parseRegex(), add, mask);
            if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
            this.next();
        } else if (ch == ')') {                 // such as (?-i)
            this.offset ++;
            this.next();
            tok = Token.createModifierGroup(this.parseRegex(), add, mask);
        } else
            throw ex("parser.factor.3", this.offset);

        return tok;
    }
    Token processIndependent() throws ParseException {
        this.next();
        Token tok = Token.createLook(Token.INDEPENDENT, this.parseRegex());
        if (this.read() != T_RPAREN)  throw ex("parser.factor.1", this.offset-1);
        this.next();                            // Skips ')'
        return tok;
    }
    Token processBacksolidus_c() throws ParseException {
        int ch2;                                // Must be in 0x0040-0x005f
        if (this.offset >= this.regexlen
            || ((ch2 = this.regex.charAt(this.offset++)) & 0xffe0) != 0x0040)
            throw ex("parser.atom.1", this.offset-1);
        this.next();
        return Token.createChar(ch2-0x40);
    }
    Token processBacksolidus_C() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_i() throws ParseException {
        Token tok = Token.createChar('i');
        this.next();
        return tok;
    }
    Token processBacksolidus_I() throws ParseException {
        throw ex("parser.process.1", this.offset);
    }
    Token processBacksolidus_g() throws ParseException {
        this.next();
        return Token.getGraphemePattern();
    }
    Token processBacksolidus_X() throws ParseException {
        this.next();
        return Token.getCombiningCharacterSequence();
    }
    Token processBackreference() throws ParseException {
        int refnum = this.chardata-'0';
        int finalRefnum = refnum;

        if (this.parennumber <= refnum)
            throw ex("parser.parse.2", this.offset-2);

        while  (this.offset < this.regexlen) {
            final int ch = this.regex.charAt(this.offset);
            if ('0' <= ch && ch <= '9') {
                refnum = (refnum * 10) + (ch - '0');
                if (refnum < this.parennumber) {
                    ++this.offset;
                    finalRefnum = refnum;
                    this.chardata = ch;
                }
                else {
                    break;
                }
            }
            else {
                break;
            }
        }

        Token tok = Token.createBackReference(finalRefnum);
        this.hasBackReferences = true;
        if (this.references == null)  this.references = new Vector();
        this.references.addElement(new ReferencePosition(finalRefnum, this.offset-2));
        this.next();
        return tok;
    }

    // ----------------------------------------------------------------

    /**
     * factor ::= ('^' | '$' | '\A' | '\Z' | '\z' | '\b' | '\B' | '\<' | '\>'
     *            | atom (('*' | '+' | '?' | minmax ) '?'? )?)
     *            | '(?=' regex ')'  | '(?!' regex ')'  | '(?&lt;=' regex ')'  | '(?&lt;!' regex ')'
     *            | '(?#' [^)]* ')'
     * minmax ::= '{' min (',' max?)? '}'
     * min ::= [0-9]+
     * max ::= [0-9]+
     */
    Token parseFactor() throws ParseException {        
        int ch = this.read();
        Token tok;
        switch (ch) {
          case T_CARET:         return this.processCaret();
          case T_DOLLAR:        return this.processDollar();
          case T_LOOKAHEAD:     return this.processLookahead();
          case T_NEGATIVELOOKAHEAD: return this.processNegativelookahead();
          case T_LOOKBEHIND:    return this.processLookbehind();
          case T_NEGATIVELOOKBEHIND: return this.processNegativelookbehind();

          case T_COMMENT:
            this.next();
            return Token.createEmpty();

          case T_BACKSOLIDUS:
            switch (this.chardata) {
              case 'A': return this.processBacksolidus_A();
              case 'Z': return this.processBacksolidus_Z();
              case 'z': return this.processBacksolidus_z();
              case 'b': return this.processBacksolidus_b();
              case 'B': return this.processBacksolidus_B();
              case '<': return this.processBacksolidus_lt();
              case '>': return this.processBacksolidus_gt();
            }
                                                // through down
        }
        tok = this.parseAtom();
        ch = this.read();
        switch (ch) {
          case T_STAR:  return this.processStar(tok);
          case T_PLUS:  return this.processPlus(tok);
          case T_QUESTION: return this.processQuestion(tok);
          case T_CHAR:
            if (this.chardata == '{' && this.offset < this.regexlen) {

                int off = this.offset;          // this.offset -> next of '{'
                int min = 0, max = -1;

                if ((ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {

                    min = ch -'0';
                    while (off < this.regexlen
                           && (ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {
                        min = min*10 +ch-'0';
                        if (min < 0)
                            throw ex("parser.quantifier.5", this.offset);
                    }
                }
                else {
                    throw ex("parser.quantifier.1", this.offset);
                }

                max = min;
                if (ch == ',') {

                   if (off >= this.regexlen) {
                       throw ex("parser.quantifier.3", this.offset);
                   }
                   else if ((ch = this.regex.charAt(off++)) >= '0' && ch <= '9') {                       

                        max = ch -'0';       // {min,max}
                        while (off < this.regexlen
                               && (ch = this.regex.charAt(off++)) >= '0'
                               && ch <= '9') {
                            max = max*10 +ch-'0';
                            if (max < 0)
                                throw ex("parser.quantifier.5", this.offset);
                        }

                        if (min > max)
                            throw ex("parser.quantifier.4", this.offset);
                   }
                   else { // assume {min,}
                        max = -1;           
                    }
                }

               if (ch != '}')
                   throw ex("parser.quantifier.2", this.offset);

               if (this.checkQuestion(off)) {  // off -> next of '}'
                    tok = Token.createNGClosure(tok);
                    this.offset = off+1;
                } else {
                    tok = Token.createClosure(tok);
                    this.offset = off;
                }

                tok.setMin(min);
                tok.setMax(max);
                //System.err.println("CLOSURE: "+min+", "+max);
                this.next();
            }
        }
        return tok;
    }

    /**
     * atom ::= char | '.' | char-class | '(' regex ')' | '(?:' regex ')' | '\' [0-9]
     *          | '\w' | '\W' | '\d' | '\D' | '\s' | '\S' | category-block
     *          | '(?>' regex ')'
     * char ::= '\\' | '\' [efnrt] | bmp-code | character-1
     */
    Token parseAtom() throws ParseException {
        int ch = this.read();
        Token tok = null;
        switch (ch) {
          case T_LPAREN:        return this.processParen();
          case T_LPAREN2:       return this.processParen2(); // '(?:'
          case T_CONDITION:     return this.processCondition(); // '(?('
          case T_MODIFIERS:     return this.processModifiers(); // (?modifiers ... )
          case T_INDEPENDENT:   return this.processIndependent();
          case T_DOT:
            this.next();                    // Skips '.'
            tok = Token.token_dot;
            break;

            /**
             * char-class ::= '[' ( '^'? range ','?)+ ']'
             * range ::= '\d' | '\w' | '\s' | category-block | range-char
             *           | range-char '-' range-char
             * range-char ::= '\[' | '\]' | '\\' | '\' [,-efnrtv] | bmp-code | character-2
             * bmp-char ::= '\' 'u' [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F]
             */
          case T_LBRACKET:      return this.parseCharacterClass(true);
          case T_SET_OPERATIONS: return this.parseSetOperations();

          case T_BACKSOLIDUS:
            switch (this.chardata) {
              case 'd':  case 'D':
              case 'w':  case 'W':
              case 's':  case 'S':
                tok = this.getTokenForShorthand(this.chardata);
                this.next();
                return tok;

              case 'e':  case 'f':  case 'n':  case 'r':
              case 't':  case 'u':  case 'v':  case 'x':
                {
                    int ch2 = this.decodeEscaped();
                    if (ch2 < 0x10000) {
                        tok = Token.createChar(ch2);
                    } else {
                        tok = Token.createString(REUtil.decomposeToSurrogates(ch2));
                    }
                }
                break;

              case 'c': return this.processBacksolidus_c();
              case 'C': return this.processBacksolidus_C();
              case 'i': return this.processBacksolidus_i();
              case 'I': return this.processBacksolidus_I();
              case 'g': return this.processBacksolidus_g();
              case 'X': return this.processBacksolidus_X();
              case '1':  case '2':  case '3':  case '4':
              case '5':  case '6':  case '7':  case '8':  case '9':
                return this.processBackreference();

              case 'P':
              case 'p':
                int pstart = this.offset;
                tok = processBacksolidus_pP(this.chardata);
                if (tok == null)  throw this.ex("parser.atom.5", pstart);
                break;

              default:
                tok = Token.createChar(this.chardata);
            }
            this.next();
            break;

          case T_CHAR:
            if (this.chardata == ']' || this.chardata == '{' || this.chardata == '}')
                throw this.ex("parser.atom.4", this.offset-1);
            tok = Token.createChar(this.chardata);
            int high = this.chardata;
            this.next();
            if (REUtil.isHighSurrogate(high)
                && this.read() == T_CHAR && REUtil.isLowSurrogate(this.chardata)) {
                char[] sur = new char[2];
                sur[0] = (char)high;
                sur[1] = (char)this.chardata;
                tok = Token.createParen(Token.createString(new String(sur)), 0);
                this.next();
            }
            break;

          default:
            throw this.ex("parser.atom.4", this.offset-1);
        }
        return tok;
    }

    protected RangeToken processBacksolidus_pP(int c) throws ParseException {

        this.next();
        if (this.read() != T_CHAR || this.chardata != '{')
            throw this.ex("parser.atom.2", this.offset-1);

        // handle category escape
        boolean positive = c == 'p';
        int namestart = this.offset;
        int nameend = this.regex.indexOf('}', namestart);

        if (nameend < 0)
            throw this.ex("parser.atom.3", this.offset);

        String pname = this.regex.substring(namestart, nameend);
        this.offset = nameend+1;

        return Token.getRange(pname, positive, this.isSet(RegularExpression.XMLSCHEMA_MODE));
    }

    int processCIinCharacterClass(RangeToken tok, int c) {
        return this.decodeEscaped();
    }

    /**
     * char-class ::= '[' ( '^'? range ','?)+ ']'
     * range ::= '\d' | '\w' | '\s' | category-block | range-char
     *           | range-char '-' range-char
     * range-char ::= '\[' | '\]' | '\\' | '\' [,-efnrtv] | bmp-code | character-2
     * bmp-code ::= '\' 'u' [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F] [0-9a-fA-F]
     */
    protected RangeToken parseCharacterClass(boolean useNrange) throws ParseException {
        this.setContext(S_INBRACKETS);
        this.next();                            // '['
        boolean nrange = false;
        RangeToken base = null;
        RangeToken tok;
        if (this.read() == T_CHAR && this.chardata == '^') {
            nrange = true;
            this.next();                        // '^'
            if (useNrange) {
                tok = Token.createNRange();
            } else {
                base = Token.createRange();
                base.addRange(0, Token.UTF16_MAX);
                tok = Token.createRange();
            }
        } else {
            tok = Token.createRange();
        }
        int type;
        boolean firstloop = true;
        while ((type = this.read()) != T_EOF) {
            if (type == T_CHAR && this.chardata == ']' && !firstloop)
                break;
            int c = this.chardata;
            boolean end = false;
            if (type == T_BACKSOLIDUS) {
                switch (c) {
                  case 'd':  case 'D':
                  case 'w':  case 'W':
                  case 's':  case 'S':
                    tok.mergeRanges(this.getTokenForShorthand(c));
                    end = true;
                    break;

                  case 'i':  case 'I':
                  case 'c':  case 'C':
                    c = this.processCIinCharacterClass(tok, c);
                    if (c < 0)  end = true;
                    break;
                    
                  case 'p':
                  case 'P':
                    int pstart = this.offset;
                    RangeToken tok2 = this.processBacksolidus_pP(c);
                    if (tok2 == null)  throw this.ex("parser.atom.5", pstart);
                    tok.mergeRanges(tok2);
                    end = true;
                    break;

                  default:
                    c = this.decodeEscaped();
                } // \ + c
            } // backsolidus
                                                // POSIX Character class such as [:alnum:]
            else if (type == T_POSIX_CHARCLASS_START) {
                int nameend = this.regex.indexOf(':', this.offset);
                if (nameend < 0) throw this.ex("parser.cc.1", this.offset);
                boolean positive = true;
                if (this.regex.charAt(this.offset) == '^') {
                    this.offset ++;
                    positive = false;
                }
                String name = this.regex.substring(this.offset, nameend);
                RangeToken range = Token.getRange(name, positive,
                                                  this.isSet(RegularExpression.XMLSCHEMA_MODE));
                if (range == null)  throw this.ex("parser.cc.3", this.offset);
                tok.mergeRanges(range);
                end = true;
                if (nameend+1 >= this.regexlen || this.regex.charAt(nameend+1) != ']')
                    throw this.ex("parser.cc.1", nameend);
                this.offset = nameend+2;
            }
            else if (type == T_XMLSCHEMA_CC_SUBTRACTION && !firstloop) {
                if (nrange) {
                    nrange = false;
                    if (useNrange) {
                        tok = (RangeToken) Token.complementRanges(tok);
                    }
                    else {
                        base.subtractRanges(tok);
                        tok = base;
                    }
                }
                RangeToken range2 = this.parseCharacterClass(false);
                tok.subtractRanges(range2);
                if (this.read() != T_CHAR || this.chardata != ']') {
                    throw this.ex("parser.cc.5", this.offset);
                }
                break;                          // Exit this loop
            }
            this.next();
            if (!end) {                         // if not shorthands...
                if (this.read() != T_CHAR || this.chardata != '-') { // Here is no '-'.
                    if (!this.isSet(RegularExpression.IGNORE_CASE) || c > 0xffff) {
                        tok.addRange(c, c);
                    }
                    else {
                        addCaseInsensitiveChar(tok, c);
                    }
                }
                else if (type == T_XMLSCHEMA_CC_SUBTRACTION) {
                    throw this.ex("parser.cc.8", this.offset-1);
                }
                else {
                    this.next(); // Skips '-'
                    if ((type = this.read()) == T_EOF)  throw this.ex("parser.cc.2", this.offset);
                    if (type == T_CHAR && this.chardata == ']') {
                        if (!this.isSet(RegularExpression.IGNORE_CASE) || c > 0xffff) {
                            tok.addRange(c, c);
                        }
                        else {
                            addCaseInsensitiveChar(tok, c);
                        }
                        tok.addRange('-', '-');
                    } else {
                        int rangeend = this.chardata;
                        if (type == T_BACKSOLIDUS) {
                            rangeend = this.decodeEscaped();
                        }
                        this.next();
                        if (c > rangeend) {
                            throw this.ex("parser.ope.3", this.offset-1);
                        }
                        if (!this.isSet(RegularExpression.IGNORE_CASE) ||
                                (c > 0xffff && rangeend > 0xffff)) {
                            tok.addRange(c, rangeend);
                        }
                        else {
                            addCaseInsensitiveCharRange(tok, c, rangeend);
                        }
                    }
                }
            }
            if (this.isSet(RegularExpression.SPECIAL_COMMA)
                && this.read() == T_CHAR && this.chardata == ',') {
                this.next();
            }
            firstloop = false;
        }
        if (this.read() == T_EOF) {
            throw this.ex("parser.cc.2", this.offset);
        }
        
        if (!useNrange && nrange) {
            base.subtractRanges(tok);
            tok = base;
        }
        tok.sortRanges();
        tok.compactRanges();
        this.setContext(S_NORMAL);
        this.next();                    // Skips ']'

        return tok;
    }

    /**
     * '(?[' ... ']' (('-' | '+' | '&') '[' ... ']')? ')'
     */
    protected RangeToken parseSetOperations() throws ParseException {
        RangeToken tok = this.parseCharacterClass(false);
        int type;
        while ((type = this.read()) != T_RPAREN) {
            int ch = this.chardata;
            if (type == T_CHAR && (ch == '-' || ch == '&')
                || type == T_PLUS) {
                this.next();
                if (this.read() != T_LBRACKET) throw ex("parser.ope.1", this.offset-1);
                RangeToken t2 = this.parseCharacterClass(false);
                if (type == T_PLUS)
                    tok.mergeRanges(t2);
                else if (ch == '-')
                    tok.subtractRanges(t2);
                else if (ch == '&')
                    tok.intersectRanges(t2);
                else
                    throw new RuntimeException("ASSERT");
            } else {
                throw ex("parser.ope.2", this.offset-1);
            }
        }
        this.next();
        return tok;
    }

    Token getTokenForShorthand(int ch) {
        Token tok;
        switch (ch) {
          case 'd':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("Nd", true) : Token.token_0to9;
            break;
          case 'D':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("Nd", false) : Token.token_not_0to9;
            break;
          case 'w':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("IsWord", true) : Token.token_wordchars;
            break;
          case 'W':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("IsWord", false) : Token.token_not_wordchars;
            break;
          case 's':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("IsSpace", true) : Token.token_spaces;
            break;
          case 'S':
            tok = this.isSet(RegularExpression.USE_UNICODE_CATEGORY)
                ? Token.getRange("IsSpace", false) : Token.token_not_spaces;
            break;

          default:
            throw new RuntimeException("Internal Error: shorthands: \\u"+Integer.toString(ch, 16));
        }
        return tok;
    }

    /**
     */
    int decodeEscaped() throws ParseException {
        if (this.read() != T_BACKSOLIDUS)  throw ex("parser.next.1", this.offset-1);
        int c = this.chardata;
        switch (c) {
          case 'e':  c = 0x1b;  break; // ESCAPE U+001B
          case 'f':  c = '\f';  break; // FORM FEED U+000C
          case 'n':  c = '\n';  break; // LINE FEED U+000A
          case 'r':  c = '\r';  break; // CRRIAGE RETURN U+000D
          case 't':  c = '\t';  break; // HORIZONTAL TABULATION U+0009
          //case 'v':  c = 0x0b;  break; // VERTICAL TABULATION U+000B
          case 'x':
            this.next();
            if (this.read() != T_CHAR)  throw ex("parser.descape.1", this.offset-1);
            if (this.chardata == '{') {
                int v1 = 0;
                int uv = 0;
                do {
                    this.next();
                    if (this.read() != T_CHAR)  throw ex("parser.descape.1", this.offset-1);
                    if ((v1 = hexChar(this.chardata)) < 0)
                        break;
                    if (uv > uv*16) throw ex("parser.descape.2", this.offset-1);
                    uv = uv*16+v1;
                } while (true);
                if (this.chardata != '}')  throw ex("parser.descape.3", this.offset-1);
                if (uv > Token.UTF16_MAX)  throw ex("parser.descape.4", this.offset-1);
                c = uv;
            } else {
                int v1 = 0;
                if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                    throw ex("parser.descape.1", this.offset-1);
                int uv = v1;
                this.next();
                if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                    throw ex("parser.descape.1", this.offset-1);
                uv = uv*16+v1;
                c = uv;
            }
            break;

          case 'u':
            int v1 = 0;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            int uv = v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            c = uv;
            break;

          case 'v':
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            this.next();
            if (this.read() != T_CHAR || (v1 = hexChar(this.chardata)) < 0)
                throw ex("parser.descape.1", this.offset-1);
            uv = uv*16+v1;
            if (uv > Token.UTF16_MAX)  throw ex("parser.descappe.4", this.offset-1);
            c = uv;
            break;
          case 'A':
          case 'Z':
          case 'z':
            throw ex("parser.descape.5", this.offset-2);
          default:
        }
        return c;
    }

    static private final int hexChar(int ch) {
        if (ch < '0')  return -1;
        if (ch > 'f')  return -1;
        if (ch <= '9')  return ch-'0';
        if (ch < 'A')  return -1;
        if (ch <= 'F')  return ch-'A'+10;
        if (ch < 'a')  return -1;
        return ch-'a'+10;
    }
    
    static protected final void addCaseInsensitiveChar(RangeToken tok, int c) {
        final int[] caseMap = CaseInsensitiveMap.get(c);
        tok.addRange(c, c);
        
        if (caseMap != null) {
            for (int i=0; i<caseMap.length; i+=2) {
                tok.addRange(caseMap[i], caseMap[i]);
            }
        }

    }
    
    static protected final void addCaseInsensitiveCharRange(RangeToken tok, int start, int end) {
        int[] caseMap;
        int r1, r2;
        if (start <= end) {
            r1 = start;
            r2 = end;
        } else {
            r1 = end;
            r2 = start;
        }

        tok.addRange(r1, r2);
        for (int ch = r1;  ch <= r2;  ch++) {
            caseMap = CaseInsensitiveMap.get(ch);
            if (caseMap != null) {
                for (int i=0; i<caseMap.length; i+=2) {
                    tok.addRange(caseMap[i], caseMap[i]);
                }
            }
        }
    }
}


/**
 * 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 $
 */
public static 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;
        }
        
        final char charAt(int index) {
            return target.charAt(index);
        }
        
        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);
        }

        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;
        }

        char charAt(int index) {
            return target[index];
        }
        
        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;
        }

        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;
        }

        final char charAt(int index) {
            return target.setIndex(index);
        }

        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;
        }

        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.lang.String,int)
     * @see #setPattern(java.lang.String,int)
    static final int MARK_PARENS = 1<<0;
     */

    /**
     * "i"
     */
    static final int IGNORE_CASE = 1<<1;

    /**
     * "s"
     */
    static final int SINGLE_LINE = 1<<2;

    /**
     * "m"
     */
    static final int MULTIPLE_LINES = 1<<3;

    /**
     * "x"
     */
    static final int EXTENDED_COMMENT = 1<<4;

    /**
     * This option redefines <span class="REGEX"><kbd>\d \D \w \W \s \S</kbd></span>.
     *
     * @see #RegularExpression(java.lang.String,int)
     * @see #setPattern(java.lang.String,int)
     * @see #UNICODE_WORD_BOUNDARY
     */
    static final int USE_UNICODE_CATEGORY = 1<<5; // "u"

    /**
     * An option.
     * This enables to process locale-independent word boundary for <span class="REGEX"><kbd>\b \B \&lt; \></kbd></span>.
     * <p>By default, the engine considers a position between a word character
     * (<span class="REGEX"><Kbd>\w</kbd></span>) and a non word character
     * is a word boundary.
     * <p>By this option, the engine checks word boundaries with the method of
     * 'Unicode Regular Expression Guidelines' Revision 4.
     *
     * @see #RegularExpression(java.lang.String,int)
     * @see #setPattern(java.lang.String,int)
     */
    static final int UNICODE_WORD_BOUNDARY = 1<<6; // "w"

    /**
     * "H"
     */
    static final int PROHIBIT_HEAD_CHARACTER_OPTIMIZATION = 1<<7;
    /**
     * "F"
     */
    static final int PROHIBIT_FIXED_STRING_OPTIMIZATION = 1<<8;
    /**
     * "X". XML Schema mode.
     */
    static final int XMLSCHEMA_MODE = 1<<9;
    /**
     * ",".
     */
    static final int SPECIAL_COMMA = 1<<10;


    private static final boolean isSet(int options, int flag) {
        return (options & flag) == flag;
    }

    /**
     * Creates a new RegularExpression instance.
     *
     * @param regex A regular expression
     * @exception org.apache.xerces.utils.regex.ParseException <VAR>regex</VAR> is not conforming to the syntax.
     */
    public RegularExpression(String regex) throws ParseException {
        this(regex, null);
    }

    /**
     * Creates a new RegularExpression instance with options.
     *
     * @param regex A regular expression
     * @param options A String consisted of "i" "m" "s" "u" "w" "," "X"
     * @exception org.apache.xerces.utils.regex.ParseException <VAR>regex</VAR> is not conforming to the syntax.
     */
    public RegularExpression(String regex, String options) throws ParseException {
        this.setPattern(regex, options);
    }
    
    /**
     * Creates a new RegularExpression instance with options.
     *
     * @param regex A regular expression
     * @param options A String consisted of "i" "m" "s" "u" "w" "," "X"
     * @exception org.apache.xerces.utils.regex.ParseException <VAR>regex</VAR> is not conforming to the syntax.
     */
    public RegularExpression(String regex, String options, Locale locale) throws ParseException {
        this.setPattern(regex, options, locale);
    }

    RegularExpression(String regex, Token tok, int parens, boolean hasBackReferences, int options) {
        this.regex = regex;
        this.tokentree = tok;
        this.nofparen = parens;
        this.options = options;
        this.hasBackReferences = hasBackReferences;
    }

    /**
     *
     */
    public void setPattern(String newPattern) throws ParseException {
        this.setPattern(newPattern, Locale.getDefault());
    }
    
    public void setPattern(String newPattern, Locale locale) throws ParseException {
        this.setPattern(newPattern, this.options, locale);
    }

    private void setPattern(String newPattern, int options, Locale locale) throws ParseException {
        this.regex = newPattern;
        this.options = options;
        RegexParser rp = RegularExpression.isSet(this.options, RegularExpression.XMLSCHEMA_MODE)
                         ? new ParserForXMLSchema(locale) : new RegexParser(locale);
        this.tokentree = rp.parse(this.regex, this.options);
        this.nofparen = rp.parennumber;
        this.hasBackReferences = rp.hasBackReferences;

        this.operations = null;
        this.context = null;
    }
    /**
     *
     */
    public void setPattern(String newPattern, String options) throws ParseException {
        this.setPattern(newPattern, options, Locale.getDefault());
    }
    
    public void setPattern(String newPattern, String options, Locale locale) throws ParseException {
        this.setPattern(newPattern, REUtil.parseOptions(options), locale);
    }

    /**
     *
     */
    public String getPattern() {
        return this.regex;
    }

    /**
     * Represents this instence in String.
     */
    public String toString() {
        return this.tokentree.toString(this.options);
    }

    /**
     * Returns a option string.
     * The order of letters in it may be different from a string specified
     * in a constructor or <code>setPattern()</code>.
     *
     * @see #RegularExpression(java.lang.String,java.lang.String)
     * @see #setPattern(java.lang.String,java.lang.String)
     */
    public String getOptions() {
        return REUtil.createOptionString(this.options);
    }

    /**
     *  Return true if patterns are the same and the options are equivalent.
     */
    public boolean equals(Object obj) {
        if (obj == null)  return false;
        if (!(obj instanceof RegularExpression))
            return false;
        RegularExpression r = (RegularExpression)obj;
        return this.regex.equals(r.regex) && this.options == r.options;
    }

    boolean equals(String pattern, int options) {
        return this.regex.equals(pattern) && this.options == options;
    }

    /**
     *
     */
    public int hashCode() {
        return (this.regex+"/"+this.getOptions()).hashCode();
    }

    /**
     * Return the number of regular expression groups.
     * This method returns 1 when the regular expression has no capturing-parenthesis.
     *
     */
    public int getNumberOfGroups() {
        return this.nofparen;
    }

    // ================================================================

    private static final int WT_IGNORE = 0;
    private static final int WT_LETTER = 1;
    private static final int WT_OTHER = 2;
    private static final int getWordType0(char ch, int opts) {
        if (!isSet(opts, UNICODE_WORD_BOUNDARY)) {
            if (isSet(opts, USE_UNICODE_CATEGORY)) {
                return (Token.getRange("IsWord", true).match(ch)) ? WT_LETTER : WT_OTHER;
            }
            return isWordChar(ch) ? WT_LETTER : WT_OTHER;
        }

        switch (Character.getType(ch)) {
        case Character.UPPERCASE_LETTER:      // L
        case Character.LOWERCASE_LETTER:      // L
        case Character.TITLECASE_LETTER:      // L
        case Character.MODIFIER_LETTER:       // L
        case Character.OTHER_LETTER:          // L
        case Character.LETTER_NUMBER:         // N
        case Character.DECIMAL_DIGIT_NUMBER:  // N
        case Character.OTHER_NUMBER:          // N
        case Character.COMBINING_SPACING_MARK: // Mc
            return WT_LETTER;

        case Character.FORMAT:                // Cf
        case Character.NON_SPACING_MARK:      // Mn
        case Character.ENCLOSING_MARK:        // Mc
            return WT_IGNORE;

        case Character.CONTROL:               // Cc
            switch (ch) {
            case '\t':
            case '\n':
            case '\u000B':
            case '\f':
            case '\r':
                return WT_OTHER;
            default:
                return WT_IGNORE;
            }

        default:
            return WT_OTHER;
        }
    }

    // ================================================================

    static final int LINE_FEED = 0x000A;
    static final int CARRIAGE_RETURN = 0x000D;
    static final int LINE_SEPARATOR = 0x2028;
    static final int PARAGRAPH_SEPARATOR = 0x2029;

    private static final boolean isEOLChar(int ch) {
        return ch == LINE_FEED || ch == CARRIAGE_RETURN || ch == LINE_SEPARATOR
        || ch == PARAGRAPH_SEPARATOR;
    }

    private static final boolean isWordChar(int ch) { // Legacy word characters
        if (ch == '_')  return true;
        if (ch < '0')  return false;
        if (ch > 'z')  return false;
        if (ch <= '9')  return true;
        if (ch < 'A')  return false;
        if (ch <= 'Z')  return true;
        if (ch < 'a')  return false;
        return true;
    }

    private static final boolean matchIgnoreCase(int chardata, int ch) {
        if (chardata == ch)  return true;
        if (chardata > 0xffff || ch > 0xffff)  return false;
        char uch1 = Character.toUpperCase((char)chardata);
        char uch2 = Character.toUpperCase((char)ch);
        if (uch1 == uch2)  return true;
        return Character.toLowerCase(uch1) == Character.toLowerCase(uch2);
    }
}


/**
 * @xerces.internal
 * 
 * @version $Id: REUtil.java 828015 2009-10-21 13:56:13Z knoaman $
 */
final static class REUtil {
    private REUtil() {
    }

    static final int composeFromSurrogates(int high, int low) {
        return 0x10000 + ((high-0xd800)<<10) + low-0xdc00;
    }

    static final boolean isLowSurrogate(int ch) {
        return (ch & 0xfc00) == 0xdc00;
    }

    static final boolean isHighSurrogate(int ch) {
        return (ch & 0xfc00) == 0xd800;
    }

    static final String decomposeToSurrogates(int ch) {
        char[] chs = new char[2];
        ch -= 0x10000;
        chs[0] = (char)((ch>>10)+0xd800);
        chs[1] = (char)((ch&0x3ff)+0xdc00);
        return new String(chs);
    }

    static final String substring(CharacterIterator iterator, int begin, int end) {
        char[] src = new char[end-begin];
        for (int i = 0;  i < src.length;  i ++)
            src[i] = iterator.setIndex(i+begin);
        return new String(src);
    }

    // ================================================================

    static final int getOptionValue(int ch) {
        int ret = 0;
        switch (ch) {
          case 'i':
            ret = RegularExpression.IGNORE_CASE;
            break;
          case 'm':
            ret = RegularExpression.MULTIPLE_LINES;
            break;
          case 's':
            ret = RegularExpression.SINGLE_LINE;
            break;
          case 'x':
            ret = RegularExpression.EXTENDED_COMMENT;
            break;
          case 'u':
            ret = RegularExpression.USE_UNICODE_CATEGORY;
            break;
          case 'w':
            ret = RegularExpression.UNICODE_WORD_BOUNDARY;
            break;
          case 'F':
            ret = RegularExpression.PROHIBIT_FIXED_STRING_OPTIMIZATION;
            break;
          case 'H':
            ret = RegularExpression.PROHIBIT_HEAD_CHARACTER_OPTIMIZATION;
            break;
          case 'X':
            ret = RegularExpression.XMLSCHEMA_MODE;
            break;
          case ',':
            ret = RegularExpression.SPECIAL_COMMA;
            break;
          default:
        }
        return ret;
    }

    static final int parseOptions(String opts) throws ParseException {
        if (opts == null)  return 0;
        int options = 0;
        for (int i = 0;  i < opts.length();  i ++) {
            int v = getOptionValue(opts.charAt(i));
            if (v == 0)
                throw new ParseException("Unknown Option: "+opts.substring(i), -1);
            options |= v;
        }
        return options;
    }

    static final String createOptionString(int options) {
        StringBuilder sb = new StringBuilder(9);
        if ((options & RegularExpression.PROHIBIT_FIXED_STRING_OPTIMIZATION) != 0)
            sb.append((char)'F');
        if ((options & RegularExpression.PROHIBIT_HEAD_CHARACTER_OPTIMIZATION) != 0)
            sb.append((char)'H');
        if ((options & RegularExpression.XMLSCHEMA_MODE) != 0)
            sb.append((char)'X');
        if ((options & RegularExpression.IGNORE_CASE) != 0)
            sb.append((char)'i');
        if ((options & RegularExpression.MULTIPLE_LINES) != 0)
            sb.append((char)'m');
        if ((options & RegularExpression.SINGLE_LINE) != 0)
            sb.append((char)'s');
        if ((options & RegularExpression.USE_UNICODE_CATEGORY) != 0)
            sb.append((char)'u');
        if ((options & RegularExpression.UNICODE_WORD_BOUNDARY) != 0)
            sb.append((char)'w');
        if ((options & RegularExpression.EXTENDED_COMMENT) != 0)
            sb.append((char)'x');
        if ((options & RegularExpression.SPECIAL_COMMA) != 0)
            sb.append((char)',');
        return sb.toString().intern();
    }

    // ================================================================

    static String stripExtendedComment(String regex) {
        int len = regex.length();
        StringBuilder buffer = new StringBuilder(len);
        int offset = 0;
        int charClass = 0;
        while (offset < len) {
            int ch = regex.charAt(offset++);
                                                // Skips a white space.
            if (ch == '\t' || ch == '\n' || ch == '\f' || ch == '\r' || ch == ' ') {
                // if we are inside a character class, we keep the white space
                if (charClass > 0) {
                    buffer.append((char)ch);
                }
                continue;
            }

            if (ch == '#') {                    // Skips chracters between '#' and a line end.
                while (offset < len) {
                    ch = regex.charAt(offset++);
                    if (ch == '\r' || ch == '\n')
                        break;
                }
                continue;
            }

            int next;                           // Strips an escaped white space.
            if (ch == '\\' && offset < len) {
                if ((next = regex.charAt(offset)) == '#'
                    || next == '\t' || next == '\n' || next == '\f'
                    || next == '\r' || next == ' ') {
                    buffer.append((char)next);
                    offset ++;
                } else {                        // Other escaped character.
                    buffer.append((char)'\\');
                    buffer.append((char)next);
                    offset ++;
                }
            }
            else if (ch == '[') {
                charClass++;
                buffer.append((char)ch);
                if (offset < len) {
                    next = regex.charAt(offset);
                    if (next == '[' || next ==']') {
                        buffer.append((char)next);
                        offset ++;
                    }
                    else if (next == '^' && offset + 1 < len) {
                        next = regex.charAt(offset + 1);
                        if (next == '[' || next ==']') {
                            buffer.append((char)'^');
                            buffer.append((char)next);
                            offset += 2;
                        }
                    }
                }
            }
            else {
                if (charClass > 0 && ch == ']') {
                    --charClass;
                }
                buffer.append((char)ch);
            }
        }
        return buffer.toString();
    }

    // ================================================================

    /**
     * Sample entry.
     * <div>Usage: <KBD>org.apache.xerces.utils.regex.REUtil &lt;regex&gt; &lt;string&gt;</KBD></div>
     */
    public static void main(String[] argv) {
        String pattern = null;
        try {
            String options = "";
            String target = null;
            if( argv.length == 0 ) {
                System.out.println( "Error:Usage: java REUtil -i|-m|-s|-u|-w|-X regularExpression String" );
                System.exit( 0 );
            }
            for (int i = 0;  i < argv.length;  i ++) {
                if (argv[i].length() == 0 || argv[i].charAt(0) != '-') {
                    if (pattern == null)
                        pattern = argv[i];
                    else if (target == null)
                        target = argv[i];
                    else
                        System.err.println("Unnecessary: "+argv[i]);
                } else if (argv[i].equals("-i")) {
                    options += "i";
                } else if (argv[i].equals("-m")) {
                    options += "m";
                } else if (argv[i].equals("-s")) {
                    options += "s";
                } else if (argv[i].equals("-u")) {
                    options += "u";
                } else if (argv[i].equals("-w")) {
                    options += "w";
                } else if (argv[i].equals("-X")) {
                    options += "X";
                } else {
                    System.err.println("Unknown option: "+argv[i]);
                }
            }
            RegularExpression reg = new RegularExpression(pattern, options);
            System.out.println("RegularExpression: "+reg);
            Match match = new Match();
            reg.matches(target, match);
            for (int i = 0;  i < match.getNumberOfGroups();  i ++) {
                if (i == 0 )  System.out.print("Matched range for the whole pattern: ");
                else System.out.print("["+i+"]: ");
                if (match.getBeginning(i) < 0)
                    System.out.println("-1");
                else {
                    System.out.print(match.getBeginning(i)+", "+match.getEnd(i)+", ");
                    System.out.println("\""+match.getCapturedText(i)+"\"");
                }
            }
        } catch (ParseException pe) {
            if (pattern == null) {
                pe.printStackTrace();
            } else {
                System.err.println("org.apache.xerces.utils.regex.ParseException: "+pe.getMessage());
                String indent = "        ";
                System.err.println(indent+pattern);
                int loc = pe.getLocation();
                if (loc >= 0) {
                    System.err.print(indent);
                    for (int i = 0;  i < loc;  i ++)  System.err.print("-");
                    System.err.println("^");
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static final int CACHESIZE = 20;
    static final RegularExpression[] regexCache = new RegularExpression[CACHESIZE];
    /**
     * Creates a RegularExpression instance.
     * This method caches created instances.
     *
     * @see RegularExpression#RegularExpression(java.lang.String, java.lang.String)
     */
    public static RegularExpression createRegex(String pattern, String options)
        throws ParseException {
        RegularExpression re = null;
        int intOptions = REUtil.parseOptions(options);
        synchronized (REUtil.regexCache) {
            int i;
            for (i = 0;  i < REUtil.CACHESIZE;  i ++) {
                RegularExpression cached = REUtil.regexCache[i];
                if (cached == null) {
                    i = -1;
                    break;
                }
                if (cached.equals(pattern, intOptions)) {
                    re = cached;
                    break;
                }
            }
            if (re != null) {
                if (i != 0) {
                    System.arraycopy(REUtil.regexCache, 0, REUtil.regexCache, 1, i);
                    REUtil.regexCache[0] = re;
                }
            } else {
                re = new RegularExpression(pattern, options);
                System.arraycopy(REUtil.regexCache, 0, REUtil.regexCache, 1, REUtil.CACHESIZE-1);
                REUtil.regexCache[0] = re;
            }
        }
        return re;
    }

    /**
     *
     * @see RegularExpression#matches(java.lang.String)
     */
    public static boolean matches(String regex, String target) throws ParseException {
        return REUtil.createRegex(regex, null).matches(target);
    }

    /**
     *
     * @see RegularExpression#matches(java.lang.String)
     */
    public static boolean matches(String regex, String options, String target) throws ParseException {
        return REUtil.createRegex(regex, options).matches(target);
    }

    // ================================================================

    /**
     *
     */
    public static String quoteMeta(String literal) {
        int len = literal.length();
        StringBuffer buffer = null;
        for (int i = 0;  i < len;  i ++) {
            int ch = literal.charAt(i);
            if (".*+?{[()|\\^$".indexOf(ch) >= 0) {
                if (buffer == null) {
                    buffer = new StringBuffer(i+(len-i)*2);
                    if (i > 0)  buffer.append(literal.substring(0, i));
                }
                buffer.append((char)'\\');
                buffer.append((char)ch);
            } else if (buffer != null)
                buffer.append((char)ch);
        }
        return buffer != null ? buffer.toString() : literal;
    }

    // ================================================================

    static void dumpString(String v) {
        for (int i = 0;  i < v.length();  i ++) {
            System.out.print(Integer.toHexString(v.charAt(i)));
            System.out.print(" ");
        }
        System.out.println();
    }
}


/**
 * This class represents a node in parse tree.
 * 
 * @xerces.internal
 *
 * @version $Id: Token.java 831926 2009-11-02 15:38:53Z knoaman $
 */
static class Token implements java.io.Serializable {

    private static final long serialVersionUID = 8484976002585487481L;

    static final boolean COUNTTOKENS = true;
    static int tokens = 0;

    static final int CHAR = 0;                  // Literal char
    static final int DOT = 11;                  // .
    static final int CONCAT = 1;                // XY
    static final int UNION = 2;                 // X|Y|Z
    static final int CLOSURE = 3;               // X*
    static final int RANGE = 4;                 // [a-zA-Z] etc.
    static final int NRANGE = 5;                // [^a-zA-Z] etc.
    static final int PAREN = 6;                 // (X) or (?:X)
    static final int EMPTY = 7;                 //
    static final int ANCHOR = 8;                // ^ $ \b \B \< \> \A \Z \z
    static final int NONGREEDYCLOSURE = 9;      // *? +?
    static final int STRING = 10;               // strings
    static final int BACKREFERENCE = 12;        // back references
    static final int LOOKAHEAD = 20;            // (?=...)
    static final int NEGATIVELOOKAHEAD = 21;    // (?!...)
    static final int LOOKBEHIND = 22;           // (?<=...)
    static final int NEGATIVELOOKBEHIND = 23;   // (?<!...)
    static final int INDEPENDENT = 24;          // (?>...)
    static final int MODIFIERGROUP = 25;        // (?ims-ims:...)
    static final int CONDITION = 26;            // (?(...)yes|no)

    static final int UTF16_MAX = 0x10ffff;

    final int type;

    static Token token_dot;
    static Token token_0to9;
    static Token token_wordchars;
    static Token token_not_0to9;
    static Token token_not_wordchars;
    static Token token_spaces;
    static Token token_not_spaces;
    static Token token_empty;
    static Token token_linebeginning;
    static Token token_linebeginning2;
    static Token token_lineend;
    static Token token_stringbeginning;
    static Token token_stringend;
    static Token token_stringend2;
    static Token token_wordedge;
    static Token token_not_wordedge;
    static Token token_wordbeginning;
    static Token token_wordend;
    static {
        Token.token_empty = new Token(Token.EMPTY);

        Token.token_linebeginning = Token.createAnchor('^');
        Token.token_linebeginning2 = Token.createAnchor('@');
        Token.token_lineend = Token.createAnchor('$');
        Token.token_stringbeginning = Token.createAnchor('A');
        Token.token_stringend = Token.createAnchor('z');
        Token.token_stringend2 = Token.createAnchor('Z');
        Token.token_wordedge = Token.createAnchor('b');
        Token.token_not_wordedge = Token.createAnchor('B');
        Token.token_wordbeginning = Token.createAnchor('<');
        Token.token_wordend = Token.createAnchor('>');

        Token.token_dot = new Token(Token.DOT);

        Token.token_0to9 = Token.createRange();
        Token.token_0to9.addRange('0', '9');
        Token.token_wordchars = Token.createRange();
        Token.token_wordchars.addRange('0', '9');
        Token.token_wordchars.addRange('A', 'Z');
        Token.token_wordchars.addRange('_', '_');
        Token.token_wordchars.addRange('a', 'z');
        Token.token_spaces = Token.createRange();
        Token.token_spaces.addRange('\t', '\t');
        Token.token_spaces.addRange('\n', '\n');
        Token.token_spaces.addRange('\f', '\f');
        Token.token_spaces.addRange('\r', '\r');
        Token.token_spaces.addRange(' ', ' ');

        Token.token_not_0to9 = Token.complementRanges(Token.token_0to9);
        Token.token_not_wordchars = Token.complementRanges(Token.token_wordchars);
        Token.token_not_spaces = Token.complementRanges(Token.token_spaces);
    }

    static Token.ParenToken createLook(int type, Token child) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ParenToken(type, child, 0);
    }
    static Token.ParenToken createParen(Token child, int pnumber) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ParenToken(Token.PAREN, child, pnumber);
    }
    static Token.ClosureToken createClosure(Token tok) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ClosureToken(Token.CLOSURE, tok);
    }
    static Token.ClosureToken createNGClosure(Token tok) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ClosureToken(Token.NONGREEDYCLOSURE, tok);
    }
    static Token.ConcatToken createConcat(Token tok1, Token tok2) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ConcatToken(tok1, tok2);
    }
    static Token.UnionToken createConcat() {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.UnionToken(Token.CONCAT); // *** It is not a bug.
    }
    static Token.UnionToken createUnion() {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.UnionToken(Token.UNION);
    }
    static Token createEmpty() {
        return Token.token_empty;
    }
    static RangeToken createRange() {
        if (COUNTTOKENS)  Token.tokens ++;
        return new RangeToken(Token.RANGE);
    }
    static RangeToken createNRange() {
        if (COUNTTOKENS)  Token.tokens ++;
        return new RangeToken(Token.NRANGE);
    }
    static Token.CharToken createChar(int ch) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.CharToken(Token.CHAR, ch);
    }
    static private Token.CharToken createAnchor(int ch) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.CharToken(Token.ANCHOR, ch);
    }
    static Token.StringToken createBackReference(int refno) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.StringToken(Token.BACKREFERENCE, null, refno);
    }
    static Token.StringToken createString(String str) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.StringToken(Token.STRING, str, 0);
    }
    static Token.ModifierToken createModifierGroup(Token child, int add, int mask) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ModifierToken(child, add, mask);
    }
    static Token.ConditionToken createCondition(int refno, Token condition,
                                                Token yespat, Token nopat) {
        if (COUNTTOKENS)  Token.tokens ++;
        return new Token.ConditionToken(refno, condition, yespat, nopat);
    }

    protected Token(int type) {
        this.type = type;
    }

    /**
     * A number of children.
     */
    int size() {
        return 0;
    }
    Token getChild(int index) {
        return null;
    }
    void addChild(Token tok) {
        throw new RuntimeException("Not supported.");
    }

                                                // for RANGE or NRANGE
    protected void addRange(int start, int end) {
        throw new RuntimeException("Not supported.");
    }
    protected void sortRanges() {
        throw new RuntimeException("Not supported.");
    }
    protected void compactRanges() {
        throw new RuntimeException("Not supported.");
    }
    protected void mergeRanges(Token tok) {
        throw new RuntimeException("Not supported.");
    }
    protected void subtractRanges(Token tok) {
        throw new RuntimeException("Not supported.");
    }
    protected void intersectRanges(Token tok) {
        throw new RuntimeException("Not supported.");
    }
    static Token complementRanges(Token tok) {
        return RangeToken.complementRanges(tok);
    }


    void setMin(int min) {                      // for CLOSURE
    }
    void setMax(int max) {                      // for CLOSURE
    }
    int getMin() {                              // for CLOSURE
        return -1;
    }
    int getMax() {                              // for CLOSURE
        return -1;
    }
    int getReferenceNumber() {                  // for STRING
        return 0;
    }
    String getString() {                        // for STRING
        return null;
    }

    int getParenNumber() {
        return 0;
    }
    int getChar() {
        return -1;
    }

    public String toString() {
        return this.toString(0);
    }
    public String toString(int options) {
        return this.type == Token.DOT ? "." : "";
    }

    /**
     * How many characters are needed?
     */
    final int getMinLength() {
        switch (this.type) {
          case CONCAT:
            int sum = 0;
            for (int i = 0;  i < this.size();  i ++)
                sum += this.getChild(i).getMinLength();
            return sum;

          case CONDITION:
          case UNION:
            if (this.size() == 0)
                return 0;
            int ret = this.getChild(0).getMinLength();
            for (int i = 1;  i < this.size();  i ++) {
                int min = this.getChild(i).getMinLength();
                if (min < ret)  ret = min;
            }
            return ret;

          case CLOSURE:
          case NONGREEDYCLOSURE:
            if (this.getMin() >= 0)
                return this.getMin() * this.getChild(0).getMinLength();
            return 0;

          case EMPTY:
          case ANCHOR:
            return 0;

          case DOT:
          case CHAR:
          case RANGE:
          case NRANGE:
            return 1;

          case INDEPENDENT:
          case PAREN:
          case MODIFIERGROUP:
            return this.getChild(0).getMinLength();

          case BACKREFERENCE:
            return 0;                           // *******

          case STRING:
            return this.getString().length();

          case LOOKAHEAD:
          case NEGATIVELOOKAHEAD:
          case LOOKBEHIND:
          case NEGATIVELOOKBEHIND:
            return 0;                           // ***** Really?

          default:
            throw new RuntimeException("Token#getMinLength(): Invalid Type: "+this.type);
        }
    }

    final int getMaxLength() {
        switch (this.type) {
          case CONCAT:
            int sum = 0;
            for (int i = 0;  i < this.size();  i ++) {
                int d = this.getChild(i).getMaxLength();
                if (d < 0)  return -1;
                sum += d;
            }
            return sum;

          case CONDITION:
          case UNION:
            if (this.size() == 0)
                return 0;
            int ret = this.getChild(0).getMaxLength();
            for (int i = 1;  ret >= 0 && i < this.size();  i ++) {
                int max = this.getChild(i).getMaxLength();
                if (max < 0) {                  // infinity
                    ret = -1;
                    break;
                }
                if (max > ret)  ret = max;
            }
            return ret;

          case CLOSURE:
          case NONGREEDYCLOSURE:
            if (this.getMax() >= 0)
                                                // When this.child.getMaxLength() < 0,
                                                // this returns minus value
                return this.getMax() * this.getChild(0).getMaxLength();
            return -1;

          case EMPTY:
          case ANCHOR:
            return 0;

          case CHAR:
            return 1;
          case DOT:
          case RANGE:
          case NRANGE:
            return 2;

          case INDEPENDENT:
          case PAREN:
          case MODIFIERGROUP:
            return this.getChild(0).getMaxLength();

          case BACKREFERENCE:
            return -1;                          // ******

          case STRING:
            return this.getString().length();

          case LOOKAHEAD:
          case NEGATIVELOOKAHEAD:
          case LOOKBEHIND:
          case NEGATIVELOOKBEHIND:
            return 0;                           // ***** Really?

          default:
            throw new RuntimeException("Token#getMaxLength(): Invalid Type: "+this.type);
        }
    }

    static final int FC_CONTINUE = 0;
    static final int FC_TERMINAL = 1;
    static final int FC_ANY = 2;
    private static final boolean isSet(int options, int flag) {
        return (options & flag) == flag;
    }
    final int analyzeFirstCharacter(RangeToken result, int options) {
        switch (this.type) {
          case CONCAT:
            int ret = FC_CONTINUE;
            for (int i = 0;  i < this.size();  i ++)
                if ((ret = this.getChild(i).analyzeFirstCharacter(result, options)) != FC_CONTINUE)
                    break;
            return ret;

          case UNION:
            if (this.size() == 0)
                return FC_CONTINUE;
            /*
             *  a|b|c -> FC_TERMINAL
             *  a|.|c -> FC_ANY
             *  a|b|  -> FC_CONTINUE
             */
            int ret2 = FC_CONTINUE;
            boolean hasEmpty = false;
            for (int i = 0;  i < this.size();  i ++) {
                ret2 = this.getChild(i).analyzeFirstCharacter(result, options);
                if (ret2 == FC_ANY)
                    break;
                else if (ret2 == FC_CONTINUE)
                    hasEmpty = true;
            }
            return hasEmpty ? FC_CONTINUE : ret2;

          case CONDITION:
            int ret3 = this.getChild(0).analyzeFirstCharacter(result, options);
            if (this.size() == 1)  return FC_CONTINUE;
            if (ret3 == FC_ANY)  return ret3;
            int ret4 = this.getChild(1).analyzeFirstCharacter(result, options);
            if (ret4 == FC_ANY)  return ret4;
            return ret3 == FC_CONTINUE || ret4 == FC_CONTINUE ? FC_CONTINUE : FC_TERMINAL;

          case CLOSURE:
          case NONGREEDYCLOSURE:
            this.getChild(0).analyzeFirstCharacter(result, options);
            return FC_CONTINUE;

          case EMPTY:
          case ANCHOR:
            return FC_CONTINUE;

          case CHAR:
            int ch = this.getChar();
            result.addRange(ch, ch);
            if (ch < 0x10000 && isSet(options, RegularExpression.IGNORE_CASE)) {
                ch = Character.toUpperCase((char)ch);
                result.addRange(ch, ch);
                ch = Character.toLowerCase((char)ch);
                result.addRange(ch, ch);
            }
            return FC_TERMINAL;

          case DOT:
              return FC_ANY;

          case RANGE:
            result.mergeRanges(this);
            return FC_TERMINAL;

          case NRANGE:                          // ****
            result.mergeRanges(Token.complementRanges(this));
            return FC_TERMINAL;

          case INDEPENDENT:
          case PAREN:
            return this.getChild(0).analyzeFirstCharacter(result, options);

          case MODIFIERGROUP:
            options |= ((ModifierToken)this).getOptions();
            options &= ~((ModifierToken)this).getOptionsMask();
            return this.getChild(0).analyzeFirstCharacter(result, options);

          case BACKREFERENCE:
            result.addRange(0, UTF16_MAX);  // **** We can not optimize.
            return FC_ANY;

          case STRING:
            int cha = this.getString().charAt(0);
            int ch2;
            if (REUtil.isHighSurrogate(cha)
                && this.getString().length() >= 2
                && REUtil.isLowSurrogate((ch2 = this.getString().charAt(1))))
                cha = REUtil.composeFromSurrogates(cha, ch2);
            result.addRange(cha, cha);
            if (cha < 0x10000 && isSet(options, RegularExpression.IGNORE_CASE)) {
                cha = Character.toUpperCase((char)cha);
                result.addRange(cha, cha);
                cha = Character.toLowerCase((char)cha);
                result.addRange(cha, cha);
            }
            return FC_TERMINAL;

          case LOOKAHEAD:
          case NEGATIVELOOKAHEAD:
          case LOOKBEHIND:
          case NEGATIVELOOKBEHIND:
            return FC_CONTINUE;

          default:
            throw new RuntimeException("Token#analyzeHeadCharacter(): Invalid Type: "+this.type);
        }
    }

    private final boolean isShorterThan(Token tok) {
        if (tok == null)  return false;
        /*
        int mylength;
        if (this.type == STRING)  mylength = this.getString().length();
        else if (this.type == CHAR)  mylength = this.getChar() >= 0x10000 ? 2 : 1;
        else throw new RuntimeException("Internal Error: Illegal type: "+this.type);
        int otherlength;
        if (tok.type == STRING)  otherlength = tok.getString().length();
        else if (tok.type == CHAR)  otherlength = tok.getChar() >= 0x10000 ? 2 : 1;
        else throw new RuntimeException("Internal Error: Illegal type: "+tok.type);
        */
        int mylength;
        if (this.type == STRING)  mylength = this.getString().length();
        else throw new RuntimeException("Internal Error: Illegal type: "+this.type);
        int otherlength;
        if (tok.type == STRING)  otherlength = tok.getString().length();
        else throw new RuntimeException("Internal Error: Illegal type: "+tok.type);
        return mylength < otherlength;
    }

    static class FixedStringContainer {
        Token token = null;
        int options = 0;
        FixedStringContainer() {
        }
    }

    final void findFixedString(FixedStringContainer container, int options) {
        switch (this.type) {
          case CONCAT:
            Token prevToken = null;
            int prevOptions = 0;
            for (int i = 0;  i < this.size();  i ++) {
                this.getChild(i).findFixedString(container, options);
                if (prevToken == null || prevToken.isShorterThan(container.token)) {
                    prevToken = container.token;
                    prevOptions = container.options;
                }
            }
            container.token = prevToken;
            container.options = prevOptions;
            return;

          case UNION:
          case CLOSURE:
          case NONGREEDYCLOSURE:
          case EMPTY:
          case ANCHOR:
          case RANGE:
          case DOT:
          case NRANGE:
          case BACKREFERENCE:
          case LOOKAHEAD:
          case NEGATIVELOOKAHEAD:
          case LOOKBEHIND:
          case NEGATIVELOOKBEHIND:
          case CONDITION:
            container.token = null;
            return;

          case CHAR:                            // Ignore CHAR tokens.
            container.token = null;             // **
            return;                             // **

          case STRING:
            container.token = this;
            container.options = options;
            return;

          case INDEPENDENT:
          case PAREN:
            this.getChild(0).findFixedString(container, options);
            return;

          case MODIFIERGROUP:
            options |= ((ModifierToken)this).getOptions();
            options &= ~((ModifierToken)this).getOptionsMask();
            this.getChild(0).findFixedString(container, options);
            return;

          default:
            throw new RuntimeException("Token#findFixedString(): Invalid Type: "+this.type);
        }
    }

    boolean match(int ch) {
        throw new RuntimeException("NFAArrow#match(): Internal error: "+this.type);
    }

    // ------------------------------------------------------
    private final static Hashtable categories = new Hashtable();
    private final static Hashtable categories2 = new Hashtable();
    private static final String[] categoryNames = {
        "Cn", "Lu", "Ll", "Lt", "Lm", "Lo", "Mn", "Me", "Mc", "Nd",
        "Nl", "No", "Zs", "Zl", "Zp", "Cc", "Cf", null, "Co", "Cs",
        "Pd", "Ps", "Pe", "Pc", "Po", "Sm", "Sc", "Sk", "So", // 28
        "Pi", "Pf",  // 29, 30
        "L", "M", "N", "Z", "C", "P", "S",      // 31-37
    };

    // Schema Rec. {Datatypes} - Punctuation 
    static final int CHAR_INIT_QUOTE  = 29;     // Pi - initial quote
    static final int CHAR_FINAL_QUOTE = 30;     // Pf - final quote
    static final int CHAR_LETTER = 31;
    static final int CHAR_MARK = 32;
    static final int CHAR_NUMBER = 33;
    static final int CHAR_SEPARATOR = 34;
    static final int CHAR_OTHER = 35;
    static final int CHAR_PUNCTUATION = 36;
    static final int CHAR_SYMBOL = 37;
    
    //blockNames in UNICODE 3.1 that supported by XML Schema REC             
    private static final String[] blockNames = {
        /*0000..007F;*/ "Basic Latin",
        /*0080..00FF;*/ "Latin-1 Supplement",
        /*0100..017F;*/ "Latin Extended-A",
        /*0180..024F;*/ "Latin Extended-B",
        /*0250..02AF;*/ "IPA Extensions",
        /*02B0..02FF;*/ "Spacing Modifier Letters",
        /*0300..036F;*/ "Combining Diacritical Marks",
        /*0370..03FF;*/ "Greek",
        /*0400..04FF;*/ "Cyrillic",
        /*0530..058F;*/ "Armenian",
        /*0590..05FF;*/ "Hebrew",
        /*0600..06FF;*/ "Arabic",
        /*0700..074F;*/ "Syriac",  
        /*0780..07BF;*/ "Thaana",
        /*0900..097F;*/ "Devanagari",
        /*0980..09FF;*/ "Bengali",
        /*0A00..0A7F;*/ "Gurmukhi",
        /*0A80..0AFF;*/ "Gujarati",
        /*0B00..0B7F;*/ "Oriya",
        /*0B80..0BFF;*/ "Tamil",
        /*0C00..0C7F;*/ "Telugu",
        /*0C80..0CFF;*/ "Kannada",
        /*0D00..0D7F;*/ "Malayalam",
        /*0D80..0DFF;*/ "Sinhala",
        /*0E00..0E7F;*/ "Thai",
        /*0E80..0EFF;*/ "Lao",
        /*0F00..0FFF;*/ "Tibetan",
        /*1000..109F;*/ "Myanmar", 
        /*10A0..10FF;*/ "Georgian",
        /*1100..11FF;*/ "Hangul Jamo",
        /*1200..137F;*/ "Ethiopic",
        /*13A0..13FF;*/ "Cherokee",
        /*1400..167F;*/ "Unified Canadian Aboriginal Syllabics",
        /*1680..169F;*/ "Ogham",
        /*16A0..16FF;*/ "Runic",
        /*1780..17FF;*/ "Khmer",
        /*1800..18AF;*/ "Mongolian",
        /*1E00..1EFF;*/ "Latin Extended Additional",
        /*1F00..1FFF;*/ "Greek Extended",
        /*2000..206F;*/ "General Punctuation",
        /*2070..209F;*/ "Superscripts and Subscripts",
        /*20A0..20CF;*/ "Currency Symbols",
        /*20D0..20FF;*/ "Combining Marks for Symbols",
        /*2100..214F;*/ "Letterlike Symbols",
        /*2150..218F;*/ "Number Forms",
        /*2190..21FF;*/ "Arrows",
        /*2200..22FF;*/ "Mathematical Operators",
        /*2300..23FF;*/ "Miscellaneous Technical",
        /*2400..243F;*/ "Control Pictures",
        /*2440..245F;*/ "Optical Character Recognition",
        /*2460..24FF;*/ "Enclosed Alphanumerics",
        /*2500..257F;*/ "Box Drawing",
        /*2580..259F;*/ "Block Elements",
        /*25A0..25FF;*/ "Geometric Shapes",
        /*2600..26FF;*/ "Miscellaneous Symbols",
        /*2700..27BF;*/ "Dingbats",
        /*2800..28FF;*/ "Braille Patterns",
        /*2E80..2EFF;*/ "CJK Radicals Supplement",
        /*2F00..2FDF;*/ "Kangxi Radicals",
        /*2FF0..2FFF;*/ "Ideographic Description Characters",
        /*3000..303F;*/ "CJK Symbols and Punctuation",
        /*3040..309F;*/ "Hiragana",
        /*30A0..30FF;*/ "Katakana",
        /*3100..312F;*/ "Bopomofo",
        /*3130..318F;*/ "Hangul Compatibility Jamo",
        /*3190..319F;*/ "Kanbun",
        /*31A0..31BF;*/ "Bopomofo Extended",
        /*3200..32FF;*/ "Enclosed CJK Letters and Months",
        /*3300..33FF;*/ "CJK Compatibility",
        /*3400..4DB5;*/ "CJK Unified Ideographs Extension A",
        /*4E00..9FFF;*/ "CJK Unified Ideographs",
        /*A000..A48F;*/ "Yi Syllables",
        /*A490..A4CF;*/ "Yi Radicals",
        /*AC00..D7A3;*/ "Hangul Syllables",
        /*E000..F8FF;*/ "Private Use",
        /*F900..FAFF;*/ "CJK Compatibility Ideographs",
        /*FB00..FB4F;*/ "Alphabetic Presentation Forms",
        /*FB50..FDFF;*/ "Arabic Presentation Forms-A",
        /*FE20..FE2F;*/ "Combining Half Marks",
        /*FE30..FE4F;*/ "CJK Compatibility Forms",
        /*FE50..FE6F;*/ "Small Form Variants",
        /*FE70..FEFE;*/ "Arabic Presentation Forms-B",
        /*FEFF..FEFF;*/ "Specials",
        /*FF00..FFEF;*/ "Halfwidth and Fullwidth Forms",
         //missing Specials add manually
        /*10300..1032F;*/ "Old Italic",     // 84
        /*10330..1034F;*/ "Gothic",
        /*10400..1044F;*/ "Deseret",
        /*1D000..1D0FF;*/ "Byzantine Musical Symbols",
        /*1D100..1D1FF;*/ "Musical Symbols",
        /*1D400..1D7FF;*/ "Mathematical Alphanumeric Symbols",
        /*20000..2A6D6;*/ "CJK Unified Ideographs Extension B",
        /*2F800..2FA1F;*/ "CJK Compatibility Ideographs Supplement",
        /*E0000..E007F;*/ "Tags",
        //missing 2 private use add manually

    };
    //ADD THOSE MANUALLY
    //F0000..FFFFD; "Private Use",
    //100000..10FFFD; "Private Use"
    //FFF0..FFFD; "Specials", 
    static final String blockRanges = 
       "\u0000\u007F\u0080\u00FF\u0100\u017F\u0180\u024F\u0250\u02AF\u02B0\u02FF\u0300\u036F"
        +"\u0370\u03FF\u0400\u04FF\u0530\u058F\u0590\u05FF\u0600\u06FF\u0700\u074F\u0780\u07BF"
        +"\u0900\u097F\u0980\u09FF\u0A00\u0A7F\u0A80\u0AFF\u0B00\u0B7F\u0B80\u0BFF\u0C00\u0C7F\u0C80\u0CFF"
        +"\u0D00\u0D7F\u0D80\u0DFF\u0E00\u0E7F\u0E80\u0EFF\u0F00\u0FFF\u1000\u109F\u10A0\u10FF\u1100\u11FF"
        +"\u1200\u137F\u13A0\u13FF\u1400\u167F\u1680\u169F\u16A0\u16FF\u1780\u17FF\u1800\u18AF\u1E00\u1EFF"
        +"\u1F00\u1FFF\u2000\u206F\u2070\u209F\u20A0\u20CF\u20D0\u20FF\u2100\u214F\u2150\u218F\u2190\u21FF\u2200\u22FF"
        +"\u2300\u23FF\u2400\u243F\u2440\u245F\u2460\u24FF\u2500\u257F\u2580\u259F\u25A0\u25FF\u2600\u26FF\u2700\u27BF"
        +"\u2800\u28FF\u2E80\u2EFF\u2F00\u2FDF\u2FF0\u2FFF\u3000\u303F\u3040\u309F\u30A0\u30FF\u3100\u312F\u3130\u318F"
        +"\u3190\u319F\u31A0\u31BF\u3200\u32FF\u3300\u33FF\u3400\u4DB5\u4E00\u9FFF\uA000\uA48F\uA490\uA4CF"
        +"\uAC00\uD7A3\uE000\uF8FF\uF900\uFAFF\uFB00\uFB4F\uFB50\uFDFF"
        +"\uFE20\uFE2F\uFE30\uFE4F\uFE50\uFE6F\uFE70\uFEFE\uFEFF\uFEFF\uFF00\uFFEF";
    static final int[] nonBMPBlockRanges = {
        0x10300, 0x1032F,       // 84
        0x10330, 0x1034F,
        0x10400, 0x1044F,
        0x1D000, 0x1D0FF,
        0x1D100, 0x1D1FF,
        0x1D400, 0x1D7FF,
        0x20000, 0x2A6D6,
        0x2F800, 0x2FA1F,
        0xE0000, 0xE007F
    };
    private static final int NONBMP_BLOCK_START = 84;

    static protected RangeToken getRange(String name, boolean positive) {
        if (Token.categories.isEmpty()) {
            synchronized (Token.categories) {
                Token[] ranges = new Token[Token.categoryNames.length];
                for (int i = 0;  i < ranges.length;  i ++) {
                    ranges[i] = Token.createRange();
                }
                int type;
                for (int i = 0;  i < 0x10000;  i ++) {
                    type = Character.getType((char)i);
                    if (type == Character.START_PUNCTUATION || 
                        type == Character.END_PUNCTUATION) {
                        //build table of Pi values
                        if (i == 0x00AB || i == 0x2018 || i == 0x201B || i == 0x201C ||
                            i == 0x201F || i == 0x2039) {
                            type = CHAR_INIT_QUOTE;
                        }
                        //build table of Pf values
                        if (i == 0x00BB || i == 0x2019 || i == 0x201D || i == 0x203A ) {
                            type = CHAR_FINAL_QUOTE;
                        }
                    }
                    ranges[type].addRange(i, i);
                    switch (type) {
                      case Character.UPPERCASE_LETTER:
                      case Character.LOWERCASE_LETTER:
                      case Character.TITLECASE_LETTER:
                      case Character.MODIFIER_LETTER:
                      case Character.OTHER_LETTER:
                        type = CHAR_LETTER;
                        break;
                      case Character.NON_SPACING_MARK:
                      case Character.COMBINING_SPACING_MARK:
                      case Character.ENCLOSING_MARK:
                        type = CHAR_MARK;
                        break;
                      case Character.DECIMAL_DIGIT_NUMBER:
                      case Character.LETTER_NUMBER:
                      case Character.OTHER_NUMBER:
                        type = CHAR_NUMBER;
                        break;
                      case Character.SPACE_SEPARATOR:
                      case Character.LINE_SEPARATOR:
                      case Character.PARAGRAPH_SEPARATOR:
                        type = CHAR_SEPARATOR;
                        break;
                      case Character.CONTROL:
                      case Character.FORMAT:
                      case Character.SURROGATE:
                      case Character.PRIVATE_USE:
                      case Character.UNASSIGNED:
                        type = CHAR_OTHER;
                        break;
                      case Character.CONNECTOR_PUNCTUATION:
                      case Character.DASH_PUNCTUATION:
                      case Character.START_PUNCTUATION:
                      case Character.END_PUNCTUATION:
                      case CHAR_INIT_QUOTE:
                      case CHAR_FINAL_QUOTE:
                      case Character.OTHER_PUNCTUATION:
                        type = CHAR_PUNCTUATION;
                        break;
                      case Character.MATH_SYMBOL:
                      case Character.CURRENCY_SYMBOL:
                      case Character.MODIFIER_SYMBOL:
                      case Character.OTHER_SYMBOL:
                        type = CHAR_SYMBOL;
                        break;
                      default:
                        throw new RuntimeException("org.apache.xerces.utils.regex.Token#getRange(): Unknown Unicode category: "+type);
                    }
                    ranges[type].addRange(i, i);
                } // for all characters
                ranges[Character.UNASSIGNED].addRange(0x10000, Token.UTF16_MAX);

                for (int i = 0;  i < ranges.length;  i ++) {
                    if (Token.categoryNames[i] != null) {
                        if (i == Character.UNASSIGNED) { // Unassigned
                            ranges[i].addRange(0x10000, Token.UTF16_MAX);
                        }
                        Token.categories.put(Token.categoryNames[i], ranges[i]);
                        Token.categories2.put(Token.categoryNames[i],
                                              Token.complementRanges(ranges[i]));
                    }
                }
                //REVISIT: do we really need to support block names as in Unicode 3.1
                //         or we can just create all the names in IsBLOCKNAME format (XML Schema REC)?
                //
                StringBuilder buffer = new StringBuilder(50);
                for (int i = 0;  i < Token.blockNames.length;  i ++) {
                    Token r1 = Token.createRange();
                    int location;
                    if (i < NONBMP_BLOCK_START) {
                        location = i*2;
                        int rstart = Token.blockRanges.charAt(location);
                        int rend = Token.blockRanges.charAt(location+1);
                        //DEBUGING
                        //System.out.println(n+" " +Integer.toHexString(rstart)
                        //                     +"-"+ Integer.toHexString(rend));
                        r1.addRange(rstart, rend);
                    } else {
                        location = (i - NONBMP_BLOCK_START) * 2;
                        r1.addRange(Token.nonBMPBlockRanges[location],
                                    Token.nonBMPBlockRanges[location + 1]);
                    }
                    String n = Token.blockNames[i];
                    if (n.equals("Specials"))
                        r1.addRange(0xfff0, 0xfffd);
                    if (n.equals("Private Use")) {
                        r1.addRange(0xF0000,0xFFFFD);
                        r1.addRange(0x100000,0x10FFFD);
                    }
                    Token.categories.put(n, r1);
                    Token.categories2.put(n, Token.complementRanges(r1));
                    buffer.setLength(0);
                    buffer.append("Is");
                    if (n.indexOf(' ') >= 0) {
                        for (int ci = 0;  ci < n.length();  ci ++)
                            if (n.charAt(ci) != ' ')  buffer.append((char)n.charAt(ci));
                    }
                    else {
                        buffer.append(n);
                    }
                    Token.setAlias(buffer.toString(), n, true);
                }

                // TR#18 1.2
                Token.setAlias("ASSIGNED", "Cn", false);
                Token.setAlias("UNASSIGNED", "Cn", true);
                Token all = Token.createRange();
                all.addRange(0, Token.UTF16_MAX);
                Token.categories.put("ALL", all);
                Token.categories2.put("ALL", Token.complementRanges(all));
                Token.registerNonXS("ASSIGNED");
                Token.registerNonXS("UNASSIGNED");
                Token.registerNonXS("ALL");

                Token isalpha = Token.createRange();
                isalpha.mergeRanges(ranges[Character.UPPERCASE_LETTER]); // Lu
                isalpha.mergeRanges(ranges[Character.LOWERCASE_LETTER]); // Ll
                isalpha.mergeRanges(ranges[Character.OTHER_LETTER]); // Lo
                Token.categories.put("IsAlpha", isalpha);
                Token.categories2.put("IsAlpha", Token.complementRanges(isalpha));
                Token.registerNonXS("IsAlpha");

                Token isalnum = Token.createRange();
                isalnum.mergeRanges(isalpha);   // Lu Ll Lo
                isalnum.mergeRanges(ranges[Character.DECIMAL_DIGIT_NUMBER]); // Nd
                Token.categories.put("IsAlnum", isalnum);
                Token.categories2.put("IsAlnum", Token.complementRanges(isalnum));
                Token.registerNonXS("IsAlnum");

                Token isspace = Token.createRange();
                isspace.mergeRanges(Token.token_spaces);
                isspace.mergeRanges(ranges[CHAR_SEPARATOR]); // Z
                Token.categories.put("IsSpace", isspace);
                Token.categories2.put("IsSpace", Token.complementRanges(isspace));
                Token.registerNonXS("IsSpace");

                Token isword = Token.createRange();
                isword.mergeRanges(isalnum);     // Lu Ll Lo Nd
                isword.addRange('_', '_');
                Token.categories.put("IsWord", isword);
                Token.categories2.put("IsWord", Token.complementRanges(isword));
                Token.registerNonXS("IsWord");

                Token isascii = Token.createRange();
                isascii.addRange(0, 127);
                Token.categories.put("IsASCII", isascii);
                Token.categories2.put("IsASCII", Token.complementRanges(isascii));
                Token.registerNonXS("IsASCII");

                Token isnotgraph = Token.createRange();
                isnotgraph.mergeRanges(ranges[CHAR_OTHER]);
                isnotgraph.addRange(' ', ' ');
                Token.categories.put("IsGraph", Token.complementRanges(isnotgraph));
                Token.categories2.put("IsGraph", isnotgraph);
                Token.registerNonXS("IsGraph");

                Token isxdigit = Token.createRange();
                isxdigit.addRange('0', '9');
                isxdigit.addRange('A', 'F');
                isxdigit.addRange('a', 'f');
                Token.categories.put("IsXDigit", Token.complementRanges(isxdigit));
                Token.categories2.put("IsXDigit", isxdigit);
                Token.registerNonXS("IsXDigit");

                Token.setAlias("IsDigit", "Nd", true);
                Token.setAlias("IsUpper", "Lu", true);
                Token.setAlias("IsLower", "Ll", true);
                Token.setAlias("IsCntrl", "C", true);
                Token.setAlias("IsPrint", "C", false);
                Token.setAlias("IsPunct", "P", true);
                Token.registerNonXS("IsDigit");
                Token.registerNonXS("IsUpper");
                Token.registerNonXS("IsLower");
                Token.registerNonXS("IsCntrl");
                Token.registerNonXS("IsPrint");
                Token.registerNonXS("IsPunct");

                Token.setAlias("alpha", "IsAlpha", true);
                Token.setAlias("alnum", "IsAlnum", true);
                Token.setAlias("ascii", "IsASCII", true);
                Token.setAlias("cntrl", "IsCntrl", true);
                Token.setAlias("digit", "IsDigit", true);
                Token.setAlias("graph", "IsGraph", true);
                Token.setAlias("lower", "IsLower", true);
                Token.setAlias("print", "IsPrint", true);
                Token.setAlias("punct", "IsPunct", true);
                Token.setAlias("space", "IsSpace", true);
                Token.setAlias("upper", "IsUpper", true);
                Token.setAlias("word", "IsWord", true); // Perl extension
                Token.setAlias("xdigit", "IsXDigit", true);
                Token.registerNonXS("alpha");
                Token.registerNonXS("alnum");
                Token.registerNonXS("ascii");
                Token.registerNonXS("cntrl");
                Token.registerNonXS("digit");
                Token.registerNonXS("graph");
                Token.registerNonXS("lower");
                Token.registerNonXS("print");
                Token.registerNonXS("punct");
                Token.registerNonXS("space");
                Token.registerNonXS("upper");
                Token.registerNonXS("word");
                Token.registerNonXS("xdigit");
            } // synchronized
        } // if null
        RangeToken tok = positive ? (RangeToken)Token.categories.get(name)
            : (RangeToken)Token.categories2.get(name);
        //if (tok == null) System.out.println(name);
        return tok;
    }
    static protected RangeToken getRange(String name, boolean positive, boolean xs) {
        RangeToken range = Token.getRange(name, positive);
        if (xs && range != null && Token.isRegisterNonXS(name))
            range = null;
        return range;
    }

    static Hashtable nonxs = null;
    /**
     * This method is called by only getRange().
     * So this method need not MT-safe.
     */
    static protected void registerNonXS(String name) {
        if (Token.nonxs == null)
            Token.nonxs = new Hashtable();
        Token.nonxs.put(name, name);
    }
    static protected boolean isRegisterNonXS(String name) {
        if (Token.nonxs == null)
            return false;
        //DEBUG
        //System.err.println("isRegisterNonXS: "+name);
        return Token.nonxs.containsKey(name);
    }

    private static void setAlias(String newName, String name, boolean positive) {
        Token t1 = (Token)Token.categories.get(name);
        Token t2 = (Token)Token.categories2.get(name);
        if (positive) {
            Token.categories.put(newName, t1);
            Token.categories2.put(newName, t2);
        } else {
            Token.categories2.put(newName, t1);
            Token.categories.put(newName, t2);
        }
    }

    // ------------------------------------------------------

    static final String viramaString =
    "\u094D"// ;DEVANAGARI SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u09CD"//;BENGALI SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0A4D"//;GURMUKHI SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0ACD"//;GUJARATI SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0B4D"//;ORIYA SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0BCD"//;TAMIL SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0C4D"//;TELUGU SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0CCD"//;KANNADA SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0D4D"//;MALAYALAM SIGN VIRAMA;Mn;9;ON;;;;;N;;;;;
    +"\u0E3A"//;THAI CHARACTER PHINTHU;Mn;9;ON;;;;;N;THAI VOWEL SIGN PHINTHU;;;;
    +"\u0F84";//;TIBETAN MARK HALANTA;Mn;9;ON;;;;;N;TIBETAN VIRAMA;;;;

    static private Token token_grapheme = null;
    static synchronized Token getGraphemePattern() {
        if (Token.token_grapheme != null)
            return Token.token_grapheme;

        Token base_char = Token.createRange();  // [{ASSIGNED}]-[{M},{C}]
        base_char.mergeRanges(Token.getRange("ASSIGNED", true));
        base_char.subtractRanges(Token.getRange("M", true));
        base_char.subtractRanges(Token.getRange("C", true));

        Token virama = Token.createRange();
        for (int i = 0;  i < Token.viramaString.length(); i++) {
            virama.addRange(i, i);
        }

        Token combiner_wo_virama = Token.createRange();
        combiner_wo_virama.mergeRanges(Token.getRange("M", true));
        combiner_wo_virama.addRange(0x1160, 0x11ff); // hangul_medial and hangul_final
        combiner_wo_virama.addRange(0xff9e, 0xff9f); // extras

        Token left = Token.createUnion();       // base_char?
        left.addChild(base_char);
        left.addChild(Token.token_empty);

        Token foo = Token.createUnion();
        foo.addChild(Token.createConcat(virama, Token.getRange("L", true)));
        foo.addChild(combiner_wo_virama);

        foo = Token.createClosure(foo);

        foo = Token.createConcat(left, foo);

        Token.token_grapheme = foo;
        return Token.token_grapheme;
    }

    /**
     * Combing Character Sequence in Perl 5.6.
     */
    static private Token token_ccs = null;
    static synchronized Token getCombiningCharacterSequence() {
        if (Token.token_ccs != null)
            return Token.token_ccs;

        Token foo = Token.createClosure(Token.getRange("M", true)); // \pM*
        foo = Token.createConcat(Token.getRange("M", false), foo); // \PM + \pM*
        Token.token_ccs = foo;
        return Token.token_ccs;
    }

    // ------------------------------------------------------

    // ------------------------------------------------------
    /**
     * This class represents a node in parse tree.
     */
    static class StringToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = -4614366944218504172L;
        
        String string;
        final int refNumber;

        StringToken(int type, String str, int n) {
            super(type);
            this.string = str;
            this.refNumber = n;
        }

        int getReferenceNumber() {              // for STRING
            return this.refNumber;
        }
        String getString() {                    // for STRING
            return this.string;
        }
        
        public String toString(int options) {
            if (this.type == BACKREFERENCE)
                return "\\"+this.refNumber;
            else
                return REUtil.quoteMeta(this.string);
        }
    }

    /**
     * This class represents a node in parse tree.
     */
    static class ConcatToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = 8717321425541346381L;
        
        final Token child;
        final Token child2;
        
        ConcatToken(Token t1, Token t2) {
            super(Token.CONCAT);
            this.child = t1;
            this.child2 = t2;
        }

        int size() {
            return 2;
        }
        Token getChild(int index) {
            return index == 0 ? this.child : this.child2;
        }

        public String toString(int options) {
            String ret;
            if (this.child2.type == CLOSURE && this.child2.getChild(0) == this.child) {
                ret = this.child.toString(options)+"+";
            } else if (this.child2.type == NONGREEDYCLOSURE && this.child2.getChild(0) == this.child) {
                ret = this.child.toString(options)+"+?";
            } else
                ret = this.child.toString(options)+this.child2.toString(options);
            return ret;
        }
    }

    /**
     * This class represents a node in parse tree.
     */
    static class CharToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = -4394272816279496989L;
        
        final int chardata;

        CharToken(int type, int ch) {
            super(type);
            this.chardata = ch;
        }

        int getChar() {
            return this.chardata;
        }

        public String toString(int options) {
            String ret;
            switch (this.type) {
              case CHAR:
                switch (this.chardata) {
                  case '|':  case '*':  case '+':  case '?':
                  case '(':  case ')':  case '.':  case '[':
                  case '{':  case '\\':
                    ret = "\\"+(char)this.chardata;
                    break;
                  case '\f':  ret = "\\f";  break;
                  case '\n':  ret = "\\n";  break;
                  case '\r':  ret = "\\r";  break;
                  case '\t':  ret = "\\t";  break;
                  case 0x1b:  ret = "\\e";  break;
                    //case 0x0b:  ret = "\\v";  break;
                  default:
                    if (this.chardata >= 0x10000) {
                        String pre = "0"+Integer.toHexString(this.chardata);
                        ret = "\\v"+pre.substring(pre.length()-6, pre.length());
                    } else
                        ret = ""+(char)this.chardata;
                }
                break;

              case ANCHOR:
                if (this == Token.token_linebeginning || this == Token.token_lineend)
                    ret = ""+(char)this.chardata;
                else 
                    ret = "\\"+(char)this.chardata;
                break;

              default:
                ret = null;
            }
            return ret;
        }

        boolean match(int ch) {
            if (this.type == CHAR) {
                return ch == this.chardata;
            } else
                throw new RuntimeException("NFAArrow#match(): Internal error: "+this.type);
        }
    }

    /**
     * This class represents a node in parse tree.
     */
    static class ClosureToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = 1308971930673997452L;
        
        int min;
        int max;
        final Token child;

        ClosureToken(int type, Token tok) {
            super(type);
            this.child = tok;
            this.setMin(-1);
            this.setMax(-1);
        }

        int size() {
            return 1;
        }
        Token getChild(int index) {
            return this.child;
        }

        final void setMin(int min) {
            this.min = min;
        }
        final void setMax(int max) {
            this.max = max;
        }
        final int getMin() {
            return this.min;
        }
        final int getMax() {
            return this.max;
        }

        public String toString(int options) {
            String ret;
            if (this.type == CLOSURE) {
                if (this.getMin() < 0 && this.getMax() < 0) {
                    ret = this.child.toString(options)+"*";
                } else if (this.getMin() == this.getMax()) {
                    ret = this.child.toString(options)+"{"+this.getMin()+"}";
                } else if (this.getMin() >= 0 && this.getMax() >= 0) {
                    ret = this.child.toString(options)+"{"+this.getMin()+","+this.getMax()+"}";
                } else if (this.getMin() >= 0 && this.getMax() < 0) {
                    ret = this.child.toString(options)+"{"+this.getMin()+",}";
                } else
                    throw new RuntimeException("Token#toString(): CLOSURE "
                                               +this.getMin()+", "+this.getMax());
            } else {
                if (this.getMin() < 0 && this.getMax() < 0) {
                    ret = this.child.toString(options)+"*?";
                } else if (this.getMin() == this.getMax()) {
                    ret = this.child.toString(options)+"{"+this.getMin()+"}?";
                } else if (this.getMin() >= 0 && this.getMax() >= 0) {
                    ret = this.child.toString(options)+"{"+this.getMin()+","+this.getMax()+"}?";
                } else if (this.getMin() >= 0 && this.getMax() < 0) {
                    ret = this.child.toString(options)+"{"+this.getMin()+",}?";
                } else
                    throw new RuntimeException("Token#toString(): NONGREEDYCLOSURE "
                                               +this.getMin()+", "+this.getMax());
            }
            return ret;
        }
    }

    /**
     * This class represents a node in parse tree.
     */
    static class ParenToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = -5938014719827987704L;
        
        final Token child;
        final int parennumber;

        ParenToken(int type, Token tok, int paren) {
            super(type);
            this.child = tok;
            this.parennumber = paren;
        }

        int size() {
            return 1;
        }
        Token getChild(int index) {
            return this.child;
        }

        int getParenNumber() {
            return this.parennumber;
        }

        public String toString(int options) {
            String ret = null;
            switch (this.type) {
              case PAREN:
                if (this.parennumber == 0) {
                    ret = "(?:"+this.child.toString(options)+")";
                } else {
                    ret = "("+this.child.toString(options)+")";
                }
                break;

              case LOOKAHEAD:
                ret = "(?="+this.child.toString(options)+")";
                break;
              case NEGATIVELOOKAHEAD:
                ret = "(?!"+this.child.toString(options)+")";
                break;
              case LOOKBEHIND:
                ret = "(?<="+this.child.toString(options)+")";
                break;
              case NEGATIVELOOKBEHIND:
                ret = "(?<!"+this.child.toString(options)+")";
                break;
              case INDEPENDENT:
                ret = "(?>"+this.child.toString(options)+")";
                break;
            }
            return ret;
        }
    }

    /**
     * (?(condition)yes-pattern|no-pattern)
     */
    static class ConditionToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = 4353765277910594411L;
        
        final int refNumber;
        final Token condition;
        final Token yes;
        final Token no;
        ConditionToken(int refno, Token cond, Token yespat, Token nopat) {
            super(Token.CONDITION);
            this.refNumber = refno;
            this.condition = cond;
            this.yes = yespat;
            this.no = nopat;
        }
        int size() {
            return this.no == null ? 1 : 2;
        }
        Token getChild(int index) {
            if (index == 0)  return this.yes;
            if (index == 1)  return this.no;
            throw new RuntimeException("Internal Error: "+index);
        }

        public String toString(int options) {
            String ret;
            if (refNumber > 0) {
                ret = "(?("+refNumber+")";
            } else if (this.condition.type == Token.ANCHOR) {
                ret = "(?("+this.condition+")";
            } else {
                ret = "(?"+this.condition;
            }

            if (this.no == null) {
                ret += this.yes+")";
            } else {
                ret += this.yes+"|"+this.no+")";
            }
            return ret;
        }
    }

    /**
     * (ims-ims: .... )
     */
    static class ModifierToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = -9114536559696480356L;
        
        final Token child;
        final int add;
        final int mask;

        ModifierToken(Token tok, int add, int mask) {
            super(Token.MODIFIERGROUP);
            this.child = tok;
            this.add = add;
            this.mask = mask;
        }

        int size() {
            return 1;
        }
        Token getChild(int index) {
            return this.child;
        }

        int getOptions() {
            return this.add;
        }
        int getOptionsMask() {
            return this.mask;
        }

        public String toString(int options) {
            return "(?"
                +(this.add == 0 ? "" : REUtil.createOptionString(this.add))
                +(this.mask == 0 ? "" : REUtil.createOptionString(this.mask))
                +":"
                +this.child.toString(options)
                +")";
        }
    }

    /**
     * This class represents a node in parse tree.
     * for UNION or CONCAT.
     */
    static class UnionToken extends Token implements java.io.Serializable {

        private static final long serialVersionUID = -2568843945989489861L;
        
        Vector children;

        UnionToken(int type) {
            super(type);
        }

        void addChild(Token tok) {
            if (tok == null)  return;
            if (this.children == null)  this.children = new Vector();
            if (this.type == UNION) {
                this.children.addElement(tok);
                return;
            }
                                                // This is CONCAT, and new child is CONCAT.
            if (tok.type == CONCAT) {
                for (int i = 0;  i < tok.size();  i ++)
                    this.addChild(tok.getChild(i)); // Recursion
                return;
            }
            int size = this.children.size();
            if (size == 0) {
                this.children.addElement(tok);
                return;
            }
            Token previous = (Token)this.children.elementAt(size-1);
            if (!((previous.type == CHAR || previous.type == STRING)
                  && (tok.type == CHAR || tok.type == STRING))) {
                this.children.addElement(tok);
                return;
            }
            
            //System.err.println("Merge '"+previous+"' and '"+tok+"'.");

            StringBuffer buffer;
            int nextMaxLength = (tok.type == CHAR ? 2 : tok.getString().length());
            if (previous.type == CHAR) {        // Replace previous token by STRING
                buffer = new StringBuffer(2 + nextMaxLength);
                int ch = previous.getChar();
                if (ch >= 0x10000)
                    buffer.append(REUtil.decomposeToSurrogates(ch));
                else
                    buffer.append((char)ch);
                previous = Token.createString(null);
                this.children.setElementAt(previous, size-1);
            } else {                            // STRING
                buffer = new StringBuffer(previous.getString().length() + nextMaxLength);
                buffer.append(previous.getString());
            }

            if (tok.type == CHAR) {
                int ch = tok.getChar();
                if (ch >= 0x10000)
                    buffer.append(REUtil.decomposeToSurrogates(ch));
                else
                    buffer.append((char)ch);
            } else {
                buffer.append(tok.getString());
            }

            ((StringToken)previous).string = new String(buffer);
        }

        int size() {
            return this.children == null ? 0 : this.children.size();
        }
        Token getChild(int index) {
            return (Token)this.children.elementAt(index);
        }

        public String toString(int options) {
            String ret;
            if (this.type == CONCAT) {
                if (this.children.size() == 2) {
                    Token ch = this.getChild(0);
                    Token ch2 = this.getChild(1);
                    if (ch2.type == CLOSURE && ch2.getChild(0) == ch) {
                        ret = ch.toString(options)+"+";
                    } else if (ch2.type == NONGREEDYCLOSURE && ch2.getChild(0) == ch) {
                        ret = ch.toString(options)+"+?";
                    } else
                        ret = ch.toString(options)+ch2.toString(options);
                } else {
                    StringBuffer sb = new StringBuffer();
                    for (int i = 0;  i < this.children.size();  i ++) {
                        sb.append(((Token)this.children.elementAt(i)).toString(options));
                    }
                    ret = new String(sb);
                }
                return ret;
            }
            if (this.children.size() == 2 && this.getChild(1).type == EMPTY) {
                ret = this.getChild(0).toString(options)+"?";
            } else if (this.children.size() == 2
                       && this.getChild(0).type == EMPTY) {
                ret = this.getChild(1).toString(options)+"??";
            } else {
                StringBuffer sb = new StringBuffer();
                sb.append(((Token)this.children.elementAt(0)).toString(options));
                for (int i = 1;  i < this.children.size();  i ++) {
                    sb.append((char)'|');
                    sb.append(((Token)this.children.elementAt(i)).toString(options));
                }
                ret = new String(sb);
            }
            return ret;
        }
    }
}

}