content: package cn.edu.nju.moon.redos.regex;
  /*
   * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
   * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
   */
  
  /*
   * pGREAT is developed based on the {java.util.regex.Pattern}
   */
  
  import java.text.Normalizer;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.NoSuchElementException;
  import java.util.Set;
  import java.util.Spliterator;
  import java.util.Spliterators;
  import java.util.function.Predicate;
  import java.util.regex.PatternSyntaxException;
  import java.util.stream.Stream;
  import java.util.stream.StreamSupport;
  
  import cn.edu.nju.moon.redos.Trace;
  import cn.edu.nju.moon.redos.utils.ReScuePatternUtils;
  import cn.edu.nju.moon.redos.utils.NodeRelation;
  import cn.edu.nju.moon.redos.utils.RegexViewer;
  import prefuse.data.Schema;
  import prefuse.data.Table;
  
  public final class ReScuePattern
      implements java.io.Serializable
  {	
      /**
       * Enables Unix lines mode.
       *
       * <p> In this mode, only the <tt>'\n'</tt> line terminator is recognized
       * in the behavior of <tt>.</tt>, <tt>^</tt>, and <tt>$</tt>.
       *
       * <p> Unix lines mode can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?d)</tt>.
       */
      public static final int UNIX_LINES = 0x01;
  
      /**
       * Enables case-insensitive matching.
       *
       * <p> By default, case-insensitive matching assumes that only characters
       * in the US-ASCII charset are being matched.  Unicode-aware
       * case-insensitive matching can be enabled by specifying the {@link
       * #UNICODE_CASE} flag in conjunction with this flag.
       *
       * <p> Case-insensitive matching can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?i)</tt>.
       *
       * <p> Specifying this flag may impose a slight performance penalty.  </p>
       */
      public static final int CASE_INSENSITIVE = 0x02;
  
      /**
       * Permits whitespace and comments in pattern.
       *
       * <p> In this mode, whitespace is ignored, and embedded comments starting
       * with <tt>#</tt> are ignored until the end of a line.
       *
       * <p> Comments mode can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?x)</tt>.
       */
      public static final int COMMENTS = 0x04;
  
      /**
       * Enables multiline mode.
       *
       * <p> In multiline mode the expressions <tt>^</tt> and <tt>$</tt> match
       * just after or just before, respectively, a line terminator or the end of
       * the input sequence.  By default these expressions only match at the
       * beginning and the end of the entire input sequence.
       *
       * <p> Multiline mode can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?m)</tt>.  </p>
       */
      public static final int MULTILINE = 0x08;
  
      /**
       * Enables literal parsing of the pattern.
       *
       * <p> When this flag is specified then the input string that specifies
       * the pattern is treated as a sequence of literal characters.
       * Metacharacters or escape sequences in the input sequence will be
       * given no special meaning.
       *
       * <p>The flags CASE_INSENSITIVE and UNICODE_CASE retain their impact on
       * matching when used in conjunction with this flag. The other flags
       * become superfluous.
       *
       * <p> There is no embedded flag character for enabling literal parsing.
       * @since 1.5
       */
      public static final int LITERAL = 0x10;
  
      /**
       * Enables dotall mode.
       *
       * <p> In dotall mode, the expression <tt>.</tt> matches any character,
       * including a line terminator.  By default this expression does not match
       * line terminators.
       *
       * <p> Dotall mode can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?s)</tt>.  (The <tt>s</tt> is a mnemonic for
       * "single-line" mode, which is what this is called in Perl.)  </p>
       */
      public static final int DOTALL = 0x20;
  
      /**
       * Enables Unicode-aware case folding.
       *
       * <p> When this flag is specified then case-insensitive matching, when
       * enabled by the {@link #CASE_INSENSITIVE} flag, is done in a manner
       * consistent with the Unicode Standard.  By default, case-insensitive
       * matching assumes that only characters in the US-ASCII charset are being
       * matched.
       *
       * <p> Unicode-aware case folding can also be enabled via the embedded flag
       * expression&nbsp;<tt>(?u)</tt>.
       *
       * <p> Specifying this flag may impose a performance penalty.  </p>
       */
      public static final int UNICODE_CASE = 0x40;
  
      /**
       * Enables canonical equivalence.
       *
       * <p> When this flag is specified then two characters will be considered
       * to match if, and only if, their full canonical decompositions match.
       * The expression <tt>"a&#92;u030A"</tt>, for example, will match the
       * string <tt>"&#92;u00E5"</tt> when this flag is specified.  By default,
       * matching does not take canonical equivalence into account.
       *
       * <p> There is no embedded flag character for enabling canonical
       * equivalence.
       *
       * <p> Specifying this flag may impose a performance penalty.  </p>
       */
      public static final int CANON_EQ = 0x80;
  
      /**
       * Enables the Unicode version of <i>Predefined character classes</i> and
       * <i>POSIX character classes</i>.
       *
       * <p> When this flag is specified then the (US-ASCII only)
       * <i>Predefined character classes</i> and <i>POSIX character classes</i>
       * are in conformance with
       * <a href="http://www.unicode.org/reports/tr18/"><i>Unicode Technical
       * Standard #18: Unicode Regular Expression</i></a>
       * <i>Annex C: Compatibility Properties</i>.
       * <p>
       * The UNICODE_CHARACTER_CLASS mode can also be enabled via the embedded
       * flag expression&nbsp;<tt>(?U)</tt>.
       * <p>
       * The flag implies UNICODE_CASE, that is, it enables Unicode-aware case
       * folding.
       * <p>
       * Specifying this flag may impose a performance penalty.  </p>
       * @since 1.7
       */
      public static final int UNICODE_CHARACTER_CLASS = 0x100;
  
      /* Pattern has only two serialized components: The pattern string
       * and the flags, which are all that is needed to recompile the pattern
       * when it is deserialized.
       */
  
      /** use serialVersionUID from Merlin b59 for interoperability */
      private static final long serialVersionUID = 5073258162644648461L;
  
      /**
       * The original regular-expression pattern string.
       *
       * @serial
       */
      private String pattern;
  
      /**
       * The original pattern flags.
       *
       * @serial
       */
      private int flags;
  
      /**
       * Boolean indicating this Pattern is compiled; this is necessary in order
       * to lazily compile deserialized Patterns.
       */
      private transient volatile boolean compiled = false;
  
      /**
       * The normalized pattern string.
       */
      private transient String normalizedPattern;
  
      /**
       * The starting point of state machine for the find operation.  This allows
       * a match to start anywhere in the input.
       */
      // transient means not to serialize
      public transient Node root;
  
      /**
       * The root of object tree for a match operation.  The pattern is matched
       * at the beginning.  This may include a find that uses BnM or a First
       * node.
       */
      transient Node matchRoot;
  
      /**
       * Temporary storage used by parsing pattern slice.
       */
      transient int[] buffer;
  
      /**
       * Map the "name" of the "named capturing group" to its group id
       * node.
       */
      transient volatile Map<String, Integer> namedGroups;
  
      /**
       * Temporary storage used while parsing group references.
       */
      transient GroupHead[] groupNodes;
  
      /**
       * Temporary null terminated code point array used by pattern compiling.
       */
      private transient int[] temp;
  
      /**
       * The number of capturing groups in this Pattern. Used by matchers to
       * allocate storage needed to perform a match.
       */
      transient int capturingGroupCount;
  
      /**
       * The local variable count used by parsing tree. Used by matchers to
       * allocate storage needed to perform a match.
       */
      transient int localCount;
  
      /**
       * Index into the pattern string that keeps track of how much has been
       * parsed.
       */
      private transient int cursor;
  
      /**
       * Holds the length of the pattern string.
       */
      private transient int patternLength;
  
      /**
       * If the Start node might possibly match supplementary characters.
       * It is set to true during compiling if
       * (1) There is supplementary char in pattern, or
       * (2) There is complement node of Category or Block
       */
      private transient boolean hasSupplementary;    
  
  	/**
       * Compiles the given regular expression into a pattern.
       *
       * @param  regex
       *         The expression to be compiled
       * @return the given regular expression compiled into a pattern
       * @throws  PatternSyntaxException
       *          If the expression's syntax is invalid
       */
      public static ReScuePattern compile(String regex) {
          return new ReScuePattern(regex, 0);
      }
  
      /**
       * Compiles the given regular expression into a pattern with the given
       * flags.
       *
       * @param  regex
       *         The expression to be compiled
       *
       * @param  flags
       *         Match flags, a bit mask that may include
       *         {@link #CASE_INSENSITIVE}, {@link #MULTILINE}, {@link #DOTALL},
       *         {@link #UNICODE_CASE}, {@link #CANON_EQ}, {@link #UNIX_LINES},
       *         {@link #LITERAL}, {@link #UNICODE_CHARACTER_CLASS}
       *         and {@link #COMMENTS}
       *
       * @return the given regular expression compiled into a pattern with the given flags
       * @throws  IllegalArgumentException
       *          If bit values other than those corresponding to the defined
       *          match flags are set in <tt>flags</tt>
       *
       * @throws  PatternSyntaxException
       *          If the expression's syntax is invalid
       */
      public static ReScuePattern compile(String regex, int flags) {
          return new ReScuePattern(regex, flags);
      }
  
      /**
       * Returns the regular expression from which this pattern was compiled.
       *
       * @return  The source of this pattern
       */
      public String pattern() {
          return pattern;
      }
  
      /**
       * <p>Returns the string representation of this pattern. This
       * is the regular expression from which this pattern was
       * compiled.</p>
       *
       * @return  The string representation of this pattern
       * @since 1.5
       */
      public String toString() {
          return pattern;
      }
  
      /**
       * Creates a matcher that will match the given input against this pattern.
       *
       * @param  input
       *         The character sequence to be matched
       *
       * @return  A new matcher for this pattern
       */
      public ReScueMatcher matcher(CharSequence input, Trace trace) {
          if (!compiled) {
              synchronized(this) {
                  if (!compiled)
                      compile();
              }
          }
          ReScueMatcher m = new ReScueMatcher(this, input, trace);
          return m;
      }
  
      /**
       * Returns this pattern's match flags.
       *
       * @return  The match flags specified when this pattern was compiled
       */
      public int flags() {
          return flags;
      }
  
      /**
       * Compiles the given regular expression and attempts to match the given
       * input against it.
       *
       * <p> An invocation of this convenience method of the form
       *
       * <blockquote><pre>
       * Pattern.matches(regex, input);</pre></blockquote>
       *
       * behaves in exactly the same way as the expression
       *
       * <blockquote><pre>
       * Pattern.compile(regex).matcher(input).matches()</pre></blockquote>
       *
       * <p> If a pattern is to be used multiple times, compiling it once and reusing
       * it will be more efficient than invoking this method each time.  </p>
       *
       * @param  regex
       *         The expression to be compiled
       *
       * @param  input
       *         The character sequence to be matched
       * @return whether or not the regular expression matches on the input
       * @throws CatastrophicBacktrackingException 
       * @throws  PatternSyntaxException
       *          If the expression's syntax is invalid
       */
      public static boolean matches(String regex, CharSequence input, Trace trace){
          ReScuePattern p = ReScuePattern.compile(regex);
          ReScueMatcher m = p.matcher(input, trace);
          return m.matches();
      }
  
      /**
       * Splits the given input sequence around matches of this pattern.
       *
       * <p> The array returned by this method contains each substring of the
       * input sequence that is terminated by another subsequence that matches
       * this pattern or is terminated by the end of the input sequence.  The
       * substrings in the array are in the order in which they occur in the
       * input. If this pattern does not match any subsequence of the input then
       * the resulting array has just one element, namely the input sequence in
       * string form.
       *
       * <p> When there is a positive-width match at the beginning of the input
       * sequence then an empty leading substring is included at the beginning
       * of the resulting array. A zero-width match at the beginning however
       * never produces such empty leading substring.
       *
       * <p> The <tt>limit</tt> parameter controls the number of times the
       * pattern is applied and therefore affects the length of the resulting
       * array.  If the limit <i>n</i> is greater than zero then the pattern
       * will be applied at most <i>n</i>&nbsp;-&nbsp;1 times, the array's
       * length will be no greater than <i>n</i>, and the array's last entry
       * will contain all input beyond the last matched delimiter.  If <i>n</i>
       * is non-positive then the pattern will be applied as many times as
       * possible and the array can have any length.  If <i>n</i> is zero then
       * the pattern will be applied as many times as possible, the array can
       * have any length, and trailing empty strings will be discarded.
       *
       * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
       * results with these parameters:
       *
       * <blockquote><table cellpadding=1 cellspacing=0
       *              summary="Split examples showing regex, limit, and result">
       * <tr><th align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
       *     <th align="left"><i>Limit&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
       *     <th align="left"><i>Result&nbsp;&nbsp;&nbsp;&nbsp;</i></th></tr>
       * <tr><td align=center>:</td>
       *     <td align=center>2</td>
       *     <td><tt>{ "boo", "and:foo" }</tt></td></tr>
       * <tr><td align=center>:</td>
       *     <td align=center>5</td>
       *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
       * <tr><td align=center>:</td>
       *     <td align=center>-2</td>
       *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
       * <tr><td align=center>o</td>
       *     <td align=center>5</td>
       *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
       * <tr><td align=center>o</td>
       *     <td align=center>-2</td>
       *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
       * <tr><td align=center>o</td>
       *     <td align=center>0</td>
       *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
       * </table></blockquote>
       *
       * @param  input
       *         The character sequence to be split
       *
       * @param  limit
       *         The result threshold, as described above
       *
       * @return  The array of strings computed by splitting the input
       *          around matches of this pattern
       * @throws CatastrophicBacktrackingException 
       */
      public String[] split(CharSequence input, int limit, Trace trace){
          int index = 0;
          boolean matchLimited = limit > 0;
          ArrayList<String> matchList = new ArrayList<>();
          ReScueMatcher m = matcher(input, trace);
  
          // Add segments before each match found
          while(m.find().matchSuccess) {
              if (!matchLimited || matchList.size() < limit - 1) {
                  if (index == 0 && index == m.start() && m.start() == m.end()) {
                      // no empty leading substring included for zero-width match
                      // at the beginning of the input char sequence.
                      continue;
                  }
                  String match = input.subSequence(index, m.start()).toString();
                  matchList.add(match);
                  index = m.end();
              } else if (matchList.size() == limit - 1) { // last one
                  String match = input.subSequence(index,
                                                   input.length()).toString();
                  matchList.add(match);
                  index = m.end();
              }
          }
  
          // If no match was found, return this
          if (index == 0)
              return new String[] {input.toString()};
  
          // Add remaining segment
          if (!matchLimited || matchList.size() < limit)
              matchList.add(input.subSequence(index, input.length()).toString());
  
          // Construct result
          int resultSize = matchList.size();
          if (limit == 0)
              while (resultSize > 0 && matchList.get(resultSize-1).equals(""))
                  resultSize--;
          String[] result = new String[resultSize];
          return matchList.subList(0, resultSize).toArray(result);
      }
  
      /**
       * Splits the given input sequence around matches of this pattern.
       *
       * <p> This method works as if by invoking the two-argument {@link
       * #split(java.lang.CharSequence, int) split} method with the given input
       * sequence and a limit argument of zero.  Trailing empty strings are
       * therefore not included in the resulting array. </p>
       *
       * <p> The input <tt>"boo:and:foo"</tt>, for example, yields the following
       * results with these expressions:
       *
       * <blockquote><table cellpadding=1 cellspacing=0
       *              summary="Split examples showing regex and result">
       * <tr><th align="left"><i>Regex&nbsp;&nbsp;&nbsp;&nbsp;</i></th>
       *     <th align="left"><i>Result</i></th></tr>
       * <tr><td align=center>:</td>
       *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
       * <tr><td align=center>o</td>
       *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
       * </table></blockquote>
       *
       *
       * @param  input
       *         The character sequence to be split
       *
       * @return  The array of strings computed by splitting the input
       *          around matches of this pattern
       * @throws CatastrophicBacktrackingException 
       */
      public String[] split(CharSequence input, Trace trace){
          return split(input, 0, trace);
      }
  
      /**
       * Returns a literal pattern <code>String</code> for the specified
       * <code>String</code>.
       *
       * <p>This method produces a <code>String</code> that can be used to
       * create a <code>Pattern</code> that would match the string
       * <code>s</code> as if it were a literal pattern.</p> Metacharacters
       * or escape sequences in the input sequence will be given no special
       * meaning.
       *
       * @param  s The string to be literalized
       * @return  A literal string replacement
       * @since 1.5
       */
      public static String quote(String s) {
          int slashEIndex = s.indexOf("\\E");
          if (slashEIndex == -1)
              return "\\Q" + s + "\\E";
  
          StringBuilder sb = new StringBuilder(s.length() * 2);
          sb.append("\\Q");
          slashEIndex = 0;
          int current = 0;
          while ((slashEIndex = s.indexOf("\\E", current)) != -1) {
              sb.append(s.substring(current, slashEIndex));
              current = slashEIndex + 2;
              sb.append("\\E\\\\E\\Q");
          }
          sb.append(s.substring(current, s.length()));
          sb.append("\\E");
          return sb.toString();
      }
  
      /**
       * Recompile the Pattern instance from a stream.  The original pattern
       * string is read in and the object tree is recompiled from it.
       */
      private void readObject(java.io.ObjectInputStream s)
          throws java.io.IOException, ClassNotFoundException {
  
          // Read in all fields
          s.defaultReadObject();
  
          // Initialize counts
          capturingGroupCount = 1;
          localCount = 0;
  
          // if length > 0, the Pattern is lazily compiled
          compiled = false;
          if (pattern.length() == 0) {
              root = new Start(lastAccept);
              matchRoot = lastAccept;
              compiled = true;
          }
      }
  
      /**
       * This private constructor is used to create all Patterns. The pattern
       * string and match flags are all that is needed to completely describe
       * a Pattern. An empty pattern string results in an object tree with
       * only a Start node and a LastNode node.
       */
      private ReScuePattern(String p, int f) {
          pattern = p;
          flags = f;
  
          // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
          if ((flags & UNICODE_CHARACTER_CLASS) != 0)
              flags |= UNICODE_CASE;
  
          // Reset group index count
          capturingGroupCount = 1;
          localCount = 0;
  
          if (pattern.length() > 0) {
              compile();
          } else {
              root = new Start(lastAccept);
              matchRoot = lastAccept;
          }
      }
  
      /**
       * The pattern is converted to normalizedD form and then a pure group
       * is constructed to match canonical equivalences of the characters.
       */
      private void normalize() {
          boolean inCharClass = false;
          int lastCodePoint = -1;
  
          // Convert pattern into normalizedD form
          normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
          patternLength = normalizedPattern.length();
  
          // Modify pattern to match canonical equivalences
          StringBuilder newPattern = new StringBuilder(patternLength);
          for(int i=0; i<patternLength; ) {
              int c = normalizedPattern.codePointAt(i);
              StringBuilder sequenceBuffer;
              if ((Character.getType(c) == Character.NON_SPACING_MARK)
                  && (lastCodePoint != -1)) {
                  sequenceBuffer = new StringBuilder();
                  sequenceBuffer.appendCodePoint(lastCodePoint);
                  sequenceBuffer.appendCodePoint(c);
                  while(Character.getType(c) == Character.NON_SPACING_MARK) {
                      i += Character.charCount(c);
                      if (i >= patternLength)
                          break;
                      c = normalizedPattern.codePointAt(i);
                      sequenceBuffer.appendCodePoint(c);
                  }
                  String ea = produceEquivalentAlternation(
                                                 sequenceBuffer.toString());
                  newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
                  newPattern.append("(?:").append(ea).append(")");
              } else if (c == '[' && lastCodePoint != '\\') {
                  i = normalizeCharClass(newPattern, i);
              } else {
                  newPattern.appendCodePoint(c);
              }
              lastCodePoint = c;
              i += Character.charCount(c);
          }
          normalizedPattern = newPattern.toString();
      }
  
      /**
       * Complete the character class being parsed and add a set
       * of alternations to it that will match the canonical equivalences
       * of the characters within the class.
       */
      private int normalizeCharClass(StringBuilder newPattern, int i) {
          StringBuilder charClass = new StringBuilder();
          StringBuilder eq = null;
          int lastCodePoint = -1;
          String result;
  
          i++;
          charClass.append("[");
          while(true) {
              int c = normalizedPattern.codePointAt(i);
              StringBuilder sequenceBuffer;
  
              if (c == ']' && lastCodePoint != '\\') {
                  charClass.append((char)c);
                  break;
              } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
                  sequenceBuffer = new StringBuilder();
                  sequenceBuffer.appendCodePoint(lastCodePoint);
                  while(Character.getType(c) == Character.NON_SPACING_MARK) {
                      sequenceBuffer.appendCodePoint(c);
                      i += Character.charCount(c);
                      if (i >= normalizedPattern.length())
                          break;
                      c = normalizedPattern.codePointAt(i);
                  }
                  String ea = produceEquivalentAlternation(
                                                    sequenceBuffer.toString());
  
                  charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
                  if (eq == null)
                      eq = new StringBuilder();
                  eq.append('|');
                  eq.append(ea);
              } else {
                  charClass.appendCodePoint(c);
                  i++;
              }
              if (i == normalizedPattern.length())
                  throw error("Unclosed character class");
              lastCodePoint = c;
          }
  
          if (eq != null) {
              result = "(?:"+charClass.toString()+eq.toString()+")";
          } else {
              result = charClass.toString();
          }
  
          newPattern.append(result);
          return i;
      }
  
      /**
       * Given a specific sequence composed of a regular character and
       * combining marks that follow it, produce the alternation that will
       * match all canonical equivalences of that sequence.
       */
      private String produceEquivalentAlternation(String source) {
          int len = countChars(source, 0, 1);
          if (source.length() == len)
              // source has one character.
              return source;
  
          String base = source.substring(0,len);
          String combiningMarks = source.substring(len);
  
          String[] perms = producePermutations(combiningMarks);
          StringBuilder result = new StringBuilder(source);
  
          // Add combined permutations
          for(int x=0; x<perms.length; x++) {
              String next = base + perms[x];
              if (x>0)
                  result.append("|"+next);
              next = composeOneStep(next);
              if (next != null)
                  result.append("|"+produceEquivalentAlternation(next));
          }
          return result.toString();
      }
  
      /**
       * Returns an array of strings that have all the possible
       * permutations of the characters in the input string.
       * This is used to get a list of all possible orderings
       * of a set of combining marks. Note that some of the permutations
       * are invalid because of combining class collisions, and these
       * possibilities must be removed because they are not canonically
       * equivalent.
       */
      private String[] producePermutations(String input) {
          if (input.length() == countChars(input, 0, 1))
              return new String[] {input};
  
          if (input.length() == countChars(input, 0, 2)) {
              int c0 = Character.codePointAt(input, 0);
              int c1 = Character.codePointAt(input, Character.charCount(c0));
              if (getClass(c1) == getClass(c0)) {
                  return new String[] {input};
              }
              String[] result = new String[2];
              result[0] = input;
              StringBuilder sb = new StringBuilder(2);
              sb.appendCodePoint(c1);
              sb.appendCodePoint(c0);
              result[1] = sb.toString();
              return result;
          }
  
          int length = 1;
          int nCodePoints = countCodePoints(input);
          for(int x=1; x<nCodePoints; x++)
              length = length * (x+1);
  
          String[] temp = new String[length];
  
          int combClass[] = new int[nCodePoints];
          for(int x=0, i=0; x<nCodePoints; x++) {
              int c = Character.codePointAt(input, i);
              combClass[x] = getClass(c);
              i +=  Character.charCount(c);
          }
  
          // For each char, take it out and add the permutations
          // of the remaining chars
          int index = 0;
          int len;
          // offset maintains the index in code units.
  loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
              len = countChars(input, offset, 1);
              boolean skip = false;
              for(int y=x-1; y>=0; y--) {
                  if (combClass[y] == combClass[x]) {
                      continue loop;
                  }
              }
              StringBuilder sb = new StringBuilder(input);
              String otherChars = sb.delete(offset, offset+len).toString();
              String[] subResult = producePermutations(otherChars);
  
              String prefix = input.substring(offset, offset+len);
              for(int y=0; y<subResult.length; y++)
                  temp[index++] =  prefix + subResult[y];
          }
          String[] result = new String[index];
          for (int x=0; x<index; x++)
              result[x] = temp[x];
          return result;
      }
  
      private int getClass(int c) {
          return sun.text.Normalizer.getCombiningClass(c);
      }
  
      /**
       * Attempts to compose input by combining the first character
       * with the first combining mark following it. Returns a String
       * that is the composition of the leading character with its first
       * combining mark followed by the remaining combining marks. Returns
       * null if the first two characters cannot be further composed.
       */
      private String composeOneStep(String input) {
          int len = countChars(input, 0, 2);
          String firstTwoCharacters = input.substring(0, len);
          String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
  
          if (result.equals(firstTwoCharacters))
              return null;
          else {
              String remainder = input.substring(len);
              return result + remainder;
          }
      }
  
      /**
       * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
       * See the description of `quotemeta' in perlfunc(1).
       */
      private void RemoveQEQuoting() {
          final int pLen = patternLength;
          int i = 0;
          while (i < pLen-1) {
              if (temp[i] != '\\')
                  i += 1;
              else if (temp[i + 1] != 'Q')
                  i += 2;
              else
                  break;
          }
          if (i >= pLen - 1)    // No \Q sequence found
              return;
          int j = i;
          i += 2;
          int[] newtemp = new int[j + 3*(pLen-i) + 2];
          System.arraycopy(temp, 0, newtemp, 0, j);
  
          boolean inQuote = true;
          boolean beginQuote = true;
          while (i < pLen) {
              int c = temp[i++];
              if (!ASCII.isAscii(c) || ASCII.isAlpha(c)) {
                  newtemp[j++] = c;
              } else if (ASCII.isDigit(c)) {
                  if (beginQuote) {
                      /*
                       * A unicode escape \[0xu] could be before this quote,
                       * and we don't want this numeric char to processed as
                       * part of the escape.
                       */
                      newtemp[j++] = '\\';
                      newtemp[j++] = 'x';
                      newtemp[j++] = '3';
                  }
                  newtemp[j++] = c;
              } else if (c != '\\') {
                  if (inQuote) newtemp[j++] = '\\';
                  newtemp[j++] = c;
              } else if (inQuote) {
                  if (temp[i] == 'E') {
                      i++;
                      inQuote = false;
                  } else {
                      newtemp[j++] = '\\';
                      newtemp[j++] = '\\';
                  }
              } else {
                  if (temp[i] == 'Q') {
                      i++;
                      inQuote = true;
                      beginQuote = true;
                      continue;
                  } else {
                      newtemp[j++] = c;
                      if (i != pLen)
                          newtemp[j++] = temp[i++];
                  }
              }
  
              beginQuote = false;
          }
  
          patternLength = j;
          temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
      }
  
      /**
       * Copies regular expression to an int array and invokes the parsing
       * of the expression which will create the object tree.
       */
      private void compile() {
          // Handle canonical equivalences
          if (has(CANON_EQ) && !has(LITERAL)) {
              normalize();
          } else {
              normalizedPattern = pattern;
          }
          patternLength = normalizedPattern.length();
  
          // Copy pattern to int array for convenience
          // Use double zero to terminate pattern
          temp = new int[patternLength + 2];
  
          hasSupplementary = false;
          int c, count = 0;
          // Convert all chars into code points
          for (int x = 0; x < patternLength; x += Character.charCount(c)) {
              c = normalizedPattern.codePointAt(x);
              if (isSupplementary(c)) {
                  hasSupplementary = true;
              }
              temp[count++] = c;
          }
  
          patternLength = count;   // patternLength now in code points
  
          if (! has(LITERAL))
              RemoveQEQuoting();
  
          // Allocate all temporary objects here.
          buffer = new int[32];
          groupNodes = new GroupHead[10];
          namedGroups = null;
  
          if (has(LITERAL)) {
              // Literal pattern handling
              matchRoot = newSlice(temp, patternLength, hasSupplementary);
              matchRoot.next = lastAccept;
          } else {
              // Start recursive descent parsing
              matchRoot = expr(lastAccept);
              // Check extra pattern characters
              if (patternLength != cursor) {
                  if (peek() == ')') {
                      throw error("Unmatched closing ')'");
                  } else {
                      throw error("Unexpected internal error");
                  }
              }
          }
  
          // Peephole optimization
          if (matchRoot instanceof Slice) {
              root = BnM.optimize(matchRoot);
              if (root == matchRoot) {
                  root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
              }
          } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
              root = matchRoot;
          } else {
              root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
          }
  
          // Release temporary storage
          temp = null;
          buffer = null;
          groupNodes = null;
          patternLength = 0;
          compiled = true;
      }
  
      Map<String, Integer> namedGroups() {
          if (namedGroups == null)
              namedGroups = new HashMap<>(2);
          return namedGroups;
      }
  
      /**
       * Used to print out a subtree of the Pattern to help with debugging.
       */
      public static void printObjectTree(Node node) {
          while(node != null) {
              if (node instanceof Prolog) {
                  System.out.println(node);
                  printObjectTree(((Prolog)node).loop);
                  System.out.println("**** end contents prolog loop");
              } else if (node instanceof Loop) {
                  System.out.println(node);
                  printObjectTree(((Loop)node).body);
                  System.out.println("**** end contents Loop body");
              } else if (node instanceof Curly) {
                  System.out.println(node);
                  printObjectTree(((Curly)node).atom);
                  System.out.println("**** end contents Curly body");
              } else if (node instanceof GroupCurly) {
                  System.out.println(node);
                  printObjectTree(((GroupCurly)node).atom);
                  System.out.println("**** end contents GroupCurly body");
              } else if (node instanceof GroupTail) {
                  System.out.println(node);
                  System.out.println("Tail next is "+node.next);
                  return;
              } else {
                  System.out.println(node);
              }
              node = node.next;
              if (node != null)
                  System.out.println("->next:");
              if (node == ReScuePattern.accept) {
                  System.out.println("Accept Node");
                  node = null;
              }
         }
      }
  
      /**
       * Used to accumulate information about a subtree of the object graph
       * so that optimizations can be applied to the subtree.
       */
      static final class TreeInfo {
          int minLength;
          int maxLength;
          boolean maxValid;
          boolean deterministic;
  
          TreeInfo() {
              reset();
          }
          void reset() {
              minLength = 0;
              maxLength = 0;
              maxValid = true;
              deterministic = true;
          }
      }
  
      /*
       * The following private methods are mainly used to improve the
       * readability of the code. In order to let the Java compiler easily
       * inline them, we should not put many assertions or error checks in them.
       */
  
      /**
       * Indicates whether a particular flag is set or not.
       */
      private boolean has(int f) {
          return (flags & f) != 0;
      }
  
      /**
       * Match next character, signal error if failed.
       */
      private void accept(int ch, String s) {
          int testChar = temp[cursor++];
          if (has(COMMENTS))
              testChar = parsePastWhitespace(testChar);
          if (ch != testChar) {
              throw error(s);
          }
      }
  
      /**
       * Mark the end of pattern with a specific character.
       */
      private void mark(int c) {
          temp[patternLength] = c;
      }
  
      /**
       * Peek the next character, and do not advance the cursor.
       */
      private int peek() {
          int ch = temp[cursor];
          if (has(COMMENTS))
              ch = peekPastWhitespace(ch);
          return ch;
      }
  
      /**
       * Read the next character, and advance the cursor by one.
       */
      private int read() {
          int ch = temp[cursor++];
          if (has(COMMENTS))
              ch = parsePastWhitespace(ch);
          return ch;
      }
  
      /**
       * Read the next character, and advance the cursor by one,
       * ignoring the COMMENTS setting
       */
      private int readEscaped() {
          int ch = temp[cursor++];
          return ch;
      }
  
      /**
       * Advance the cursor by one, and peek the next character.
       */
      private int next() {
          int ch = temp[++cursor];
          if (has(COMMENTS))
              ch = peekPastWhitespace(ch);
          return ch;
      }
  
      /**
       * Advance the cursor by one, and peek the next character,
       * ignoring the COMMENTS setting
       */
      private int nextEscaped() {
          int ch = temp[++cursor];
          return ch;
      }
  
      /**
       * If in xmode peek past whitespace and comments.
       */
      private int peekPastWhitespace(int ch) {
          while (ASCII.isSpace(ch) || ch == '#') {
              while (ASCII.isSpace(ch))
                  ch = temp[++cursor];
              if (ch == '#') {
                  ch = peekPastLine();
              }
          }
          return ch;
      }
  
      /**
       * If in xmode parse past whitespace and comments.
       */
      private int parsePastWhitespace(int ch) {
          while (ASCII.isSpace(ch) || ch == '#') {
              while (ASCII.isSpace(ch))
                  ch = temp[cursor++];
              if (ch == '#')
                  ch = parsePastLine();
          }
          return ch;
      }
  
      /**
       * xmode parse past comment to end of line.
       */
      private int parsePastLine() {
          int ch = temp[cursor++];
          while (ch != 0 && !isLineSeparator(ch))
              ch = temp[cursor++];
          return ch;
      }
  
      /**
       * xmode peek past comment to end of line.
       */
      private int peekPastLine() {
          int ch = temp[++cursor];
          while (ch != 0 && !isLineSeparator(ch))
              ch = temp[++cursor];
          return ch;
      }
  
      /**
       * Determines if character is a line separator in the current mode
       */
      private boolean isLineSeparator(int ch) {
          if (has(UNIX_LINES)) {
              return ch == '\n';
          } else {
              return (ch == '\n' ||
                      ch == '\r' ||
                      (ch|1) == '\u2029' ||
                      ch == '\u0085');
          }
      }
  
      /**
       * Read the character after the next one, and advance the cursor by two.
       */
      private int skip() {
          int i = cursor;
          int ch = temp[i+1];
          cursor = i + 2;
          return ch;
      }
  
      /**
       * Unread one next character, and retreat cursor by one.
       */
      private void unread() {
          cursor--;
      }
  
      /**
       * Internal method used for handling all syntax errors. The pattern is
       * displayed with a pointer to aid in locating the syntax error.
       */
      private PatternSyntaxException error(String s) {
          return new PatternSyntaxException(s, normalizedPattern,  cursor - 1);
      }
  
      /**
       * Determines if there is any supplementary character or unpaired
       * surrogate in the specified range.
       */
      private boolean findSupplementary(int start, int end) {
          for (int i = start; i < end; i++) {
              if (isSupplementary(temp[i]))
                  return true;
          }
          return false;
      }
  
      /**
       * Determines if the specified code point is a supplementary
       * character or unpaired surrogate.
       */
      private static final boolean isSupplementary(int ch) {
          return ch >= Character.MIN_SUPPLEMENTARY_CODE_POINT ||
                 Character.isSurrogate((char)ch);
      }
  
      /**
       *  The following methods handle the main parsing. They are sorted
       *  according to their precedence order, the lowest one first.
       */
  
      /**
       * The expression is parsed with branch nodes added for alternations.
       * This may be called recursively to parse sub expressions that may
       * contain alternations.
       */
      private Node expr(Node end) {
          Node prev = null;
          Node firstTail = null;
          Branch branch = null;
          Node branchConn = null;
  
          for (;;) {
              Node node = sequence(end);
              Node nodeTail = root;      //double return
              if (prev == null) {
                  prev = node;
                  firstTail = nodeTail;
              } else {
                  // Branch
                  if (branchConn == null) {
                      branchConn = new BranchConn("BranchEnd");
                      branchConn.next = end;
                  }
                  if (node == end) {
                      // if the node returned from sequence() is "end"
                      // we have an empty expr, set a null atom into
                      // the branch to indicate to go "next" directly.
                      node = null;
                  } else {
                      // the "tail.next" of each atom goes to branchConn
                      nodeTail.next = branchConn;
                  }
                  if (prev == branch) {
                      branch.add(node);
                  } else {
                      if (prev == end) {
                          prev = null;
                      } else {
                          // replace the "end" with "branchConn" at its tail.next
                          // when put the "prev" into the branch as the first atom.
                          firstTail.next = branchConn;
                      }
                      prev = branch = new Branch(prev, node, branchConn, "|");
                  }
              }
              if (peek() != '|') {
                  return prev;
              }
              next();
          }
      }
  
      @SuppressWarnings("fallthrough")
      /**
       * Parsing of sequences between alternations.
       */
      private Node sequence(Node end) {
          Node head = null;
          Node tail = null;
          Node node = null;
      LOOP:
          for (;;) {
              int ch = peek();
              switch (ch) {
              case '(':
                  // Because group handles its own closure,
                  // we need to treat it differently
                  node = group0();
                  // Check for comment or flag group
                  if (node == null)
                      continue;
                  if (head == null)
                      head = node;
                  else
                      tail.next = node;
                  // Double return: Tail was returned in root
                  tail = root;
                  continue;
              case '[':
                  node = clazz(true);
                  break;
              case '\\':
                  ch = nextEscaped();
                  if (ch == 'p' || ch == 'P') {
                      boolean oneLetter = true;
                      boolean comp = (ch == 'P');
                      ch = next(); // Consume { if present
                      if (ch != '{') {
                          unread();
                      } else {
                          oneLetter = false;
                      }
                      node = family(oneLetter, comp);
                  } else {
                      unread();
                      node = atom();
                  }
                  break;
              case '^':
                  next();
                  if (has(MULTILINE)) {
                      if (has(UNIX_LINES))
                          node = new UnixCaret("^");
                      else
                          node = new Caret("^");
                  } else {
                      node = new Begin("^");
                  }
                  break;
              case '$':
                  next();
                  if (has(UNIX_LINES))
                      node = new UnixDollar(has(MULTILINE), "$");
                  else
                      node = new Dollar(has(MULTILINE), "$");
                  break;
              case '.':
                  next();
                  if (has(DOTALL)) {
                      node = new All(".");
                  } else {
                      if (has(UNIX_LINES))
                          node = new UnixDot(".");
                      else {
                          node = new Dot(".");
                      }
                  }
                  break;
              case '|':
              case ')':
                  break LOOP;
              case ']': // Now interpreting dangling ] and } as literals
              case '}':
                  node = atom();
                  break;
              case '?':
              case '*':
              case '+':
                  next();
                  throw error("Dangling meta character '" + ((char)ch) + "'");
              case 0:
                  if (cursor >= patternLength) {
                      break LOOP;
                  }
                  // Fall through
              default:
                  node = atom();
                  break;
              }
  
              node = closure(node);
  
              if (head == null) {
                  head = tail = node;
              } else {
                  tail.next = node;
                  tail = node;
              }
          }
          if (head == null) {
              return end;
          }
          tail.next = end;
          root = tail;      //double return
          return head;
      }
  
      @SuppressWarnings("fallthrough")
      /**
       * Parse and add a new Single or Slice.
       */
      private Node atom() {
          int first = 0;
          int prev = -1;
          boolean hasSupplementary = false;
          int ch = peek();
          for (;;) {
              switch (ch) {
              case '*':
              case '+':
              case '?':
              case '{':
                  if (first > 1) {
                      cursor = prev;    // Unwind one character
                      first--;
                  }
                  break;
              case '$':
              case '.':
              case '^':
              case '(':
              case '[':
              case '|':
              case ')':
                  break;
              case '\\':
                  ch = nextEscaped();
                  if (ch == 'p' || ch == 'P') { // Property
                      if (first > 0) { // Slice is waiting; handle it first
                          unread();
                          break;
                      } else { // No slice; just return the family node
                          boolean comp = (ch == 'P');
                          boolean oneLetter = true;
                          ch = next(); // Consume { if present
                          if (ch != '{')
                              unread();
                          else
                              oneLetter = false;
                          return family(oneLetter, comp);
                      }
                  }
                  unread();
                  prev = cursor;
                  ch = escape(false, first == 0, false);
                  if (ch >= 0) {
                      append(ch, first);
                      first++;
                      if (isSupplementary(ch)) {
                          hasSupplementary = true;
                      }
                      ch = peek();
                      continue;
                  } else if (first == 0) {
                      return root;
                  }
                  // Unwind meta escape sequence
                  cursor = prev;
                  break;
              case 0:
                  if (cursor >= patternLength) {
                      break;
                  }
                  // Fall through
              default:
                  prev = cursor;
                  append(ch, first);
                  first++;
                  if (isSupplementary(ch)) {
                      hasSupplementary = true;
                  }
                  ch = next();
                  continue;
              }
              break;
          }
          if (first == 1) {
              return newSingle(buffer[0]);
          } else {
              return newSlice(buffer, first, hasSupplementary);
          }
      }
  
      private void append(int ch, int len) {
          if (len >= buffer.length) {
              int[] tmp = new int[len+len];
              System.arraycopy(buffer, 0, tmp, 0, len);
              buffer = tmp;
          }
          buffer[len] = ch;
      }
  
      /**
       * Parses a backref greedily, taking as many numbers as it
       * can. The first digit is always treated as a backref, but
       * multi digit numbers are only treated as a backref if at
       * least that many backrefs exist at this point in the regex.
       */
      private Node ref(int refNum) {
          boolean done = false;
          while(!done) {
              int ch = peek();
              switch(ch) {
              case '0':
              case '1':
              case '2':
              case '3':
              case '4':
              case '5':
              case '6':
              case '7':
              case '8':
              case '9':
                  int newRefNum = (refNum * 10) + (ch - '0');
                  // Add another number if it doesn't make a group
                  // that doesn't exist
                  if (capturingGroupCount - 1 < newRefNum) {
                      done = true;
                      break;
                  }
                  refNum = newRefNum;
                  read();
                  break;
              default:
                  done = true;
                  break;
              }
          }
          if (has(CASE_INSENSITIVE))
              return new CIBackRef(refNum, has(UNICODE_CASE), "\\" + refNum);
          else
              return new BackRef(refNum, "\\" + refNum);
      }
  
      /**
       * Parses an escape sequence to determine the actual value that needs
       * to be matched.
       * If -1 is returned and create was true a new object was added to the tree
       * to handle the escape sequence.
       * If the returned value is greater than zero, it is the value that
       * matches the escape sequence.
       */
      private int escape(boolean inclass, boolean create, boolean isrange) {
          int ch = skip();
          switch (ch) {
          case '0':
              return o();
          case '1':
          case '2':
          case '3':
          case '4':
          case '5':
          case '6':
          case '7':
          case '8':
          case '9':
              if (inclass) break;
              if (create) {
                  root = ref((ch - '0'));
              }
              return -1;
          case 'A':
              if (inclass) break;
              if (create) root = new Begin("\\A");
              return -1;
          case 'B':
              if (inclass) break;
              if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS), "\\B");
              return -1;
          case 'C':
              break;
          case 'D':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.DIGIT).complement()
                                 : new Ctype(ASCII.DIGIT).complement();
              return -1;
          case 'E':
          case 'F':
              break;
          case 'G':
              if (inclass) break;
              if (create) root = new LastMatch("\\G");
              return -1;
          case 'H':
              if (create) root = new HorizWS("\\H").complement();
              return -1;
          case 'I':
          case 'J':
          case 'K':
          case 'L':
          case 'M':
          case 'N':
          case 'O':
          case 'P':
          case 'Q':
              break;
          case 'R':
              if (inclass) break;
              if (create) root = new LineEnding("\\R");
              return -1;
          case 'S':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.WHITE_SPACE).complement()
                                 : new Ctype(ASCII.SPACE).complement();
              return -1;
          case 'T':
          case 'U':
              break;
          case 'V':
              if (create) root = new VertWS("\\V").complement();
              return -1;
          case 'W':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.WORD).complement()
                                 : new Ctype(ASCII.WORD).complement();
              return -1;
          case 'X':
          case 'Y':
              break;
          case 'Z':
              if (inclass) break;
              if (create) {
                  if (has(UNIX_LINES))
                      root = new UnixDollar(false, "\\Z");
                  else
                      root = new Dollar(false, "\\Z");
              }
              return -1;
          case 'a':
              return '\007';
          case 'b':
              if (inclass) break;
              if (create) root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS), "\\b");
              return -1;
          case 'c':
              return c();
          case 'd':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.DIGIT)
                                 : new Ctype(ASCII.DIGIT);
              return -1;
          case 'e':
              return '\033';
          case 'f':
              return '\f';
          case 'g':
              break;
          case 'h':
              if (create) root = new HorizWS("\\h");
              return -1;
          case 'i':
          case 'j':
              break;
          case 'k':
              if (inclass)
                  break;
              if (read() != '<')
                  throw error("\\k is not followed by '<' for named capturing group");
              String name = groupname(read());
              if (!namedGroups().containsKey(name))
                  throw error("(named capturing group <"+ name+"> does not exit");
              if (create) {
                  if (has(CASE_INSENSITIVE))
                      root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE), "\\" + namedGroups().get(name));
                  else
                      root = new BackRef(namedGroups().get(name), "\\" + namedGroups().get(name));
              }
              return -1;
          case 'l':
          case 'm':
              break;
          case 'n':
              return '\n';
          case 'o':
          case 'p':
          case 'q':
              break;
          case 'r':
              return '\r';
          case 's':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.WHITE_SPACE)
                                 : new Ctype(ASCII.SPACE);
              return -1;
          case 't':
              return '\t';
          case 'u':
              return u();
          case 'v':
              // '\v' was implemented as VT/0x0B in releases < 1.8 (though
              // undocumented). In JDK8 '\v' is specified as a predefined
              // character class for all vertical whitespace characters.
              // So [-1, root=VertWS node] pair is returned (instead of a
              // single 0x0B). This breaks the range if '\v' is used as
              // the start or end value, such as [\v-...] or [...-\v], in
              // which a single definite value (0x0B) is expected. For
              // compatibility concern '\013'/0x0B is returned if isrange.
              if (isrange)
                  return '\013';
              if (create) root = new VertWS("\\v");
              return -1;
          case 'w':
              if (create) root = has(UNICODE_CHARACTER_CLASS)
                                 ? new Utype(UnicodeProp.WORD)
                                 : new Ctype(ASCII.WORD);
              return -1;
          case 'x':
              return x();
          case 'y':
              break;
          case 'z':
              if (inclass) break;
              if (create) root = new End("\\z");
              return -1;
          default:
              return ch;
          }
          throw error("Illegal/unsupported escape sequence");
      }
  
      /**
       * Parse a character class, and return the node that matches it.
       *
       * Consumes a ] on the way out if consume is true. Usually consume
       * is true except for the case of [abc&&def] where def is a separate
       * right hand node with "understood" brackets.
       */
      private CharProperty clazz(boolean consume) {
          CharProperty prev = null;
          CharProperty node = null;
          BitClass bits = new BitClass("");
          boolean include = true;
          boolean firstInClass = true;
          int ch = next();
          for (;;) {
              switch (ch) {
                  case '^':
                      // Negates if first char in a class, otherwise literal
                      if (firstInClass) {
                          if (temp[cursor-1] != '[')
                              break;
                          ch = next();
                          include = !include;
                          continue;
                      } else {
                          // ^ not first in class, treat as literal
                          break;
                      }
                  case '[':
                      firstInClass = false;
                      node = clazz(true);
                      if (prev == null)
                          prev = node;
                      else
                          prev = union(prev, node);
                      ch = peek();
                      continue;
                  case '&':
                      firstInClass = false;
                      ch = next();
                      if (ch == '&') {
                          ch = next();
                          CharProperty rightNode = null;
                          while (ch != ']' && ch != '&') {
                              if (ch == '[') {
                                  if (rightNode == null)
                                      rightNode = clazz(true);
                                  else
                                      rightNode = union(rightNode, clazz(true));
                              } else { // abc&&def
                                  unread();
                                  rightNode = clazz(false);
                              }
                              ch = peek();
                          }
                          if (rightNode != null)
                              node = rightNode;
                          if (prev == null) {
                              if (rightNode == null)
                                  throw error("Bad class syntax");
                              else
                                  prev = rightNode;
                          } else {
                              prev = intersection(prev, node);
                          }
                      } else {
                          // treat as a literal &
                          unread();
                          break;
                      }
                      continue;
                  case 0:
                      firstInClass = false;
                      if (cursor >= patternLength)
                          throw error("Unclosed character class");
                      break;
                  case ']':
                      firstInClass = false;
                      if (prev != null) {
                          if (consume)
                              next();
                          return prev;
                      }
                      break;
                  default:
                      firstInClass = false;
                      break;
              }
              node = range(bits);
              if (include) {
                  if (prev == null) {
                      prev = node;
                  } else {
                      if (prev != node)
                          prev = union(prev, node);
                  }
              } else {
                  if (prev == null) {
                      prev = node.complement();
                  } else {
                      if (prev != node)
                          prev = setDifference(prev, node);
                  }
              }
              ch = peek();
          }
      }
  
      private CharProperty bitsOrSingle(BitClass bits, int ch) {
          /* Bits can only handle codepoints in [u+0000-u+00ff] range.
             Use "single" node instead of bits when dealing with unicode
             case folding for codepoints listed below.
             (1)Uppercase out of range: u+00ff, u+00b5
                toUpperCase(u+00ff) -> u+0178
                toUpperCase(u+00b5) -> u+039c
             (2)LatinSmallLetterLongS u+17f
                toUpperCase(u+017f) -> u+0053
             (3)LatinSmallLetterDotlessI u+131
                toUpperCase(u+0131) -> u+0049
             (4)LatinCapitalLetterIWithDotAbove u+0130
                toLowerCase(u+0130) -> u+0069
             (5)KelvinSign u+212a
                toLowerCase(u+212a) ==> u+006B
             (6)AngstromSign u+212b
                toLowerCase(u+212b) ==> u+00e5
          */
          int d;
          if (ch < 256 &&
              !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
                (ch == 0xff || ch == 0xb5 ||
                 ch == 0x49 || ch == 0x69 ||  //I and i
                 ch == 0x53 || ch == 0x73 ||  //S and s
                 ch == 0x4b || ch == 0x6b ||  //K and k
                 ch == 0xc5 || ch == 0xe5)))  //A+ring
              return bits.add(ch, flags());
          return newSingle(ch);
      }
  
      /**
       * Parse a single character or a character range in a character class
       * and return its representative node.
       */
      private CharProperty range(BitClass bits) {
          int ch = peek();
          if (ch == '\\') {
              ch = nextEscaped();
              if (ch == 'p' || ch == 'P') { // A property
                  boolean comp = (ch == 'P');
                  boolean oneLetter = true;
                  // Consume { if present
                  ch = next();
                  if (ch != '{')
                      unread();
                  else
                      oneLetter = false;
                  return family(oneLetter, comp);
              } else { // ordinary escape
                  boolean isrange = temp[cursor+1] == '-';
                  unread();
                  ch = escape(true, true, isrange);
                  if (ch == -1)
                      return (CharProperty) root;
              }
          } else {
              next();
          }
          if (ch >= 0) {
              if (peek() == '-') {
                  int endRange = temp[cursor+1];
                  if (endRange == '[') {
                      return bitsOrSingle(bits, ch);
                  }
                  if (endRange != ']') {
                      next();
                      int m = peek();
                      if (m == '\\') {
                          m = escape(true, false, true);
                      } else {
                          next();
                      }
                      if (m < ch) {
                          throw error("Illegal character range");
                      }
                      if (has(CASE_INSENSITIVE))
                          return caseInsensitiveRangeFor(ch, m);
                      else
                          return rangeFor(ch, m);
                  }
              }
              return bitsOrSingle(bits, ch);
          }
          throw error("Unexpected character '"+((char)ch)+"'");
      }
  
      /**
       * Parses a Unicode character family and returns its representative node.
       */
      private CharProperty family(boolean singleLetter,
                                  boolean maybeComplement)
      {
          next();
          String name;
          CharProperty node = null;
  
          if (singleLetter) {
              int c = temp[cursor];
              if (!Character.isSupplementaryCodePoint(c)) {
                  name = String.valueOf((char)c);
              } else {
                  name = new String(temp, cursor, 1);
              }
              read();
          } else {
              int i = cursor;
              mark('}');
              while(read() != '}') {
              }
              mark('\000');
              int j = cursor;
              if (j > patternLength)
                  throw error("Unclosed character family");
              if (i + 1 >= j)
                  throw error("Empty character family");
              name = new String(temp, i, j-i-1);
          }
  
          int i = name.indexOf('=');
          if (i != -1) {
              // property construct \p{name=value}
              String value = name.substring(i + 1);
              name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
              if ("sc".equals(name) || "script".equals(name)) {
                  node = unicodeScriptPropertyFor(value);
              } else if ("blk".equals(name) || "block".equals(name)) {
                  node = unicodeBlockPropertyFor(value);
              } else if ("gc".equals(name) || "general_category".equals(name)) {
                  node = charPropertyNodeFor(value);
              } else {
                  throw error("Unknown Unicode property {name=<" + name + ">, "
                               + "value=<" + value + ">}");
              }
          } else {
              if (name.startsWith("In")) {
                  // \p{inBlockName}
                  node = unicodeBlockPropertyFor(name.substring(2));
              } else if (name.startsWith("Is")) {
                  // \p{isGeneralCategory} and \p{isScriptName}
                  name = name.substring(2);
                  UnicodeProp uprop = UnicodeProp.forName(name);
                  if (uprop != null)
                      node = new Utype(uprop);
                  if (node == null)
                      node = CharPropertyNames.charPropertyFor(name);
                  if (node == null)
                      node = unicodeScriptPropertyFor(name);
              } else {
                  if (has(UNICODE_CHARACTER_CLASS)) {
                      UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
                      if (uprop != null)
                          node = new Utype(uprop);
                  }
                  if (node == null)
                      node = charPropertyNodeFor(name);
              }
          }
          if (maybeComplement) {
              if (node instanceof Category || node instanceof Block)
                  hasSupplementary = true;
              node = node.complement();
          }
          return node;
      }
  
  
      /**
       * Returns a CharProperty matching all characters belong to
       * a UnicodeScript.
       */
      private CharProperty unicodeScriptPropertyFor(String name) {
          final Character.UnicodeScript script;
          try {
              script = Character.UnicodeScript.forName(name);
          } catch (IllegalArgumentException iae) {
              throw error("Unknown character script name {" + name + "}");
          }
          return new Script(script);
      }
  
      /**
       * Returns a CharProperty matching all characters in a UnicodeBlock.
       */
      private CharProperty unicodeBlockPropertyFor(String name) {
          final Character.UnicodeBlock block;
          try {
              block = Character.UnicodeBlock.forName(name);
          } catch (IllegalArgumentException iae) {
              throw error("Unknown character block name {" + name + "}");
          }
          return new Block(block);
      }
  
      /**
       * Returns a CharProperty matching all characters in a named property.
       */
      private CharProperty charPropertyNodeFor(String name) {
          CharProperty p = CharPropertyNames.charPropertyFor(name);
          if (p == null)
              throw error("Unknown character property name {" + name + "}");
          return p;
      }
  
      /**
       * Parses and returns the name of a "named capturing group", the trailing
       * ">" is consumed after parsing.
       */
      private String groupname(int ch) {
          StringBuilder sb = new StringBuilder();
          sb.append(Character.toChars(ch));
          while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
                 ASCII.isDigit(ch)) {
              sb.append(Character.toChars(ch));
          }
          if (sb.length() == 0)
              throw error("named capturing group has 0 length name");
          if (ch != '>')
              throw error("named capturing group is missing trailing '>'");
          return sb.toString();
      }
  
      /**
       * Parses a group and returns the head node of a set of nodes that process
       * the group. Sometimes a double return system is used where the tail is
       * returned in root.
       */
      private Node group0() {
          boolean capturingGroup = false;
          Node head = null;
          Node tail = null;
          int save = flags;
          root = null;
          int ch = next();
          if (ch == '?') {
              ch = skip();
              switch (ch) {
              case ':':   //  (?:xxx) pure group
                  head = createGroup(true);
                  tail = root;
                  head.next = expr(tail);
                  break;
              case '=':   // (?=xxx) and (?!xxx) lookahead
              case '!':
                  head = createGroup(true);
                  tail = root;
                  head.next = expr(tail);
                  if (ch == '=') {
                      head = tail = new Pos(head, "(?=xxx)");
                  } else {
                      head = tail = new Neg(head, "(?!xxx)");
                  }
                  break;
              case '>':   // (?>xxx)  independent group
                  head = createGroup(true);
                  tail = root;
                  head.next = expr(tail);
                  head = tail = new Ques(head, INDEPENDENT, "(?>xxx)");
                  break;
              case '<':   // (?<xxx)  look behind
                  ch = read();
                  if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
                      // named captured group
                      String name = groupname(ch);
                      if (namedGroups().containsKey(name))
                          throw error("Named capturing group <" + name
                                      + "> is already defined");
                      capturingGroup = true;
                      head = createGroup(false);
                      tail = root;
                      namedGroups().put(name, capturingGroupCount-1);
                      head.next = expr(tail);
                      break;
                  }
                  int start = cursor;
                  head = createGroup(true);
                  tail = root;
                  head.next = expr(tail);
                  tail.next = lookbehindEnd;
                  TreeInfo info = new TreeInfo();
                  head.study(info);
                  if (info.maxValid == false) {
                      throw error("Look-behind group does not have "
                                  + "an obvious maximum length");
                  }
                  boolean hasSupplementary = findSupplementary(start, patternLength);
                  if (ch == '=') {
                      head = tail = (hasSupplementary ?
                                     new BehindS(head, info.maxLength,
                                                 info.minLength, "(<=xxx)") :
                                     new Behind(head, info.maxLength,
                                                info.minLength, "(<=xxx)"));
                  } else if (ch == '!') {
                      head = tail = (hasSupplementary ?
                                     new NotBehindS(head, info.maxLength,
                                                    info.minLength, "(<!xxx)") :
                                     new NotBehind(head, info.maxLength,
                                                   info.minLength, "(<!xxx)"));
                  } else {
                      throw error("Unknown look-behind group");
                  }
                  break;
              case '$':
              case '@':
                  throw error("Unknown group type");
              default:    // (?xxx:) inlined match flags
                  unread();
                  addFlag();
                  ch = read();
                  if (ch == ')') {
                      return null;    // Inline modifier only
                  }
                  if (ch != ':') {
                      throw error("Unknown inline modifier");
                  }
                  head = createGroup(true);
                  tail = root;
                  head.next = expr(tail);
                  break;
              }
          } else { // (xxx) a regular group
              capturingGroup = true;
              head = createGroup(false);
              tail = root;
              head.next = expr(tail);
          }
  
          accept(')', "Unclosed group");
          flags = save;
  
          // Check for quantifiers
          Node node = closure(head);
          if (node == head) { // No closure
              root = tail;
              return node;    // Dual return
          }
          if (head == tail) { // Zero length assertion
              root = node;
              return node;    // Dual return
          }
  
          if (node instanceof Ques) {
              Ques ques = (Ques) node;
              if (ques.type == POSSESSIVE) {
                  root = node;
                  return node;
              }
              tail.next = new BranchConn("BranchEnd");
              tail = tail.next;
              if (ques.type == GREEDY) {
                  head = new Branch(head, null, tail, "?");
              } else { // Reluctant quantifier
                  head = new Branch(null, head, tail, "?Lazy");
              }
              root = tail;
              return head;
          } else if (node instanceof Curly) {
              Curly curly = (Curly) node;
              if (curly.type == POSSESSIVE) {
                  root = node;
                  return node;
              }
              // Discover if the group is deterministic
              TreeInfo info = new TreeInfo();
              if (head.study(info)) { // Deterministic
                  GroupTail temp = (GroupTail) tail;
                  String self_str = head == null ? curly.self : "GroupHead: (\n" + curly.self;
                  head = root = new GroupCurly(head.next, curly.cmin,
                                     curly.cmax, curly.type,
                                     ((GroupTail)tail).localIndex,
                                     ((GroupTail)tail).groupIndex,
  //                                             capturingGroup, "(){" + curly.cmin + "," + curly.cmax + "}");
                  						     capturingGroup, self_str);
                  return head;
              } else { // Non-deterministic
                  int temp = ((GroupHead) head).localIndex;
                  Loop loop;
                  if (curly.type == GREEDY)
                      loop = new Loop(this.localCount, temp, "Loop");
                  else  // Reluctant Curly
                      loop = new LazyLoop(this.localCount, temp, "LoopLazy");
                  Prolog prolog = new Prolog(loop);
                  this.localCount += 1;
                  loop.cmin = curly.cmin;
                  loop.cmax = curly.cmax;
                  loop.body = head;
                  tail.next = loop;
                  root = loop;
                  return prolog; // Dual return
              }
          }
          throw error("Internal logic error");
      }
  
      /**
       * Create group head and tail nodes using double return. If the group is
       * created with anonymous true then it is a pure group and should not
       * affect group counting.
       */
      private Node createGroup(boolean anonymous) {
          int localIndex = localCount++;
          int groupIndex = 0;
          if (!anonymous)
              groupIndex = capturingGroupCount++;
          GroupHead head = new GroupHead(localIndex, "(");
          root = new GroupTail(localIndex, groupIndex, ")");
          if (!anonymous && groupIndex < 10)
              groupNodes[groupIndex] = head;
          return head;
      }
  
      @SuppressWarnings("fallthrough")
      /**
       * Parses inlined match flags and set them appropriately.
       */
      private void addFlag() {
          int ch = peek();
          for (;;) {
              switch (ch) {
              case 'i':
                  flags |= CASE_INSENSITIVE;
                  break;
              case 'm':
                  flags |= MULTILINE;
                  break;
              case 's':
                  flags |= DOTALL;
                  break;
              case 'd':
                  flags |= UNIX_LINES;
                  break;
              case 'u':
                  flags |= UNICODE_CASE;
                  break;
              case 'c':
                  flags |= CANON_EQ;
                  break;
              case 'x':
                  flags |= COMMENTS;
                  break;
              case 'U':
                  flags |= (UNICODE_CHARACTER_CLASS | UNICODE_CASE);
                  break;
              case '-': // subFlag then fall through
                  ch = next();
                  subFlag();
              default:
                  return;
              }
              ch = next();
          }
      }
  
      @SuppressWarnings("fallthrough")
      /**
       * Parses the second part of inlined match flags and turns off
       * flags appropriately.
       */
      private void subFlag() {
          int ch = peek();
          for (;;) {
              switch (ch) {
              case 'i':
                  flags &= ~CASE_INSENSITIVE;
                  break;
              case 'm':
                  flags &= ~MULTILINE;
                  break;
              case 's':
                  flags &= ~DOTALL;
                  break;
              case 'd':
                  flags &= ~UNIX_LINES;
                  break;
              case 'u':
                  flags &= ~UNICODE_CASE;
                  break;
              case 'c':
                  flags &= ~CANON_EQ;
                  break;
              case 'x':
                  flags &= ~COMMENTS;
                  break;
              case 'U':
                  flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
              default:
                  return;
              }
              ch = next();
          }
      }
  
      static final int MAX_REPS   = 0x7FFFFFFF;
  
      static final int GREEDY     = 0;
  
      static final int LAZY       = 1;
  
      static final int POSSESSIVE = 2;
  
      static final int INDEPENDENT = 3;
  
      /**
       * Processes repetition. If the next character peeked is a quantifier
       * then new nodes must be appended to handle the repetition.
       * Prev could be a single or a group, so it could be a chain of nodes.
       */
      private Node closure(Node prev) {
          Node atom;
          int ch = peek();
          switch (ch) {
          case '?':
              ch = next();
              if (ch == '?') {
                  next();
                  return new Ques(prev, LAZY, "?Lazy");
              } else if (ch == '+') {
                  next();
                  return new Ques(prev, POSSESSIVE, "?Poss");
              }
              return new Ques(prev, GREEDY, "?");
          case '*':
              ch = next();
              if (ch == '?') {
                  next();
                  return new Curly(prev, 0, MAX_REPS, LAZY, "*Lazy");
              } else if (ch == '+') {
                  next();
                  return new Curly(prev, 0, MAX_REPS, POSSESSIVE, "*Poss");
              }
              return new Curly(prev, 0, MAX_REPS, GREEDY, "*");
          case '+':
              ch = next();
              if (ch == '?') {
                  next();
                  return new Curly(prev, 1, MAX_REPS, LAZY, "+Lazy");
              } else if (ch == '+') {
                  next();
                  return new Curly(prev, 1, MAX_REPS, POSSESSIVE, "+Poss");
              }
              return new Curly(prev, 1, MAX_REPS, GREEDY, "+");
          case '{':
              ch = temp[cursor+1];
              if (ASCII.isDigit(ch)) {
                  skip();
                  int cmin = 0;
                  do {
                      cmin = cmin * 10 + (ch - '0');
                  } while (ASCII.isDigit(ch = read()));
                  int cmax = cmin;
                  if (ch == ',') {
                      ch = read();
                      cmax = MAX_REPS;
                      if (ch != '}') {
                          cmax = 0;
                          while (ASCII.isDigit(ch)) {
                              cmax = cmax * 10 + (ch - '0');
                              ch = read();
                          }
                      }
                  }
                  if (ch != '}')
                      throw error("Unclosed counted closure");
                  if (((cmin) | (cmax) | (cmax - cmin)) < 0)
                      throw error("Illegal repetition range");
                  Curly curly;
                  ch = peek();
                  if (ch == '?') {
                      next();
                      curly = new Curly(prev, cmin, cmax, LAZY, "{" + cmin + "," + cmax + "}Lazy");
                  } else if (ch == '+') {
                      next();
                      curly = new Curly(prev, cmin, cmax, POSSESSIVE, "{" + cmin + "," + cmax + "}Poss");
                  } else {
                      curly = new Curly(prev, cmin, cmax, GREEDY, "{" + cmin + "," + cmax + "}");
                  }
                  return curly;
              } else {
                  throw error("Illegal repetition");
              }
          default:
              return prev;
          }
      }
  
      /**
       *  Utility method for parsing control escape sequences.
       */
      private int c() {
          if (cursor < patternLength) {
              return read() ^ 64;
          }
          throw error("Illegal control escape sequence");
      }
  
      /**
       *  Utility method for parsing octal escape sequences.
       */
      private int o() {
          int n = read();
          if (((n-'0')|('7'-n)) >= 0) {
              int m = read();
              if (((m-'0')|('7'-m)) >= 0) {
                  int o = read();
                  if ((((o-'0')|('7'-o)) >= 0) && (((n-'0')|('3'-n)) >= 0)) {
                      return (n - '0') * 64 + (m - '0') * 8 + (o - '0');
                  }
                  unread();
                  return (n - '0') * 8 + (m - '0');
              }
              unread();
              return (n - '0');
          }
          throw error("Illegal octal escape sequence");
      }
  
      /**
       *  Utility method for parsing hexadecimal escape sequences.
       */
      private int x() {
          int n = read();
          if (ASCII.isHexDigit(n)) {
              int m = read();
              if (ASCII.isHexDigit(m)) {
                  return ASCII.toDigit(n) * 16 + ASCII.toDigit(m);
              }
          } else if (n == '{' && ASCII.isHexDigit(peek())) {
              int ch = 0;
              while (ASCII.isHexDigit(n = read())) {
                  ch = (ch << 4) + ASCII.toDigit(n);
                  if (ch > Character.MAX_CODE_POINT)
                      throw error("Hexadecimal codepoint is too big");
              }
              if (n != '}')
                  throw error("Unclosed hexadecimal escape sequence");
              return ch;
          }
          throw error("Illegal hexadecimal escape sequence");
      }
  
      /**
       *  Utility method for parsing unicode escape sequences.
       */
      private int cursor() {
          return cursor;
      }
  
      private void setcursor(int pos) {
          cursor = pos;
      }
  
      private int uxxxx() {
          int n = 0;
          for (int i = 0; i < 4; i++) {
              int ch = read();
              if (!ASCII.isHexDigit(ch)) {
                  throw error("Illegal Unicode escape sequence");
              }
              n = n * 16 + ASCII.toDigit(ch);
          }
          return n;
      }
  
      private int u() {
          int n = uxxxx();
          if (Character.isHighSurrogate((char)n)) {
              int cur = cursor();
              if (read() == '\\' && read() == 'u') {
                  int n2 = uxxxx();
                  if (Character.isLowSurrogate((char)n2))
                      return Character.toCodePoint((char)n, (char)n2);
              }
              setcursor(cur);
          }
          return n;
      }
  
      //
      // Utility methods for code point support
      //
  
      private static final int countChars(CharSequence seq, int index,
                                          int lengthInCodePoints) {
          // optimization
          if (lengthInCodePoints == 1 && !Character.isHighSurrogate(seq.charAt(index))) {
              assert (index >= 0 && index < seq.length());
              return 1;
          }
          int length = seq.length();
          int x = index;
          if (lengthInCodePoints >= 0) {
              assert (index >= 0 && index < length);
              for (int i = 0; x < length && i < lengthInCodePoints; i++) {
                  if (Character.isHighSurrogate(seq.charAt(x++))) {
                      if (x < length && Character.isLowSurrogate(seq.charAt(x))) {
                          x++;
                      }
                  }
              }
              return x - index;
          }
  
          assert (index >= 0 && index <= length);
          if (index == 0) {
              return 0;
          }
          int len = -lengthInCodePoints;
          for (int i = 0; x > 0 && i < len; i++) {
              if (Character.isLowSurrogate(seq.charAt(--x))) {
                  if (x > 0 && Character.isHighSurrogate(seq.charAt(x-1))) {
                      x--;
                  }
              }
          }
          return index - x;
      }
  
      private static final int countCodePoints(CharSequence seq) {
          int length = seq.length();
          int n = 0;
          for (int i = 0; i < length; ) {
              n++;
              if (Character.isHighSurrogate(seq.charAt(i++))) {
                  if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
                      i++;
                  }
              }
          }
          return n;
      }
  
      /**
       *  Creates a bit vector for matching Latin-1 values. A normal BitClass
       *  never matches values above Latin-1, and a complemented BitClass always
       *  matches values above Latin-1.
       */
      private static final class BitClass extends BmpCharProperty {
          final boolean[] bits;
          BitClass(String self) { super(self); bits = new boolean[256]; }
          private BitClass(boolean[] bits, String self) { super(self); this.bits = bits; }
          BitClass add(int c, int flags) {
              assert c >= 0 && c <= 255;
              if ((flags & CASE_INSENSITIVE) != 0) {
                  if (ASCII.isAscii(c)) {
                      bits[ASCII.toUpper(c)] = true;
                      bits[ASCII.toLower(c)] = true;
                      
                      this.self = self + (char) (ASCII.toUpper(c));
                      this.self = self + (char) (ASCII.toLower(c));
                  } else if ((flags & UNICODE_CASE) != 0) {
                      bits[Character.toLowerCase(c)] = true;
                      bits[Character.toUpperCase(c)] = true;
                      
                      this.self = self + (char) (ASCII.toUpper(c));
                      this.self = self + (char) (ASCII.toLower(c));
                  }
              }
              bits[c] = true;
              this.self = self + (char) c;
              return this;
          }
          boolean isSatisfiedBy(int ch) {
              return ch < 256 && bits[ch];
          }
      }
  
      /**
       *  Returns a suitably optimized, single character matcher.
       */
      private CharProperty newSingle(final int ch) {
          if (has(CASE_INSENSITIVE)) {
              int lower, upper;
              if (has(UNICODE_CASE)) {
                  upper = Character.toUpperCase(ch);
                  lower = Character.toLowerCase(upper);
                  if (upper != lower)
                      return new SingleU(lower);
              } else if (ASCII.isAscii(ch)) {
                  lower = ASCII.toLower(ch);
                  upper = ASCII.toUpper(ch);
                  if (lower != upper)
                      return new SingleI(lower, upper);
              }
          }
          if (isSupplementary(ch))
              return new SingleS(ch);    // Match a given Unicode character
          return new Single(ch);         // Match a given BMP character
      }
  
      /**
       *  Utility method for creating a string slice matcher.
       */
      private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
          int[] tmp = new int[count];
          if (has(CASE_INSENSITIVE)) {
              if (has(UNICODE_CASE)) {
                  for (int i = 0; i < count; i++) {
                      tmp[i] = Character.toLowerCase(
                                   Character.toUpperCase(buf[i]));
                  }
                  return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
              }
              for (int i = 0; i < count; i++) {
                  tmp[i] = ASCII.toLower(buf[i]);
              }
              return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
          }
          for (int i = 0; i < count; i++) {
              tmp[i] = buf[i];
          }
          return hasSupplementary ? new SliceS(tmp) : new Slice(tmp);
      }
  
      /**
       * The following classes are the building components of the object
       * tree that represents a compiled regular expression. The object tree
       * is made of individual elements that handle constructs in the Pattern.
       * Each type of object knows how to match its equivalent construct with
       * the match() method.
       */
  
      /**
       * Base class for all node classes. Subclasses should override the match()
       * method as appropriate. This class is an accepting node, so its match()
       * always returns true.
       * 
       * @pGREAT instrument this class to provide main functionality
       */
      public static class Node extends Object {
      	// For which string (or char) in the regex, create this node
      	String self;
      	
      	// All possible next node, these vars are used to generate regex graph
          Node next;
          Node next_self; // Prepare for start without ^ regex's pump-along
          Node atom; // Curly
          Node atom_self;
          Node body; // Prolog
          Node[] atoms; // Branch
          Node conn; // BranchEnd
          GroupHead head; // GroupRef
          Loop loop; // Prolog
          Node cond, yes, not; // Conditions
          
      	CharProperty lhs; // This 2 vars lead to memory cost
      	CharProperty rhs; // But deprecated, because these 2 will not be called match and not occur in stack
          
          Node(String self) {
          	this.self = self;
              next = ReScuePattern.accept;
          }
          /**
           * This method implements the classic accept node.
           */
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              matcher.last = i;
              matcher.groups[0] = matcher.first;
              matcher.groups[1] = matcher.last;
              return true;
          }
          
          boolean match(ReScueMatcher matcher, int i, CharSequence seq, boolean isTraced){
  			if (isTraced) {
  				if (trace.logMatch(this, i)) {
  					return this.match(matcher, i, seq);
  				}
  				else return false;
  			} else return this.match(matcher, i, seq);
          }
          /**
           * This method is good for all zero length assertions.
           */
          boolean study(TreeInfo info) {
              if (next != null) {
                  return next.study(info);
              } else {
                  return info.deterministic;
              }
          }
      }
  
      static class LastNode extends Node {
          LastNode(String self) {
  			super(self);
  		}
  
  		/**
           * This method implements the classic accept node with
           * the addition of a check to see if the match occurred
           * using all of the input.
           */
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (matcher.acceptMode == ReScueMatcher.ENDANCHOR && i != matcher.to)
                  return false;
              matcher.last = i;
              matcher.groups[0] = matcher.first;
              matcher.groups[1] = matcher.last;
              return true;
          }
      }
  
      /**
       * Used for REs that can start anywhere within the input string.
       * This basically tries to match repeatedly at each spot in the
       * input string, moving forward after each try. An anchored search
       * or a BnM will bypass this node completely.
       */
      static class Start extends Node {    	
          int minLength;
          Start(Node node) {
          	super("");
              this.next = node;
              TreeInfo info = new TreeInfo();
              next.study(info);
              minLength = info.minLength;
              
              if (this.next != null) this.next.next_self = this.next;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (i > matcher.to - minLength) {
                  matcher.hitEnd = true;
                  return false;
              }
              int guard = matcher.to - minLength;
              for (; i <= guard; i++) {
                  if (next.match(matcher, i, seq, true)) {
                      matcher.first = i;
                      matcher.groups[0] = matcher.first;
                      matcher.groups[1] = matcher.last;
                      return true;
                  }
              }
              matcher.hitEnd = true;
              return false;
          }
          boolean study(TreeInfo info) {
              next.study(info);
              info.maxValid = false;
              info.deterministic = false;
              return false;
          }
      }
  
      /*
       * StartS supports supplementary characters, including unpaired surrogates.
       */
      static final class StartS extends Start {
          StartS(Node node) {
              super(node);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (i > matcher.to - minLength) {
                  matcher.hitEnd = true;
                  return false;
              }
              int guard = matcher.to - minLength;
              while (i <= guard) {
                  //if ((ret = next.match(matcher, i, seq)) || i == guard)
                  if (next.match(matcher, i, seq, true)) {
                      matcher.first = i;
                      matcher.groups[0] = matcher.first;
                      matcher.groups[1] = matcher.last;
                      return true;
                  }
                  if (i == guard)
                      break;
                  // Optimization to move to the next character. This is
                  // faster than countChars(seq, i, 1).
                  if (Character.isHighSurrogate(seq.charAt(i++))) {
                      if (i < seq.length() &&
                          Character.isLowSurrogate(seq.charAt(i))) {
                          i++;
                      }
                  }
              }
              matcher.hitEnd = true;
              return false;
          }
      }
  
      /**
       * Node to anchor at the beginning of input. This object implements the
       * match for a \A sequence, and the caret anchor will use this if not in
       * multiline mode.
       */
      static final class Begin extends Node {
          Begin(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int fromIndex = (matcher.anchoringBounds) ?
                  matcher.from : 0;
              if (i == fromIndex && next.match(matcher, i, seq, true)) {
                  matcher.first = i;
                  matcher.groups[0] = i;
                  matcher.groups[1] = matcher.last;
                  return true;
              } else {
                  return false;
              }
          }
      }
  
      /**
       * Node to anchor at the end of input. This is the absolute end, so this
       * should not match at the last newline before the end as $ will.
       */
      static final class End extends Node {
          End(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int endIndex = (matcher.anchoringBounds) ?
                  matcher.to : matcher.getTextLength();
              if (i == endIndex) {
                  matcher.hitEnd = true;
                  return next.match(matcher, i, seq, true);
              }
              return false;
          }
      }
  
      /**
       * Node to anchor at the beginning of a line. This is essentially the
       * object to match for the multiline ^.
       */
      static final class Caret extends Node {
          Caret(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int startIndex = matcher.from;
              int endIndex = matcher.to;
              if (!matcher.anchoringBounds) {
                  startIndex = 0;
                  endIndex = matcher.getTextLength();
              }
              // Perl does not match ^ at end of input even after newline
              if (i == endIndex) {
                  matcher.hitEnd = true;
                  return false;
              }                      
              if (i > startIndex) {
                  char ch = seq.charAt(i-1);
                  if (ch != '\n' && ch != '\r'
                      && (ch|1) != '\u2029'
                      && ch != '\u0085' ) {
                      return false;
                  }
                  // Should treat /r/n as one newline
                  if (ch == '\r' && seq.charAt(i) == '\n')
                      return false;
              }
              return next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Node to anchor at the beginning of a line when in unixdot mode.
       */
      static final class UnixCaret extends Node {
          UnixCaret(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int startIndex = matcher.from;
              int endIndex = matcher.to;
              if (!matcher.anchoringBounds) {
                  startIndex = 0;
                  endIndex = matcher.getTextLength();
              }
              // Perl does not match ^ at end of input even after newline
              if (i == endIndex) {
                  matcher.hitEnd = true;
                  return false;
              }
              if (i > startIndex) {
                  char ch = seq.charAt(i-1);
                  if (ch != '\n') {
                      return false;
                  }
              }
              return next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Node to match the location where the last match ended.
       * This is used for the \G construct.
       */
      static final class LastMatch extends Node {
          LastMatch(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (i != matcher.oldLast)
                  return false;
              return next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Node to anchor at the end of a line or the end of input based on the
       * multiline mode.
       *
       * When not in multiline mode, the $ can only match at the very end
       * of the input, unless the input ends in a line terminator in which
       * it matches right before the last line terminator.
       *
       * Note that \r\n is considered an atomic line terminator.
       *
       * Like ^ the $ operator matches at a position, it does not match the
       * line terminators themselves.
       */
      static final class Dollar extends Node {
          boolean multiline;
          Dollar(boolean mul, String self) {
          	super(self);
              multiline = mul;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int endIndex = (matcher.anchoringBounds) ?
                  matcher.to : matcher.getTextLength();
              if (!multiline) {
                  if (i < endIndex - 2)
                      return false;
                  if (i == endIndex - 2) {
                      char ch = seq.charAt(i);
                      if (ch != '\r')
                          return false;
                      ch = seq.charAt(i + 1);
                      if (ch != '\n')
                          return false;
                  }
              }
              // Matches before any line terminator; also matches at the
              // end of input
              // Before line terminator:
              // If multiline, we match here no matter what
              // If not multiline, fall through so that the end
              // is marked as hit; this must be a /r/n or a /n
              // at the very end so the end was hit; more input
              // could make this not match here
              if (i < endIndex) {
                  char ch = seq.charAt(i);
                   if (ch == '\n') {
                       // No match between \r\n
                       if (i > 0 && seq.charAt(i-1) == '\r')
                           return false;
                       if (multiline)
                           return next.match(matcher, i, seq, true);
                   } else if (ch == '\r' || ch == '\u0085' ||
                              (ch|1) == '\u2029') {
                       if (multiline)
                           return next.match(matcher, i, seq, true);
                   } else { // No line terminator, no match
                       return false;
                   }
              }
              // Matched at current end so hit end
              matcher.hitEnd = true;
              // If a $ matches because of end of input, then more input
              // could cause it to fail!
              matcher.requireEnd = true;
              return next.match(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              next.study(info);
              return info.deterministic;
          }
      }
  
      /**
       * Node to anchor at the end of a line or the end of input based on the
       * multiline mode when in unix lines mode.
       */
      static final class UnixDollar extends Node {
          boolean multiline;
          UnixDollar(boolean mul, String self) {
          	super(self);
              multiline = mul;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int endIndex = (matcher.anchoringBounds) ?
                  matcher.to : matcher.getTextLength();
              if (i < endIndex) {
                  char ch = seq.charAt(i);
                  if (ch == '\n') {
                      // If not multiline, then only possible to
                      // match at very end or one before end
                      if (multiline == false && i != endIndex - 1)
                          return false;
                      // If multiline return next.match without setting
                      // matcher.hitEnd
                      if (multiline)
                          return next.match(matcher, i, seq, true);
                  } else {
                      return false;
                  }
              }
              // Matching because at the end or 1 before the end;
              // more input could change this so set hitEnd
              matcher.hitEnd = true;
              // If a $ matches because of end of input, then more input
              // could cause it to fail!
              matcher.requireEnd = true;
              return next.match(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              next.study(info);
              return info.deterministic;
          }
      }
  
      /**
       * Node class that matches a Unicode line ending '\R'
       */
      static final class LineEnding extends Node {
          LineEnding(String self) {
  			super(self);
  		}
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              // (u+000Du+000A|[u+000Au+000Bu+000Cu+000Du+0085u+2028u+2029])
              if (i < matcher.to) {
                  int ch = seq.charAt(i);
                  if (ch == 0x0A || ch == 0x0B || ch == 0x0C ||
                      ch == 0x85 || ch == 0x2028 || ch == 0x2029)
                      return next.match(matcher, i + 1, seq, true);
                  if (ch == 0x0D) {
                      i++;
                      if (i < matcher.to && seq.charAt(i) == 0x0A)
                          i++;
                      return next.match(matcher, i, seq, true);
                  }
              } else {
                  matcher.hitEnd = true;
              }
              return false;
          }
          boolean study(TreeInfo info) {
              info.minLength++;
              info.maxLength += 2;
              return next.study(info);
          }
      }
  
      /**
       * Abstract node class to match one character satisfying some
       * boolean property.
       */
      private static abstract class CharProperty extends Node {
      	public CharProperty(String self){
      		super(self);
      	}
      	public CharProperty(CharProperty lhs, CharProperty rhs) {
      		super(lhs == null ? rhs.self : (rhs == null ? lhs.self : lhs.self + rhs.self));
      		this.lhs = lhs;
      		this.rhs = rhs;
      	}
      	
          abstract boolean isSatisfiedBy(int ch);
          CharProperty complement() {
              return new CharProperty(self) {
                      boolean isSatisfiedBy(int ch) {
                          return ! CharProperty.this.isSatisfiedBy(ch);}};
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (i < matcher.to) {
                  int ch = Character.codePointAt(seq, i);
                  return isSatisfiedBy(ch)
                      && next.match(matcher, i+Character.charCount(ch), seq, true);
              } else {
                  matcher.hitEnd = true;
                  return false;
              }
          }
          boolean study(TreeInfo info) {
              info.minLength++;
              info.maxLength++;
              return next.study(info);
          }
  //        public String getGroupElements() {
  //        	String result = "";
  //        	try {
  //				for (int i = this.lower; i <= this.upper; i++) {
  //					char[] tmp = Character.toChars(i);
  //		        	result = result + (new String(tmp));
  //				}
  //			} catch (NoSuchFieldException | SecurityException e) {
  //				e.printStackTrace();
  //			}
  //        }
      }
  
      /**
       * Optimized version of CharProperty that works only for
       * properties never satisfied by Supplementary characters.
       */
      private static abstract class BmpCharProperty extends CharProperty {
          BmpCharProperty(String self) {
  			super(self);
  		}
  
  		boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (i < matcher.to) {
                  return isSatisfiedBy(seq.charAt(i))
                      && next.match(matcher, i+1, seq, true);
              } else {
                  matcher.hitEnd = true;
                  return false;
              }
          }
      }
  
      /**
       * Node class that matches a Supplementary Unicode character
       */
      static final class SingleS extends CharProperty {
          final int c;
          SingleS(int c) {
          	super(ReScuePatternUtils.convertString(c));
          	this.c = c;
          }
          boolean isSatisfiedBy(int ch) {
              return ch == c;
          }
          
          public String getSliceBuffer(){
          	String result = "";
          	char[] tmp = Character.toChars(c);
          	result = result + (new String(tmp));
          	return result;
          }
      }
  
      /**
       * Optimization -- matches a given BMP character
       */
      static final class Single extends BmpCharProperty {
          final int c;
          Single(int c) {
          	super(ReScuePatternUtils.convertString(c));
          	this.c = c;
          }
          boolean isSatisfiedBy(int ch) {
              return ch == c;
          }
          
          public String getSliceBuffer(){
          	String result = "";
          	char[] tmp = Character.toChars(c);
          	result = result + (new String(tmp));
          	return result;
          }
      }
  
      /**
       * Case insensitive matches a given BMP character
       */
      static final class SingleI extends BmpCharProperty {
          final int lower;
          final int upper;
          SingleI(int lower, int upper) {
          	super(ReScuePatternUtils.convertString(upper));
              this.lower = lower;
              this.upper = upper;
          }
          boolean isSatisfiedBy(int ch) {
              return ch == lower || ch == upper;
          }
          
          public String getSliceBuffer(){
          	String result = "";
          	char[] tmp = Character.toChars(lower);
          	result = result + (new String(tmp));
          	return result;
          }
      }
  
      /**
       * Unicode case insensitive matches a given Unicode character
       */
      static final class SingleU extends CharProperty {
          final int lower;
          SingleU(int lower) {
          	super(ReScuePatternUtils.convertString(lower));
              this.lower = lower;
          }
          boolean isSatisfiedBy(int ch) {
              return lower == ch ||
                  lower == Character.toLowerCase(Character.toUpperCase(ch));
          }
          
          public String getSliceBuffer(){
          	String result = "";
          	char[] tmp = Character.toChars(lower);
          	result = result + (new String(tmp));
          	return result;
          }
      }
  
      /**
       * Node class that matches a Unicode block.
       */
      static final class Block extends CharProperty {
          final Character.UnicodeBlock block;
          Block(Character.UnicodeBlock block) {
          	super(block.toString());
              this.block = block;
          }
          boolean isSatisfiedBy(int ch) {
              return block == Character.UnicodeBlock.of(ch);
          }
      }
  
      /**
       * Node class that matches a Unicode script
       */
      static final class Script extends CharProperty {
          final Character.UnicodeScript script;
          Script(Character.UnicodeScript script) {
          	super(script.name());
              this.script = script;
          }
          boolean isSatisfiedBy(int ch) {
              return script == Character.UnicodeScript.of(ch);
          }
      }
  
      /**
       * Node class that matches a Unicode category.
       */
      static final class Category extends CharProperty {
          final int typeMask;
          Category(int typeMask) {
          	super("CategoryMask: " + typeMask);
          	this.typeMask = typeMask;
          }
          boolean isSatisfiedBy(int ch) {
              return (typeMask & (1 << Character.getType(ch))) != 0;
          }
      }
  
      /**
       * Node class that matches a Unicode "type"
       */
      static final class Utype extends CharProperty {
          final UnicodeProp uprop;
          Utype(UnicodeProp uprop) {
          	super(uprop.name());
          	this.uprop = uprop;
          }
          boolean isSatisfiedBy(int ch) {
              return uprop.is(ch);
          }
      }
  
      /**
       * Node class that matches a POSIX type.
       */
      static final class Ctype extends BmpCharProperty {
          final int ctype;
          Ctype(int ctype) { super("POSIX type: " + ctype); this.ctype = ctype;}
          boolean isSatisfiedBy(int ch) {
              return ch < 128 && ASCII.isType(ch, ctype);
          }
      }
  
      /**
       * Node class that matches a Perl vertical whitespace
       */
      static final class VertWS extends BmpCharProperty {
          VertWS(String self) {
  			super(self);
  		}
  
  		boolean isSatisfiedBy(int cp) {
              return (cp >= 0x0A && cp <= 0x0D) ||
                     cp == 0x85 || cp == 0x2028 || cp == 0x2029;
          }
      }
  
      /**
       * Node class that matches a Perl horizontal whitespace
       */
      static final class HorizWS extends BmpCharProperty {
          HorizWS(String self) {
  			super(self);
  		}
  
  		boolean isSatisfiedBy(int cp) {
              return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
                     cp == 0x1680 || cp == 0x180e ||
                     cp >= 0x2000 && cp <= 0x200a ||
                     cp == 0x202f || cp == 0x205f || cp == 0x3000;
          }
      }
  
      /**
       * Base class for all Slice nodes
       */
      static class SliceNode extends Node {
          int[] buffer;
          SliceNode(int[] buf) {
          	super(ReScuePatternUtils.convertString(buf));
              buffer = buf;
          }
          boolean study(TreeInfo info) {
              info.minLength += buffer.length;
              info.maxLength += buffer.length;
              return next.study(info);
          }
          
          /**
           * 杩欎釜鍑芥暟鐢ㄤ簬灏唅nt鍖栫殑unicode瀛楃杞洖string
           * @return slice鐨刡uffer杞殑unicode瀛楃涓�
           */
          public String getSliceBuffer(){
          	String result = "";
          	for (int b : buffer) {
          		char[] tmp = Character.toChars(b);
          		result = result + (new String(tmp));
          	}
          	return result;
          }
      }
  
      /**
       * Node class for a case sensitive/BMP-only sequence of literal
       * characters.
       */
      static final class Slice extends SliceNode {
          Slice(int[] buf) {
              super(buf);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] buf = buffer;
              int len = buf.length;
              for (int j=0; j<len; j++) {
                  if ((i+j) >= matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  if (buf[j] != seq.charAt(i+j))
                      return false;
              }
              return next.match(matcher, i+len, seq, true);
          }
      }
  
      /**
       * Node class for a case_insensitive/BMP-only sequence of literal
       * characters.
       */
      static class SliceI extends SliceNode {
          SliceI(int[] buf) {
              super(buf);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] buf = buffer;
              int len = buf.length;
              for (int j=0; j<len; j++) {
                  if ((i+j) >= matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  int c = seq.charAt(i+j);
                  if (buf[j] != c &&
                      buf[j] != ASCII.toLower(c))
                      return false;
              }
              return next.match(matcher, i+len, seq, true);
          }
      }
  
      /**
       * Node class for a unicode_case_insensitive/BMP-only sequence of
       * literal characters. Uses unicode case folding.
       */
      static final class SliceU extends SliceNode {
          SliceU(int[] buf) {
              super(buf);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] buf = buffer;
              int len = buf.length;
              for (int j=0; j<len; j++) {
                  if ((i+j) >= matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  int c = seq.charAt(i+j);
                  if (buf[j] != c &&
                      buf[j] != Character.toLowerCase(Character.toUpperCase(c)))
                      return false;
              }
              return next.match(matcher, i+len, seq, true);
          }
      }
  
      /**
       * Node class for a case sensitive sequence of literal characters
       * including supplementary characters.
       */
      static final class SliceS extends SliceNode {
          SliceS(int[] buf) {
              super(buf);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] buf = buffer;
              int x = i;
              for (int j = 0; j < buf.length; j++) {
                  if (x >= matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  int c = Character.codePointAt(seq, x);
                  if (buf[j] != c)
                      return false;
                  x += Character.charCount(c);
                  if (x > matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
              }
              return next.match(matcher, x, seq, true);
          }
      }
  
      /**
       * Node class for a case insensitive sequence of literal characters
       * including supplementary characters.
       */
      static class SliceIS extends SliceNode {
          SliceIS(int[] buf) {
              super(buf);
          }
          int toLower(int c) {
              return ASCII.toLower(c);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] buf = buffer;
              int x = i;
              for (int j = 0; j < buf.length; j++) {
                  if (x >= matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  int c = Character.codePointAt(seq, x);
                  if (buf[j] != c && buf[j] != toLower(c))
                      return false;
                  x += Character.charCount(c);
                  if (x > matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
              }
              return next.match(matcher, x, seq, true);
          }
      }
  
      /**
       * Node class for a case insensitive sequence of literal characters.
       * Uses unicode case folding.
       */
      static final class SliceUS extends SliceIS {
          SliceUS(int[] buf) {
              super(buf);
          }
          int toLower(int c) {
              return Character.toLowerCase(Character.toUpperCase(c));
          }
      }
  
      private static boolean inRange(int lower, int ch, int upper) {
          return lower <= ch && ch <= upper;
      }
  
      /**
       * Returns node for matching characters within an explicit value range.
       */
      private static CharProperty rangeFor(final int lower,
                                           final int upper) {
          return new CharProperty(ReScuePatternUtils.convertString(lower) + "-" + ReScuePatternUtils.convertString(upper)) {
                  boolean isSatisfiedBy(int ch) {
                      return inRange(lower, ch, upper);}};
      }
  
      /**
       * Returns node for matching characters within an explicit value
       * range in a case insensitive manner.
       */
      private CharProperty caseInsensitiveRangeFor(final int lower,
                                                   final int upper) {
          if (has(UNICODE_CASE))
              return new CharProperty(ReScuePatternUtils.convertString(lower) + "-" + ReScuePatternUtils.convertString(upper)) {
                  boolean isSatisfiedBy(int ch) {
                      if (inRange(lower, ch, upper))
                          return true;
                      int up = Character.toUpperCase(ch);
                      return inRange(lower, up, upper) ||
                             inRange(lower, Character.toLowerCase(up), upper);}};
          return new CharProperty(ReScuePatternUtils.convertString(lower) + "-" + ReScuePatternUtils.convertString(upper)) {
              boolean isSatisfiedBy(int ch) {
                  return inRange(lower, ch, upper) ||
                      ASCII.isAscii(ch) &&
                          (inRange(lower, ASCII.toUpper(ch), upper) ||
                           inRange(lower, ASCII.toLower(ch), upper));
              }};
      }
  
      /**
       * Implements the Unicode category ALL and the dot metacharacter when
       * in dotall mode.
       */
      static final class All extends CharProperty {
          public All(String self) {
  			super(self);
  		}
  
  		boolean isSatisfiedBy(int ch) {
              return true;
          }
      }
  
      /**
       * Node class for the dot metacharacter when dotall is not enabled.
       */
      static final class Dot extends CharProperty {
          public Dot(String self) {
  			super(self);
  		}
  
  		boolean isSatisfiedBy(int ch) {
              return (ch != '\n' && ch != '\r'
                      && (ch|1) != '\u2029'
                      && ch != '\u0085');
          }
      }
  
      /**
       * Node class for the dot metacharacter when dotall is not enabled
       * but UNIX_LINES is enabled.
       */
      static final class UnixDot extends CharProperty {
          public UnixDot(String self) {
  			super(self);
  		}
  
  		boolean isSatisfiedBy(int ch) {
              return ch != '\n';
          }
      }
  
      /**
       * The 0 or 1 quantifier. This one class implements all three types.
       */
      static final class Ques extends Node {
  //        Node atom;
          int type;
          Ques(Node node, int type, String self) {
          	super(self);
              this.atom = node;
              this.type = type;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              switch (type) {
              case GREEDY:
                  return (atom.match(matcher, i, seq, true) && next.match(matcher, matcher.last, seq, true))
                      || next.match(matcher, i, seq, true);
              case LAZY:
                  return next.match(matcher, i, seq, true)
                      || (atom.match(matcher, i, seq, true) && next.match(matcher, matcher.last, seq, true));
              case POSSESSIVE:
                  if (atom.match(matcher, i, seq, true)) i = matcher.last;
                  return next.match(matcher, i, seq, true);
              default:
                  return atom.match(matcher, i, seq, true) && next.match(matcher, matcher.last, seq, true);
              }
          }
          boolean study(TreeInfo info) {
              if (type != INDEPENDENT) {
                  int minL = info.minLength;
                  atom.study(info);
                  info.minLength = minL;
                  info.deterministic = false;
                  return next.study(info);
              } else {
                  atom.study(info);
                  return next.study(info);
              }
          }
      }
  
      /**
       * Handles the curly-brace style repetition with a specified minimum and
       * maximum occurrences. The * quantifier is handled as a special case.
       * This class handles the three types.
       */
      static final class Curly extends Node {
  //        Node atom;
          int type;
          int cmin;
          int cmax;
  
          Curly(Node node, int cmin, int cmax, int type, String self) {
          	super(self);
              this.atom = node;
              this.type = type;
              this.cmin = cmin;
              this.cmax = cmax;
              if (this.atom != null) this.atom.atom_self = this.atom;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
          	if (this.next != null && this.next.next_self == null) this.next.next_self = this.next;
          	
              int j;
              for (j = 0; j < cmin; j++) {
                  if (atom.match(matcher, i, seq, true)) {
                      i = matcher.last;
                      continue;
                  }
                  return false;
              }
              if (type == GREEDY)
                  return match0(matcher, i, j, seq);
              else if (type == LAZY)
                  return match1(matcher, i, j, seq);
              else
                  return match2(matcher, i, j, seq);
          }
          // Greedy match.
          // i is the index to start matching at
          // j is the number of atoms that have matched
          boolean match0(ReScueMatcher matcher, int i, int j, CharSequence seq){
              if (j >= cmax) {
                  // We have matched the maximum... continue with the rest of
                  // the regular expression
                  return next.match(matcher, i, seq, true);
              }
              int backLimit = j;
              while (atom.match(matcher, i, seq, true)) {
                  // k is the length of this match
                  int k = matcher.last - i;
                  if (k == 0) // Zero length match
                      break;
                  // Move up index and number matched
                  i = matcher.last;
                  j++;
                  // We are greedy so match as many as we can
                  while (j < cmax) {
                      if (!atom.match(matcher, i, seq, true))
                          break;
                      if (i + k != matcher.last) {
                          if (match0(matcher, matcher.last, j+1, seq))
                              return true;
                          break;
                      }
                      i += k;
                      j++;
                  }
                  // Handle backing off if match fails
                  while (j >= backLimit) {
                  	if (next.match(matcher, i, seq, true))
                          return true;
                      i -= k;
                      j--;
                  }
                  return false;
              }
              return next.match(matcher, i, seq, true);
          }
          // Reluctant match. At this point, the minimum has been satisfied.
          // i is the index to start matching at
          // j is the number of atoms that have matched
          boolean match1(ReScueMatcher matcher, int i, int j, CharSequence seq){
              for (;;) {
                  // Try finishing match without consuming any more
                  if (next.match(matcher, i, seq, true))
                      return true;
                  // At the maximum, no match found
                  if (j >= cmax)
                      return false;
                  // Okay, must try one more atom
                  if (!atom.match(matcher, i, seq, true))
                      return false;
                  // If we haven't moved forward then must break out
                  if (i == matcher.last)
                      return false;
                  // Move up index and number matched
                  i = matcher.last;
                  j++;
              }
          }
          boolean match2(ReScueMatcher matcher, int i, int j, CharSequence seq){
              for (; j < cmax; j++) {
                  if (!atom.match(matcher, i, seq, true))
                      break;
                  if (i == matcher.last)
                      break;
                  i = matcher.last;
              }
              return next.match(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              // Save original info
              int minL = info.minLength;
              int maxL = info.maxLength;
              boolean maxV = info.maxValid;
              boolean detm = info.deterministic;
              info.reset();
  
              atom.study(info);
  
              int temp = info.minLength * cmin + minL;
              if (temp < minL) {
                  temp = 0xFFFFFFF; // arbitrary large number
              }
              info.minLength = temp;
  
              if (maxV & info.maxValid) {
                  temp = info.maxLength * cmax + maxL;
                  info.maxLength = temp;
                  if (temp < maxL) {
                      info.maxValid = false;
                  }
              } else {
                  info.maxValid = false;
              }
  
              if (info.deterministic && cmin == cmax)
                  info.deterministic = detm;
              else
                  info.deterministic = false;
              return next.study(info);
          }
      }
  
      /**
       * Handles the curly-brace style repetition with a specified minimum and
       * maximum occurrences in deterministic cases. This is an iterative
       * optimization over the Prolog and Loop system which would handle this
       * in a recursive way. The * quantifier is handled as a special case.
       * If capture is true then this class saves group settings and ensures
       * that groups are unset when backing off of a group match.
       */
      static final class GroupCurly extends Node {
  //        Node atom;
          int type;
          int cmin;
          int cmax;
          int localIndex;
          int groupIndex;
          boolean capture;
  
          GroupCurly(Node node, int cmin, int cmax, int type, int local,
                     int group, boolean capture, String self) {
          	super(self);
              this.atom = node;
              this.type = type;
              this.cmin = cmin;
              this.cmax = cmax;
              this.localIndex = local;
              this.groupIndex = group;
              this.capture = capture;
              if (this.atom != null) this.atom.atom_self = this.atom;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
          	if (this.next != null && this.next.next_self == null) this.next.next_self = this.next;
          	
              int[] groups = matcher.groups;
              int[] locals = matcher.locals;
              int save0 = locals[localIndex];
              int save1 = 0;
              int save2 = 0;
  
              if (capture) {
                  save1 = groups[groupIndex];
                  save2 = groups[groupIndex+1];
              }
  
              // Notify GroupTail there is no need to setup group info
              // because it will be set here
              locals[localIndex] = -1;
  
              boolean ret = true;
              for (int j = 0; j < cmin; j++) {
                  if (atom.match(matcher, i, seq, true)) {
                      if (capture) {
                          groups[groupIndex] = i;
                          groups[groupIndex+1] = matcher.last;
                      }
                      i = matcher.last;
                  } else {
                      ret = false;
                      break;
                  }
              }
              if (ret) {
                  if (type == GREEDY) {
                      ret = match0(matcher, i, cmin, seq);
                  } else if (type == LAZY) {
                      ret = match1(matcher, i, cmin, seq);
                  } else {
                      ret = match2(matcher, i, cmin, seq);
                  }
              }
              if (!ret) {
                  locals[localIndex] = save0;
                  if (capture) {
                      groups[groupIndex] = save1;
                      groups[groupIndex+1] = save2;
                  }
              }
              return ret;
          }
          // Aggressive group match
          boolean match0(ReScueMatcher matcher, int i, int j, CharSequence seq){
              // don't back off passing the starting "j"
              int min = j;
              int[] groups = matcher.groups;
              int save0 = 0;
              int save1 = 0;
              if (capture) {
                  save0 = groups[groupIndex];
                  save1 = groups[groupIndex+1];
              }
              for (;;) {
                  if (j >= cmax)
                      break;
                  if (!atom.match(matcher, i, seq, true))
                      break;
                  int k = matcher.last - i;
                  if (k <= 0) {
                      if (capture) {
                          groups[groupIndex] = i;
                          groups[groupIndex+1] = i + k;
                      }
                      i = i + k;
                      break;
                  }
                  for (;;) {
                      if (capture) {
                          groups[groupIndex] = i;
                          groups[groupIndex+1] = i + k;
                      }
                      i = i + k;
                      if (++j >= cmax)
                          break;
                      if (!atom.match(matcher, i, seq, true))
                          break;
                      if (i + k != matcher.last) {
                          if (match0(matcher, i, j, seq))
                              return true;
                          break;
                      }
                  }
                  while (j > min) {
                      if (next.match(matcher, i, seq, true)) {
                          if (capture) {
                              groups[groupIndex+1] = i;
                              groups[groupIndex] = i - k;
                          }
                          return true;
                      }
                      // backing off
                      i = i - k;
                      if (capture) {
                          groups[groupIndex+1] = i;
                          groups[groupIndex] = i - k;
                      }
                      j--;
  
                  }
                  break;
              }
              if (capture) {
                  groups[groupIndex] = save0;
                  groups[groupIndex+1] = save1;
              }
              return next.match(matcher, i, seq, true);
          }
          // Reluctant matching
          boolean match1(ReScueMatcher matcher, int i, int j, CharSequence seq){
              for (;;) {
                  if (next.match(matcher, i, seq, true))
                      return true;
                  if (j >= cmax)
                      return false;
                  if (!atom.match(matcher, i, seq, true))
                      return false;
                  if (i == matcher.last)
                      return false;
                  if (capture) {
                      matcher.groups[groupIndex] = i;
                      matcher.groups[groupIndex+1] = matcher.last;
                  }
                  i = matcher.last;
                  j++;
              }
          }
          // Possessive matching
          boolean match2(ReScueMatcher matcher, int i, int j, CharSequence seq){
              for (; j < cmax; j++) {
                  if (!atom.match(matcher, i, seq, true)) {
                      break;
                  }
                  if (capture) {
                      matcher.groups[groupIndex] = i;
                      matcher.groups[groupIndex+1] = matcher.last;
                  }
                  if (i == matcher.last) {
                      break;
                  }
                  i = matcher.last;
              }
              return next.match(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              // Save original info
              int minL = info.minLength;
              int maxL = info.maxLength;
              boolean maxV = info.maxValid;
              boolean detm = info.deterministic;
              info.reset();
  
              atom.study(info);
  
              int temp = info.minLength * cmin + minL;
              if (temp < minL) {
                  temp = 0xFFFFFFF; // Arbitrary large number
              }
              info.minLength = temp;
  
              if (maxV & info.maxValid) {
                  temp = info.maxLength * cmax + maxL;
                  info.maxLength = temp;
                  if (temp < maxL) {
                      info.maxValid = false;
                  }
              } else {
                  info.maxValid = false;
              }
  
              if (info.deterministic && cmin == cmax) {
                  info.deterministic = detm;
              } else {
                  info.deterministic = false;
              }
              return next.study(info);
          }
      }
  
      /**
       * A Guard node at the end of each atom node in a Branch. It
       * serves the purpose of chaining the "match" operation to
       * "next" but not the "study", so we can collect the TreeInfo
       * of each atom node without including the TreeInfo of the
       * "next".
       */
      static final class BranchConn extends Node {
          BranchConn(String self) {super(self);};
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              return next.match(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              return info.deterministic;
          }
      }
  
      /**
       * Handles the branching of alternations. Note this is also used for
       * the ? quantifier to branch between the case where it matches once
       * and where it does not occur.
       */
      static final class Branch extends Node {
          int size = 2;
          Branch(Node first, Node second, Node branchConn, String self) {
          	super(self);
          	this.atoms = new Node[2];
              conn = branchConn;
              atoms[0] = first;
              atoms[1] = second;
          }
  
          void add(Node node) {
              if (size >= atoms.length) {
                  Node[] tmp = new Node[atoms.length*2];
                  System.arraycopy(atoms, 0, tmp, 0, atoms.length);
                  atoms = tmp;
              }
              atoms[size++] = node;
          }
  
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              for (int n = 0; n < size; n++) {
                  if (atoms[n] == null) {
                      if (conn.next.match(matcher, i, seq, true))
                          return true;
                  } else if (atoms[n].match(matcher, i, seq, true)) {
                      return true;
                  }
              }
              return false;
          }
  
          boolean study(TreeInfo info) {
              int minL = info.minLength;
              int maxL = info.maxLength;
              boolean maxV = info.maxValid;
  
              int minL2 = Integer.MAX_VALUE; //arbitrary large enough num
              int maxL2 = -1;
              for (int n = 0; n < size; n++) {
                  info.reset();
                  if (atoms[n] != null)
                      atoms[n].study(info);
                  minL2 = Math.min(minL2, info.minLength);
                  maxL2 = Math.max(maxL2, info.maxLength);
                  maxV = (maxV & info.maxValid);
              }
  
              minL += minL2;
              maxL += maxL2;
  
              info.reset();
              conn.next.study(info);
  
              info.minLength += minL;
              info.maxLength += maxL;
              info.maxValid &= maxV;
              info.deterministic = false;
              return false;
          }
      }
  
      /**
       * The GroupHead saves the location where the group begins in the locals
       * and restores them when the match is done.
       *
       * The matchRef is used when a reference to this group is accessed later
       * in the expression. The locals will have a negative value in them to
       * indicate that we do not want to unset the group if the reference
       * doesn't match.
       */
      static final class GroupHead extends Node {
          int localIndex;
          GroupHead(int localCount, String self) {
          	super(self);
              localIndex = localCount;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int save = matcher.locals[localIndex];
              matcher.locals[localIndex] = i;
              boolean ret = next.match(matcher, i, seq, true);
              matcher.locals[localIndex] = save;
              return ret;
          }
          boolean matchRef(ReScueMatcher matcher, int i, CharSequence seq){
              int save = matcher.locals[localIndex];
              matcher.locals[localIndex] = ~i; // HACK
              boolean ret = next.match(matcher, i, seq, true);
              matcher.locals[localIndex] = save;
              return ret;
          }
      }
  
      /**
       * Recursive reference to a group in the regular expression. It calls
       * matchRef because if the reference fails to match we would not unset
       * the group.
       */
      static final class GroupRef extends Node {
          GroupRef(GroupHead head, String self) {
          	super(self);
              this.head = head;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              return head.matchRef(matcher, i, seq)
                  && next.match(matcher, matcher.last, seq, true);
          }
          boolean study(TreeInfo info) {
              info.maxValid = false;
              info.deterministic = false;
              return next.study(info);
          }
      }
  
      /**
       * The GroupTail handles the setting of group beginning and ending
       * locations when groups are successfully matched. It must also be able to
       * unset groups that have to be backed off of.
       *
       * The GroupTail node is also used when a previous group is referenced,
       * and in that case no group information needs to be set.
       */
      static final class GroupTail extends Node {
          int localIndex;
          int groupIndex;
          GroupTail(int localCount, int groupCount, String self) {
          	super(self);
              localIndex = localCount;
              groupIndex = groupCount + groupCount;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int tmp = matcher.locals[localIndex];
              if (tmp >= 0) { // This is the normal group case.
                  // Save the group so we can unset it if it
                  // backs off of a match.
                  int groupStart = matcher.groups[groupIndex];
                  int groupEnd = matcher.groups[groupIndex+1];
  
                  matcher.groups[groupIndex] = tmp;
                  matcher.groups[groupIndex+1] = i;
                  if (next.match(matcher, i, seq, true)) {
                      return true;
                  }
                  matcher.groups[groupIndex] = groupStart;
                  matcher.groups[groupIndex+1] = groupEnd;
                  return false;
              } else {
                  // This is a group reference case. We don't need to save any
                  // group info because it isn't really a group.
                  matcher.last = i;
                  return true;
              }
          }
      }
  
      /**
       * This sets up a loop to handle a recursive quantifier structure.
       */
      static final class Prolog extends Node {
  //        Loop loop;
          Prolog(Loop loop) {
          	super(loop.self);
              this.loop = loop;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              return loop.matchInit(matcher, i, seq, true);
          }
          boolean study(TreeInfo info) {
              return loop.study(info);
          }
      }
  
      /**
       * Handles the repetition count for a greedy Curly. The matchInit
       * is called from the Prolog to save the index of where the group
       * beginning is stored. A zero length group check occurs in the
       * normal match but is skipped in the matchInit.
       */
      static class Loop extends Node {
  //        Node body;
          int countIndex; // local count index in matcher locals
          int beginIndex; // group beginning index
          int cmin, cmax;
          Loop(int countIndex, int beginIndex, String self) {
          	super(self);
              this.countIndex = countIndex;
              this.beginIndex = beginIndex;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              // Avoid infinite loop in zero-length case.
              if (i > matcher.locals[beginIndex]) {
                  int count = matcher.locals[countIndex];
  
                  // This block is for before we reach the minimum
                  // iterations required for the loop to match
                  if (count < cmin) {
                      matcher.locals[countIndex] = count + 1;
                      boolean b = body.match(matcher, i, seq, true);
                      // If match failed we must backtrack, so
                      // the loop count should NOT be incremented
                      if (!b)
                          matcher.locals[countIndex] = count;
                      // Return success or failure since we are under
                      // minimum
                      return b;
                  }
                  // This block is for after we have the minimum
                  // iterations required for the loop to match
                  if (count < cmax) {
                      matcher.locals[countIndex] = count + 1;
                      boolean b = body.match(matcher, i, seq, true);
                      // If match failed we must backtrack, so
                      // the loop count should NOT be incremented
                      if (!b)
                          matcher.locals[countIndex] = count;
                      else
                          return true;
                  }
              }
              return next.match(matcher, i, seq, true);
          }
          boolean matchInit(ReScueMatcher matcher, int i, CharSequence seq, boolean isTraced) {
  			if (isTraced) {
  				if (trace.logMatch(this, i)) return this.matchInit(matcher, i, seq);
  				else return false;
  			} else return this.matchInit(matcher, i, seq);
          }
          boolean matchInit(ReScueMatcher matcher, int i, CharSequence seq){
              int save = matcher.locals[countIndex];
              boolean ret = false;
              if (0 < cmin) {
                  matcher.locals[countIndex] = 1;
                  ret = body.match(matcher, i, seq, true);
              } else if (0 < cmax) {
                  matcher.locals[countIndex] = 1;
                  ret = body.match(matcher, i, seq, true);
                  if (ret == false)
                      ret = next.match(matcher, i, seq, true);
              } else {
                  ret = next.match(matcher, i, seq, true);
              }
              matcher.locals[countIndex] = save;
              return ret;
          }
          boolean study(TreeInfo info) {
              info.maxValid = false;
              info.deterministic = false;
              return false;
          }
      }
  
      /**
       * Handles the repetition count for a reluctant Curly. The matchInit
       * is called from the Prolog to save the index of where the group
       * beginning is stored. A zero length group check occurs in the
       * normal match but is skipped in the matchInit.
       */
      static final class LazyLoop extends Loop {
          LazyLoop(int countIndex, int beginIndex, String self) {
              super(countIndex, beginIndex, self);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              // Check for zero length group
              if (i > matcher.locals[beginIndex]) {
                  int count = matcher.locals[countIndex];
                  if (count < cmin) {
                      matcher.locals[countIndex] = count + 1;
                      boolean result = body.match(matcher, i, seq, true);
                      // If match failed we must backtrack, so
                      // the loop count should NOT be incremented
                      if (!result)
                          matcher.locals[countIndex] = count;
                      return result;
                  }
                  if (next.match(matcher, i, seq, true))
                      return true;
                  if (count < cmax) {
                      matcher.locals[countIndex] = count + 1;
                      boolean result = body.match(matcher, i, seq, true);
                      // If match failed we must backtrack, so
                      // the loop count should NOT be incremented
                      if (!result)
                          matcher.locals[countIndex] = count;
                      return result;
                  }
                  return false;
              }
              return next.match(matcher, i, seq, true);
          }
          boolean matchInit(ReScueMatcher matcher, int i, CharSequence seq){
              int save = matcher.locals[countIndex];
              boolean ret = false;
              if (0 < cmin) {
                  matcher.locals[countIndex] = 1;
                  ret = body.match(matcher, i, seq, true);
              } else if (next.match(matcher, i, seq, true)) {
                  ret = true;
              } else if (0 < cmax) {
                  matcher.locals[countIndex] = 1;
                  ret = body.match(matcher, i, seq, true);
              }
              matcher.locals[countIndex] = save;
              return ret;
          }
          boolean study(TreeInfo info) {
              info.maxValid = false;
              info.deterministic = false;
              return false;
          }
      }
  
      /**
       * Refers to a group in the regular expression. Attempts to match
       * whatever the group referred to last matched.
       */
      static class BackRef extends Node {
          int groupIndex;
          BackRef(int groupCount, String self) {
              super(self);
              groupIndex = groupCount + groupCount;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int j = matcher.groups[groupIndex];
              int k = matcher.groups[groupIndex+1];
  
              int groupSize = k - j;
              // If the referenced group didn't match, neither can this
              if (j < 0)
                  return false;
  
              // If there isn't enough input left no match
              if (i + groupSize > matcher.to) {
                  matcher.hitEnd = true;
                  return false;
              }
              // Check each new char to make sure it matches what the group
              // referenced matched last time around
              for (int index=0; index<groupSize; index++){
                  if (seq.charAt(i+index) != seq.charAt(j+index))
                      return false;
              }
  
              return next.match(matcher, i+groupSize, seq, true);
          }
          boolean study(TreeInfo info) {
              info.maxValid = false;
              return next.study(info);
          }
      }
  
      static class CIBackRef extends Node {
          int groupIndex;
          boolean doUnicodeCase;
          CIBackRef(int groupCount, boolean doUnicodeCase, String self) {
              super(self);
              groupIndex = groupCount + groupCount;
              this.doUnicodeCase = doUnicodeCase;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int j = matcher.groups[groupIndex];
              int k = matcher.groups[groupIndex+1];
  
              int groupSize = k - j;
  
              // If the referenced group didn't match, neither can this
              if (j < 0)
                  return false;
  
              // If there isn't enough input left no match
              if (i + groupSize > matcher.to) {
                  matcher.hitEnd = true;
                  return false;
              }
  
              // Check each new char to make sure it matches what the group
              // referenced matched last time around
              int x = i;
              for (int index=0; index<groupSize; index++) {
                  int c1 = Character.codePointAt(seq, x);
                  int c2 = Character.codePointAt(seq, j);
                  if (c1 != c2) {
                      if (doUnicodeCase) {
                          int cc1 = Character.toUpperCase(c1);
                          int cc2 = Character.toUpperCase(c2);
                          if (cc1 != cc2 &&
                              Character.toLowerCase(cc1) !=
                              Character.toLowerCase(cc2))
                              return false;
                      } else {
                          if (ASCII.toLower(c1) != ASCII.toLower(c2))
                              return false;
                      }
                  }
                  x += Character.charCount(c1);
                  j += Character.charCount(c2);
              }
  
              return next.match(matcher, i+groupSize, seq, true);
          }
          boolean study(TreeInfo info) {
              info.maxValid = false;
              return next.study(info);
          }
      }
  
      /**
       * Searches until the next instance of its atom. This is useful for
       * finding the atom efficiently without passing an instance of it
       * (greedy problem) and without a lot of wasted search time (reluctant
       * problem).
       */
      static final class First extends Node {
  //        Node atom;
          First(Node node) {
          	super(node.self);
              this.atom = BnM.optimize(node);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (atom instanceof BnM) {
                  return atom.match(matcher, i, seq, true)
                      && next.match(matcher, matcher.last, seq, true);
              }
              for (;;) {
                  if (i > matcher.to) {
                      matcher.hitEnd = true;
                      return false;
                  }
                  if (atom.match(matcher, i, seq, true)) {
                      return next.match(matcher, matcher.last, seq, true);
                  }
                  i += countChars(seq, i, 1);
                  matcher.first++;
              }
          }
          boolean study(TreeInfo info) {
              atom.study(info);
              info.maxValid = false;
              info.deterministic = false;
              return next.study(info);
          }
      }
  
      static final class Conditional extends Node {
  //        Node cond, yes, not;
          Conditional(Node cond, Node yes, Node not, String self) {
          	super(self);
              this.cond = cond;
              this.yes = yes;
              this.not = not;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              if (cond.match(matcher, i, seq, true)) {
                  return yes.match(matcher, i, seq, true);
              } else {
                  return not.match(matcher, i, seq, true);
              }
          }
          boolean study(TreeInfo info) {
              int minL = info.minLength;
              int maxL = info.maxLength;
              boolean maxV = info.maxValid;
              info.reset();
              yes.study(info);
  
              int minL2 = info.minLength;
              int maxL2 = info.maxLength;
              boolean maxV2 = info.maxValid;
              info.reset();
              not.study(info);
  
              info.minLength = minL + Math.min(minL2, info.minLength);
              info.maxLength = maxL + Math.max(maxL2, info.maxLength);
              info.maxValid = (maxV & maxV2 & info.maxValid);
              info.deterministic = false;
              return next.study(info);
          }
      }
  
      /**
       * Zero width positive lookahead.
       */
      static final class Pos extends Node {
  //        Node cond;
          Pos(Node cond, String self) {
          	super(self);
              this.cond = cond;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int savedTo = matcher.to;
              boolean conditionMatched = false;
  
              // Relax transparent region boundaries for lookahead
              if (matcher.transparentBounds)
                  matcher.to = matcher.getTextLength();
              try {
                  conditionMatched = cond.match(matcher, i, seq, true);
              } finally {
                  // Reinstate region boundaries
                  matcher.to = savedTo;
              }
              return conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Zero width negative lookahead.
       */
      static final class Neg extends Node {
  //        Node cond;
          Neg(Node cond, String self) {
          	super(self);
              this.cond = cond;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int savedTo = matcher.to;
              boolean conditionMatched = false;
  
              // Relax transparent region boundaries for lookahead
              if (matcher.transparentBounds)
                  matcher.to = matcher.getTextLength();
              try {
                  if (i < matcher.to) {
                      conditionMatched = !cond.match(matcher, i, seq, true);
                  } else {
                      // If a negative lookahead succeeds then more input
                      // could cause it to fail!
                      matcher.requireEnd = true;
                      conditionMatched = !cond.match(matcher, i, seq, true);
                  }
              } finally {
                  // Reinstate region boundaries
                  matcher.to = savedTo;
              }
              return conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * For use with lookbehinds; matches the position where the lookbehind
       * was encountered.
       */
      static Node lookbehindEnd = new Node("") {
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              return i == matcher.lookbehindTo;
          }
      };
  
      /**
       * Zero width positive lookbehind.
       */
      static class Behind extends Node {
  //        Node cond;
          int rmax, rmin;
          Behind(Node cond, int rmax, int rmin, String self) {
          	super(self);
              this.cond = cond;
              this.rmax = rmax;
              this.rmin = rmin;
          }
  
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int savedFrom = matcher.from;
              boolean conditionMatched = false;
              int startIndex = (!matcher.transparentBounds) ?
                               matcher.from : 0;
              int from = Math.max(i - rmax, startIndex);
              // Set end boundary
              int savedLBT = matcher.lookbehindTo;
              matcher.lookbehindTo = i;
              // Relax transparent region boundaries for lookbehind
              if (matcher.transparentBounds)
                  matcher.from = 0;
              for (int j = i - rmin; !conditionMatched && j >= from; j--) {
                  conditionMatched = cond.match(matcher, j, seq, true);
              }
              matcher.from = savedFrom;
              matcher.lookbehindTo = savedLBT;
              return conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Zero width positive lookbehind, including supplementary
       * characters or unpaired surrogates.
       */
      static final class BehindS extends Behind {
          BehindS(Node cond, int rmax, int rmin, String self) {
              super(cond, rmax, rmin, self);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int rmaxChars = countChars(seq, i, -rmax);
              int rminChars = countChars(seq, i, -rmin);
              int savedFrom = matcher.from;
              int startIndex = (!matcher.transparentBounds) ?
                               matcher.from : 0;
              boolean conditionMatched = false;
              int from = Math.max(i - rmaxChars, startIndex);
              // Set end boundary
              int savedLBT = matcher.lookbehindTo;
              matcher.lookbehindTo = i;
              // Relax transparent region boundaries for lookbehind
              if (matcher.transparentBounds)
                  matcher.from = 0;
  
              for (int j = i - rminChars;
                   !conditionMatched && j >= from;
                   j -= j>from ? countChars(seq, j, -1) : 1) {
                  conditionMatched = cond.match(matcher, j, seq, true);
              }
              matcher.from = savedFrom;
              matcher.lookbehindTo = savedLBT;
              return conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Zero width negative lookbehind.
       */
      static class NotBehind extends Node {
  //        Node cond;
          int rmax, rmin;
          NotBehind(Node cond, int rmax, int rmin, String self) {
          	super(self);
              this.cond = cond;
              this.rmax = rmax;
              this.rmin = rmin;
          }
  
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int savedLBT = matcher.lookbehindTo;
              int savedFrom = matcher.from;
              boolean conditionMatched = false;
              int startIndex = (!matcher.transparentBounds) ?
                               matcher.from : 0;
              int from = Math.max(i - rmax, startIndex);
              matcher.lookbehindTo = i;
              // Relax transparent region boundaries for lookbehind
              if (matcher.transparentBounds)
                  matcher.from = 0;
              for (int j = i - rmin; !conditionMatched && j >= from; j--) {
                  conditionMatched = cond.match(matcher, j, seq, true);
              }
              // Reinstate region boundaries
              matcher.from = savedFrom;
              matcher.lookbehindTo = savedLBT;
              return !conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Zero width negative lookbehind, including supplementary
       * characters or unpaired surrogates.
       */
      static final class NotBehindS extends NotBehind {
          NotBehindS(Node cond, int rmax, int rmin, String self) {
              super(cond, rmax, rmin, self);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int rmaxChars = countChars(seq, i, -rmax);
              int rminChars = countChars(seq, i, -rmin);
              int savedFrom = matcher.from;
              int savedLBT = matcher.lookbehindTo;
              boolean conditionMatched = false;
              int startIndex = (!matcher.transparentBounds) ?
                               matcher.from : 0;
              int from = Math.max(i - rmaxChars, startIndex);
              matcher.lookbehindTo = i;
              // Relax transparent region boundaries for lookbehind
              if (matcher.transparentBounds)
                  matcher.from = 0;
              for (int j = i - rminChars;
                   !conditionMatched && j >= from;
                   j -= j>from ? countChars(seq, j, -1) : 1) {
                  conditionMatched = cond.match(matcher, j, seq, true);
              }
              //Reinstate region boundaries
              matcher.from = savedFrom;
              matcher.lookbehindTo = savedLBT;
              return !conditionMatched && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Returns the set union of two CharProperty nodes.
       */
      private static CharProperty union(final CharProperty lhs,
                                        final CharProperty rhs) {
          return new CharProperty(lhs, rhs) {
                  boolean isSatisfiedBy(int ch) {
                      return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
      }
  
      /**
       * Returns the set intersection of two CharProperty nodes.
       */
      private static CharProperty intersection(final CharProperty lhs,
                                               final CharProperty rhs) {
          return new CharProperty(lhs, rhs) {
                  boolean isSatisfiedBy(int ch) {
                      return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
      }
  
      /**
       * Returns the set difference of two CharProperty nodes.
       */
      private static CharProperty setDifference(final CharProperty lhs,
                                                final CharProperty rhs) {
          return new CharProperty(lhs, rhs) {
                  boolean isSatisfiedBy(int ch) {
                      return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
      }
  
      /**
       * Handles word boundaries. Includes a field to allow this one class to
       * deal with the different types of word boundaries we can match. The word
       * characters include underscores, letters, and digits. Non spacing marks
       * can are also part of a word if they have a base character, otherwise
       * they are ignored for purposes of finding word boundaries.
       */
      static final class Bound extends Node {
          static int LEFT = 0x1;
          static int RIGHT= 0x2;
          static int BOTH = 0x3;
          static int NONE = 0x4;
          int type;
          boolean useUWORD;
          Bound(int n, boolean useUWORD, String self) {
          	super(self);
              type = n;
              this.useUWORD = useUWORD;
          }
  
          boolean isWord(int ch) {
              return useUWORD ? UnicodeProp.WORD.is(ch)
                              : (ch == '_' || Character.isLetterOrDigit(ch));
          }
  
          int check(ReScueMatcher matcher, int i, CharSequence seq) {
              int ch;
              boolean left = false;
              int startIndex = matcher.from;
              int endIndex = matcher.to;
              if (matcher.transparentBounds) {
                  startIndex = 0;
                  endIndex = matcher.getTextLength();
              }
              if (i > startIndex) {
                  ch = Character.codePointBefore(seq, i);
                  left = (isWord(ch) ||
                      ((Character.getType(ch) == Character.NON_SPACING_MARK)
                       && hasBaseCharacter(matcher, i-1, seq)));
              }
              boolean right = false;
              if (i < endIndex) {
                  ch = Character.codePointAt(seq, i);
                  right = (isWord(ch) ||
                      ((Character.getType(ch) == Character.NON_SPACING_MARK)
                       && hasBaseCharacter(matcher, i, seq)));
              } else {
                  // Tried to access char past the end
                  matcher.hitEnd = true;
                  // The addition of another char could wreck a boundary
                  matcher.requireEnd = true;
              }
              return ((left ^ right) ? (right ? LEFT : RIGHT) : NONE);
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              return (check(matcher, i, seq) & type) > 0
                  && next.match(matcher, i, seq, true);
          }
      }
  
      /**
       * Non spacing marks only count as word characters in bounds calculations
       * if they have a base character.
       */
      private static boolean hasBaseCharacter(ReScueMatcher matcher, int i,
                                              CharSequence seq)
      {
          int start = (!matcher.transparentBounds) ?
              matcher.from : 0;
          for (int x=i; x >= start; x--) {
              int ch = Character.codePointAt(seq, x);
              if (Character.isLetterOrDigit(ch))
                  return true;
              if (Character.getType(ch) == Character.NON_SPACING_MARK)
                  continue;
              return false;
          }
          return false;
      }
  
      /**
       * Attempts to match a slice in the input using the Boyer-Moore string
       * matching algorithm. The algorithm is based on the idea that the
       * pattern can be shifted farther ahead in the search text if it is
       * matched right to left.
       * <p>
       * The pattern is compared to the input one character at a time, from
       * the rightmost character in the pattern to the left. If the characters
       * all match the pattern has been found. If a character does not match,
       * the pattern is shifted right a distance that is the maximum of two
       * functions, the bad character shift and the good suffix shift. This
       * shift moves the attempted match position through the input more
       * quickly than a naive one position at a time check.
       * <p>
       * The bad character shift is based on the character from the text that
       * did not match. If the character does not appear in the pattern, the
       * pattern can be shifted completely beyond the bad character. If the
       * character does occur in the pattern, the pattern can be shifted to
       * line the pattern up with the next occurrence of that character.
       * <p>
       * The good suffix shift is based on the idea that some subset on the right
       * side of the pattern has matched. When a bad character is found, the
       * pattern can be shifted right by the pattern length if the subset does
       * not occur again in pattern, or by the amount of distance to the
       * next occurrence of the subset in the pattern.
       *
       * Boyer-Moore search methods adapted from code by Amy Yu.
       */
      static class BnM extends Node {
          int[] buffer;
          int[] lastOcc;
          int[] optoSft;
  
          /**
           * Pre calculates arrays needed to generate the bad character
           * shift and the good suffix shift. Only the last seven bits
           * are used to see if chars match; This keeps the tables small
           * and covers the heavily used ASCII range, but occasionally
           * results in an aliased match for the bad character shift.
           */
          static Node optimize(Node node) {
              if (!(node instanceof Slice)) {
                  return node;
              }
  
              int[] src = ((Slice) node).buffer;
              int patternLength = src.length;
              // The BM algorithm requires a bit of overhead;
              // If the pattern is short don't use it, since
              // a shift larger than the pattern length cannot
              // be used anyway.
              if (patternLength < 4) {
                  return node;
              }
              int i, j, k;
              int[] lastOcc = new int[128];
              int[] optoSft = new int[patternLength];
              // Precalculate part of the bad character shift
              // It is a table for where in the pattern each
              // lower 7-bit value occurs
              for (i = 0; i < patternLength; i++) {
                  lastOcc[src[i]&0x7F] = i + 1;
              }
              // Precalculate the good suffix shift
              // i is the shift amount being considered
  NEXT:       for (i = patternLength; i > 0; i--) {
                  // j is the beginning index of suffix being considered
                  for (j = patternLength - 1; j >= i; j--) {
                      // Testing for good suffix
                      if (src[j] == src[j-i]) {
                          // src[j..len] is a good suffix
                          optoSft[j-1] = i;
                      } else {
                          // No match. The array has already been
                          // filled up with correct values before.
                          continue NEXT;
                      }
                  }
                  // This fills up the remaining of optoSft
                  // any suffix can not have larger shift amount
                  // then its sub-suffix. Why???
                  while (j > 0) {
                      optoSft[--j] = i;
                  }
              }
              // Set the guard value because of unicode compression
              optoSft[patternLength-1] = 1;
              if (node instanceof SliceS)
                  return new BnMS(src, lastOcc, optoSft, node.next);
              return new BnM(src, lastOcc, optoSft, node.next);
          }
          BnM(int[] src, int[] lastOcc, int[] optoSft, Node next) {
          	super(ReScuePatternUtils.convertString(src));
              this.buffer = src;
              this.lastOcc = lastOcc;
              this.optoSft = optoSft;
              this.next = next;
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] src = buffer;
              int patternLength = src.length;
              int last = matcher.to - patternLength;
  
              // Loop over all possible match positions in text
  NEXT:       while (i <= last) {
                  // Loop over pattern from right to left
                  for (int j = patternLength - 1; j >= 0; j--) {
                      int ch = seq.charAt(i+j);
                      if (ch != src[j]) {
                          // Shift search to the right by the maximum of the
                          // bad character shift and the good suffix shift
                          i += Math.max(j + 1 - lastOcc[ch&0x7F], optoSft[j]);
                          continue NEXT;
                      }
                  }
                  // Entire pattern matched starting at i
                  matcher.first = i;
                  boolean ret = next.match(matcher, i + patternLength, seq, true);
                  if (ret) {
                      matcher.first = i;
                      matcher.groups[0] = matcher.first;
                      matcher.groups[1] = matcher.last;
                      return true;
                  }
                  i++;
              }
              // BnM is only used as the leading node in the unanchored case,
              // and it replaced its Start() which always searches to the end
              // if it doesn't find what it's looking for, so hitEnd is true.
              matcher.hitEnd = true;
              return false;
          }
          boolean study(TreeInfo info) {
              info.minLength += buffer.length;
              info.maxValid = false;
              return next.study(info);
          }
          
          /**
           * 杩欎釜鍑芥暟鐢ㄤ簬灏唅nt鍖栫殑unicode瀛楃杞洖string
           * @return slice鐨刡uffer杞殑unicode瀛楃涓�
           */
          public String getSliceBuffer(){
          	String result = "";
          	for (int b : buffer) {
          		char[] tmp = Character.toChars(b);
          		result = result + (new String(tmp));
          	}
          	return result;
          }
      }
  
      /**
       * Supplementary support version of BnM(). Unpaired surrogates are
       * also handled by this class.
       */
      static final class BnMS extends BnM {
          int lengthInChars;
  
          BnMS(int[] src, int[] lastOcc, int[] optoSft, Node next) {
              super(src, lastOcc, optoSft, next);
              for (int x = 0; x < buffer.length; x++) {
                  lengthInChars += Character.charCount(buffer[x]);
              }
          }
          boolean match(ReScueMatcher matcher, int i, CharSequence seq){
              int[] src = buffer;
              int patternLength = src.length;
              int last = matcher.to - lengthInChars;
  
              // Loop over all possible match positions in text
  NEXT:       while (i <= last) {
                  // Loop over pattern from right to left
                  int ch;
                  for (int j = countChars(seq, i, patternLength), x = patternLength - 1;
                       j > 0; j -= Character.charCount(ch), x--) {
                      ch = Character.codePointBefore(seq, i+j);
                      if (ch != src[x]) {
                          // Shift search to the right by the maximum of the
                          // bad character shift and the good suffix shift
                          int n = Math.max(x + 1 - lastOcc[ch&0x7F], optoSft[x]);
                          i += countChars(seq, i, n);
                          continue NEXT;
                      }
                  }
                  // Entire pattern matched starting at i
                  matcher.first = i;
                  boolean ret = next.match(matcher, i + lengthInChars, seq, true);
                  if (ret) {
                      matcher.first = i;
                      matcher.groups[0] = matcher.first;
                      matcher.groups[1] = matcher.last;
                      return true;
                  }
                  i += countChars(seq, i, 1);
              }
              matcher.hitEnd = true;
              return false;
          }
      }
  
  ///////////////////////////////////////////////////////////////////////////////
  ///////////////////////////////////////////////////////////////////////////////
  
      /**
       *  This must be the very first initializer.
       */
      static Node accept = new Node("Exit");
  
      static Node lastAccept = new LastNode("Acc");
  
      private static class CharPropertyNames {
  
          static CharProperty charPropertyFor(String name) {
              CharPropertyFactory m = map.get(name);
              return m == null ? null : m.make();
          }
  
          private static abstract class CharPropertyFactory {
              abstract CharProperty make();
          }
  
          private static void defCategory(String name,
                                          final int typeMask) {
              map.put(name, new CharPropertyFactory() {
                      CharProperty make() { return new Category(typeMask);}});
          }
  
          private static void defRange(String name,
                                       final int lower, final int upper) {
              map.put(name, new CharPropertyFactory() {
                      CharProperty make() { return rangeFor(lower, upper);}});
          }
  
          private static void defCtype(String name,
                                       final int ctype) {
              map.put(name, new CharPropertyFactory() {
                      CharProperty make() { return new Ctype(ctype);}});
          }
  
          private static abstract class CloneableProperty
              extends CharProperty implements Cloneable
          {
              public CloneableProperty(String self) {
  				super(self);
  			}
  
  			public CloneableProperty clone() {
                  try {
                      return (CloneableProperty) super.clone();
                  } catch (CloneNotSupportedException e) {
                      throw new AssertionError(e);
                  }
              }
          }
  
          private static void defClone(String name,
                                       final CloneableProperty p) {
              map.put(name, new CharPropertyFactory() {
                      CharProperty make() { return p.clone();}});
          }
  
          private static final HashMap<String, CharPropertyFactory> map
              = new HashMap<>();
  
          static {
              // Unicode character property aliases, defined in
              // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
              defCategory("Cn", 1<<Character.UNASSIGNED);
              defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
              defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
              defCategory("Lt", 1<<Character.TITLECASE_LETTER);
              defCategory("Lm", 1<<Character.MODIFIER_LETTER);
              defCategory("Lo", 1<<Character.OTHER_LETTER);
              defCategory("Mn", 1<<Character.NON_SPACING_MARK);
              defCategory("Me", 1<<Character.ENCLOSING_MARK);
              defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
              defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
              defCategory("Nl", 1<<Character.LETTER_NUMBER);
              defCategory("No", 1<<Character.OTHER_NUMBER);
              defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
              defCategory("Zl", 1<<Character.LINE_SEPARATOR);
              defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
              defCategory("Cc", 1<<Character.CONTROL);
              defCategory("Cf", 1<<Character.FORMAT);
              defCategory("Co", 1<<Character.PRIVATE_USE);
              defCategory("Cs", 1<<Character.SURROGATE);
              defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
              defCategory("Ps", 1<<Character.START_PUNCTUATION);
              defCategory("Pe", 1<<Character.END_PUNCTUATION);
              defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
              defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
              defCategory("Sm", 1<<Character.MATH_SYMBOL);
              defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
              defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
              defCategory("So", 1<<Character.OTHER_SYMBOL);
              defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
              defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
              defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
                                (1<<Character.LOWERCASE_LETTER) |
                                (1<<Character.TITLECASE_LETTER) |
                                (1<<Character.MODIFIER_LETTER)  |
                                (1<<Character.OTHER_LETTER)));
              defCategory("M", ((1<<Character.NON_SPACING_MARK) |
                                (1<<Character.ENCLOSING_MARK)   |
                                (1<<Character.COMBINING_SPACING_MARK)));
              defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
                                (1<<Character.LETTER_NUMBER)        |
                                (1<<Character.OTHER_NUMBER)));
              defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
                                (1<<Character.LINE_SEPARATOR)  |
                                (1<<Character.PARAGRAPH_SEPARATOR)));
              defCategory("C", ((1<<Character.CONTROL)     |
                                (1<<Character.FORMAT)      |
                                (1<<Character.PRIVATE_USE) |
                                (1<<Character.SURROGATE))); // Other
              defCategory("P", ((1<<Character.DASH_PUNCTUATION)      |
                                (1<<Character.START_PUNCTUATION)     |
                                (1<<Character.END_PUNCTUATION)       |
                                (1<<Character.CONNECTOR_PUNCTUATION) |
                                (1<<Character.OTHER_PUNCTUATION)     |
                                (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
                                (1<<Character.FINAL_QUOTE_PUNCTUATION)));
              defCategory("S", ((1<<Character.MATH_SYMBOL)     |
                                (1<<Character.CURRENCY_SYMBOL) |
                                (1<<Character.MODIFIER_SYMBOL) |
                                (1<<Character.OTHER_SYMBOL)));
              defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
                                 (1<<Character.LOWERCASE_LETTER) |
                                 (1<<Character.TITLECASE_LETTER)));
              defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
                                 (1<<Character.LOWERCASE_LETTER) |
                                 (1<<Character.TITLECASE_LETTER) |
                                 (1<<Character.MODIFIER_LETTER)  |
                                 (1<<Character.OTHER_LETTER)     |
                                 (1<<Character.DECIMAL_DIGIT_NUMBER)));
              defRange("L1", 0x00, 0xFF); // Latin-1
              map.put("all", new CharPropertyFactory() {
                      CharProperty make() { return new All("all"); }});
  
              // Posix regular expression character classes, defined in
              // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
              defRange("ASCII", 0x00, 0x7F);   // ASCII
              defCtype("Alnum", ASCII.ALNUM);  // Alphanumeric characters
              defCtype("Alpha", ASCII.ALPHA);  // Alphabetic characters
              defCtype("Blank", ASCII.BLANK);  // Space and tab characters
              defCtype("Cntrl", ASCII.CNTRL);  // Control characters
              defRange("Digit", '0', '9');     // Numeric characters
              defCtype("Graph", ASCII.GRAPH);  // printable and visible
              defRange("Lower", 'a', 'z');     // Lower-case alphabetic
              defRange("Print", 0x20, 0x7E);   // Printable characters
              defCtype("Punct", ASCII.PUNCT);  // Punctuation characters
              defCtype("Space", ASCII.SPACE);  // Space characters
              defRange("Upper", 'A', 'Z');     // Upper-case alphabetic
              defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
  
              // Java character properties, defined by methods in Character.java
              defClone("javaLowerCase", new CloneableProperty("javaLowerCase") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isLowerCase(ch);}});
              defClone("javaUpperCase", new CloneableProperty("javaUpperCase") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isUpperCase(ch);}});
              defClone("javaAlphabetic", new CloneableProperty("javaAlphabetic") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isAlphabetic(ch);}});
              defClone("javaIdeographic", new CloneableProperty("javaIdeographic") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isIdeographic(ch);}});
              defClone("javaTitleCase", new CloneableProperty("javaTitleCase") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isTitleCase(ch);}});
              defClone("javaDigit", new CloneableProperty("javaDigit") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isDigit(ch);}});
              defClone("javaDefined", new CloneableProperty("javaDefined") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isDefined(ch);}});
              defClone("javaLetter", new CloneableProperty("javaLetter") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isLetter(ch);}});
              defClone("javaLetterOrDigit", new CloneableProperty("javaLetterOrDigit") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isLetterOrDigit(ch);}});
              defClone("javaJavaIdentifierStart", new CloneableProperty("javaJavaIdentifierStart") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isJavaIdentifierStart(ch);}});
              defClone("javaJavaIdentifierPart", new CloneableProperty("javaJavaIdentifierPart") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isJavaIdentifierPart(ch);}});
              defClone("javaUnicodeIdentifierStart", new CloneableProperty("javaUnicodeIdentifierStart") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isUnicodeIdentifierStart(ch);}});
              defClone("javaUnicodeIdentifierPart", new CloneableProperty("javaUnicodeIdentifierPart") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isUnicodeIdentifierPart(ch);}});
              defClone("javaIdentifierIgnorable", new CloneableProperty("javaIdentifierIgnorable") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isIdentifierIgnorable(ch);}});
              defClone("javaSpaceChar", new CloneableProperty("javaSpaceChar") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isSpaceChar(ch);}});
              defClone("javaWhitespace", new CloneableProperty("javaWhitespace") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isWhitespace(ch);}});
              defClone("javaISOControl", new CloneableProperty("javaISOControl") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isISOControl(ch);}});
              defClone("javaMirrored", new CloneableProperty("javaMirrored") {
                  boolean isSatisfiedBy(int ch) {
                      return Character.isMirrored(ch);}});
          }
      }
  
      /**
       * Creates a predicate which can be used to match a string.
       *
       * @return  The predicate which can be used for matching on a string
       * @since   1.8
       */
      public Predicate<String> asPredicate (Trace trace) {
          return s -> matcher(s, trace).find().matchSuccess;
      }
  
      /**
       * Creates a stream from the given input sequence around matches of this
       * pattern.
       *
       * <p> The stream returned by this method contains each substring of the
       * input sequence that is terminated by another subsequence that matches
       * this pattern or is terminated by the end of the input sequence.  The
       * substrings in the stream are in the order in which they occur in the
       * input. Trailing empty strings will be discarded and not encountered in
       * the stream.
       *
       * <p> If this pattern does not match any subsequence of the input then
       * the resulting stream has just one element, namely the input sequence in
       * string form.
       *
       * <p> When there is a positive-width match at the beginning of the input
       * sequence then an empty leading substring is included at the beginning
       * of the stream. A zero-width match at the beginning however never produces
       * such empty leading substring.
       *
       * <p> If the input sequence is mutable, it must remain constant during the
       * execution of the terminal stream operation.  Otherwise, the result of the
       * terminal stream operation is undefined.
       *
       * @param   input
       *          The character sequence to be split
       *
       * @return  The stream of strings computed by splitting the input
       *          around matches of this pattern
       * @see     #split(CharSequence)
       * @since   1.8
       */
      public Stream<String> splitAsStream(final CharSequence input, Trace trace) {
          class MatcherIterator implements Iterator<String> {
              private final ReScueMatcher matcher;
              // The start position of the next sub-sequence of input
              // when current == input.length there are no more elements
              private int current;
              // null if the next element, if any, needs to obtained
              private String nextElement;
              // > 0 if there are N next empty elements
              private int emptyElementCount;
  
              MatcherIterator() {
                  this.matcher = matcher(input, trace);
              }
  
              public String next() {
                  if (!hasNext())
                      throw new NoSuchElementException();
  
                  if (emptyElementCount == 0) {
                      String n = nextElement;
                      nextElement = null;
                      return n;
                  } else {
                      emptyElementCount--;
                      return "";
                  }
              }
  
              public boolean hasNext() {
                  if (nextElement != null || emptyElementCount > 0)
                      return true;
  
                  if (current == input.length())
                      return false;
  
                  // Consume the next matching element
  				// Count sequence of matching empty elements
  				while (matcher.find().matchSuccess) {
  					nextElement = input.subSequence(current, matcher.start()).toString();
  					current = matcher.end();
  					if (!nextElement.isEmpty()) {
  						return true;
  					} else if (current > 0) { // no empty leading substring for
  												// zero-width
  												// match at the beginning of the
  												// input
  						emptyElementCount++;
  					}
  				}
  
                  // Consume last matching element
                  nextElement = input.subSequence(current, input.length()).toString();
                  current = input.length();
                  if (!nextElement.isEmpty()) {
                      return true;
                  } else {
                      // Ignore a terminal sequence of matching empty elements
                      emptyElementCount = 0;
                      nextElement = null;
                      return false;
                  }
              }
          }
          return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
                  new MatcherIterator(), Spliterator.ORDERED | Spliterator.NONNULL), false);
      }
      
      ////////////////////////////////////////////////////
      /*
       * Most of the additional code are here
       */
      public static Trace trace; // Trace of one matching
      private Set<Node> nodes = new HashSet<Node>(); // All nodes (states) of a compiled regex
      
      /**
       * Get all nodes (states) of a compiled regex
       */
      public Set<Node> getAllNodes() {
      	if (nodes.isEmpty()) traverseAllNodes();
      	return nodes;
      }
      
      /**
       * Print all nodes (for testing)
       */
      public void printAllNodes() {
      	if (nodes.isEmpty()) traverseAllNodes();
      	allNode(root, true);
      }
      
      /**
       * Traverse all node without printing
       */
      private void traverseAllNodes() {
      	if (nodes.isEmpty()) {
      		allNode(root, false);
      	}
      }
      
      /**
       * Get all pure text from the compiled regex
       * That is, buffers and chars of all slice and single node
       */
      public List<String> getAllSlices() {
      	if (nodes.isEmpty()) traverseAllNodes();
      	List<String> slices = new ArrayList<String>();
      	for (Node n : nodes) {
      		if (n instanceof SliceNode) slices.add(((SliceNode) n).getSliceBuffer());
      		if (n instanceof BnM) slices.add(((BnM) n).getSliceBuffer());
      		if (n instanceof Single) slices.add(((Single) n).getSliceBuffer());
      		if (n instanceof SingleI) slices.add(((SingleI) n).getSliceBuffer());
      		if (n instanceof SingleS) slices.add(((SingleS) n).getSliceBuffer());
      		if (n instanceof SingleU) slices.add(((SingleU) n).getSliceBuffer());
      	}
  //    	slices.add(pattern);
      	String[] forceSlice = pattern.split("[\\[({})\\]]");
      	for (String fs : forceSlice) {
      		if (fs.length() == 0) continue;
      		else if (fs.length() == 3 && fs.charAt(1) == '-') {
      			for (char i = fs.charAt(0); i <= fs.charAt(2); i++){
      				String c = "" + i;
  	    			if (!slices.contains(c)) {
  	    				slices.add(c);
  //	    				System.out.print(c + " ");
  	    			}
      			}
      		} else {
      			if (!slices.contains(fs)) {
      				slices.add(fs);
  //    				System.out.print(fs + " ");
      			}
      		}
      	}
  //    	System.out.println();
      	return slices;
      }
      
      /**
       * Traverse node recursively
       * @param node Current node
       * @param print Print or not
       */
      private void allNode(Node node, boolean print) {
  		if (node == null) {
  			if (print) System.out.println("End");
  		} else {
  			if (print) System.out.println(node);
  			nodes.add(node);
  			
  			// Curly
  			if (node.atom != null && !nodes.contains(node.atom)) allNode(node.atom, print);
  			if (node.atom_self != null && !nodes.contains(node.atom_self)) allNode(node.atom_self, print);
  			// Branch
  			if (node.atoms != null) {
  				for (Node a : node.atoms) {
  					if (!nodes.contains(a)) allNode(a, print);
  				}
  			}
  			if (node.conn != null && !nodes.contains(node.conn)) allNode(node.conn, print);
  			// Loop
  			if (node.body != null && !nodes.contains(node.body)) allNode(node.body, print);
  			// Prolog
  			if (node.loop != null && !nodes.contains(node.loop)) allNode(node.loop, print);
  			// GroupRef
  			if (node.head != null && !nodes.contains(node.head)) allNode(node.head, print);
  			// Conditional
  			if (node.cond != null && !nodes.contains(node.cond)) allNode(node.cond, print);
  			if (node.yes != null && !nodes.contains(node.yes)) allNode(node.yes, print);
  			if (node.not != null && !nodes.contains(node.not)) allNode(node.not, print);
  			
  			if (node.next != null && !nodes.contains(node.next)) allNode(node.next, print);
  			// Start
  			if (node.next_self != null && !nodes.contains(node.next_self)) allNode(node.next_self, print);
  		}
      }
      
      
      /**
       * Get parent-child relation between the nodes (source-destination of a state transition)
       * Currently we can get a relation of directly child and parents <child, list<node> parents>
       */
      @Deprecated
      public NodeRelation getNodeRelation() {
      	NodeRelation result = new NodeRelation();
      	Set<Node> visitedNodes = new HashSet<Node>();
      	nodeChild(visitedNodes, result, null, root);
      	return result;
      }
      
      /**
       * Traverse all node, and get the source-destination relation
       * @param visitedNodes
       * @param relation
       * @param prev
       * @param cur
       */
      @Deprecated
      private void nodeChild(Set<Node> visitedNodes, NodeRelation relation, Node prev, Node cur) {
      	if (cur == null) { // 涓嶅簲璇ュ嚭鐜扮殑鎯呭喌
      		System.out.println("Error: node is null");
  		} else {
  			if (visitedNodes.contains(cur)) {
  				relation.addParent(cur, prev);
  			} else {
  				visitedNodes.add(cur);
  				relation.addParent(cur, prev);
  			
  				// Curly
  				if (cur.atom != null) nodeChild(visitedNodes, relation, cur, cur.atom);
  				if (cur.atom != null && cur.atom_self != null) nodeChild(visitedNodes, relation, cur.atom, cur.atom_self);
  				// Branch
  				if (cur.atoms != null) {
  					for (Node a : cur.atoms) {
  						nodeChild(visitedNodes, relation, cur, a);
  					}
  				}
  				if (cur.conn != null) nodeChild(visitedNodes, relation, cur, cur.conn);
  				// Loop
  				if (cur.body != null) nodeChild(visitedNodes, relation, cur, cur.body);
  				// Prolog
  				if (cur.loop != null) nodeChild(visitedNodes, relation, cur, cur.loop);
  				// GroupRef
  				if (cur.head != null) nodeChild(visitedNodes, relation, cur, cur.head);
  				// Conditional
  				if (cur.cond != null) nodeChild(visitedNodes, relation, cur, cur.cond);
  				if (cur.yes != null) nodeChild(visitedNodes, relation, cur, cur.yes);
  				if (cur.not != null) nodeChild(visitedNodes, relation, cur, cur.not);
  				// Next
  				if (cur.next != null) nodeChild(visitedNodes, relation, cur, cur.next);
  				// the node after Start
  				if (cur.next_self != null) nodeChild(visitedNodes, relation, cur, cur.next_self);
  			}
  		}
      }
      
      /**
       * Get all destination node of a parent node
       * @param node
       * @return
       */
      public List<Node> getChildNodes(Node node) {
      	List<Node> result = new ArrayList<Node>();
      	
      	// All possible next node
          if (node.atom != null) result.add(node.atom);
          if (node.atom_self != null) result.add(node.atom_self);
          if (node.body != null) result.add(node.body);
          if (node.atoms != null) {
          	for (Node a : node.atoms) if (a != null) result.add(a);
          }
          if (node.conn != null) result.add(node.conn);
          if (node.head != null) result.add(node.head);
          if (node.loop != null) result.add(node.loop);
          if (node.cond != null) result.add(node.cond);
          if (node.yes != null) result.add(node.yes);
          if (node.not != null) result.add(node.not);
          if (node.next != null) result.add(node.next);
          if (node.next_self != null) result.add(node.next_self);
          return result;
      }
      
      /**
       * Paint the regex by {prefuse.jar}
       */
      int nodeIndex = 0;
      boolean painted = false;
      public Map<Integer, Node> nodeMap = new HashMap<Integer, Node>();
      public void paintRegex() {
      	HashMap<Node, Integer> visitedNodes = new HashMap<Node, Integer>();
          HashMap<Node, List<Node>> visitedEdges = new HashMap<Node, List<Node>>();
          
      	Schema n_sch = new Schema();
      	n_sch.addColumn("Node", String.class);
      	n_sch.lockSchema();
      	Table nodes = n_sch.instantiate();
      	
      	Schema e_sch = new Schema();
      	e_sch.addColumn("from", int.class);
      	e_sch.addColumn("to", int.class);
      	e_sch.addColumn("name", String.class);
      	Table edges = e_sch.instantiate();
      	
      	nodeIndex = 0;
      	paintNode(null, root, "", nodes, edges, visitedNodes, visitedEdges);
      	RegexViewer.paintRegex(this, nodes, edges, true, "from", "to", "Node");
      	painted = true;
      }
      
      public void paintTrace(Trace t){
      	if (painted) RegexViewer.paintLog(this, t.getLogNode(), t.getLogIdx());
      	else {
      		paintRegex();
      		RegexViewer.paintLog(this, t.getLogNode(), t.getLogIdx());
      	}
      }
      
      /**
       * Traverse all node recursively to collect node information for painting
       * @param prev Previous node
       * @param cur Current node
       * @param edgename Edge name
       * @param nodes A table storing all nodes
       * @param edges A table storing all edges
       * @param visitedNodes
       * @param visitedEdges
       */
      private void paintNode(Node prev, Node cur, String edgename, Table nodes, Table edges, HashMap<Node, Integer> visitedNodes, HashMap<Node, List<Node>> visitedEdges) {
      	// Exit recurse
      	if (cur == null) return ;
      	
      	// Root node
      	if (prev == null) {
      		int rid = nodes.addRow();
  //    		nodes.set(rid, "Node", cur.toString().split("[$@]")[1] + "\n" + cur.self);
      		nodeMap.put(nodeIndex, cur);
      		nodes.set(rid, "Node", (nodeIndex++) + ": " + cur.toString().split("[$@]")[1] + "\n" + cur.self);
      		visitedNodes.put(cur, rid);
      		
      		paintNode(cur, cur.next, "next", nodes, edges, visitedNodes, visitedEdges);
      	// Not root node
  		} else {
  			if (!visitedNodes.containsKey(cur)) {
  				// Save the node
  				int rid = nodes.addRow();
  //				nodes.set(rid, "Node", cur.toString().split("\\$")[1] + "\n" + cur.self);
  				nodeMap.put(nodeIndex, cur);
  				nodes.set(rid, "Node", (nodeIndex++) + ": " + cur.toString().split("[$@]")[1] + "\n" + cur.self);
  				visitedNodes.put(cur, rid);
  				
  				// Save the edge
  				// prev->cur Node prev outdegree = 0
  				if (!visitedEdges.containsKey(prev)) {
  					int erid = edges.addRow();
  					edges.set(erid, "from", visitedNodes.get(prev));
  					edges.set(erid, "to", visitedNodes.get(cur));
  					edges.set(erid, "name", edgename);
  					
  					ArrayList<Node> tos = new ArrayList<Node>();
  					tos.add(cur);
  					visitedEdges.put(cur, tos);
  				// prev->cur Node prev outdegree > 0
  				} else if (!visitedEdges.get(prev).contains(cur)) {
  					int erid = edges.addRow();
  					edges.set(erid, "from", visitedNodes.get(prev));
  					edges.set(erid, "to", visitedNodes.get(cur));
  					edges.set(erid, "name", edgename);
  					
  					visitedEdges.get(prev).add(cur);
  				}
  				
  				// Visit children of the node, normal state
  				// Curly
  				if (cur.atom != null) {
  					paintNode(cur, cur.atom, "atom", nodes, edges, visitedNodes, visitedEdges);
  				}
  				if (cur.atom_self != null) paintNode(cur, cur.atom_self, "atom_self", nodes, edges, visitedNodes, visitedEdges);
  				// Branch
  				if (cur.atoms != null) {
  					int i = 0;
  					for (Node a : cur.atoms) {
  						paintNode(cur, a, "atoms[" + i + "]", nodes , edges, visitedNodes, visitedEdges);
  						i++;
  					}
  				}
  				// Conn
  				if (cur.conn != null) paintNode(cur, cur.conn, "conn", nodes, edges, visitedNodes, visitedEdges);
  				// Loop
  				if (cur.body != null) paintNode(cur, cur.body, "body", nodes, edges, visitedNodes, visitedEdges);
  				// Prolog
  				if (cur.loop != null) paintNode(cur, cur.loop, "loop", nodes, edges, visitedNodes, visitedEdges);
  				// GroupRef
  				if (cur.head != null) paintNode(cur, cur.head, "head", nodes, edges, visitedNodes, visitedEdges);
  				// Conditional
  				if (cur.cond != null) paintNode(cur, cur.cond, "cond", nodes, edges, visitedNodes, visitedEdges);
  				if (cur.yes != null) paintNode(cur, cur.yes, "yes", nodes, edges, visitedNodes, visitedEdges);
  				if (cur.not != null) paintNode(cur, cur.not, "not", nodes, edges, visitedNodes, visitedEdges);
  				// Next
  				if (cur.next != null) paintNode(cur, cur.next, "next", nodes, edges, visitedNodes, visitedEdges);
  				if (cur.next_self != null) paintNode(cur, cur.next_self, "next_self", nodes, edges, visitedNodes, visitedEdges);
  			} else { // If node is visited, only save the edge
  				// prev->cur Node prev outdegree = 0
  				if (!visitedEdges.containsKey(prev)) {
  					int erid = edges.addRow();
  					edges.set(erid, "from", visitedNodes.get(prev));
  					edges.set(erid, "to", visitedNodes.get(cur));
  					edges.set(erid, "name", edgename);
  					
  					ArrayList<Node> tos = new ArrayList<Node>();
  					tos.add(cur);
  					visitedEdges.put(cur, tos);
  				// prev->cur Node prev outdegree > 0
  				} else if (!visitedEdges.get(prev).contains(cur)) {
  					int erid = edges.addRow();
  					edges.set(erid, "from", visitedNodes.get(prev));
  					edges.set(erid, "to", visitedNodes.get(cur));
  					edges.set(erid, "name", edgename);
  					
  					visitedEdges.get(prev).add(cur);
  				}
  			}
      	}
      }
  }
  