src/java.base/share/classes/java/util/regex/Pattern.java

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   1 /*
   2  * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.regex;
  27 
  28 import java.text.Normalizer;

  29 import java.util.Locale;
  30 import java.util.Iterator;
  31 import java.util.Map;
  32 import java.util.ArrayList;
  33 import java.util.HashMap;



  34 import java.util.Arrays;
  35 import java.util.NoSuchElementException;
  36 import java.util.Spliterator;
  37 import java.util.Spliterators;
  38 import java.util.function.Predicate;
  39 import java.util.stream.Stream;
  40 import java.util.stream.StreamSupport;
  41 
  42 
  43 /**
  44  * A compiled representation of a regular expression.
  45  *
  46  * <p> A regular expression, specified as a string, must first be compiled into
  47  * an instance of this class.  The resulting pattern can then be used to create
  48  * a {@link Matcher} object that can match arbitrary {@linkplain
  49  * java.lang.CharSequence character sequences} against the regular
  50  * expression.  All of the state involved in performing a match resides in the
  51  * matcher, so many matchers can share the same pattern.
  52  *
  53  * <p> A typical invocation sequence is thus


 967 
 968     /**
 969      * The starting point of state machine for the find operation.  This allows
 970      * a match to start anywhere in the input.
 971      */
 972     transient Node root;
 973 
 974     /**
 975      * The root of object tree for a match operation.  The pattern is matched
 976      * at the beginning.  This may include a find that uses BnM or a First
 977      * node.
 978      */
 979     transient Node matchRoot;
 980 
 981     /**
 982      * Temporary storage used by parsing pattern slice.
 983      */
 984     transient int[] buffer;
 985 
 986     /**





 987      * Map the "name" of the "named capturing group" to its group id
 988      * node.
 989      */
 990     transient volatile Map<String, Integer> namedGroups;
 991 
 992     /**
 993      * Temporary storage used while parsing group references.
 994      */
 995     transient GroupHead[] groupNodes;
 996 
 997     /**


















 998      * Temporary null terminated code point array used by pattern compiling.
 999      */
1000     private transient int[] temp;
1001 
1002     /**
1003      * The number of capturing groups in this Pattern. Used by matchers to
1004      * allocate storage needed to perform a match.
1005      */
1006     transient int capturingGroupCount;
1007 
1008     /**
1009      * The local variable count used by parsing tree. Used by matchers to
1010      * allocate storage needed to perform a match.
1011      */
1012     transient int localCount;
1013 
1014     /**
1015      * Index into the pattern string that keeps track of how much has been
1016      * parsed.
1017      */
1018     private transient int cursor;
1019 
1020     /**
1021      * Holds the length of the pattern string.
1022      */
1023     private transient int patternLength;
1024 
1025     /**
1026      * If the Start node might possibly match supplementary characters.
1027      * It is set to true during compiling if
1028      * (1) There is supplementary char in pattern, or
1029      * (2) There is complement node of Category or Block
1030      */
1031     private transient boolean hasSupplementary;
1032 
1033     /**
1034      * Compiles the given regular expression into a pattern.
1035      *
1036      * @param  regex
1037      *         The expression to be compiled
1038      * @return the given regular expression compiled into a pattern
1039      * @throws  PatternSyntaxException
1040      *          If the expression's syntax is invalid
1041      */
1042     public static Pattern compile(String regex) {
1043         return new Pattern(regex, 0);
1044     }
1045 
1046     /**
1047      * Compiles the given regular expression into a pattern with the given
1048      * flags.
1049      *


1321         } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1322 
1323         return sb.append(s, current, s.length())
1324                 .append("\\E")
1325                 .toString();
1326     }
1327 
1328     /**
1329      * Recompile the Pattern instance from a stream.  The original pattern
1330      * string is read in and the object tree is recompiled from it.
1331      */
1332     private void readObject(java.io.ObjectInputStream s)
1333         throws java.io.IOException, ClassNotFoundException {
1334 
1335         // Read in all fields
1336         s.defaultReadObject();
1337 
1338         // Initialize counts
1339         capturingGroupCount = 1;
1340         localCount = 0;

1341 
1342         // if length > 0, the Pattern is lazily compiled
1343         if (pattern.length() == 0) {
1344             root = new Start(lastAccept);
1345             matchRoot = lastAccept;
1346             compiled = true;
1347         }
1348     }
1349 
1350     /**
1351      * This private constructor is used to create all Patterns. The pattern
1352      * string and match flags are all that is needed to completely describe
1353      * a Pattern. An empty pattern string results in an object tree with
1354      * only a Start node and a LastNode node.
1355      */
1356     private Pattern(String p, int f) {
1357         if ((f & ~ALL_FLAGS) != 0) {
1358             throw new IllegalArgumentException("Unknown flag 0x"
1359                                                + Integer.toHexString(f));
1360         }
1361         pattern = p;
1362         flags = f;
1363 
1364         // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1365         if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1366             flags |= UNICODE_CASE;
1367 
1368         // Reset group index count
1369         capturingGroupCount = 1;
1370         localCount = 0;

1371 
1372         if (pattern.length() > 0) {
1373             compile();
1374         } else {
1375             root = new Start(lastAccept);
1376             matchRoot = lastAccept;
1377         }
1378     }
1379 
1380     /**
1381      * The pattern is converted to normalized form ({@linkplain
1382      * java.text.Normalizer.Form.NFD NFD}, canonical decomposition)
1383      * and then a pure group is constructed to match canonical
1384      * equivalences of the characters.



1385      */
1386     private void normalize() {
1387         int lastCodePoint = -1;
1388 
1389         // Convert pattern into normalized form
1390         normalizedPattern = Normalizer.normalize(pattern, Normalizer.Form.NFD);
1391         patternLength = normalizedPattern.length();
1392 
1393         // Modify pattern to match canonical equivalences
1394         StringBuilder newPattern = new StringBuilder(patternLength);
1395         for(int i=0; i<patternLength; ) {
1396             int c = normalizedPattern.codePointAt(i);
1397             StringBuilder sequenceBuffer;
1398             if ((Character.getType(c) == Character.NON_SPACING_MARK)
1399                 && (lastCodePoint != -1)) {
1400                 sequenceBuffer = new StringBuilder();
1401                 sequenceBuffer.appendCodePoint(lastCodePoint);
1402                 sequenceBuffer.appendCodePoint(c);
1403                 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1404                     i += Character.charCount(c);
1405                     if (i >= patternLength)
1406                         break;
1407                     c = normalizedPattern.codePointAt(i);
1408                     sequenceBuffer.appendCodePoint(c);
1409                 }
1410                 String ea = produceEquivalentAlternation(
1411                                                sequenceBuffer.toString());
1412                 newPattern.setLength(newPattern.length()-Character.charCount(lastCodePoint));
1413                 newPattern.append("(?:").append(ea).append(")");
1414             } else if (c == '[' && lastCodePoint != '\\') {
1415                 i = normalizeCharClass(newPattern, i);
1416             } else {
1417                 newPattern.appendCodePoint(c);




1418             }
1419             lastCodePoint = c;
1420             i += Character.charCount(c);
1421         }
1422         normalizedPattern = newPattern.toString();






1423     }
1424 
1425     /**
1426      * Complete the character class being parsed and add a set
1427      * of alternations to it that will match the canonical equivalences
1428      * of the characters within the class.
1429      */
1430     private int normalizeCharClass(StringBuilder newPattern, int i) {
1431         StringBuilder charClass = new StringBuilder();
1432         StringBuilder eq = null;
1433         int lastCodePoint = -1;
1434         String result;
1435 
1436         i++;
1437         charClass.append("[");
1438         while(true) {
1439             int c = normalizedPattern.codePointAt(i);
1440             StringBuilder sequenceBuffer;
1441 
1442             if (c == ']' && lastCodePoint != '\\') {
1443                 charClass.append((char)c);
1444                 break;
1445             } else if (Character.getType(c) == Character.NON_SPACING_MARK) {
1446                 sequenceBuffer = new StringBuilder();
1447                 sequenceBuffer.appendCodePoint(lastCodePoint);
1448                 while(Character.getType(c) == Character.NON_SPACING_MARK) {
1449                     sequenceBuffer.appendCodePoint(c);
1450                     i += Character.charCount(c);
1451                     if (i >= normalizedPattern.length())


1452                         break;
1453                     c = normalizedPattern.codePointAt(i);

1454                 }
1455                 String ea = produceEquivalentAlternation(
1456                                                   sequenceBuffer.toString());
1457 
1458                 charClass.setLength(charClass.length()-Character.charCount(lastCodePoint));
1459                 if (eq == null)
1460                     eq = new StringBuilder();
1461                 eq.append('|');
1462                 eq.append(ea);
1463             } else {
1464                 charClass.appendCodePoint(c);
1465                 i++;




1466             }
1467             if (i == normalizedPattern.length())
1468                 throw error("Unclosed character class");
1469             lastCodePoint = c;
1470         }
1471 
1472         if (eq != null) {
1473             result = "(?:"+charClass.toString()+eq.toString()+")";
1474         } else {
1475             result = charClass.toString();



1476         }
1477 
1478         newPattern.append(result);
1479         return i;


1480     }
1481 
1482     /**
1483      * Given a specific sequence composed of a regular character and
1484      * combining marks that follow it, produce the alternation that will
1485      * match all canonical equivalences of that sequence.
1486      */
1487     private String produceEquivalentAlternation(String source) {
1488         int len = countChars(source, 0, 1);
1489         if (source.length() == len)
1490             // source has one character.
1491             return source;
1492 
1493         String base = source.substring(0,len);
1494         String combiningMarks = source.substring(len);
1495 

1496         String[] perms = producePermutations(combiningMarks);
1497         StringBuilder result = new StringBuilder(source);
1498 
1499         // Add combined permutations
1500         for(int x=0; x<perms.length; x++) {
1501             String next = base + perms[x];
1502             if (x>0)
1503                 result.append("|"+next);
1504             next = composeOneStep(next);
1505             if (next != null)
1506                 result.append("|"+produceEquivalentAlternation(next));

1507         }
1508         return result.toString();
1509     }
1510 
1511     /**
1512      * Returns an array of strings that have all the possible
1513      * permutations of the characters in the input string.
1514      * This is used to get a list of all possible orderings
1515      * of a set of combining marks. Note that some of the permutations
1516      * are invalid because of combining class collisions, and these
1517      * possibilities must be removed because they are not canonically
1518      * equivalent.
1519      */
1520     private String[] producePermutations(String input) {
1521         if (input.length() == countChars(input, 0, 1))
1522             return new String[] {input};
1523 
1524         if (input.length() == countChars(input, 0, 2)) {
1525             int c0 = Character.codePointAt(input, 0);
1526             int c1 = Character.codePointAt(input, Character.charCount(c0));
1527             if (getClass(c1) == getClass(c0)) {
1528                 return new String[] {input};
1529             }
1530             String[] result = new String[2];
1531             result[0] = input;
1532             StringBuilder sb = new StringBuilder(2);
1533             sb.appendCodePoint(c1);
1534             sb.appendCodePoint(c0);
1535             result[1] = sb.toString();
1536             return result;
1537         }
1538 
1539         int length = 1;
1540         int nCodePoints = countCodePoints(input);


1558 loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1559             len = countChars(input, offset, 1);
1560             for(int y=x-1; y>=0; y--) {
1561                 if (combClass[y] == combClass[x]) {
1562                     continue loop;
1563                 }
1564             }
1565             StringBuilder sb = new StringBuilder(input);
1566             String otherChars = sb.delete(offset, offset+len).toString();
1567             String[] subResult = producePermutations(otherChars);
1568 
1569             String prefix = input.substring(offset, offset+len);
1570             for (String sre : subResult)
1571                 temp[index++] = prefix + sre;
1572         }
1573         String[] result = new String[index];
1574         System.arraycopy(temp, 0, result, 0, index);
1575         return result;
1576     }
1577 
1578     private int getClass(int c) {
1579         return sun.text.Normalizer.getCombiningClass(c);
1580     }
1581 
1582     /**
1583      * Attempts to compose input by combining the first character
1584      * with the first combining mark following it. Returns a String
1585      * that is the composition of the leading character with its first
1586      * combining mark followed by the remaining combining marks. Returns
1587      * null if the first two characters cannot be further composed.
1588      */
1589     private String composeOneStep(String input) {
1590         int len = countChars(input, 0, 2);
1591         String firstTwoCharacters = input.substring(0, len);
1592         String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);
1593 
1594         if (result.equals(firstTwoCharacters))
1595             return null;
1596         else {
1597             String remainder = input.substring(len);
1598             return result + remainder;
1599         }
1600     }
1601 
1602     /**
1603      * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1604      * See the description of `quotemeta' in perlfunc(1).
1605      */
1606     private void RemoveQEQuoting() {
1607         final int pLen = patternLength;
1608         int i = 0;
1609         while (i < pLen-1) {
1610             if (temp[i] != '\\')
1611                 i += 1;
1612             else if (temp[i + 1] != 'Q')
1613                 i += 2;


1660                     newtemp[j++] = c;
1661                     if (i != pLen)
1662                         newtemp[j++] = temp[i++];
1663                 }
1664             }
1665 
1666             beginQuote = false;
1667         }
1668 
1669         patternLength = j;
1670         temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1671     }
1672 
1673     /**
1674      * Copies regular expression to an int array and invokes the parsing
1675      * of the expression which will create the object tree.
1676      */
1677     private void compile() {
1678         // Handle canonical equivalences
1679         if (has(CANON_EQ) && !has(LITERAL)) {
1680             normalize();
1681         } else {
1682             normalizedPattern = pattern;
1683         }
1684         patternLength = normalizedPattern.length();
1685 
1686         // Copy pattern to int array for convenience
1687         // Use double zero to terminate pattern
1688         temp = new int[patternLength + 2];
1689 
1690         hasSupplementary = false;
1691         int c, count = 0;
1692         // Convert all chars into code points
1693         for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1694             c = normalizedPattern.codePointAt(x);
1695             if (isSupplementary(c)) {
1696                 hasSupplementary = true;
1697             }
1698             temp[count++] = c;
1699         }
1700 
1701         patternLength = count;   // patternLength now in code points
1702 
1703         if (! has(LITERAL))
1704             RemoveQEQuoting();
1705 
1706         // Allocate all temporary objects here.
1707         buffer = new int[32];
1708         groupNodes = new GroupHead[10];
1709         namedGroups = null;

1710 
1711         if (has(LITERAL)) {
1712             // Literal pattern handling
1713             matchRoot = newSlice(temp, patternLength, hasSupplementary);
1714             matchRoot.next = lastAccept;
1715         } else {
1716             // Start recursive descent parsing
1717             matchRoot = expr(lastAccept);
1718             // Check extra pattern characters
1719             if (patternLength != cursor) {
1720                 if (peek() == ')') {
1721                     throw error("Unmatched closing ')'");
1722                 } else {
1723                     throw error("Unexpected internal error");
1724                 }
1725             }
1726         }
1727 
1728         // Peephole optimization
1729         if (matchRoot instanceof Slice) {
1730             root = BnM.optimize(matchRoot);
1731             if (root == matchRoot) {
1732                 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1733             }
1734         } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1735             root = matchRoot;
1736         } else {
1737             root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1738         }
1739 













1740         // Release temporary storage
1741         temp = null;
1742         buffer = null;
1743         groupNodes = null;
1744         patternLength = 0;
1745         compiled = true;

1746     }
1747 
1748     Map<String, Integer> namedGroups() {
1749         Map<String, Integer> groups = namedGroups;
1750         if (groups == null) {
1751             namedGroups = groups = new HashMap<>(2);
1752         }
1753         return groups;
1754     }
1755 
1756     /**
1757      * Used to print out a subtree of the Pattern to help with debugging.
1758      */
1759     private static void printObjectTree(Node node) {
1760         while(node != null) {
1761             if (node instanceof Prolog) {
1762                 System.out.println(node);
1763                 printObjectTree(((Prolog)node).loop);
1764                 System.out.println("**** end contents prolog loop");
1765             } else if (node instanceof Loop) {
1766                 System.out.println(node);
1767                 printObjectTree(((Loop)node).body);
1768                 System.out.println("**** end contents Loop body");
1769             } else if (node instanceof Curly) {
1770                 System.out.println(node);
1771                 printObjectTree(((Curly)node).atom);
1772                 System.out.println("**** end contents Curly body");
1773             } else if (node instanceof GroupCurly) {
1774                 System.out.println(node);
1775                 printObjectTree(((GroupCurly)node).atom);
1776                 System.out.println("**** end contents GroupCurly body");
1777             } else if (node instanceof GroupTail) {
1778                 System.out.println(node);
1779                 System.out.println("Tail next is "+node.next);
1780                 return;
1781             } else {
1782                 System.out.println(node);
1783             }
1784             node = node.next;
1785             if (node != null)
1786                 System.out.println("->next:");
1787             if (node == Pattern.accept) {
1788                 System.out.println("Accept Node");
1789                 node = null;
1790             }
1791        }
1792     }
1793 
1794     /**
1795      * Used to accumulate information about a subtree of the object graph
1796      * so that optimizations can be applied to the subtree.
1797      */
1798     static final class TreeInfo {
1799         int minLength;
1800         int maxLength;
1801         boolean maxValid;
1802         boolean deterministic;
1803 
1804         TreeInfo() {
1805             reset();
1806         }
1807         void reset() {
1808             minLength = 0;
1809             maxLength = 0;
1810             maxValid = true;
1811             deterministic = true;
1812         }
1813     }
1814 


2066         Node node = null;
2067     LOOP:
2068         for (;;) {
2069             int ch = peek();
2070             switch (ch) {
2071             case '(':
2072                 // Because group handles its own closure,
2073                 // we need to treat it differently
2074                 node = group0();
2075                 // Check for comment or flag group
2076                 if (node == null)
2077                     continue;
2078                 if (head == null)
2079                     head = node;
2080                 else
2081                     tail.next = node;
2082                 // Double return: Tail was returned in root
2083                 tail = root;
2084                 continue;
2085             case '[':
2086                 node = clazz(true);



2087                 break;
2088             case '\\':
2089                 ch = nextEscaped();
2090                 if (ch == 'p' || ch == 'P') {
2091                     boolean oneLetter = true;
2092                     boolean comp = (ch == 'P');
2093                     ch = next(); // Consume { if present
2094                     if (ch != '{') {
2095                         unread();
2096                     } else {
2097                         oneLetter = false;
2098                     }
2099                     node = family(oneLetter, comp);




2100                 } else {
2101                     unread();
2102                     node = atom();
2103                 }
2104                 break;
2105             case '^':
2106                 next();
2107                 if (has(MULTILINE)) {
2108                     if (has(UNIX_LINES))
2109                         node = new UnixCaret();
2110                     else
2111                         node = new Caret();
2112                 } else {
2113                     node = new Begin();
2114                 }
2115                 break;
2116             case '$':
2117                 next();
2118                 if (has(UNIX_LINES))
2119                     node = new UnixDollar(has(MULTILINE));
2120                 else
2121                     node = new Dollar(has(MULTILINE));
2122                 break;
2123             case '.':
2124                 next();
2125                 if (has(DOTALL)) {
2126                     node = new All();
2127                 } else {
2128                     if (has(UNIX_LINES))
2129                         node = new UnixDot();
2130                     else {
2131                         node = new Dot();
2132                     }
2133                 }
2134                 break;
2135             case '|':
2136             case ')':
2137                 break LOOP;
2138             case ']': // Now interpreting dangling ] and } as literals
2139             case '}':
2140                 node = atom();
2141                 break;
2142             case '?':
2143             case '*':
2144             case '+':
2145                 next();
2146                 throw error("Dangling meta character '" + ((char)ch) + "'");
2147             case 0:
2148                 if (cursor >= patternLength) {
2149                     break LOOP;
2150                 }
2151                 // Fall through
2152             default:
2153                 node = atom();
2154                 break;
2155             }
2156 
2157             node = closure(node);
2158 





2159             if (head == null) {
2160                 head = tail = node;
2161             } else {
2162                 tail.next = node;
2163                 tail = node;
2164             }
2165         }
2166         if (head == null) {
2167             return end;
2168         }
2169         tail.next = end;
2170         root = tail;      //double return
2171         return head;
2172     }
2173 
2174     @SuppressWarnings("fallthrough")
2175     /**
2176      * Parse and add a new Single or Slice.
2177      */
2178     private Node atom() {


2196             case '^':
2197             case '(':
2198             case '[':
2199             case '|':
2200             case ')':
2201                 break;
2202             case '\\':
2203                 ch = nextEscaped();
2204                 if (ch == 'p' || ch == 'P') { // Property
2205                     if (first > 0) { // Slice is waiting; handle it first
2206                         unread();
2207                         break;
2208                     } else { // No slice; just return the family node
2209                         boolean comp = (ch == 'P');
2210                         boolean oneLetter = true;
2211                         ch = next(); // Consume { if present
2212                         if (ch != '{')
2213                             unread();
2214                         else
2215                             oneLetter = false;
2216                         return family(oneLetter, comp);



2217                     }
2218                 }
2219                 unread();
2220                 prev = cursor;
2221                 ch = escape(false, first == 0, false);
2222                 if (ch >= 0) {
2223                     append(ch, first);
2224                     first++;
2225                     if (isSupplementary(ch)) {
2226                         hasSupplementary = true;
2227                     }
2228                     ch = peek();
2229                     continue;
2230                 } else if (first == 0) {
2231                     return root;
2232                 }
2233                 // Unwind meta escape sequence
2234                 cursor = prev;
2235                 break;
2236             case 0:
2237                 if (cursor >= patternLength) {
2238                     break;
2239                 }
2240                 // Fall through
2241             default:
2242                 prev = cursor;
2243                 append(ch, first);
2244                 first++;
2245                 if (isSupplementary(ch)) {
2246                     hasSupplementary = true;
2247                 }
2248                 ch = next();
2249                 continue;
2250             }
2251             break;
2252         }
2253         if (first == 1) {
2254             return newSingle(buffer[0]);
2255         } else {
2256             return newSlice(buffer, first, hasSupplementary);
2257         }
2258     }
2259 
2260     private void append(int ch, int len) {
2261         if (len >= buffer.length) {
2262             int[] tmp = new int[len+len];
2263             System.arraycopy(buffer, 0, tmp, 0, len);
2264             buffer = tmp;
2265         }
2266         buffer[len] = ch;
2267     }
2268 
2269     /**
2270      * Parses a backref greedily, taking as many numbers as it
2271      * can. The first digit is always treated as a backref, but
2272      * multi digit numbers are only treated as a backref if at
2273      * least that many backrefs exist at this point in the regex.
2274      */


2285             case '5':
2286             case '6':
2287             case '7':
2288             case '8':
2289             case '9':
2290                 int newRefNum = (refNum * 10) + (ch - '0');
2291                 // Add another number if it doesn't make a group
2292                 // that doesn't exist
2293                 if (capturingGroupCount - 1 < newRefNum) {
2294                     done = true;
2295                     break;
2296                 }
2297                 refNum = newRefNum;
2298                 read();
2299                 break;
2300             default:
2301                 done = true;
2302                 break;
2303             }
2304         }

2305         if (has(CASE_INSENSITIVE))
2306             return new CIBackRef(refNum, has(UNICODE_CASE));
2307         else
2308             return new BackRef(refNum);
2309     }
2310 
2311     /**
2312      * Parses an escape sequence to determine the actual value that needs
2313      * to be matched.
2314      * If -1 is returned and create was true a new object was added to the tree
2315      * to handle the escape sequence.
2316      * If the returned value is greater than zero, it is the value that
2317      * matches the escape sequence.
2318      */
2319     private int escape(boolean inclass, boolean create, boolean isrange) {
2320         int ch = skip();
2321         switch (ch) {
2322         case '0':
2323             return o();
2324         case '1':


2329         case '6':
2330         case '7':
2331         case '8':
2332         case '9':
2333             if (inclass) break;
2334             if (create) {
2335                 root = ref((ch - '0'));
2336             }
2337             return -1;
2338         case 'A':
2339             if (inclass) break;
2340             if (create) root = new Begin();
2341             return -1;
2342         case 'B':
2343             if (inclass) break;
2344             if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2345             return -1;
2346         case 'C':
2347             break;
2348         case 'D':
2349             if (create) root = has(UNICODE_CHARACTER_CLASS)
2350                                ? new Utype(UnicodeProp.DIGIT).complement()
2351                                : new Ctype(ASCII.DIGIT).complement();




2352             return -1;
2353         case 'E':
2354         case 'F':
2355             break;
2356         case 'G':
2357             if (inclass) break;
2358             if (create) root = new LastMatch();
2359             return -1;
2360         case 'H':
2361             if (create) root = new HorizWS().complement();




2362             return -1;
2363         case 'I':
2364         case 'J':
2365         case 'K':
2366         case 'L':
2367         case 'M':
2368             break;
2369         case 'N':
2370             return N();
2371         case 'O':
2372         case 'P':
2373         case 'Q':
2374             break;
2375         case 'R':
2376             if (inclass) break;
2377             if (create) root = new LineEnding();
2378             return -1;
2379         case 'S':
2380             if (create) root = has(UNICODE_CHARACTER_CLASS)
2381                                ? new Utype(UnicodeProp.WHITE_SPACE).complement()
2382                                : new Ctype(ASCII.SPACE).complement();




2383             return -1;
2384         case 'T':
2385         case 'U':
2386             break;
2387         case 'V':
2388             if (create) root = new VertWS().complement();




2389             return -1;
2390         case 'W':
2391             if (create) root = has(UNICODE_CHARACTER_CLASS)
2392                                ? new Utype(UnicodeProp.WORD).complement()
2393                                : new Ctype(ASCII.WORD).complement();




2394             return -1;
2395         case 'X':
2396             if (inclass) break;
2397             if (create) {
2398                 root = new XGrapheme();
2399             }
2400             return -1;
2401         case 'Y':
2402             break;
2403         case 'Z':
2404             if (inclass) break;
2405             if (create) {
2406                 if (has(UNIX_LINES))
2407                     root = new UnixDollar(false);
2408                 else
2409                     root = new Dollar(false);
2410             }
2411             return -1;
2412         case 'a':
2413             return '\007';
2414         case 'b':
2415             if (inclass) break;
2416             if (create) {
2417                 if (peek() == '{') {
2418                     if (skip() == 'g') {
2419                         if (read() == '}') {
2420                             root = new GraphemeBound();
2421                             return -1;
2422                         }
2423                         break;  // error missing trailing }
2424                     }
2425                     unread(); unread();
2426                 }
2427                 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2428             }
2429             return -1;
2430         case 'c':
2431             return c();
2432         case 'd':
2433             if (create) root = has(UNICODE_CHARACTER_CLASS)
2434                                ? new Utype(UnicodeProp.DIGIT)
2435                                : new Ctype(ASCII.DIGIT);



2436             return -1;
2437         case 'e':
2438             return '\033';
2439         case 'f':
2440             return '\f';
2441         case 'g':
2442             break;
2443         case 'h':
2444             if (create) root = new HorizWS();




2445             return -1;
2446         case 'i':
2447         case 'j':
2448             break;
2449         case 'k':
2450             if (inclass)
2451                 break;
2452             if (read() != '<')
2453                 throw error("\\k is not followed by '<' for named capturing group");
2454             String name = groupname(read());
2455             if (!namedGroups().containsKey(name))
2456                 throw error("(named capturing group <"+ name+"> does not exit");
2457             if (create) {

2458                 if (has(CASE_INSENSITIVE))
2459                     root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2460                 else
2461                     root = new BackRef(namedGroups().get(name));
2462             }
2463             return -1;
2464         case 'l':
2465         case 'm':
2466             break;
2467         case 'n':
2468             return '\n';
2469         case 'o':
2470         case 'p':
2471         case 'q':
2472             break;
2473         case 'r':
2474             return '\r';
2475         case 's':
2476             if (create) root = has(UNICODE_CHARACTER_CLASS)
2477                                ? new Utype(UnicodeProp.WHITE_SPACE)
2478                                : new Ctype(ASCII.SPACE);



2479             return -1;
2480         case 't':
2481             return '\t';
2482         case 'u':
2483             return u();
2484         case 'v':
2485             // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2486             // undocumented). In JDK8 '\v' is specified as a predefined
2487             // character class for all vertical whitespace characters.
2488             // So [-1, root=VertWS node] pair is returned (instead of a
2489             // single 0x0B). This breaks the range if '\v' is used as
2490             // the start or end value, such as [\v-...] or [...-\v], in
2491             // which a single definite value (0x0B) is expected. For
2492             // compatibility concern '\013'/0x0B is returned if isrange.
2493             if (isrange)
2494                 return '\013';
2495             if (create) root = new VertWS();




2496             return -1;
2497         case 'w':
2498             if (create) root = has(UNICODE_CHARACTER_CLASS)
2499                                ? new Utype(UnicodeProp.WORD)
2500                                : new Ctype(ASCII.WORD);



2501             return -1;
2502         case 'x':
2503             return x();
2504         case 'y':
2505             break;
2506         case 'z':
2507             if (inclass) break;
2508             if (create) root = new End();
2509             return -1;
2510         default:
2511             return ch;
2512         }
2513         throw error("Illegal/unsupported escape sequence");
2514     }
2515 
2516     /**
2517      * Parse a character class, and return the node that matches it.
2518      *
2519      * Consumes a ] on the way out if consume is true. Usually consume
2520      * is true except for the case of [abc&&def] where def is a separate
2521      * right hand node with "understood" brackets.
2522      */
2523     private CharProperty clazz(boolean consume) {
2524         CharProperty prev = null;
2525         CharProperty node = null;
2526         BitClass bits = new BitClass();
2527         boolean include = true;
2528         boolean firstInClass = true;


2529         int ch = next();
2530         for (;;) {
2531             switch (ch) {
2532                 case '^':
2533                     // Negates if first char in a class, otherwise literal
2534                     if (firstInClass) {
2535                         if (temp[cursor-1] != '[')
2536                             break;
2537                         ch = next();
2538                         include = !include;
2539                         continue;
2540                     } else {
2541                         // ^ not first in class, treat as literal
2542                         break;
2543                     }


2544                 case '[':
2545                     firstInClass = false;
2546                     node = clazz(true);
2547                     if (prev == null)
2548                         prev = node;
2549                     else
2550                         prev = union(prev, node);
2551                     ch = peek();
2552                     continue;
2553                 case '&':
2554                     firstInClass = false;
2555                     ch = next();
2556                     if (ch == '&') {
2557                         ch = next();
2558                         CharProperty rightNode = null;
2559                         while (ch != ']' && ch != '&') {
2560                             if (ch == '[') {
2561                                 if (rightNode == null)
2562                                     rightNode = clazz(true);
2563                                 else
2564                                     rightNode = union(rightNode, clazz(true));
2565                             } else { // abc&&def
2566                                 unread();
2567                                 rightNode = clazz(false);
2568                             }
2569                             ch = peek();
2570                         }
2571                         if (rightNode != null)
2572                             node = rightNode;
2573                         if (prev == null) {
2574                             if (rightNode == null)









2575                                 throw error("Bad class syntax");
2576                             else
2577                                 prev = rightNode;
2578                         } else {
2579                             prev = intersection(prev, node);
2580                         }
2581                     } else {
2582                         // treat as a literal &
2583                         unread();
2584                         break;
2585                     }
2586                     continue;
2587                 case 0:
2588                     firstInClass = false;
2589                     if (cursor >= patternLength)
2590                         throw error("Unclosed character class");
2591                     break;
2592                 case ']':
2593                     firstInClass = false;
2594                     if (prev != null) {
2595                         if (consume)
2596                             next();






2597                         return prev;
2598                     }
2599                     break;
2600                 default:
2601                     firstInClass = false;
2602                     break;
2603             }
2604             node = range(bits);
2605             if (include) {
2606                 if (prev == null) {
2607                     prev = node;
2608                 } else {
2609                     if (prev != node)
2610                         prev = union(prev, node);
2611                 }
2612             } else {
2613                 if (prev == null) {
2614                     prev = node.complement();
2615                 } else {
2616                     if (prev != node)
2617                         prev = setDifference(prev, node);
2618                 }

2619             }
2620             ch = peek();
2621         }
2622     }
2623 
2624     private CharProperty bitsOrSingle(BitClass bits, int ch) {
2625         /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2626            Use "single" node instead of bits when dealing with unicode
2627            case folding for codepoints listed below.
2628            (1)Uppercase out of range: u+00ff, u+00b5
2629               toUpperCase(u+00ff) -> u+0178
2630               toUpperCase(u+00b5) -> u+039c
2631            (2)LatinSmallLetterLongS u+17f
2632               toUpperCase(u+017f) -> u+0053
2633            (3)LatinSmallLetterDotlessI u+131
2634               toUpperCase(u+0131) -> u+0049
2635            (4)LatinCapitalLetterIWithDotAbove u+0130
2636               toLowerCase(u+0130) -> u+0069
2637            (5)KelvinSign u+212a
2638               toLowerCase(u+212a) ==> u+006B
2639            (6)AngstromSign u+212b
2640               toLowerCase(u+212b) ==> u+00e5
2641         */
2642         int d;
2643         if (ch < 256 &&
2644             !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2645               (ch == 0xff || ch == 0xb5 ||
2646                ch == 0x49 || ch == 0x69 ||  //I and i
2647                ch == 0x53 || ch == 0x73 ||  //S and s
2648                ch == 0x4b || ch == 0x6b ||  //K and k
2649                ch == 0xc5 || ch == 0xe5)))  //A+ring
2650             return bits.add(ch, flags());
2651         return newSingle(ch);



























2652     }
2653 
2654     /**
2655      * Parse a single character or a character range in a character class
2656      * and return its representative node.
2657      */
2658     private CharProperty range(BitClass bits) {
2659         int ch = peek();
2660         if (ch == '\\') {
2661             ch = nextEscaped();
2662             if (ch == 'p' || ch == 'P') { // A property
2663                 boolean comp = (ch == 'P');
2664                 boolean oneLetter = true;
2665                 // Consume { if present
2666                 ch = next();
2667                 if (ch != '{')
2668                     unread();
2669                 else
2670                     oneLetter = false;
2671                 return family(oneLetter, comp);
2672             } else { // ordinary escape
2673                 boolean isrange = temp[cursor+1] == '-';
2674                 unread();
2675                 ch = escape(true, true, isrange);
2676                 if (ch == -1)
2677                     return (CharProperty) root;
2678             }
2679         } else {
2680             next();
2681         }
2682         if (ch >= 0) {
2683             if (peek() == '-') {
2684                 int endRange = temp[cursor+1];
2685                 if (endRange == '[') {
2686                     return bitsOrSingle(bits, ch);
2687                 }
2688                 if (endRange != ']') {
2689                     next();
2690                     int m = peek();
2691                     if (m == '\\') {
2692                         m = escape(true, false, true);
2693                     } else {
2694                         next();
2695                     }
2696                     if (m < ch) {
2697                         throw error("Illegal character range");
2698                     }
2699                     if (has(CASE_INSENSITIVE))
2700                         return caseInsensitiveRangeFor(ch, m);
2701                     else
2702                         return rangeFor(ch, m);



2703                 }
2704             }
2705             return bitsOrSingle(bits, ch);
2706         }
2707         throw error("Unexpected character '"+((char)ch)+"'");
2708     }
2709 
2710     /**
2711      * Parses a Unicode character family and returns its representative node.
2712      */
2713     private CharProperty family(boolean singleLetter,
2714                                 boolean maybeComplement)
2715     {
2716         next();
2717         String name;
2718         CharProperty node = null;
2719 
2720         if (singleLetter) {
2721             int c = temp[cursor];
2722             if (!Character.isSupplementaryCodePoint(c)) {
2723                 name = String.valueOf((char)c);
2724             } else {
2725                 name = new String(temp, cursor, 1);
2726             }
2727             read();
2728         } else {
2729             int i = cursor;
2730             mark('}');
2731             while(read() != '}') {
2732             }
2733             mark('\000');
2734             int j = cursor;
2735             if (j > patternLength)
2736                 throw error("Unclosed character family");
2737             if (i + 1 >= j)
2738                 throw error("Empty character family");
2739             name = new String(temp, i, j-i-1);
2740         }
2741 
2742         int i = name.indexOf('=');
2743         if (i != -1) {
2744             // property construct \p{name=value}
2745             String value = name.substring(i + 1);
2746             name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2747             switch (name) {
2748                 case "sc":
2749                 case "script":
2750                     node = unicodeScriptPropertyFor(value);
2751                     break;
2752                 case "blk":
2753                 case "block":
2754                     node = unicodeBlockPropertyFor(value);
2755                     break;
2756                 case "gc":
2757                 case "general_category":
2758                     node = charPropertyNodeFor(value);
2759                     break;
2760                 default:



2761                     throw error("Unknown Unicode property {name=<" + name + ">, "
2762                                 + "value=<" + value + ">}");
2763             }
2764         } else {
2765             if (name.startsWith("In")) {
2766                 // \p{inBlockName}
2767                 node = unicodeBlockPropertyFor(name.substring(2));
2768             } else if (name.startsWith("Is")) {
2769                 // \p{isGeneralCategory} and \p{isScriptName}
2770                 name = name.substring(2);
2771                 UnicodeProp uprop = UnicodeProp.forName(name);
2772                 if (uprop != null)
2773                     node = new Utype(uprop);
2774                 if (node == null)
2775                     node = CharPropertyNames.charPropertyFor(name);
2776                 if (node == null)
2777                     node = unicodeScriptPropertyFor(name);
2778             } else {
2779                 if (has(UNICODE_CHARACTER_CLASS)) {
2780                     UnicodeProp uprop = UnicodeProp.forPOSIXName(name);
2781                     if (uprop != null)
2782                         node = new Utype(uprop);
2783                 }
2784                 if (node == null)
2785                     node = charPropertyNodeFor(name);
2786             }


2787         }
2788         if (maybeComplement) {
2789             if (node instanceof Category || node instanceof Block)


2790                 hasSupplementary = true;
2791             node = node.complement();
2792         }
2793         return node;
2794     }
2795 
2796 
2797     /**
2798      * Returns a CharProperty matching all characters belong to
2799      * a UnicodeScript.
2800      */
2801     private CharProperty unicodeScriptPropertyFor(String name) {
2802         final Character.UnicodeScript script;
2803         try {
2804             script = Character.UnicodeScript.forName(name);
2805         } catch (IllegalArgumentException iae) {
2806             throw error("Unknown character script name {" + name + "}");
2807         }
2808         return new Script(script);
2809     }
2810 
2811     /**
2812      * Returns a CharProperty matching all characters in a UnicodeBlock.
2813      */
2814     private CharProperty unicodeBlockPropertyFor(String name) {
2815         final Character.UnicodeBlock block;
2816         try {
2817             block = Character.UnicodeBlock.forName(name);
2818         } catch (IllegalArgumentException iae) {
2819             throw error("Unknown character block name {" + name + "}");
2820         }
2821         return new Block(block);
2822     }
2823 
2824     /**
2825      * Returns a CharProperty matching all characters in a named property.
2826      */
2827     private CharProperty charPropertyNodeFor(String name) {
2828         CharProperty p = CharPropertyNames.charPropertyFor(name);
2829         if (p == null)
2830             throw error("Unknown character property name {" + name + "}");
2831         return p;



2832     }
2833 
2834     /**
2835      * Parses and returns the name of a "named capturing group", the trailing
2836      * ">" is consumed after parsing.
2837      */
2838     private String groupname(int ch) {
2839         StringBuilder sb = new StringBuilder();
2840         sb.append(Character.toChars(ch));
2841         while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2842                ASCII.isDigit(ch)) {
2843             sb.append(Character.toChars(ch));
2844         }
2845         if (sb.length() == 0)
2846             throw error("named capturing group has 0 length name");
2847         if (ch != '>')
2848             throw error("named capturing group is missing trailing '>'");
2849         return sb.toString();
2850     }
2851 
2852     /**
2853      * Parses a group and returns the head node of a set of nodes that process
2854      * the group. Sometimes a double return system is used where the tail is
2855      * returned in root.
2856      */
2857     private Node group0() {
2858         boolean capturingGroup = false;
2859         Node head = null;
2860         Node tail = null;
2861         int save = flags;

2862         root = null;
2863         int ch = next();
2864         if (ch == '?') {
2865             ch = skip();
2866             switch (ch) {
2867             case ':':   //  (?:xxx) pure group
2868                 head = createGroup(true);
2869                 tail = root;
2870                 head.next = expr(tail);
2871                 break;
2872             case '=':   // (?=xxx) and (?!xxx) lookahead
2873             case '!':
2874                 head = createGroup(true);
2875                 tail = root;
2876                 head.next = expr(tail);
2877                 if (ch == '=') {
2878                     head = tail = new Pos(head);
2879                 } else {
2880                     head = tail = new Neg(head);
2881                 }
2882                 break;
2883             case '>':   // (?>xxx)  independent group
2884                 head = createGroup(true);
2885                 tail = root;
2886                 head.next = expr(tail);
2887                 head = tail = new Ques(head, INDEPENDENT);
2888                 break;
2889             case '<':   // (?<xxx)  look behind
2890                 ch = read();
2891                 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2892                     // named captured group
2893                     String name = groupname(ch);
2894                     if (namedGroups().containsKey(name))
2895                         throw error("Named capturing group <" + name
2896                                     + "> is already defined");
2897                     capturingGroup = true;
2898                     head = createGroup(false);
2899                     tail = root;
2900                     namedGroups().put(name, capturingGroupCount-1);
2901                     head.next = expr(tail);
2902                     break;
2903                 }
2904                 int start = cursor;
2905                 head = createGroup(true);
2906                 tail = root;
2907                 head.next = expr(tail);


2911                 if (info.maxValid == false) {
2912                     throw error("Look-behind group does not have "
2913                                 + "an obvious maximum length");
2914                 }
2915                 boolean hasSupplementary = findSupplementary(start, patternLength);
2916                 if (ch == '=') {
2917                     head = tail = (hasSupplementary ?
2918                                    new BehindS(head, info.maxLength,
2919                                                info.minLength) :
2920                                    new Behind(head, info.maxLength,
2921                                               info.minLength));
2922                 } else if (ch == '!') {
2923                     head = tail = (hasSupplementary ?
2924                                    new NotBehindS(head, info.maxLength,
2925                                                   info.minLength) :
2926                                    new NotBehind(head, info.maxLength,
2927                                                  info.minLength));
2928                 } else {
2929                     throw error("Unknown look-behind group");
2930                 }



2931                 break;
2932             case '$':
2933             case '@':
2934                 throw error("Unknown group type");
2935             default:    // (?xxx:) inlined match flags
2936                 unread();
2937                 addFlag();
2938                 ch = read();
2939                 if (ch == ')') {
2940                     return null;    // Inline modifier only
2941                 }
2942                 if (ch != ':') {
2943                     throw error("Unknown inline modifier");
2944                 }
2945                 head = createGroup(true);
2946                 tail = root;
2947                 head.next = expr(tail);
2948                 break;
2949             }
2950         } else { // (xxx) a regular group
2951             capturingGroup = true;
2952             head = createGroup(false);
2953             tail = root;
2954             head.next = expr(tail);
2955         }
2956 
2957         accept(')', "Unclosed group");
2958         flags = save;
2959 
2960         // Check for quantifiers
2961         Node node = closure(head);
2962         if (node == head) { // No closure
2963             root = tail;
2964             return node;    // Dual return
2965         }
2966         if (head == tail) { // Zero length assertion
2967             root = node;
2968             return node;    // Dual return
2969         }
2970 





2971         if (node instanceof Ques) {
2972             Ques ques = (Ques) node;
2973             if (ques.type == POSSESSIVE) {
2974                 root = node;
2975                 return node;
2976             }
2977             tail.next = new BranchConn();
2978             tail = tail.next;
2979             if (ques.type == GREEDY) {
2980                 head = new Branch(head, null, tail);
2981             } else { // Reluctant quantifier
2982                 head = new Branch(null, head, tail);
2983             }
2984             root = tail;
2985             return head;
2986         } else if (node instanceof Curly) {
2987             Curly curly = (Curly) node;
2988             if (curly.type == POSSESSIVE) {
2989                 root = node;
2990                 return node;
2991             }
2992             // Discover if the group is deterministic
2993             TreeInfo info = new TreeInfo();
2994             if (head.study(info)) { // Deterministic
2995                 GroupTail temp = (GroupTail) tail;
2996                 head = root = new GroupCurly(head.next, curly.cmin,
2997                                    curly.cmax, curly.type,
2998                                    ((GroupTail)tail).localIndex,
2999                                    ((GroupTail)tail).groupIndex,
3000                                              capturingGroup);
3001                 return head;
3002             } else { // Non-deterministic
3003                 int temp = ((GroupHead) head).localIndex;
3004                 Loop loop;
3005                 if (curly.type == GREEDY)
3006                     loop = new Loop(this.localCount, temp);
3007                 else  // Reluctant Curly



3008                     loop = new LazyLoop(this.localCount, temp);

3009                 Prolog prolog = new Prolog(loop);
3010                 this.localCount += 1;
3011                 loop.cmin = curly.cmin;
3012                 loop.cmax = curly.cmax;
3013                 loop.body = head;
3014                 tail.next = loop;
3015                 root = loop;
3016                 return prolog; // Dual return
3017             }
3018         }
3019         throw error("Internal logic error");
3020     }
3021 
3022     /**
3023      * Create group head and tail nodes using double return. If the group is
3024      * created with anonymous true then it is a pure group and should not
3025      * affect group counting.
3026      */
3027     private Node createGroup(boolean anonymous) {
3028         int localIndex = localCount++;
3029         int groupIndex = 0;
3030         if (!anonymous)
3031             groupIndex = capturingGroupCount++;
3032         GroupHead head = new GroupHead(localIndex);
3033         root = new GroupTail(localIndex, groupIndex);




3034         if (!anonymous && groupIndex < 10)
3035             groupNodes[groupIndex] = head;
3036         return head;
3037     }
3038 
3039     @SuppressWarnings("fallthrough")
3040     /**
3041      * Parses inlined match flags and set them appropriately.
3042      */
3043     private void addFlag() {
3044         int ch = peek();
3045         for (;;) {
3046             switch (ch) {
3047             case 'i':
3048                 flags |= CASE_INSENSITIVE;
3049                 break;
3050             case 'm':
3051                 flags |= MULTILINE;
3052                 break;
3053             case 's':


3102             case 'u':
3103                 flags &= ~UNICODE_CASE;
3104                 break;
3105             case 'c':
3106                 flags &= ~CANON_EQ;
3107                 break;
3108             case 'x':
3109                 flags &= ~COMMENTS;
3110                 break;
3111             case 'U':
3112                 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3113             default:
3114                 return;
3115             }
3116             ch = next();
3117         }
3118     }
3119 
3120     static final int MAX_REPS   = 0x7FFFFFFF;
3121 
3122     static final int GREEDY     = 0;
3123 
3124     static final int LAZY       = 1;
3125 
3126     static final int POSSESSIVE = 2;
3127 
3128     static final int INDEPENDENT = 3;















3129 
3130     /**
3131      * Processes repetition. If the next character peeked is a quantifier
3132      * then new nodes must be appended to handle the repetition.
3133      * Prev could be a single or a group, so it could be a chain of nodes.
3134      */
3135     private Node closure(Node prev) {
3136         Node atom;
3137         int ch = peek();
3138         switch (ch) {
3139         case '?':
3140             ch = next();
3141             if (ch == '?') {
3142                 next();
3143                 return new Ques(prev, LAZY);
3144             } else if (ch == '+') {
3145                 next();
3146                 return new Ques(prev, POSSESSIVE);
3147             }
3148             return new Ques(prev, GREEDY);
3149         case '*':
3150             ch = next();
3151             if (ch == '?') {
3152                 next();
3153                 return new Curly(prev, 0, MAX_REPS, LAZY);
3154             } else if (ch == '+') {
3155                 next();
3156                 return new Curly(prev, 0, MAX_REPS, POSSESSIVE);
3157             }
3158             return new Curly(prev, 0, MAX_REPS, GREEDY);
3159         case '+':
3160             ch = next();
3161             if (ch == '?') {
3162                 next();
3163                 return new Curly(prev, 1, MAX_REPS, LAZY);
3164             } else if (ch == '+') {
3165                 next();
3166                 return new Curly(prev, 1, MAX_REPS, POSSESSIVE);
3167             }
3168             return new Curly(prev, 1, MAX_REPS, GREEDY);
3169         case '{':
3170             ch = temp[cursor+1];
3171             if (ASCII.isDigit(ch)) {
3172                 skip();
3173                 int cmin = 0;
3174                 do {
3175                     cmin = cmin * 10 + (ch - '0');
3176                 } while (ASCII.isDigit(ch = read()));
3177                 int cmax = cmin;
3178                 if (ch == ',') {
3179                     ch = read();
3180                     cmax = MAX_REPS;
3181                     if (ch != '}') {
3182                         cmax = 0;
3183                         while (ASCII.isDigit(ch)) {
3184                             cmax = cmax * 10 + (ch - '0');
3185                             ch = read();
3186                         }
3187                     }
3188                 }
3189                 if (ch != '}')
3190                     throw error("Unclosed counted closure");
3191                 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3192                     throw error("Illegal repetition range");
3193                 Curly curly;
3194                 ch = peek();
3195                 if (ch == '?') {
3196                     next();
3197                     curly = new Curly(prev, cmin, cmax, LAZY);
3198                 } else if (ch == '+') {
3199                     next();
3200                     curly = new Curly(prev, cmin, cmax, POSSESSIVE);
3201                 } else {
3202                     curly = new Curly(prev, cmin, cmax, GREEDY);
3203                 }
3204                 return curly;
3205             } else {
3206                 throw error("Illegal repetition");
3207             }
3208         default:
3209             return prev;
3210         }
3211     }
3212 
3213     /**
3214      *  Utility method for parsing control escape sequences.
3215      */
3216     private int c() {
3217         if (cursor < patternLength) {
3218             return read() ^ 64;
3219         }
3220         throw error("Illegal control escape sequence");
3221     }
3222 


3359 
3360     private static final int countCodePoints(CharSequence seq) {
3361         int length = seq.length();
3362         int n = 0;
3363         for (int i = 0; i < length; ) {
3364             n++;
3365             if (Character.isHighSurrogate(seq.charAt(i++))) {
3366                 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3367                     i++;
3368                 }
3369             }
3370         }
3371         return n;
3372     }
3373 
3374     /**
3375      *  Creates a bit vector for matching Latin-1 values. A normal BitClass
3376      *  never matches values above Latin-1, and a complemented BitClass always
3377      *  matches values above Latin-1.
3378      */
3379     private static final class BitClass extends BmpCharProperty {
3380         final boolean[] bits;
3381         BitClass() { bits = new boolean[256]; }
3382         private BitClass(boolean[] bits) { this.bits = bits; }





3383         BitClass add(int c, int flags) {
3384             assert c >= 0 && c <= 255;
3385             if ((flags & CASE_INSENSITIVE) != 0) {
3386                 if (ASCII.isAscii(c)) {
3387                     bits[ASCII.toUpper(c)] = true;
3388                     bits[ASCII.toLower(c)] = true;
3389                 } else if ((flags & UNICODE_CASE) != 0) {
3390                     bits[Character.toLowerCase(c)] = true;
3391                     bits[Character.toUpperCase(c)] = true;
3392                 }
3393             }
3394             bits[c] = true;
3395             return this;
3396         }
3397         boolean isSatisfiedBy(int ch) {
3398             return ch < 256 && bits[ch];
3399         }
3400     }
3401 
3402     /**
3403      *  Returns a suitably optimized, single character matcher.
3404      */
3405     private CharProperty newSingle(final int ch) {
3406         if (has(CASE_INSENSITIVE)) {
3407             int lower, upper;
3408             if (has(UNICODE_CASE)) {
3409                 upper = Character.toUpperCase(ch);
3410                 lower = Character.toLowerCase(upper);
3411                 if (upper != lower)
3412                     return new SingleU(lower);
3413             } else if (ASCII.isAscii(ch)) {
3414                 lower = ASCII.toLower(ch);
3415                 upper = ASCII.toUpper(ch);
3416                 if (lower != upper)
3417                     return new SingleI(lower, upper);
3418             }
3419         }
3420         if (isSupplementary(ch))
3421             return new SingleS(ch);    // Match a given Unicode character
3422         return new Single(ch);         // Match a given BMP character
3423     }
3424 
3425     /**
3426      *  Utility method for creating a string slice matcher.
3427      */
3428     private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3429         int[] tmp = new int[count];
3430         if (has(CASE_INSENSITIVE)) {
3431             if (has(UNICODE_CASE)) {
3432                 for (int i = 0; i < count; i++) {
3433                     tmp[i] = Character.toLowerCase(
3434                                  Character.toUpperCase(buf[i]));
3435                 }
3436                 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3437             }
3438             for (int i = 0; i < count; i++) {
3439                 tmp[i] = ASCII.toLower(buf[i]);
3440             }
3441             return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3442         }


3810                     if (i < matcher.to && seq.charAt(i) == 0x0A)
3811                         i++;
3812                     return next.match(matcher, i, seq);
3813                 }
3814             } else {
3815                 matcher.hitEnd = true;
3816             }
3817             return false;
3818         }
3819         boolean study(TreeInfo info) {
3820             info.minLength++;
3821             info.maxLength += 2;
3822             return next.study(info);
3823         }
3824     }
3825 
3826     /**
3827      * Abstract node class to match one character satisfying some
3828      * boolean property.
3829      */
3830     private abstract static class CharProperty extends Node {
3831         abstract boolean isSatisfiedBy(int ch);
3832         CharProperty complement() {
3833             return new CharProperty() {
3834                     boolean isSatisfiedBy(int ch) {
3835                         return ! CharProperty.this.isSatisfiedBy(ch);}};
3836         }
3837         boolean match(Matcher matcher, int i, CharSequence seq) {
3838             if (i < matcher.to) {
3839                 int ch = Character.codePointAt(seq, i);
3840                 return isSatisfiedBy(ch)
3841                     && next.match(matcher, i+Character.charCount(ch), seq);
3842             } else {
3843                 matcher.hitEnd = true;
3844                 return false;
3845             }
3846         }
3847         boolean study(TreeInfo info) {
3848             info.minLength++;
3849             info.maxLength++;
3850             return next.study(info);
3851         }
3852     }
3853 
3854     /**
3855      * Optimized version of CharProperty that works only for
3856      * properties never satisfied by Supplementary characters.
3857      */
3858     private abstract static class BmpCharProperty extends CharProperty {



3859         boolean match(Matcher matcher, int i, CharSequence seq) {
3860             if (i < matcher.to) {
3861                 return isSatisfiedBy(seq.charAt(i))
3862                     && next.match(matcher, i+1, seq);
3863             } else {
3864                 matcher.hitEnd = true;
3865                 return false;
3866             }
3867         }
3868     }
3869 
3870     /**
3871      * Node class that matches a Supplementary Unicode character
3872      */
3873     static final class SingleS extends CharProperty {
3874         final int c;
3875         SingleS(int c) { this.c = c; }
3876         boolean isSatisfiedBy(int ch) {
3877             return ch == c;
3878         }
3879     }
3880 
3881     /**
3882      * Optimization -- matches a given BMP character
3883      */
3884     static final class Single extends BmpCharProperty {
3885         final int c;
3886         Single(int c) { this.c = c; }
3887         boolean isSatisfiedBy(int ch) {
3888             return ch == c;
3889         }
3890     }
3891 
3892     /**
3893      * Case insensitive matches a given BMP character
3894      */
3895     static final class SingleI extends BmpCharProperty {
3896         final int lower;
3897         final int upper;
3898         SingleI(int lower, int upper) {
3899             this.lower = lower;
3900             this.upper = upper;
3901         }
3902         boolean isSatisfiedBy(int ch) {
3903             return ch == lower || ch == upper;
3904         }
3905     }
3906 
3907     /**
3908      * Unicode case insensitive matches a given Unicode character
3909      */
3910     static final class SingleU extends CharProperty {
3911         final int lower;
3912         SingleU(int lower) {
3913             this.lower = lower;
3914         }
3915         boolean isSatisfiedBy(int ch) {
3916             return lower == ch ||
3917                 lower == Character.toLowerCase(Character.toUpperCase(ch));
3918         }
3919     }
3920 
3921     /**
3922      * Node class that matches a Unicode block.
3923      */
3924     static final class Block extends CharProperty {
3925         final Character.UnicodeBlock block;
3926         Block(Character.UnicodeBlock block) {
3927             this.block = block;
3928         }
3929         boolean isSatisfiedBy(int ch) {
3930             return block == Character.UnicodeBlock.of(ch);
3931         }
3932     }
3933 
3934     /**
3935      * Node class that matches a Unicode script
3936      */
3937     static final class Script extends CharProperty {
3938         final Character.UnicodeScript script;
3939         Script(Character.UnicodeScript script) {
3940             this.script = script;
3941         }
3942         boolean isSatisfiedBy(int ch) {
3943             return script == Character.UnicodeScript.of(ch);
3944         }
3945     }
3946 
3947     /**
3948      * Node class that matches a Unicode category.
3949      */
3950     static final class Category extends CharProperty {
3951         final int typeMask;
3952         Category(int typeMask) { this.typeMask = typeMask; }
3953         boolean isSatisfiedBy(int ch) {
3954             return (typeMask & (1 << Character.getType(ch))) != 0;
3955         }


3956     }
3957 
3958     /**
3959      * Node class that matches a Unicode "type"
3960      */
3961     static final class Utype extends CharProperty {
3962         final UnicodeProp uprop;
3963         Utype(UnicodeProp uprop) { this.uprop = uprop; }
3964         boolean isSatisfiedBy(int ch) {
3965             return uprop.is(ch);


3966         }
3967     }
3968 
3969     /**
3970      * Node class that matches a POSIX type.
3971      */
3972     static final class Ctype extends BmpCharProperty {
3973         final int ctype;
3974         Ctype(int ctype) { this.ctype = ctype; }
3975         boolean isSatisfiedBy(int ch) {
3976             return ch < 128 && ASCII.isType(ch, ctype);
3977         }
3978     }
3979 
3980     /**
3981      * Node class that matches a Perl vertical whitespace
3982      */
3983     static final class VertWS extends BmpCharProperty {
3984         boolean isSatisfiedBy(int cp) {
3985             return (cp >= 0x0A && cp <= 0x0D) ||
3986                    cp == 0x85 || cp == 0x2028 || cp == 0x2029;
3987         }


3988     }
3989 
3990     /**
3991      * Node class that matches a Perl horizontal whitespace
3992      */
3993     static final class HorizWS extends BmpCharProperty {
3994         boolean isSatisfiedBy(int cp) {
3995             return cp == 0x09 || cp == 0x20 || cp == 0xa0 ||
3996                    cp == 0x1680 || cp == 0x180e ||
3997                    cp >= 0x2000 && cp <= 0x200a ||
3998                    cp == 0x202f || cp == 0x205f || cp == 0x3000;
3999         }
4000     }
4001 
4002     /**
4003      * Node class that matches an unicode extended grapheme cluster
4004      */
4005     static class XGrapheme extends Node {
4006         boolean match(Matcher matcher, int i, CharSequence seq) {
4007             if (i < matcher.to) {
4008                 int ch0 = Character.codePointAt(seq, i);
4009                     i += Character.charCount(ch0);
4010                 while (i < matcher.to) {
4011                     int ch1 = Character.codePointAt(seq, i);
4012                     if (Grapheme.isBoundary(ch0, ch1))
4013                         break;
4014                     ch0 = ch1;
4015                     i += Character.charCount(ch1);
4016                 }
4017                 return next.match(matcher, i, seq);
4018             }


4200                     return false;
4201                 }
4202             }
4203             return next.match(matcher, x, seq);
4204         }
4205     }
4206 
4207     /**
4208      * Node class for a case insensitive sequence of literal characters.
4209      * Uses unicode case folding.
4210      */
4211     static final class SliceUS extends SliceIS {
4212         SliceUS(int[] buf) {
4213             super(buf);
4214         }
4215         int toLower(int c) {
4216             return Character.toLowerCase(Character.toUpperCase(c));
4217         }
4218     }
4219 
4220     private static boolean inRange(int lower, int ch, int upper) {
4221         return lower <= ch && ch <= upper;
4222     }
4223 
4224     /**
4225      * Returns node for matching characters within an explicit value range.
4226      */
4227     private static CharProperty rangeFor(final int lower,
4228                                          final int upper) {
4229         return new CharProperty() {
4230                 boolean isSatisfiedBy(int ch) {
4231                     return inRange(lower, ch, upper);}};
4232     }
4233 
4234     /**
4235      * Returns node for matching characters within an explicit value
4236      * range in a case insensitive manner.
4237      */
4238     private CharProperty caseInsensitiveRangeFor(final int lower,
4239                                                  final int upper) {
4240         if (has(UNICODE_CASE))
4241             return new CharProperty() {
4242                 boolean isSatisfiedBy(int ch) {
4243                     if (inRange(lower, ch, upper))
4244                         return true;
4245                     int up = Character.toUpperCase(ch);
4246                     return inRange(lower, up, upper) ||
4247                            inRange(lower, Character.toLowerCase(up), upper);}};
4248         return new CharProperty() {
4249             boolean isSatisfiedBy(int ch) {
4250                 return inRange(lower, ch, upper) ||
4251                     ASCII.isAscii(ch) &&
4252                         (inRange(lower, ASCII.toUpper(ch), upper) ||
4253                          inRange(lower, ASCII.toLower(ch), upper));
4254             }};
4255     }
4256 
4257     /**
4258      * Implements the Unicode category ALL and the dot metacharacter when
4259      * in dotall mode.
4260      */
4261     static final class All extends CharProperty {
4262         boolean isSatisfiedBy(int ch) {
4263             return true;
4264         }
4265     }
4266 
4267     /**
4268      * Node class for the dot metacharacter when dotall is not enabled.
4269      */
4270     static final class Dot extends CharProperty {
4271         boolean isSatisfiedBy(int ch) {
4272             return (ch != '\n' && ch != '\r'
4273                     && (ch|1) != '\u2029'
4274                     && ch != '\u0085');
4275         }
4276     }
4277 
4278     /**
4279      * Node class for the dot metacharacter when dotall is not enabled
4280      * but UNIX_LINES is enabled.
4281      */
4282     static final class UnixDot extends CharProperty {
4283         boolean isSatisfiedBy(int ch) {
4284             return ch != '\n';
4285         }
4286     }
4287 
4288     /**
4289      * The 0 or 1 quantifier. This one class implements all three types.
4290      */
4291     static final class Ques extends Node {
4292         Node atom;
4293         int type;
4294         Ques(Node node, int type) {
4295             this.atom = node;
4296             this.type = type;
4297         }
4298         boolean match(Matcher matcher, int i, CharSequence seq) {
4299             switch (type) {
4300             case GREEDY:
4301                 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4302                     || next.match(matcher, i, seq);
4303             case LAZY:
4304                 return next.match(matcher, i, seq)
4305                     || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4306             case POSSESSIVE:
4307                 if (atom.match(matcher, i, seq)) i = matcher.last;
4308                 return next.match(matcher, i, seq);
4309             default:
4310                 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4311             }
4312         }
4313         boolean study(TreeInfo info) {
4314             if (type != INDEPENDENT) {
4315                 int minL = info.minLength;
4316                 atom.study(info);
4317                 info.minLength = minL;
4318                 info.deterministic = false;
4319                 return next.study(info);
4320             } else {
4321                 atom.study(info);
4322                 return next.study(info);
4323             }
4324         }
4325     }
4326 
4327     /**









































































4328      * Handles the curly-brace style repetition with a specified minimum and
4329      * maximum occurrences. The * quantifier is handled as a special case.
4330      * This class handles the three types.
4331      */
4332     static final class Curly extends Node {
4333         Node atom;
4334         int type;
4335         int cmin;
4336         int cmax;
4337 
4338         Curly(Node node, int cmin, int cmax, int type) {
4339             this.atom = node;
4340             this.type = type;
4341             this.cmin = cmin;
4342             this.cmax = cmax;
4343         }
4344         boolean match(Matcher matcher, int i, CharSequence seq) {
4345             int j;
4346             for (j = 0; j < cmin; j++) {
4347                 if (atom.match(matcher, i, seq)) {
4348                     i = matcher.last;
4349                     continue;
4350                 }
4351                 return false;
4352             }
4353             if (type == GREEDY)
4354                 return match0(matcher, i, j, seq);
4355             else if (type == LAZY)
4356                 return match1(matcher, i, j, seq);
4357             else
4358                 return match2(matcher, i, j, seq);
4359         }
4360         // Greedy match.
4361         // i is the index to start matching at
4362         // j is the number of atoms that have matched
4363         boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4364             if (j >= cmax) {
4365                 // We have matched the maximum... continue with the rest of
4366                 // the regular expression
4367                 return next.match(matcher, i, seq);
4368             }
4369             int backLimit = j;
4370             while (atom.match(matcher, i, seq)) {
4371                 // k is the length of this match
4372                 int k = matcher.last - i;
4373                 if (k == 0) // Zero length match
4374                     break;
4375                 // Move up index and number matched


4457             }
4458 
4459             if (info.deterministic && cmin == cmax)
4460                 info.deterministic = detm;
4461             else
4462                 info.deterministic = false;
4463             return next.study(info);
4464         }
4465     }
4466 
4467     /**
4468      * Handles the curly-brace style repetition with a specified minimum and
4469      * maximum occurrences in deterministic cases. This is an iterative
4470      * optimization over the Prolog and Loop system which would handle this
4471      * in a recursive way. The * quantifier is handled as a special case.
4472      * If capture is true then this class saves group settings and ensures
4473      * that groups are unset when backing off of a group match.
4474      */
4475     static final class GroupCurly extends Node {
4476         Node atom;
4477         int type;
4478         int cmin;
4479         int cmax;
4480         int localIndex;
4481         int groupIndex;
4482         boolean capture;
4483 
4484         GroupCurly(Node node, int cmin, int cmax, int type, int local,
4485                    int group, boolean capture) {
4486             this.atom = node;
4487             this.type = type;
4488             this.cmin = cmin;
4489             this.cmax = cmax;
4490             this.localIndex = local;
4491             this.groupIndex = group;
4492             this.capture = capture;
4493         }
4494         boolean match(Matcher matcher, int i, CharSequence seq) {
4495             int[] groups = matcher.groups;
4496             int[] locals = matcher.locals;
4497             int save0 = locals[localIndex];
4498             int save1 = 0;
4499             int save2 = 0;
4500 
4501             if (capture) {
4502                 save1 = groups[groupIndex];
4503                 save2 = groups[groupIndex+1];
4504             }
4505 
4506             // Notify GroupTail there is no need to setup group info
4507             // because it will be set here
4508             locals[localIndex] = -1;
4509 
4510             boolean ret = true;
4511             for (int j = 0; j < cmin; j++) {
4512                 if (atom.match(matcher, i, seq)) {
4513                     if (capture) {
4514                         groups[groupIndex] = i;
4515                         groups[groupIndex+1] = matcher.last;
4516                     }
4517                     i = matcher.last;
4518                 } else {
4519                     ret = false;
4520                     break;
4521                 }
4522             }
4523             if (ret) {
4524                 if (type == GREEDY) {
4525                     ret = match0(matcher, i, cmin, seq);
4526                 } else if (type == LAZY) {
4527                     ret = match1(matcher, i, cmin, seq);
4528                 } else {
4529                     ret = match2(matcher, i, cmin, seq);
4530                 }
4531             }
4532             if (!ret) {
4533                 locals[localIndex] = save0;
4534                 if (capture) {
4535                     groups[groupIndex] = save1;
4536                     groups[groupIndex+1] = save2;
4537                 }
4538             }
4539             return ret;
4540         }
4541         // Aggressive group match
4542         boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4543             // don't back off passing the starting "j"
4544             int min = j;
4545             int[] groups = matcher.groups;
4546             int save0 = 0;


4752 
4753             info.minLength += minL;
4754             info.maxLength += maxL;
4755             info.maxValid &= maxV;
4756             info.deterministic = false;
4757             return false;
4758         }
4759     }
4760 
4761     /**
4762      * The GroupHead saves the location where the group begins in the locals
4763      * and restores them when the match is done.
4764      *
4765      * The matchRef is used when a reference to this group is accessed later
4766      * in the expression. The locals will have a negative value in them to
4767      * indicate that we do not want to unset the group if the reference
4768      * doesn't match.
4769      */
4770     static final class GroupHead extends Node {
4771         int localIndex;

4772         GroupHead(int localCount) {
4773             localIndex = localCount;
4774         }
4775         boolean match(Matcher matcher, int i, CharSequence seq) {
4776             int save = matcher.locals[localIndex];
4777             matcher.locals[localIndex] = i;
4778             boolean ret = next.match(matcher, i, seq);
4779             matcher.locals[localIndex] = save;
4780             return ret;
4781         }
4782         boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4783             int save = matcher.locals[localIndex];
4784             matcher.locals[localIndex] = ~i; // HACK
4785             boolean ret = next.match(matcher, i, seq);
4786             matcher.locals[localIndex] = save;
4787             return ret;
4788         }
4789     }
4790 
4791     /**


4859         }
4860         boolean match(Matcher matcher, int i, CharSequence seq) {
4861             return loop.matchInit(matcher, i, seq);
4862         }
4863         boolean study(TreeInfo info) {
4864             return loop.study(info);
4865         }
4866     }
4867 
4868     /**
4869      * Handles the repetition count for a greedy Curly. The matchInit
4870      * is called from the Prolog to save the index of where the group
4871      * beginning is stored. A zero length group check occurs in the
4872      * normal match but is skipped in the matchInit.
4873      */
4874     static class Loop extends Node {
4875         Node body;
4876         int countIndex; // local count index in matcher locals
4877         int beginIndex; // group beginning index
4878         int cmin, cmax;

4879         Loop(int countIndex, int beginIndex) {
4880             this.countIndex = countIndex;
4881             this.beginIndex = beginIndex;

4882         }
4883         boolean match(Matcher matcher, int i, CharSequence seq) {
4884             // Avoid infinite loop in zero-length case.
4885             if (i > matcher.locals[beginIndex]) {
4886                 int count = matcher.locals[countIndex];
4887 
4888                 // This block is for before we reach the minimum
4889                 // iterations required for the loop to match
4890                 if (count < cmin) {
4891                     matcher.locals[countIndex] = count + 1;
4892                     boolean b = body.match(matcher, i, seq);
4893                     // If match failed we must backtrack, so
4894                     // the loop count should NOT be incremented
4895                     if (!b)
4896                         matcher.locals[countIndex] = count;
4897                     // Return success or failure since we are under
4898                     // minimum
4899                     return b;
4900                 }
4901                 // This block is for after we have the minimum
4902                 // iterations required for the loop to match
4903                 if (count < cmax) {








4904                     matcher.locals[countIndex] = count + 1;
4905                     boolean b = body.match(matcher, i, seq);
4906                     // If match failed we must backtrack, so
4907                     // the loop count should NOT be incremented
4908                     if (!b)
4909                         matcher.locals[countIndex] = count;
4910                     else
4911                         return true;





4912                 }
4913             }
4914             return next.match(matcher, i, seq);
4915         }
4916         boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4917             int save = matcher.locals[countIndex];
4918             boolean ret = false;



4919             if (0 < cmin) {
4920                 matcher.locals[countIndex] = 1;
4921                 ret = body.match(matcher, i, seq);
4922             } else if (0 < cmax) {
4923                 matcher.locals[countIndex] = 1;
4924                 ret = body.match(matcher, i, seq);
4925                 if (ret == false)
4926                     ret = next.match(matcher, i, seq);
4927             } else {
4928                 ret = next.match(matcher, i, seq);
4929             }
4930             matcher.locals[countIndex] = save;
4931             return ret;
4932         }
4933         boolean study(TreeInfo info) {
4934             info.maxValid = false;
4935             info.deterministic = false;
4936             return false;
4937         }
4938     }


5345             int startIndex = (!matcher.transparentBounds) ?
5346                              matcher.from : 0;
5347             int from = Math.max(i - rmaxChars, startIndex);
5348             matcher.lookbehindTo = i;
5349             // Relax transparent region boundaries for lookbehind
5350             if (matcher.transparentBounds)
5351                 matcher.from = 0;
5352             for (int j = i - rminChars;
5353                  !conditionMatched && j >= from;
5354                  j -= j>from ? countChars(seq, j, -1) : 1) {
5355                 conditionMatched = cond.match(matcher, j, seq);
5356             }
5357             //Reinstate region boundaries
5358             matcher.from = savedFrom;
5359             matcher.lookbehindTo = savedLBT;
5360             return !conditionMatched && next.match(matcher, i, seq);
5361         }
5362     }
5363 
5364     /**
5365      * Returns the set union of two CharProperty nodes.
5366      */
5367     private static CharProperty union(final CharProperty lhs,
5368                                       final CharProperty rhs) {
5369         return new CharProperty() {
5370                 boolean isSatisfiedBy(int ch) {
5371                     return lhs.isSatisfiedBy(ch) || rhs.isSatisfiedBy(ch);}};
5372     }
5373 
5374     /**
5375      * Returns the set intersection of two CharProperty nodes.
5376      */
5377     private static CharProperty intersection(final CharProperty lhs,
5378                                              final CharProperty rhs) {
5379         return new CharProperty() {
5380                 boolean isSatisfiedBy(int ch) {
5381                     return lhs.isSatisfiedBy(ch) && rhs.isSatisfiedBy(ch);}};
5382     }
5383 
5384     /**
5385      * Returns the set difference of two CharProperty nodes.
5386      */
5387     private static CharProperty setDifference(final CharProperty lhs,
5388                                               final CharProperty rhs) {
5389         return new CharProperty() {
5390                 boolean isSatisfiedBy(int ch) {
5391                     return ! rhs.isSatisfiedBy(ch) && lhs.isSatisfiedBy(ch);}};
5392     }
5393 
5394     /**
5395      * Handles word boundaries. Includes a field to allow this one class to
5396      * deal with the different types of word boundaries we can match. The word
5397      * characters include underscores, letters, and digits. Non spacing marks
5398      * can are also part of a word if they have a base character, otherwise
5399      * they are ignored for purposes of finding word boundaries.
5400      */
5401     static final class Bound extends Node {
5402         static int LEFT = 0x1;
5403         static int RIGHT= 0x2;
5404         static int BOTH = 0x3;
5405         static int NONE = 0x4;
5406         int type;
5407         boolean useUWORD;
5408         Bound(int n, boolean useUWORD) {
5409             type = n;
5410             this.useUWORD = useUWORD;
5411         }
5412 
5413         boolean isWord(int ch) {
5414             return useUWORD ? UnicodeProp.WORD.is(ch)
5415                             : (ch == '_' || Character.isLetterOrDigit(ch));
5416         }
5417 
5418         int check(Matcher matcher, int i, CharSequence seq) {
5419             int ch;
5420             boolean left = false;
5421             int startIndex = matcher.from;
5422             int endIndex = matcher.to;
5423             if (matcher.transparentBounds) {
5424                 startIndex = 0;
5425                 endIndex = matcher.getTextLength();
5426             }
5427             if (i > startIndex) {
5428                 ch = Character.codePointBefore(seq, i);
5429                 left = (isWord(ch) ||
5430                     ((Character.getType(ch) == Character.NON_SPACING_MARK)
5431                      && hasBaseCharacter(matcher, i-1, seq)));
5432             }
5433             boolean right = false;
5434             if (i < endIndex) {


5640                         i += countChars(seq, i, n);
5641                         continue NEXT;
5642                     }
5643                 }
5644                 // Entire pattern matched starting at i
5645                 matcher.first = i;
5646                 boolean ret = next.match(matcher, i + lengthInChars, seq);
5647                 if (ret) {
5648                     matcher.first = i;
5649                     matcher.groups[0] = matcher.first;
5650                     matcher.groups[1] = matcher.last;
5651                     return true;
5652                 }
5653                 i += countChars(seq, i, 1);
5654             }
5655             matcher.hitEnd = true;
5656             return false;
5657         }
5658     }
5659 
5660 ///////////////////////////////////////////////////////////////////////////////
5661 ///////////////////////////////////////////////////////////////////////////////


















































5662 
5663     /**
5664      *  This must be the very first initializer.
5665      */
5666     static Node accept = new Node();



5667 
5668     static Node lastAccept = new LastNode();















5669 
5670     private static class CharPropertyNames {





5671 
5672         static CharProperty charPropertyFor(String name) {
5673             CharPropertyFactory m = map.get(name);
5674             return m == null ? null : m.make();


5675         }
5676 
5677         private abstract static class CharPropertyFactory {
5678             abstract CharProperty make();



5679         }
5680 
5681         private static void defCategory(String name,
5682                                         final int typeMask) {
5683             map.put(name, new CharPropertyFactory() {
5684                     CharProperty make() { return new Category(typeMask);}});


5685         }
5686 
5687         private static void defRange(String name,
5688                                      final int lower, final int upper) {
5689             map.put(name, new CharPropertyFactory() {
5690                     CharProperty make() { return rangeFor(lower, upper);}});
5691         }
5692 
5693         private static void defCtype(String name,
5694                                      final int ctype) {
5695             map.put(name, new CharPropertyFactory() {
5696                     CharProperty make() { return new Ctype(ctype);}});





5697         }
5698 
5699         private abstract static class CloneableProperty
5700             extends CharProperty implements Cloneable
5701         {
5702             public CloneableProperty clone() {
5703                 try {
5704                     return (CloneableProperty) super.clone();
5705                 } catch (CloneNotSupportedException e) {
5706                     throw new AssertionError(e);
5707                 }
5708             }
5709         }
5710 
5711         private static void defClone(String name,
5712                                      final CloneableProperty p) {
5713             map.put(name, new CharPropertyFactory() {
5714                     CharProperty make() { return p.clone();}});
5715         }
5716 
5717         private static final HashMap<String, CharPropertyFactory> map
5718             = new HashMap<>();
5719 
5720         static {
5721             // Unicode character property aliases, defined in
5722             // http://www.unicode.org/Public/UNIDATA/PropertyValueAliases.txt
5723             defCategory("Cn", 1<<Character.UNASSIGNED);
5724             defCategory("Lu", 1<<Character.UPPERCASE_LETTER);
5725             defCategory("Ll", 1<<Character.LOWERCASE_LETTER);
5726             defCategory("Lt", 1<<Character.TITLECASE_LETTER);
5727             defCategory("Lm", 1<<Character.MODIFIER_LETTER);
5728             defCategory("Lo", 1<<Character.OTHER_LETTER);
5729             defCategory("Mn", 1<<Character.NON_SPACING_MARK);
5730             defCategory("Me", 1<<Character.ENCLOSING_MARK);
5731             defCategory("Mc", 1<<Character.COMBINING_SPACING_MARK);
5732             defCategory("Nd", 1<<Character.DECIMAL_DIGIT_NUMBER);
5733             defCategory("Nl", 1<<Character.LETTER_NUMBER);
5734             defCategory("No", 1<<Character.OTHER_NUMBER);
5735             defCategory("Zs", 1<<Character.SPACE_SEPARATOR);
5736             defCategory("Zl", 1<<Character.LINE_SEPARATOR);
5737             defCategory("Zp", 1<<Character.PARAGRAPH_SEPARATOR);
5738             defCategory("Cc", 1<<Character.CONTROL);
5739             defCategory("Cf", 1<<Character.FORMAT);
5740             defCategory("Co", 1<<Character.PRIVATE_USE);
5741             defCategory("Cs", 1<<Character.SURROGATE);
5742             defCategory("Pd", 1<<Character.DASH_PUNCTUATION);
5743             defCategory("Ps", 1<<Character.START_PUNCTUATION);
5744             defCategory("Pe", 1<<Character.END_PUNCTUATION);
5745             defCategory("Pc", 1<<Character.CONNECTOR_PUNCTUATION);
5746             defCategory("Po", 1<<Character.OTHER_PUNCTUATION);
5747             defCategory("Sm", 1<<Character.MATH_SYMBOL);
5748             defCategory("Sc", 1<<Character.CURRENCY_SYMBOL);
5749             defCategory("Sk", 1<<Character.MODIFIER_SYMBOL);
5750             defCategory("So", 1<<Character.OTHER_SYMBOL);
5751             defCategory("Pi", 1<<Character.INITIAL_QUOTE_PUNCTUATION);
5752             defCategory("Pf", 1<<Character.FINAL_QUOTE_PUNCTUATION);
5753             defCategory("L", ((1<<Character.UPPERCASE_LETTER) |
5754                               (1<<Character.LOWERCASE_LETTER) |
5755                               (1<<Character.TITLECASE_LETTER) |
5756                               (1<<Character.MODIFIER_LETTER)  |
5757                               (1<<Character.OTHER_LETTER)));
5758             defCategory("M", ((1<<Character.NON_SPACING_MARK) |
5759                               (1<<Character.ENCLOSING_MARK)   |
5760                               (1<<Character.COMBINING_SPACING_MARK)));
5761             defCategory("N", ((1<<Character.DECIMAL_DIGIT_NUMBER) |
5762                               (1<<Character.LETTER_NUMBER)        |
5763                               (1<<Character.OTHER_NUMBER)));
5764             defCategory("Z", ((1<<Character.SPACE_SEPARATOR) |
5765                               (1<<Character.LINE_SEPARATOR)  |
5766                               (1<<Character.PARAGRAPH_SEPARATOR)));
5767             defCategory("C", ((1<<Character.CONTROL)     |
5768                               (1<<Character.FORMAT)      |
5769                               (1<<Character.PRIVATE_USE) |
5770                               (1<<Character.SURROGATE))); // Other
5771             defCategory("P", ((1<<Character.DASH_PUNCTUATION)      |
5772                               (1<<Character.START_PUNCTUATION)     |
5773                               (1<<Character.END_PUNCTUATION)       |
5774                               (1<<Character.CONNECTOR_PUNCTUATION) |
5775                               (1<<Character.OTHER_PUNCTUATION)     |
5776                               (1<<Character.INITIAL_QUOTE_PUNCTUATION) |
5777                               (1<<Character.FINAL_QUOTE_PUNCTUATION)));
5778             defCategory("S", ((1<<Character.MATH_SYMBOL)     |
5779                               (1<<Character.CURRENCY_SYMBOL) |
5780                               (1<<Character.MODIFIER_SYMBOL) |
5781                               (1<<Character.OTHER_SYMBOL)));
5782             defCategory("LC", ((1<<Character.UPPERCASE_LETTER) |
5783                                (1<<Character.LOWERCASE_LETTER) |
5784                                (1<<Character.TITLECASE_LETTER)));
5785             defCategory("LD", ((1<<Character.UPPERCASE_LETTER) |
5786                                (1<<Character.LOWERCASE_LETTER) |
5787                                (1<<Character.TITLECASE_LETTER) |
5788                                (1<<Character.MODIFIER_LETTER)  |
5789                                (1<<Character.OTHER_LETTER)     |
5790                                (1<<Character.DECIMAL_DIGIT_NUMBER)));
5791             defRange("L1", 0x00, 0xFF); // Latin-1
5792             map.put("all", new CharPropertyFactory() {
5793                     CharProperty make() { return new All(); }});
5794 
5795             // Posix regular expression character classes, defined in
5796             // http://www.unix.org/onlinepubs/009695399/basedefs/xbd_chap09.html
5797             defRange("ASCII", 0x00, 0x7F);   // ASCII
5798             defCtype("Alnum", ASCII.ALNUM);  // Alphanumeric characters
5799             defCtype("Alpha", ASCII.ALPHA);  // Alphabetic characters
5800             defCtype("Blank", ASCII.BLANK);  // Space and tab characters
5801             defCtype("Cntrl", ASCII.CNTRL);  // Control characters
5802             defRange("Digit", '0', '9');     // Numeric characters
5803             defCtype("Graph", ASCII.GRAPH);  // printable and visible
5804             defRange("Lower", 'a', 'z');     // Lower-case alphabetic
5805             defRange("Print", 0x20, 0x7E);   // Printable characters
5806             defCtype("Punct", ASCII.PUNCT);  // Punctuation characters
5807             defCtype("Space", ASCII.SPACE);  // Space characters
5808             defRange("Upper", 'A', 'Z');     // Upper-case alphabetic
5809             defCtype("XDigit",ASCII.XDIGIT); // hexadecimal digits
5810 
5811             // Java character properties, defined by methods in Character.java
5812             defClone("javaLowerCase", new CloneableProperty() {
5813                 boolean isSatisfiedBy(int ch) {
5814                     return Character.isLowerCase(ch);}});
5815             defClone("javaUpperCase", new CloneableProperty() {
5816                 boolean isSatisfiedBy(int ch) {
5817                     return Character.isUpperCase(ch);}});
5818             defClone("javaAlphabetic", new CloneableProperty() {
5819                 boolean isSatisfiedBy(int ch) {
5820                     return Character.isAlphabetic(ch);}});
5821             defClone("javaIdeographic", new CloneableProperty() {
5822                 boolean isSatisfiedBy(int ch) {
5823                     return Character.isIdeographic(ch);}});
5824             defClone("javaTitleCase", new CloneableProperty() {
5825                 boolean isSatisfiedBy(int ch) {
5826                     return Character.isTitleCase(ch);}});
5827             defClone("javaDigit", new CloneableProperty() {
5828                 boolean isSatisfiedBy(int ch) {
5829                     return Character.isDigit(ch);}});
5830             defClone("javaDefined", new CloneableProperty() {
5831                 boolean isSatisfiedBy(int ch) {
5832                     return Character.isDefined(ch);}});
5833             defClone("javaLetter", new CloneableProperty() {
5834                 boolean isSatisfiedBy(int ch) {
5835                     return Character.isLetter(ch);}});
5836             defClone("javaLetterOrDigit", new CloneableProperty() {
5837                 boolean isSatisfiedBy(int ch) {
5838                     return Character.isLetterOrDigit(ch);}});
5839             defClone("javaJavaIdentifierStart", new CloneableProperty() {
5840                 boolean isSatisfiedBy(int ch) {
5841                     return Character.isJavaIdentifierStart(ch);}});
5842             defClone("javaJavaIdentifierPart", new CloneableProperty() {
5843                 boolean isSatisfiedBy(int ch) {
5844                     return Character.isJavaIdentifierPart(ch);}});
5845             defClone("javaUnicodeIdentifierStart", new CloneableProperty() {
5846                 boolean isSatisfiedBy(int ch) {
5847                     return Character.isUnicodeIdentifierStart(ch);}});
5848             defClone("javaUnicodeIdentifierPart", new CloneableProperty() {
5849                 boolean isSatisfiedBy(int ch) {
5850                     return Character.isUnicodeIdentifierPart(ch);}});
5851             defClone("javaIdentifierIgnorable", new CloneableProperty() {
5852                 boolean isSatisfiedBy(int ch) {
5853                     return Character.isIdentifierIgnorable(ch);}});
5854             defClone("javaSpaceChar", new CloneableProperty() {
5855                 boolean isSatisfiedBy(int ch) {
5856                     return Character.isSpaceChar(ch);}});
5857             defClone("javaWhitespace", new CloneableProperty() {
5858                 boolean isSatisfiedBy(int ch) {
5859                     return Character.isWhitespace(ch);}});
5860             defClone("javaISOControl", new CloneableProperty() {
5861                 boolean isSatisfiedBy(int ch) {
5862                     return Character.isISOControl(ch);}});
5863             defClone("javaMirrored", new CloneableProperty() {
5864                 boolean isSatisfiedBy(int ch) {
5865                     return Character.isMirrored(ch);}});
5866         }









5867     }
5868 
5869     /**







5870      * Creates a predicate which can be used to match a string.
5871      *
5872      * @return  The predicate which can be used for matching on a string
5873      * @since   1.8
5874      */
5875     public Predicate<String> asPredicate() {
5876         return s -> matcher(s).find();
5877     }
5878 
5879     /**
5880      * Creates a stream from the given input sequence around matches of this
5881      * pattern.
5882      *
5883      * <p> The stream returned by this method contains each substring of the
5884      * input sequence that is terminated by another subsequence that matches
5885      * this pattern or is terminated by the end of the input sequence.  The
5886      * substrings in the stream are in the order in which they occur in the
5887      * input. Trailing empty strings will be discarded and not encountered in
5888      * the stream.
5889      *


   1 /*
   2  * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.regex;
  27 
  28 import java.text.Normalizer;
  29 import java.text.Normalizer.Form;
  30 import java.util.Locale;
  31 import java.util.Iterator;
  32 import java.util.Map;
  33 import java.util.ArrayList;
  34 import java.util.HashMap;
  35 import java.util.LinkedHashSet;
  36 import java.util.List;
  37 import java.util.Set;
  38 import java.util.Arrays;
  39 import java.util.NoSuchElementException;
  40 import java.util.Spliterator;
  41 import java.util.Spliterators;
  42 import java.util.function.Predicate;
  43 import java.util.stream.Stream;
  44 import java.util.stream.StreamSupport;
  45 
  46 
  47 /**
  48  * A compiled representation of a regular expression.
  49  *
  50  * <p> A regular expression, specified as a string, must first be compiled into
  51  * an instance of this class.  The resulting pattern can then be used to create
  52  * a {@link Matcher} object that can match arbitrary {@linkplain
  53  * java.lang.CharSequence character sequences} against the regular
  54  * expression.  All of the state involved in performing a match resides in the
  55  * matcher, so many matchers can share the same pattern.
  56  *
  57  * <p> A typical invocation sequence is thus


 971 
 972     /**
 973      * The starting point of state machine for the find operation.  This allows
 974      * a match to start anywhere in the input.
 975      */
 976     transient Node root;
 977 
 978     /**
 979      * The root of object tree for a match operation.  The pattern is matched
 980      * at the beginning.  This may include a find that uses BnM or a First
 981      * node.
 982      */
 983     transient Node matchRoot;
 984 
 985     /**
 986      * Temporary storage used by parsing pattern slice.
 987      */
 988     transient int[] buffer;
 989 
 990     /**
 991      * A temporary storage used for predicate for double return.
 992      */
 993     transient CharPredicate predicate;
 994 
 995     /**
 996      * Map the "name" of the "named capturing group" to its group id
 997      * node.
 998      */
 999     transient volatile Map<String, Integer> namedGroups;
1000 
1001     /**
1002      * Temporary storage used while parsing group references.
1003      */
1004     transient GroupHead[] groupNodes;
1005 
1006     /**
1007      * Temporary storage used to store the top level closure nodes.
1008      */
1009     transient List<Node> topClosureNodes;
1010 
1011     /**
1012      * The number of top greedy closure nodes in this Pattern. Used by
1013      * matchers to allocate storage needed for a IntHashSet to keep the
1014      * beginning pos {@code i} of all failed match.
1015      */
1016     transient int localTCNCount;
1017 
1018     /*
1019      * Turn off the stop-exponential-backtracking optimization if there
1020      * is a group ref in the pattern.
1021      */
1022     transient boolean hasGroupRef;
1023 
1024     /**
1025      * Temporary null terminated code point array used by pattern compiling.
1026      */
1027     private transient int[] temp;
1028 
1029     /**
1030      * The number of capturing groups in this Pattern. Used by matchers to
1031      * allocate storage needed to perform a match.
1032      */
1033     transient int capturingGroupCount;
1034 
1035     /**
1036      * The local variable count used by parsing tree. Used by matchers to
1037      * allocate storage needed to perform a match.
1038      */
1039     transient int localCount;
1040 
1041     /**
1042      * Index into the pattern string that keeps track of how much has been
1043      * parsed.
1044      */
1045     private transient int cursor;
1046 
1047     /**
1048      * Holds the length of the pattern string.
1049      */
1050     private transient int patternLength;
1051 
1052     /**
1053      * If the Start node might possibly match supplementary characters.
1054      * It is set to true during compiling if
1055      * (1) There is supplementary char in pattern, or
1056      * (2) There is complement node of a "family" CharProperty
1057      */
1058     private transient boolean hasSupplementary;
1059 
1060     /**
1061      * Compiles the given regular expression into a pattern.
1062      *
1063      * @param  regex
1064      *         The expression to be compiled
1065      * @return the given regular expression compiled into a pattern
1066      * @throws  PatternSyntaxException
1067      *          If the expression's syntax is invalid
1068      */
1069     public static Pattern compile(String regex) {
1070         return new Pattern(regex, 0);
1071     }
1072 
1073     /**
1074      * Compiles the given regular expression into a pattern with the given
1075      * flags.
1076      *


1348         } while ((slashEIndex = s.indexOf("\\E", current)) != -1);
1349 
1350         return sb.append(s, current, s.length())
1351                 .append("\\E")
1352                 .toString();
1353     }
1354 
1355     /**
1356      * Recompile the Pattern instance from a stream.  The original pattern
1357      * string is read in and the object tree is recompiled from it.
1358      */
1359     private void readObject(java.io.ObjectInputStream s)
1360         throws java.io.IOException, ClassNotFoundException {
1361 
1362         // Read in all fields
1363         s.defaultReadObject();
1364 
1365         // Initialize counts
1366         capturingGroupCount = 1;
1367         localCount = 0;
1368         localTCNCount = 0;
1369 
1370         // if length > 0, the Pattern is lazily compiled
1371         if (pattern.length() == 0) {
1372             root = new Start(lastAccept);
1373             matchRoot = lastAccept;
1374             compiled = true;
1375         }
1376     }
1377 
1378     /**
1379      * This private constructor is used to create all Patterns. The pattern
1380      * string and match flags are all that is needed to completely describe
1381      * a Pattern. An empty pattern string results in an object tree with
1382      * only a Start node and a LastNode node.
1383      */
1384     private Pattern(String p, int f) {
1385         if ((f & ~ALL_FLAGS) != 0) {
1386             throw new IllegalArgumentException("Unknown flag 0x"
1387                                                + Integer.toHexString(f));
1388         }
1389         pattern = p;
1390         flags = f;
1391 
1392         // to use UNICODE_CASE if UNICODE_CHARACTER_CLASS present
1393         if ((flags & UNICODE_CHARACTER_CLASS) != 0)
1394             flags |= UNICODE_CASE;
1395 
1396         // Reset group index count
1397         capturingGroupCount = 1;
1398         localCount = 0;
1399         localTCNCount = 0;
1400 
1401         if (pattern.length() > 0) {
1402             compile();
1403         } else {
1404             root = new Start(lastAccept);
1405             matchRoot = lastAccept;
1406         }
1407     }
1408 
1409     /**
1410      * The pattern is converted to normalized form ({@link
1411      * java.text.Normalizer.Form.NFC NFC}, canonical decomposition,
1412      * followed by canonical composition for the character class
1413      * part, and {@link java.text.Normalizer.Form.NFD NFD},
1414      * canonical decomposition) for the rest), and then a pure
1415      * group is constructed to match canonical equivalences of the
1416      * characters.
1417      */
1418     private static String normalize(String pattern) {
1419         int plen = pattern.length();
1420         StringBuilder pbuf = new StringBuilder(plen);
1421         char last = 0;
1422         int lastStart = 0;
1423         char cc = 0;
1424         for (int i = 0; i < plen;) {
1425             char c = pattern.charAt(i);
1426             if (cc == 0 &&    // top level
1427                 c == '\\' && i + 1 < plen && pattern.charAt(i + 1) == '\\') {
1428                 i += 2; last = 0;
1429                 continue;











1430             }
1431             if (c == '[' && last != '\\') {
1432                 if (cc == 0) {
1433                     if (lastStart < i)
1434                         normalizeSlice(pattern, lastStart, i, pbuf);
1435                     lastStart = i;
1436                 }
1437                 cc++;
1438             } else if (c == ']' && last != '\\') {
1439                 cc--;
1440                 if (cc == 0) {
1441                     normalizeClazz(pattern, lastStart, i + 1, pbuf);
1442                     lastStart = i + 1;
1443                 }


1444             }
1445             last = c;
1446             i++;
1447         }
1448         assert (cc == 0);
1449         if (lastStart < plen)
1450             normalizeSlice(pattern, lastStart, plen, pbuf);
1451         return pbuf.toString();
1452     }
1453 
1454     private static void normalizeSlice(String src, int off, int limit,
1455                                        StringBuilder dst)
1456     {
1457         int len = src.length();
1458         int off0 = off;
1459         while (off < limit && ASCII.isAscii(src.charAt(off))) {
1460             off++;
1461         }
1462         if (off == limit) {
1463             dst.append(src, off0, limit);
1464             return;
1465         }
1466         off--;
1467         if (off < off0)
1468             off = off0;
1469         else
1470             dst.append(src, off0, off);
1471         while (off < limit) {
1472             int ch0 = src.codePointAt(off);
1473             if (".$|()[]{}^?*+\\".indexOf(ch0) != -1) {
1474                 dst.append((char)ch0);
1475                 off++;
1476                 continue;
1477             }
1478             int j = off + Character.charCount(ch0);
1479             int ch1;
1480             while (j < limit) {
1481                 ch1 = src.codePointAt(j);
1482                 if (Grapheme.isBoundary(ch0, ch1))
1483                     break;
1484                 ch0 = ch1;
1485                 j += Character.charCount(ch1);
1486             }
1487             String seq = src.substring(off, j);
1488             String nfd = Normalizer.normalize(seq, Normalizer.Form.NFD);
1489             off = j;
1490             if (nfd.length() > 1) {
1491                 ch0 = nfd.codePointAt(0);
1492                 ch1 = nfd.codePointAt(Character.charCount(ch0));
1493                 if (Character.getType(ch1) == Character.NON_SPACING_MARK) {
1494                     Set<String> altns = new LinkedHashSet<>();
1495                     altns.add(seq);
1496                     produceEquivalentAlternation(nfd, altns);
1497                     dst.append("(?:");
1498                     altns.forEach( s -> dst.append(s + "|"));
1499                     dst.delete(dst.length() - 1, dst.length());
1500                     dst.append(")");
1501                     continue;
1502                 }



1503             }
1504             String nfc = Normalizer.normalize(seq, Normalizer.Form.NFC);
1505             if (!seq.equals(nfc) && !nfd.equals(nfc))
1506                 dst.append("(?:" + seq + "|" + nfd  + "|" + nfc + ")");
1507             else if (!seq.equals(nfd))
1508                 dst.append("(?:" + seq + "|" + nfd + ")");
1509             else
1510                 dst.append(seq);
1511         }
1512     }
1513 
1514     private static void normalizeClazz(String src, int off, int limit,
1515                                        StringBuilder dst)
1516     {
1517         dst.append(Normalizer.normalize(src.substring(off, limit), Form.NFC));
1518     }
1519 
1520     /**
1521      * Given a specific sequence composed of a regular character and
1522      * combining marks that follow it, produce the alternation that will
1523      * match all canonical equivalences of that sequence.
1524      */
1525     private static void produceEquivalentAlternation(String src,
1526                                                      Set<String> dst)
1527     {
1528         int len = countChars(src, 0, 1);
1529         if (src.length() == len) {
1530             dst.add(src);  // source has one character.
1531             return;
1532         }
1533         String base = src.substring(0,len);
1534         String combiningMarks = src.substring(len);
1535         String[] perms = producePermutations(combiningMarks);


1536         // Add combined permutations
1537         for(int x = 0; x < perms.length; x++) {
1538             String next = base + perms[x];
1539             dst.add(next);

1540             next = composeOneStep(next);
1541             if (next != null) {
1542                 produceEquivalentAlternation(next, dst);
1543             }
1544         }

1545     }
1546 
1547     /**
1548      * Returns an array of strings that have all the possible
1549      * permutations of the characters in the input string.
1550      * This is used to get a list of all possible orderings
1551      * of a set of combining marks. Note that some of the permutations
1552      * are invalid because of combining class collisions, and these
1553      * possibilities must be removed because they are not canonically
1554      * equivalent.
1555      */
1556     private static String[] producePermutations(String input) {
1557         if (input.length() == countChars(input, 0, 1))
1558             return new String[] {input};
1559 
1560         if (input.length() == countChars(input, 0, 2)) {
1561             int c0 = Character.codePointAt(input, 0);
1562             int c1 = Character.codePointAt(input, Character.charCount(c0));
1563             if (getClass(c1) == getClass(c0)) {
1564                 return new String[] {input};
1565             }
1566             String[] result = new String[2];
1567             result[0] = input;
1568             StringBuilder sb = new StringBuilder(2);
1569             sb.appendCodePoint(c1);
1570             sb.appendCodePoint(c0);
1571             result[1] = sb.toString();
1572             return result;
1573         }
1574 
1575         int length = 1;
1576         int nCodePoints = countCodePoints(input);


1594 loop:   for(int x=0, offset=0; x<nCodePoints; x++, offset+=len) {
1595             len = countChars(input, offset, 1);
1596             for(int y=x-1; y>=0; y--) {
1597                 if (combClass[y] == combClass[x]) {
1598                     continue loop;
1599                 }
1600             }
1601             StringBuilder sb = new StringBuilder(input);
1602             String otherChars = sb.delete(offset, offset+len).toString();
1603             String[] subResult = producePermutations(otherChars);
1604 
1605             String prefix = input.substring(offset, offset+len);
1606             for (String sre : subResult)
1607                 temp[index++] = prefix + sre;
1608         }
1609         String[] result = new String[index];
1610         System.arraycopy(temp, 0, result, 0, index);
1611         return result;
1612     }
1613 
1614     private static int getClass(int c) {
1615         return sun.text.Normalizer.getCombiningClass(c);
1616     }
1617 
1618     /**
1619      * Attempts to compose input by combining the first character
1620      * with the first combining mark following it. Returns a String
1621      * that is the composition of the leading character with its first
1622      * combining mark followed by the remaining combining marks. Returns
1623      * null if the first two characters cannot be further composed.
1624      */
1625     private static String composeOneStep(String input) {
1626         int len = countChars(input, 0, 2);
1627         String firstTwoCharacters = input.substring(0, len);
1628         String result = Normalizer.normalize(firstTwoCharacters, Normalizer.Form.NFC);

1629         if (result.equals(firstTwoCharacters))
1630             return null;
1631         else {
1632             String remainder = input.substring(len);
1633             return result + remainder;
1634         }
1635     }
1636 
1637     /**
1638      * Preprocess any \Q...\E sequences in `temp', meta-quoting them.
1639      * See the description of `quotemeta' in perlfunc(1).
1640      */
1641     private void RemoveQEQuoting() {
1642         final int pLen = patternLength;
1643         int i = 0;
1644         while (i < pLen-1) {
1645             if (temp[i] != '\\')
1646                 i += 1;
1647             else if (temp[i + 1] != 'Q')
1648                 i += 2;


1695                     newtemp[j++] = c;
1696                     if (i != pLen)
1697                         newtemp[j++] = temp[i++];
1698                 }
1699             }
1700 
1701             beginQuote = false;
1702         }
1703 
1704         patternLength = j;
1705         temp = Arrays.copyOf(newtemp, j + 2); // double zero termination
1706     }
1707 
1708     /**
1709      * Copies regular expression to an int array and invokes the parsing
1710      * of the expression which will create the object tree.
1711      */
1712     private void compile() {
1713         // Handle canonical equivalences
1714         if (has(CANON_EQ) && !has(LITERAL)) {
1715             normalizedPattern = normalize(pattern);
1716         } else {
1717             normalizedPattern = pattern;
1718         }
1719         patternLength = normalizedPattern.length();
1720 
1721         // Copy pattern to int array for convenience
1722         // Use double zero to terminate pattern
1723         temp = new int[patternLength + 2];
1724 
1725         hasSupplementary = false;
1726         int c, count = 0;
1727         // Convert all chars into code points
1728         for (int x = 0; x < patternLength; x += Character.charCount(c)) {
1729             c = normalizedPattern.codePointAt(x);
1730             if (isSupplementary(c)) {
1731                 hasSupplementary = true;
1732             }
1733             temp[count++] = c;
1734         }
1735 
1736         patternLength = count;   // patternLength now in code points
1737 
1738         if (! has(LITERAL))
1739             RemoveQEQuoting();
1740 
1741         // Allocate all temporary objects here.
1742         buffer = new int[32];
1743         groupNodes = new GroupHead[10];
1744         namedGroups = null;
1745         topClosureNodes = new ArrayList<>(10);
1746 
1747         if (has(LITERAL)) {
1748             // Literal pattern handling
1749             matchRoot = newSlice(temp, patternLength, hasSupplementary);
1750             matchRoot.next = lastAccept;
1751         } else {
1752             // Start recursive descent parsing
1753             matchRoot = expr(lastAccept);
1754             // Check extra pattern characters
1755             if (patternLength != cursor) {
1756                 if (peek() == ')') {
1757                     throw error("Unmatched closing ')'");
1758                 } else {
1759                     throw error("Unexpected internal error");
1760                 }
1761             }
1762         }
1763 
1764         // Peephole optimization
1765         if (matchRoot instanceof Slice) {
1766             root = BnM.optimize(matchRoot);
1767             if (root == matchRoot) {
1768                 root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1769             }
1770         } else if (matchRoot instanceof Begin || matchRoot instanceof First) {
1771             root = matchRoot;
1772         } else {
1773             root = hasSupplementary ? new StartS(matchRoot) : new Start(matchRoot);
1774         }
1775 
1776         // Optimize the greedy Loop to prevent exponential backtracking, IF there
1777         // is no group ref in this pattern. With a non-negative localTCNCount value,
1778         // the greedy type Loop, Curly will skip the backtracking for any starting
1779         // position "i" that failed in the past.
1780         if (!hasGroupRef) {
1781             for (Node node : topClosureNodes) {
1782                 if (node instanceof Loop) {
1783                     // non-deterministic-greedy-group
1784                     ((Loop)node).posIndex = localTCNCount++;
1785                 }
1786             }
1787         }
1788 
1789         // Release temporary storage
1790         temp = null;
1791         buffer = null;
1792         groupNodes = null;
1793         patternLength = 0;
1794         compiled = true;
1795         topClosureNodes = null;
1796     }
1797 
1798     Map<String, Integer> namedGroups() {
1799         Map<String, Integer> groups = namedGroups;
1800         if (groups == null) {
1801             namedGroups = groups = new HashMap<>(2);
1802         }
1803         return groups;
1804     }
1805 
1806     /**






































1807      * Used to accumulate information about a subtree of the object graph
1808      * so that optimizations can be applied to the subtree.
1809      */
1810     static final class TreeInfo {
1811         int minLength;
1812         int maxLength;
1813         boolean maxValid;
1814         boolean deterministic;
1815 
1816         TreeInfo() {
1817             reset();
1818         }
1819         void reset() {
1820             minLength = 0;
1821             maxLength = 0;
1822             maxValid = true;
1823             deterministic = true;
1824         }
1825     }
1826 


2078         Node node = null;
2079     LOOP:
2080         for (;;) {
2081             int ch = peek();
2082             switch (ch) {
2083             case '(':
2084                 // Because group handles its own closure,
2085                 // we need to treat it differently
2086                 node = group0();
2087                 // Check for comment or flag group
2088                 if (node == null)
2089                     continue;
2090                 if (head == null)
2091                     head = node;
2092                 else
2093                     tail.next = node;
2094                 // Double return: Tail was returned in root
2095                 tail = root;
2096                 continue;
2097             case '[':
2098                 if (has(CANON_EQ) && !has(LITERAL))
2099                     node = new NFCCharProperty(clazz(true));
2100                 else
2101                     node = newCharProperty(clazz(true));
2102                 break;
2103             case '\\':
2104                 ch = nextEscaped();
2105                 if (ch == 'p' || ch == 'P') {
2106                     boolean oneLetter = true;
2107                     boolean comp = (ch == 'P');
2108                     ch = next(); // Consume { if present
2109                     if (ch != '{') {
2110                         unread();
2111                     } else {
2112                         oneLetter = false;
2113                     }
2114                     // node = newCharProperty(family(oneLetter, comp));
2115                     if (has(CANON_EQ) && !has(LITERAL))
2116                         node = new NFCCharProperty(family(oneLetter, comp));
2117                     else
2118                         node = newCharProperty(family(oneLetter, comp));
2119                 } else {
2120                     unread();
2121                     node = atom();
2122                 }
2123                 break;
2124             case '^':
2125                 next();
2126                 if (has(MULTILINE)) {
2127                     if (has(UNIX_LINES))
2128                         node = new UnixCaret();
2129                     else
2130                         node = new Caret();
2131                 } else {
2132                     node = new Begin();
2133                 }
2134                 break;
2135             case '$':
2136                 next();
2137                 if (has(UNIX_LINES))
2138                     node = new UnixDollar(has(MULTILINE));
2139                 else
2140                     node = new Dollar(has(MULTILINE));
2141                 break;
2142             case '.':
2143                 next();
2144                 if (has(DOTALL)) {
2145                     node = new CharProperty(ALL);
2146                 } else {
2147                     if (has(UNIX_LINES)) {
2148                         node = new CharProperty(UNIXDOT);
2149                     } else {
2150                         node = new CharProperty(DOT);
2151                     }
2152                 }
2153                 break;
2154             case '|':
2155             case ')':
2156                 break LOOP;
2157             case ']': // Now interpreting dangling ] and } as literals
2158             case '}':
2159                 node = atom();
2160                 break;
2161             case '?':
2162             case '*':
2163             case '+':
2164                 next();
2165                 throw error("Dangling meta character '" + ((char)ch) + "'");
2166             case 0:
2167                 if (cursor >= patternLength) {
2168                     break LOOP;
2169                 }
2170                 // Fall through
2171             default:
2172                 node = atom();
2173                 break;
2174             }
2175 
2176             node = closure(node);
2177             /* save the top dot-greedy nodes (.*, .+) as well
2178             if (node instanceof GreedyCharProperty &&
2179                 ((GreedyCharProperty)node).cp instanceof Dot) {
2180                 topClosureNodes.add(node);
2181             }
2182             */
2183             if (head == null) {
2184                 head = tail = node;
2185             } else {
2186                 tail.next = node;
2187                 tail = node;
2188             }
2189         }
2190         if (head == null) {
2191             return end;
2192         }
2193         tail.next = end;
2194         root = tail;      //double return
2195         return head;
2196     }
2197 
2198     @SuppressWarnings("fallthrough")
2199     /**
2200      * Parse and add a new Single or Slice.
2201      */
2202     private Node atom() {


2220             case '^':
2221             case '(':
2222             case '[':
2223             case '|':
2224             case ')':
2225                 break;
2226             case '\\':
2227                 ch = nextEscaped();
2228                 if (ch == 'p' || ch == 'P') { // Property
2229                     if (first > 0) { // Slice is waiting; handle it first
2230                         unread();
2231                         break;
2232                     } else { // No slice; just return the family node
2233                         boolean comp = (ch == 'P');
2234                         boolean oneLetter = true;
2235                         ch = next(); // Consume { if present
2236                         if (ch != '{')
2237                             unread();
2238                         else
2239                             oneLetter = false;
2240                         if (has(CANON_EQ) && !has(LITERAL))
2241                             return new NFCCharProperty(family(oneLetter, comp));
2242                         else
2243                             return newCharProperty(family(oneLetter, comp));
2244                     }
2245                 }
2246                 unread();
2247                 prev = cursor;
2248                 ch = escape(false, first == 0, false);
2249                 if (ch >= 0) {
2250                     append(ch, first);
2251                     first++;
2252                     if (isSupplementary(ch)) {
2253                         hasSupplementary = true;
2254                     }
2255                     ch = peek();
2256                     continue;
2257                 } else if (first == 0) {
2258                     return root;
2259                 }
2260                 // Unwind meta escape sequence
2261                 cursor = prev;
2262                 break;
2263             case 0:
2264                 if (cursor >= patternLength) {
2265                     break;
2266                 }
2267                 // Fall through
2268             default:
2269                 prev = cursor;
2270                 append(ch, first);
2271                 first++;
2272                 if (isSupplementary(ch)) {
2273                     hasSupplementary = true;
2274                 }
2275                 ch = next();
2276                 continue;
2277             }
2278             break;
2279         }
2280         if (first == 1) {
2281             return newCharProperty(single(buffer[0]));
2282         } else {
2283             return newSlice(buffer, first, hasSupplementary);
2284         }
2285     }
2286 
2287     private void append(int ch, int len) {
2288         if (len >= buffer.length) {
2289             int[] tmp = new int[len+len];
2290             System.arraycopy(buffer, 0, tmp, 0, len);
2291             buffer = tmp;
2292         }
2293         buffer[len] = ch;
2294     }
2295 
2296     /**
2297      * Parses a backref greedily, taking as many numbers as it
2298      * can. The first digit is always treated as a backref, but
2299      * multi digit numbers are only treated as a backref if at
2300      * least that many backrefs exist at this point in the regex.
2301      */


2312             case '5':
2313             case '6':
2314             case '7':
2315             case '8':
2316             case '9':
2317                 int newRefNum = (refNum * 10) + (ch - '0');
2318                 // Add another number if it doesn't make a group
2319                 // that doesn't exist
2320                 if (capturingGroupCount - 1 < newRefNum) {
2321                     done = true;
2322                     break;
2323                 }
2324                 refNum = newRefNum;
2325                 read();
2326                 break;
2327             default:
2328                 done = true;
2329                 break;
2330             }
2331         }
2332         hasGroupRef = true;
2333         if (has(CASE_INSENSITIVE))
2334             return new CIBackRef(refNum, has(UNICODE_CASE));
2335         else
2336             return new BackRef(refNum);
2337     }
2338 
2339     /**
2340      * Parses an escape sequence to determine the actual value that needs
2341      * to be matched.
2342      * If -1 is returned and create was true a new object was added to the tree
2343      * to handle the escape sequence.
2344      * If the returned value is greater than zero, it is the value that
2345      * matches the escape sequence.
2346      */
2347     private int escape(boolean inclass, boolean create, boolean isrange) {
2348         int ch = skip();
2349         switch (ch) {
2350         case '0':
2351             return o();
2352         case '1':


2357         case '6':
2358         case '7':
2359         case '8':
2360         case '9':
2361             if (inclass) break;
2362             if (create) {
2363                 root = ref((ch - '0'));
2364             }
2365             return -1;
2366         case 'A':
2367             if (inclass) break;
2368             if (create) root = new Begin();
2369             return -1;
2370         case 'B':
2371             if (inclass) break;
2372             if (create) root = new Bound(Bound.NONE, has(UNICODE_CHARACTER_CLASS));
2373             return -1;
2374         case 'C':
2375             break;
2376         case 'D':
2377             if (create) {
2378                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2379                             CharPredicates.DIGIT : CharPredicates.ASCII_DIGIT;
2380                 predicate = predicate.negate();
2381                 if (!inclass)
2382                     root = newCharProperty(predicate);
2383             }
2384             return -1;
2385         case 'E':
2386         case 'F':
2387             break;
2388         case 'G':
2389             if (inclass) break;
2390             if (create) root = new LastMatch();
2391             return -1;
2392         case 'H':
2393             if (create) {
2394                 predicate = HorizWS.negate();
2395                 if (!inclass)
2396                     root = newCharProperty(predicate);
2397             }
2398             return -1;
2399         case 'I':
2400         case 'J':
2401         case 'K':
2402         case 'L':
2403         case 'M':
2404             break;
2405         case 'N':
2406             return N();
2407         case 'O':
2408         case 'P':
2409         case 'Q':
2410             break;
2411         case 'R':
2412             if (inclass) break;
2413             if (create) root = new LineEnding();
2414             return -1;
2415         case 'S':
2416             if (create) {
2417                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2418                             CharPredicates.WHITE_SPACE : CharPredicates.ASCII_SPACE;
2419                 predicate = predicate.negate();
2420                 if (!inclass)
2421                     root = newCharProperty(predicate);
2422             }
2423             return -1;
2424         case 'T':
2425         case 'U':
2426             break;
2427         case 'V':
2428             if (create) {
2429                 predicate = VertWS.negate();
2430                 if (!inclass)
2431                     root = newCharProperty(predicate);
2432             }
2433             return -1;
2434         case 'W':
2435             if (create) {
2436                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2437                             CharPredicates.WORD : CharPredicates.ASCII_WORD;
2438                 predicate = predicate.negate();
2439                 if (!inclass)
2440                     root = newCharProperty(predicate);
2441             }
2442             return -1;
2443         case 'X':
2444             if (inclass) break;
2445             if (create) {
2446                 root = new XGrapheme();
2447             }
2448             return -1;
2449         case 'Y':
2450             break;
2451         case 'Z':
2452             if (inclass) break;
2453             if (create) {
2454                 if (has(UNIX_LINES))
2455                     root = new UnixDollar(false);
2456                 else
2457                     root = new Dollar(false);
2458             }
2459             return -1;
2460         case 'a':
2461             return '\007';
2462         case 'b':
2463             if (inclass) break;
2464             if (create) {
2465                 if (peek() == '{') {
2466                     if (skip() == 'g') {
2467                         if (read() == '}') {
2468                             root = new GraphemeBound();
2469                             return -1;
2470                         }
2471                         break;  // error missing trailing }
2472                     }
2473                     unread(); unread();
2474                 }
2475                 root = new Bound(Bound.BOTH, has(UNICODE_CHARACTER_CLASS));
2476             }
2477             return -1;
2478         case 'c':
2479             return c();
2480         case 'd':
2481             if (create) {
2482                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2483                             CharPredicates.DIGIT : CharPredicates.ASCII_DIGIT;
2484                 if (!inclass)
2485                     root = newCharProperty(predicate);
2486             }
2487             return -1;
2488         case 'e':
2489             return '\033';
2490         case 'f':
2491             return '\f';
2492         case 'g':
2493             break;
2494         case 'h':
2495             if (create) {
2496                 predicate = HorizWS;
2497                 if (!inclass)
2498                     root = newCharProperty(predicate);
2499             }
2500             return -1;
2501         case 'i':
2502         case 'j':
2503             break;
2504         case 'k':
2505             if (inclass)
2506                 break;
2507             if (read() != '<')
2508                 throw error("\\k is not followed by '<' for named capturing group");
2509             String name = groupname(read());
2510             if (!namedGroups().containsKey(name))
2511                 throw error("(named capturing group <"+ name+"> does not exit");
2512             if (create) {
2513                 hasGroupRef = true;
2514                 if (has(CASE_INSENSITIVE))
2515                     root = new CIBackRef(namedGroups().get(name), has(UNICODE_CASE));
2516                 else
2517                     root = new BackRef(namedGroups().get(name));
2518             }
2519             return -1;
2520         case 'l':
2521         case 'm':
2522             break;
2523         case 'n':
2524             return '\n';
2525         case 'o':
2526         case 'p':
2527         case 'q':
2528             break;
2529         case 'r':
2530             return '\r';
2531         case 's':
2532             if (create) {
2533                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2534                             CharPredicates.WHITE_SPACE : CharPredicates.ASCII_SPACE;
2535                 if (!inclass)
2536                     root = newCharProperty(predicate);
2537             }
2538             return -1;
2539         case 't':
2540             return '\t';
2541         case 'u':
2542             return u();
2543         case 'v':
2544             // '\v' was implemented as VT/0x0B in releases < 1.8 (though
2545             // undocumented). In JDK8 '\v' is specified as a predefined
2546             // character class for all vertical whitespace characters.
2547             // So [-1, root=VertWS node] pair is returned (instead of a
2548             // single 0x0B). This breaks the range if '\v' is used as
2549             // the start or end value, such as [\v-...] or [...-\v], in
2550             // which a single definite value (0x0B) is expected. For
2551             // compatibility concern '\013'/0x0B is returned if isrange.
2552             if (isrange)
2553                 return '\013';
2554             if (create) {
2555                 predicate = VertWS;
2556                 if (!inclass)
2557                     root = newCharProperty(predicate);
2558             }
2559             return -1;
2560         case 'w':
2561             if (create) {
2562                 predicate = has(UNICODE_CHARACTER_CLASS) ?
2563                             CharPredicates.WORD : CharPredicates.ASCII_WORD;
2564                 if (!inclass)
2565                     root = newCharProperty(predicate);
2566             }
2567             return -1;
2568         case 'x':
2569             return x();
2570         case 'y':
2571             break;
2572         case 'z':
2573             if (inclass) break;
2574             if (create) root = new End();
2575             return -1;
2576         default:
2577             return ch;
2578         }
2579         throw error("Illegal/unsupported escape sequence");
2580     }
2581 
2582     /**
2583      * Parse a character class, and return the node that matches it.
2584      *
2585      * Consumes a ] on the way out if consume is true. Usually consume
2586      * is true except for the case of [abc&&def] where def is a separate
2587      * right hand node with "understood" brackets.
2588      */
2589     private CharPredicate clazz(boolean consume) {
2590         CharPredicate prev = null;
2591         CharPredicate curr = null;
2592         BitClass bits = new BitClass();
2593         BmpCharPredicate bitsP = ch -> ch < 256 && bits.bits[ch];
2594 
2595         boolean isNeg = false;
2596         boolean hasBits = false;
2597         int ch = next();
2598 


2599         // Negates if first char in a class, otherwise literal
2600         if (ch == '^' && temp[cursor-1] == '[') {


2601             ch = next();
2602             isNeg = true;




2603         }
2604         for (;;) {
2605             switch (ch) {
2606                 case '[':
2607                     curr = clazz(true);

2608                     if (prev == null)
2609                         prev = curr;
2610                     else
2611                         prev = prev.union(curr);
2612                     ch = peek();
2613                     continue;
2614                 case '&':

2615                     ch = next();
2616                     if (ch == '&') {
2617                         ch = next();
2618                         CharPredicate right = null;
2619                         while (ch != ']' && ch != '&') {
2620                             if (ch == '[') {
2621                                 if (right == null)
2622                                     right = clazz(true);
2623                                 else
2624                                     right = right.union(clazz(true));
2625                             } else { // abc&&def
2626                                 unread();
2627                                 right = clazz(false);
2628                             }
2629                             ch = peek();
2630                         }
2631                         if (hasBits) {
2632                             // bits used, union has high precedence
2633                             if (prev == null) {
2634                                 prev = curr = bitsP;
2635                             } else {
2636                                 prev = prev.union(bitsP);
2637                             }
2638                             hasBits = false;
2639                         }
2640                         if (right != null)
2641                             curr = right;
2642                         if (prev == null) {
2643                             if (right == null)
2644                                 throw error("Bad class syntax");
2645                             else
2646                                 prev = right;
2647                         } else {
2648                             prev = prev.and(curr);
2649                         }
2650                     } else {
2651                         // treat as a literal &
2652                         unread();
2653                         break;
2654                     }
2655                     continue;
2656                 case 0:

2657                     if (cursor >= patternLength)
2658                         throw error("Unclosed character class");
2659                     break;
2660                 case ']':
2661                     if (prev != null || hasBits) {

2662                         if (consume)
2663                             next();
2664                         if (prev == null)
2665                             prev = bitsP;
2666                         else if (hasBits)
2667                             prev = prev.union(bitsP);
2668                         if (isNeg)
2669                             return prev.negate();
2670                         return prev;
2671                     }
2672                     break;
2673                 default:

2674                     break;
2675             }
2676             curr = range(bits);
2677             if (curr == null) {    // the bits used
2678                 hasBits = true;








2679             } else {
2680                 if (prev == null)
2681                     prev = curr;
2682                 else if (prev != curr)
2683                     prev = prev.union(curr);
2684             }
2685             ch = peek();
2686         }
2687     }
2688 
2689     private CharPredicate bitsOrSingle(BitClass bits, int ch) {
2690         /* Bits can only handle codepoints in [u+0000-u+00ff] range.
2691            Use "single" node instead of bits when dealing with unicode
2692            case folding for codepoints listed below.
2693            (1)Uppercase out of range: u+00ff, u+00b5
2694               toUpperCase(u+00ff) -> u+0178
2695               toUpperCase(u+00b5) -> u+039c
2696            (2)LatinSmallLetterLongS u+17f
2697               toUpperCase(u+017f) -> u+0053
2698            (3)LatinSmallLetterDotlessI u+131
2699               toUpperCase(u+0131) -> u+0049
2700            (4)LatinCapitalLetterIWithDotAbove u+0130
2701               toLowerCase(u+0130) -> u+0069
2702            (5)KelvinSign u+212a
2703               toLowerCase(u+212a) ==> u+006B
2704            (6)AngstromSign u+212b
2705               toLowerCase(u+212b) ==> u+00e5
2706         */
2707         int d;
2708         if (ch < 256 &&
2709             !(has(CASE_INSENSITIVE) && has(UNICODE_CASE) &&
2710               (ch == 0xff || ch == 0xb5 ||
2711                ch == 0x49 || ch == 0x69 ||    //I and i
2712                ch == 0x53 || ch == 0x73 ||    //S and s
2713                ch == 0x4b || ch == 0x6b ||    //K and k
2714                ch == 0xc5 || ch == 0xe5))) {  //A+ring
2715             bits.add(ch, flags());
2716             return null;
2717         }
2718         return single(ch);
2719     }
2720 
2721     /**
2722      *  Returns a suitably optimized, single character predicate
2723      */
2724     private CharPredicate single(final int ch) {
2725         if (has(CASE_INSENSITIVE)) {
2726             int lower, upper;
2727             if (has(UNICODE_CASE)) {
2728                 upper = Character.toUpperCase(ch);
2729                 lower = Character.toLowerCase(upper);
2730                 // Unicode case insensitive matches
2731                 if (upper != lower)
2732                     return SingleU(lower);
2733             } else if (ASCII.isAscii(ch)) {
2734                 lower = ASCII.toLower(ch);
2735                 upper = ASCII.toUpper(ch);
2736                 // Case insensitive matches a given BMP character
2737                 if (lower != upper)
2738                     return SingleI(lower, upper);
2739             }
2740         }
2741         if (isSupplementary(ch))
2742             return SingleS(ch);
2743         return Single(ch);  // Match a given BMP character
2744     }
2745 
2746     /**
2747      * Parse a single character or a character range in a character class
2748      * and return its representative node.
2749      */
2750     private CharPredicate range(BitClass bits) {
2751         int ch = peek();
2752         if (ch == '\\') {
2753             ch = nextEscaped();
2754             if (ch == 'p' || ch == 'P') { // A property
2755                 boolean comp = (ch == 'P');
2756                 boolean oneLetter = true;
2757                 // Consume { if present
2758                 ch = next();
2759                 if (ch != '{')
2760                     unread();
2761                 else
2762                     oneLetter = false;
2763                 return family(oneLetter, comp);
2764             } else { // ordinary escape
2765                 boolean isrange = temp[cursor+1] == '-';
2766                 unread();
2767                 ch = escape(true, true, isrange);
2768                 if (ch == -1)
2769                     return predicate;
2770             }
2771         } else {
2772             next();
2773         }
2774         if (ch >= 0) {
2775             if (peek() == '-') {
2776                 int endRange = temp[cursor+1];
2777                 if (endRange == '[') {
2778                     return bitsOrSingle(bits, ch);
2779                 }
2780                 if (endRange != ']') {
2781                     next();
2782                     int m = peek();
2783                     if (m == '\\') {
2784                         m = escape(true, false, true);
2785                     } else {
2786                         next();
2787                     }
2788                     if (m < ch) {
2789                         throw error("Illegal character range");
2790                     }
2791                     if (has(CASE_INSENSITIVE)) {
2792                         if (has(UNICODE_CASE))
2793                             return CIRangeU(ch, m);
2794                         return CIRange(ch, m);
2795                     } else {
2796                         return Range(ch, m);
2797                     }
2798                 }
2799             }
2800             return bitsOrSingle(bits, ch);
2801         }
2802         throw error("Unexpected character '"+((char)ch)+"'");
2803     }
2804 
2805     /**
2806      * Parses a Unicode character family and returns its representative node.
2807      */
2808     private CharPredicate family(boolean singleLetter, boolean isComplement) {


2809         next();
2810         String name;
2811         CharPredicate p = null;
2812 
2813         if (singleLetter) {
2814             int c = temp[cursor];
2815             if (!Character.isSupplementaryCodePoint(c)) {
2816                 name = String.valueOf((char)c);
2817             } else {
2818                 name = new String(temp, cursor, 1);
2819             }
2820             read();
2821         } else {
2822             int i = cursor;
2823             mark('}');
2824             while(read() != '}') {
2825             }
2826             mark('\000');
2827             int j = cursor;
2828             if (j > patternLength)
2829                 throw error("Unclosed character family");
2830             if (i + 1 >= j)
2831                 throw error("Empty character family");
2832             name = new String(temp, i, j-i-1);
2833         }
2834 
2835         int i = name.indexOf('=');
2836         if (i != -1) {
2837             // property construct \p{name=value}
2838             String value = name.substring(i + 1);
2839             name = name.substring(0, i).toLowerCase(Locale.ENGLISH);
2840             switch (name) {
2841                 case "sc":
2842                 case "script":
2843                     p = CharPredicates.forUnicodeScript(value);
2844                     break;
2845                 case "blk":
2846                 case "block":
2847                     p = CharPredicates.forUnicodeBlock(value);
2848                     break;
2849                 case "gc":
2850                 case "general_category":
2851                     p = CharPredicates.forProperty(value);
2852                     break;
2853                 default:
2854                     break;
2855             }
2856             if (p == null)
2857                 throw error("Unknown Unicode property {name=<" + name + ">, "
2858                              + "value=<" + value + ">}");
2859 
2860         } else {
2861             if (name.startsWith("In")) {
2862                 // \p{InBlockName}
2863                 p = CharPredicates.forUnicodeBlock(name.substring(2));
2864             } else if (name.startsWith("Is")) {
2865                 // \p{IsGeneralCategory} and \p{IsScriptName}
2866                 name = name.substring(2);
2867                 p = CharPredicates.forUnicodeProperty(name);
2868                 if (p == null)
2869                     p = CharPredicates.forProperty(name);
2870                 if (p == null)
2871                     p = CharPredicates.forUnicodeScript(name);


2872             } else {
2873                 if (has(UNICODE_CHARACTER_CLASS)) {
2874                     p = CharPredicates.forPOSIXName(name);


2875                 }
2876                 if (p == null)
2877                     p = CharPredicates.forProperty(name);
2878             }
2879             if (p == null)
2880                 throw error("Unknown character property name {In/Is" + name + "}");
2881         }
2882         if (isComplement) {
2883             // it might be too expensive to detect if a complement of
2884             // CharProperty can match "certain" supplementary. So just
2885             // go with StartS.
2886             hasSupplementary = true;
2887             p = p.negate();




























2888         }
2889         return p;
2890     }
2891 
2892     private CharProperty newCharProperty(CharPredicate p) {




2893         if (p == null)
2894             return null;
2895         if (p instanceof BmpCharPredicate)
2896             return new BmpCharProperty((BmpCharPredicate)p);
2897         else
2898             return new CharProperty(p);
2899     }
2900 
2901     /**
2902      * Parses and returns the name of a "named capturing group", the trailing
2903      * ">" is consumed after parsing.
2904      */
2905     private String groupname(int ch) {
2906         StringBuilder sb = new StringBuilder();
2907         sb.append(Character.toChars(ch));
2908         while (ASCII.isLower(ch=read()) || ASCII.isUpper(ch) ||
2909                ASCII.isDigit(ch)) {
2910             sb.append(Character.toChars(ch));
2911         }
2912         if (sb.length() == 0)
2913             throw error("named capturing group has 0 length name");
2914         if (ch != '>')
2915             throw error("named capturing group is missing trailing '>'");
2916         return sb.toString();
2917     }
2918 
2919     /**
2920      * Parses a group and returns the head node of a set of nodes that process
2921      * the group. Sometimes a double return system is used where the tail is
2922      * returned in root.
2923      */
2924     private Node group0() {
2925         boolean capturingGroup = false;
2926         Node head = null;
2927         Node tail = null;
2928         int save = flags;
2929         int saveTCNCount = topClosureNodes.size();
2930         root = null;
2931         int ch = next();
2932         if (ch == '?') {
2933             ch = skip();
2934             switch (ch) {
2935             case ':':   //  (?:xxx) pure group
2936                 head = createGroup(true);
2937                 tail = root;
2938                 head.next = expr(tail);
2939                 break;
2940             case '=':   // (?=xxx) and (?!xxx) lookahead
2941             case '!':
2942                 head = createGroup(true);
2943                 tail = root;
2944                 head.next = expr(tail);
2945                 if (ch == '=') {
2946                     head = tail = new Pos(head);
2947                 } else {
2948                     head = tail = new Neg(head);
2949                 }
2950                 break;
2951             case '>':   // (?>xxx)  independent group
2952                 head = createGroup(true);
2953                 tail = root;
2954                 head.next = expr(tail);
2955                 head = tail = new Ques(head, Qtype.INDEPENDENT);
2956                 break;
2957             case '<':   // (?<xxx)  look behind
2958                 ch = read();
2959                 if (ASCII.isLower(ch) || ASCII.isUpper(ch)) {
2960                     // named captured group
2961                     String name = groupname(ch);
2962                     if (namedGroups().containsKey(name))
2963                         throw error("Named capturing group <" + name
2964                                     + "> is already defined");
2965                     capturingGroup = true;
2966                     head = createGroup(false);
2967                     tail = root;
2968                     namedGroups().put(name, capturingGroupCount-1);
2969                     head.next = expr(tail);
2970                     break;
2971                 }
2972                 int start = cursor;
2973                 head = createGroup(true);
2974                 tail = root;
2975                 head.next = expr(tail);


2979                 if (info.maxValid == false) {
2980                     throw error("Look-behind group does not have "
2981                                 + "an obvious maximum length");
2982                 }
2983                 boolean hasSupplementary = findSupplementary(start, patternLength);
2984                 if (ch == '=') {
2985                     head = tail = (hasSupplementary ?
2986                                    new BehindS(head, info.maxLength,
2987                                                info.minLength) :
2988                                    new Behind(head, info.maxLength,
2989                                               info.minLength));
2990                 } else if (ch == '!') {
2991                     head = tail = (hasSupplementary ?
2992                                    new NotBehindS(head, info.maxLength,
2993                                                   info.minLength) :
2994                                    new NotBehind(head, info.maxLength,
2995                                                  info.minLength));
2996                 } else {
2997                     throw error("Unknown look-behind group");
2998                 }
2999                 // clear all top-closure-nodes inside lookbehind
3000                 if (saveTCNCount < topClosureNodes.size())
3001                     topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3002                 break;
3003             case '$':
3004             case '@':
3005                 throw error("Unknown group type");
3006             default:    // (?xxx:) inlined match flags
3007                 unread();
3008                 addFlag();
3009                 ch = read();
3010                 if (ch == ')') {
3011                     return null;    // Inline modifier only
3012                 }
3013                 if (ch != ':') {
3014                     throw error("Unknown inline modifier");
3015                 }
3016                 head = createGroup(true);
3017                 tail = root;
3018                 head.next = expr(tail);
3019                 break;
3020             }
3021         } else { // (xxx) a regular group
3022             capturingGroup = true;
3023             head = createGroup(false);
3024             tail = root;
3025             head.next = expr(tail);
3026         }
3027 
3028         accept(')', "Unclosed group");
3029         flags = save;
3030 
3031         // Check for quantifiers
3032         Node node = closure(head);
3033         if (node == head) { // No closure
3034             root = tail;
3035             return node;    // Dual return
3036         }
3037         if (head == tail) { // Zero length assertion
3038             root = node;
3039             return node;    // Dual return
3040         }
3041 
3042         // have group closure, clear all inner closure nodes from the
3043         // top list (no backtracking stopper optimization for inner
3044         if (saveTCNCount < topClosureNodes.size())
3045             topClosureNodes.subList(saveTCNCount, topClosureNodes.size()).clear();
3046 
3047         if (node instanceof Ques) {
3048             Ques ques = (Ques) node;
3049             if (ques.type == Qtype.POSSESSIVE) {
3050                 root = node;
3051                 return node;
3052             }
3053             tail.next = new BranchConn();
3054             tail = tail.next;
3055             if (ques.type == Qtype.GREEDY) {
3056                 head = new Branch(head, null, tail);
3057             } else { // Reluctant quantifier
3058                 head = new Branch(null, head, tail);
3059             }
3060             root = tail;
3061             return head;
3062         } else if (node instanceof Curly) {
3063             Curly curly = (Curly) node;
3064             if (curly.type == Qtype.POSSESSIVE) {
3065                 root = node;
3066                 return node;
3067             }
3068             // Discover if the group is deterministic
3069             TreeInfo info = new TreeInfo();
3070             if (head.study(info)) { // Deterministic
3071                 GroupTail temp = (GroupTail) tail;
3072                 head = root = new GroupCurly(head.next, curly.cmin,
3073                                    curly.cmax, curly.type,
3074                                    ((GroupTail)tail).localIndex,
3075                                    ((GroupTail)tail).groupIndex,
3076                                              capturingGroup);
3077                 return head;
3078             } else { // Non-deterministic
3079                 int temp = ((GroupHead) head).localIndex;
3080                 Loop loop;
3081                 if (curly.type == Qtype.GREEDY) {
3082                     loop = new Loop(this.localCount, temp);
3083                     // add the max_reps greedy to the top-closure-node list
3084                     if (curly.cmax == MAX_REPS)
3085                         topClosureNodes.add(loop);
3086                 } else {  // Reluctant Curly
3087                     loop = new LazyLoop(this.localCount, temp);
3088                 }
3089                 Prolog prolog = new Prolog(loop);
3090                 this.localCount += 1;
3091                 loop.cmin = curly.cmin;
3092                 loop.cmax = curly.cmax;
3093                 loop.body = head;
3094                 tail.next = loop;
3095                 root = loop;
3096                 return prolog; // Dual return
3097             }
3098         }
3099         throw error("Internal logic error");
3100     }
3101 
3102     /**
3103      * Create group head and tail nodes using double return. If the group is
3104      * created with anonymous true then it is a pure group and should not
3105      * affect group counting.
3106      */
3107     private Node createGroup(boolean anonymous) {
3108         int localIndex = localCount++;
3109         int groupIndex = 0;
3110         if (!anonymous)
3111             groupIndex = capturingGroupCount++;
3112         GroupHead head = new GroupHead(localIndex);
3113         root = new GroupTail(localIndex, groupIndex);
3114 
3115         // for debug/print only, head.match does NOT need the "tail" info
3116         head.tail = (GroupTail)root;
3117 
3118         if (!anonymous && groupIndex < 10)
3119             groupNodes[groupIndex] = head;
3120         return head;
3121     }
3122 
3123     @SuppressWarnings("fallthrough")
3124     /**
3125      * Parses inlined match flags and set them appropriately.
3126      */
3127     private void addFlag() {
3128         int ch = peek();
3129         for (;;) {
3130             switch (ch) {
3131             case 'i':
3132                 flags |= CASE_INSENSITIVE;
3133                 break;
3134             case 'm':
3135                 flags |= MULTILINE;
3136                 break;
3137             case 's':


3186             case 'u':
3187                 flags &= ~UNICODE_CASE;
3188                 break;
3189             case 'c':
3190                 flags &= ~CANON_EQ;
3191                 break;
3192             case 'x':
3193                 flags &= ~COMMENTS;
3194                 break;
3195             case 'U':
3196                 flags &= ~(UNICODE_CHARACTER_CLASS | UNICODE_CASE);
3197             default:
3198                 return;
3199             }
3200             ch = next();
3201         }
3202     }
3203 
3204     static final int MAX_REPS   = 0x7FFFFFFF;
3205 
3206     static enum Qtype {
3207         GREEDY, LAZY, POSSESSIVE, INDEPENDENT
3208     }


3209 
3210     private Node curly(Node prev, int cmin) {
3211         int ch = next();
3212         if (ch == '?') {
3213             next();
3214             return new Curly(prev, cmin, MAX_REPS, Qtype.LAZY);
3215         } else if (ch == '+') {
3216             next();
3217             return new Curly(prev, cmin, MAX_REPS, Qtype.POSSESSIVE);
3218         }
3219         if (prev instanceof BmpCharProperty) {
3220             return new BmpCharPropertyGreedy((BmpCharProperty)prev, cmin);
3221         } else if (prev instanceof CharProperty) {
3222             return new CharPropertyGreedy((CharProperty)prev, cmin);
3223         }
3224         return new Curly(prev, cmin, MAX_REPS, Qtype.GREEDY);
3225     }
3226 
3227     /**
3228      * Processes repetition. If the next character peeked is a quantifier
3229      * then new nodes must be appended to handle the repetition.
3230      * Prev could be a single or a group, so it could be a chain of nodes.
3231      */
3232     private Node closure(Node prev) {
3233         Node atom;
3234         int ch = peek();
3235         switch (ch) {
3236         case '?':
3237             ch = next();
3238             if (ch == '?') {
3239                 next();
3240                 return new Ques(prev, Qtype.LAZY);
3241             } else if (ch == '+') {
3242                 next();
3243                 return new Ques(prev, Qtype.POSSESSIVE);
3244             }
3245             return new Ques(prev, Qtype.GREEDY);
3246         case '*':
3247             return curly(prev, 0);








3248         case '+':
3249             return curly(prev, 1);








3250         case '{':
3251             ch = temp[cursor+1];
3252             if (ASCII.isDigit(ch)) {
3253                 skip();
3254                 int cmin = 0;
3255                 do {
3256                     cmin = cmin * 10 + (ch - '0');
3257                 } while (ASCII.isDigit(ch = read()));
3258                 int cmax = cmin;
3259                 if (ch == ',') {
3260                     ch = read();
3261                     cmax = MAX_REPS;
3262                     if (ch != '}') {
3263                         cmax = 0;
3264                         while (ASCII.isDigit(ch)) {
3265                             cmax = cmax * 10 + (ch - '0');
3266                             ch = read();
3267                         }
3268                     }
3269                 }
3270                 if (ch != '}')
3271                     throw error("Unclosed counted closure");
3272                 if (((cmin) | (cmax) | (cmax - cmin)) < 0)
3273                     throw error("Illegal repetition range");
3274                 Curly curly;
3275                 ch = peek();
3276                 if (ch == '?') {
3277                     next();
3278                     curly = new Curly(prev, cmin, cmax, Qtype.LAZY);
3279                 } else if (ch == '+') {
3280                     next();
3281                     curly = new Curly(prev, cmin, cmax, Qtype.POSSESSIVE);
3282                 } else {
3283                     curly = new Curly(prev, cmin, cmax, Qtype.GREEDY);
3284                 }
3285                 return curly;
3286             } else {
3287                 throw error("Illegal repetition");
3288             }
3289         default:
3290             return prev;
3291         }
3292     }
3293 
3294     /**
3295      *  Utility method for parsing control escape sequences.
3296      */
3297     private int c() {
3298         if (cursor < patternLength) {
3299             return read() ^ 64;
3300         }
3301         throw error("Illegal control escape sequence");
3302     }
3303 


3440 
3441     private static final int countCodePoints(CharSequence seq) {
3442         int length = seq.length();
3443         int n = 0;
3444         for (int i = 0; i < length; ) {
3445             n++;
3446             if (Character.isHighSurrogate(seq.charAt(i++))) {
3447                 if (i < length && Character.isLowSurrogate(seq.charAt(i))) {
3448                     i++;
3449                 }
3450             }
3451         }
3452         return n;
3453     }
3454 
3455     /**
3456      *  Creates a bit vector for matching Latin-1 values. A normal BitClass
3457      *  never matches values above Latin-1, and a complemented BitClass always
3458      *  matches values above Latin-1.
3459      */
3460     static final class BitClass extends BmpCharProperty {
3461         final boolean[] bits;
3462         BitClass() {
3463             this(new boolean[256]);
3464         }
3465         private BitClass(boolean[] bits) {
3466             super( ch -> ch < 256 && bits[ch]);
3467             this.bits = bits;
3468         }
3469         BitClass add(int c, int flags) {
3470             assert c >= 0 && c <= 255;
3471             if ((flags & CASE_INSENSITIVE) != 0) {
3472                 if (ASCII.isAscii(c)) {
3473                     bits[ASCII.toUpper(c)] = true;
3474                     bits[ASCII.toLower(c)] = true;
3475                 } else if ((flags & UNICODE_CASE) != 0) {
3476                     bits[Character.toLowerCase(c)] = true;
3477                     bits[Character.toUpperCase(c)] = true;
3478                 }
3479             }
3480             bits[c] = true;
3481             return this;
3482         }


























3483     }
3484 
3485     /**
3486      *  Utility method for creating a string slice matcher.
3487      */
3488     private Node newSlice(int[] buf, int count, boolean hasSupplementary) {
3489         int[] tmp = new int[count];
3490         if (has(CASE_INSENSITIVE)) {
3491             if (has(UNICODE_CASE)) {
3492                 for (int i = 0; i < count; i++) {
3493                     tmp[i] = Character.toLowerCase(
3494                                  Character.toUpperCase(buf[i]));
3495                 }
3496                 return hasSupplementary? new SliceUS(tmp) : new SliceU(tmp);
3497             }
3498             for (int i = 0; i < count; i++) {
3499                 tmp[i] = ASCII.toLower(buf[i]);
3500             }
3501             return hasSupplementary? new SliceIS(tmp) : new SliceI(tmp);
3502         }


3870                     if (i < matcher.to && seq.charAt(i) == 0x0A)
3871                         i++;
3872                     return next.match(matcher, i, seq);
3873                 }
3874             } else {
3875                 matcher.hitEnd = true;
3876             }
3877             return false;
3878         }
3879         boolean study(TreeInfo info) {
3880             info.minLength++;
3881             info.maxLength += 2;
3882             return next.study(info);
3883         }
3884     }
3885 
3886     /**
3887      * Abstract node class to match one character satisfying some
3888      * boolean property.
3889      */
3890     static class CharProperty extends Node {
3891         CharPredicate predicate;
3892 
3893         CharProperty (CharPredicate predicate) {
3894             this.predicate = predicate;

3895         }
3896         boolean match(Matcher matcher, int i, CharSequence seq) {
3897             if (i < matcher.to) {
3898                 int ch = Character.codePointAt(seq, i);
3899                 return predicate.is(ch) &&
3900                        next.match(matcher, i + Character.charCount(ch), seq);
3901             } else {
3902                 matcher.hitEnd = true;
3903                 return false;
3904             }
3905         }
3906         boolean study(TreeInfo info) {
3907             info.minLength++;
3908             info.maxLength++;
3909             return next.study(info);
3910         }
3911     }
3912 
3913     /**
3914      * Optimized version of CharProperty that works only for
3915      * properties never satisfied by Supplementary characters.
3916      */
3917     private static class BmpCharProperty extends CharProperty {
3918         BmpCharProperty (BmpCharPredicate predicate) {
3919             super(predicate);
3920         }
3921         boolean match(Matcher matcher, int i, CharSequence seq) {
3922             if (i < matcher.to) {
3923                 return predicate.is(seq.charAt(i)) &&
3924                        next.match(matcher, i + 1, seq);
3925             } else {
3926                 matcher.hitEnd = true;
3927                 return false;
3928             }
3929         }
3930     }
3931 
3932     private static class NFCCharProperty extends Node {
3933         CharPredicate predicate;
3934         NFCCharProperty (CharPredicate predicate) {
3935             this.predicate = predicate;







































































3936         }
3937 
3938         boolean match(Matcher matcher, int i, CharSequence seq) {
3939             if (i < matcher.to) {
3940                 int ch0 = Character.codePointAt(seq, i);
3941                 int n = Character.charCount(ch0);
3942                 int j = i + n;
3943                 while (j < matcher.to) {
3944                     int ch1 = Character.codePointAt(seq, j);
3945                     if (Grapheme.isBoundary(ch0, ch1))
3946                         break;
3947                     ch0 = ch1;
3948                     j += Character.charCount(ch1);
3949                 }
3950                 if (i + n == j) {    // single, assume nfc cp
3951                     if (predicate.is(ch0))
3952                         return next.match(matcher, j, seq);
3953                 } else {
3954                     while (i + n < j) {
3955                         String nfc = Normalizer.normalize(
3956                             seq.toString().substring(i, j), Normalizer.Form.NFC);
3957                         if (nfc.codePointCount(0, nfc.length()) == 1) {
3958                             if (predicate.is(nfc.codePointAt(0)) &&
3959                                 next.match(matcher, j, seq)) {
3960                                 return true;
3961                             }
3962                         }
3963 
3964                         ch0 = Character.codePointBefore(seq, j);
3965                         j -= Character.charCount(ch0);






3966                     }
3967                 }
3968                 if (j < matcher.to)
3969                     return false;






3970             }
3971             matcher.hitEnd = true;
3972             return false;
3973         }
3974 
3975         boolean study(TreeInfo info) {
3976             info.minLength++;
3977             info.deterministic = false;
3978             return next.study(info);





3979         }
3980     }
3981 
3982     /**
3983      * Node class that matches an unicode extended grapheme cluster
3984      */
3985     static class XGrapheme extends Node {
3986         boolean match(Matcher matcher, int i, CharSequence seq) {
3987             if (i < matcher.to) {
3988                 int ch0 = Character.codePointAt(seq, i);
3989                     i += Character.charCount(ch0);
3990                 while (i < matcher.to) {
3991                     int ch1 = Character.codePointAt(seq, i);
3992                     if (Grapheme.isBoundary(ch0, ch1))
3993                         break;
3994                     ch0 = ch1;
3995                     i += Character.charCount(ch1);
3996                 }
3997                 return next.match(matcher, i, seq);
3998             }


4180                     return false;
4181                 }
4182             }
4183             return next.match(matcher, x, seq);
4184         }
4185     }
4186 
4187     /**
4188      * Node class for a case insensitive sequence of literal characters.
4189      * Uses unicode case folding.
4190      */
4191     static final class SliceUS extends SliceIS {
4192         SliceUS(int[] buf) {
4193             super(buf);
4194         }
4195         int toLower(int c) {
4196             return Character.toLowerCase(Character.toUpperCase(c));
4197         }
4198     }
4199 




































































4200     /**
4201      * The 0 or 1 quantifier. This one class implements all three types.
4202      */
4203     static final class Ques extends Node {
4204         Node atom;
4205         Qtype type;
4206         Ques(Node node, Qtype type) {
4207             this.atom = node;
4208             this.type = type;
4209         }
4210         boolean match(Matcher matcher, int i, CharSequence seq) {
4211             switch (type) {
4212             case GREEDY:
4213                 return (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq))
4214                     || next.match(matcher, i, seq);
4215             case LAZY:
4216                 return next.match(matcher, i, seq)
4217                     || (atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq));
4218             case POSSESSIVE:
4219                 if (atom.match(matcher, i, seq)) i = matcher.last;
4220                 return next.match(matcher, i, seq);
4221             default:
4222                 return atom.match(matcher, i, seq) && next.match(matcher, matcher.last, seq);
4223             }
4224         }
4225         boolean study(TreeInfo info) {
4226             if (type != Qtype.INDEPENDENT) {
4227                 int minL = info.minLength;
4228                 atom.study(info);
4229                 info.minLength = minL;
4230                 info.deterministic = false;
4231                 return next.study(info);
4232             } else {
4233                 atom.study(info);
4234                 return next.study(info);
4235             }
4236         }
4237     }
4238 
4239     /**
4240      * Handles the greedy style repetition with the minimum either be
4241      * 0 or 1 and the maximum be MAX_REPS, for * and + quantifier.
4242      */
4243     static class CharPropertyGreedy extends Node {
4244         final CharPredicate predicate;
4245         final int cmin;
4246 
4247         CharPropertyGreedy(CharProperty cp, int cmin) {
4248             this.predicate = cp.predicate;
4249             this.cmin = cmin;
4250         }
4251         boolean match(Matcher matcher, int i,  CharSequence seq) {
4252             int n = 0;
4253             int to = matcher.to;
4254             // greedy, all the way down
4255             while (i < to) {
4256                 int ch = Character.codePointAt(seq, i);
4257                 if (!predicate.is(ch))
4258                    break;
4259                 i += Character.charCount(ch);
4260                 n++;
4261             }
4262             if (i >= to) {
4263                 matcher.hitEnd = true;
4264             }
4265             while (n >= cmin) {
4266                 if (next.match(matcher, i, seq))
4267                     return true;
4268                 if (n == cmin)
4269                     return false;
4270                  // backing off if match fails
4271                 int ch = Character.codePointBefore(seq, i);
4272                 i -= Character.charCount(ch);
4273                 n--;
4274             }
4275             return false;
4276         }
4277 
4278         boolean study(TreeInfo info) {
4279             info.minLength += cmin;
4280             if (info.maxValid) {
4281                 info.maxLength += MAX_REPS;
4282             }
4283             info.deterministic = false;
4284             return next.study(info);
4285         }
4286     }
4287 
4288     static final class BmpCharPropertyGreedy extends CharPropertyGreedy {
4289 
4290         BmpCharPropertyGreedy(BmpCharProperty bcp, int cmin) {
4291             super(bcp, cmin);
4292         }
4293 
4294         boolean match(Matcher matcher, int i,  CharSequence seq) {
4295             int n = 0;
4296             int to = matcher.to;
4297             while (i < to && predicate.is(seq.charAt(i))) {
4298                 i++; n++;
4299             }
4300             if (i >= to) {
4301                 matcher.hitEnd = true;
4302             }
4303             while (n >= cmin) {
4304                 if (next.match(matcher, i, seq))
4305                     return true;
4306                 i--; n--;  // backing off if match fails
4307             }
4308             return false;
4309         }
4310     }
4311 
4312     /**
4313      * Handles the curly-brace style repetition with a specified minimum and
4314      * maximum occurrences. The * quantifier is handled as a special case.
4315      * This class handles the three types.
4316      */
4317     static final class Curly extends Node {
4318         Node atom;
4319         Qtype type;
4320         int cmin;
4321         int cmax;
4322 
4323         Curly(Node node, int cmin, int cmax, Qtype type) {
4324             this.atom = node;
4325             this.type = type;
4326             this.cmin = cmin;
4327             this.cmax = cmax;
4328         }
4329         boolean match(Matcher matcher, int i, CharSequence seq) {
4330             int j;
4331             for (j = 0; j < cmin; j++) {
4332                 if (atom.match(matcher, i, seq)) {
4333                     i = matcher.last;
4334                     continue;
4335                 }
4336                 return false;
4337             }
4338             if (type == Qtype.GREEDY)
4339                 return match0(matcher, i, j, seq);
4340             else if (type == Qtype.LAZY)
4341                 return match1(matcher, i, j, seq);
4342             else
4343                 return match2(matcher, i, j, seq);
4344         }
4345         // Greedy match.
4346         // i is the index to start matching at
4347         // j is the number of atoms that have matched
4348         boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4349             if (j >= cmax) {
4350                 // We have matched the maximum... continue with the rest of
4351                 // the regular expression
4352                 return next.match(matcher, i, seq);
4353             }
4354             int backLimit = j;
4355             while (atom.match(matcher, i, seq)) {
4356                 // k is the length of this match
4357                 int k = matcher.last - i;
4358                 if (k == 0) // Zero length match
4359                     break;
4360                 // Move up index and number matched


4442             }
4443 
4444             if (info.deterministic && cmin == cmax)
4445                 info.deterministic = detm;
4446             else
4447                 info.deterministic = false;
4448             return next.study(info);
4449         }
4450     }
4451 
4452     /**
4453      * Handles the curly-brace style repetition with a specified minimum and
4454      * maximum occurrences in deterministic cases. This is an iterative
4455      * optimization over the Prolog and Loop system which would handle this
4456      * in a recursive way. The * quantifier is handled as a special case.
4457      * If capture is true then this class saves group settings and ensures
4458      * that groups are unset when backing off of a group match.
4459      */
4460     static final class GroupCurly extends Node {
4461         Node atom;
4462         Qtype type;
4463         int cmin;
4464         int cmax;
4465         int localIndex;
4466         int groupIndex;
4467         boolean capture;
4468 
4469         GroupCurly(Node node, int cmin, int cmax, Qtype type, int local,
4470                    int group, boolean capture) {
4471             this.atom = node;
4472             this.type = type;
4473             this.cmin = cmin;
4474             this.cmax = cmax;
4475             this.localIndex = local;
4476             this.groupIndex = group;
4477             this.capture = capture;
4478         }
4479         boolean match(Matcher matcher, int i, CharSequence seq) {
4480             int[] groups = matcher.groups;
4481             int[] locals = matcher.locals;
4482             int save0 = locals[localIndex];
4483             int save1 = 0;
4484             int save2 = 0;
4485 
4486             if (capture) {
4487                 save1 = groups[groupIndex];
4488                 save2 = groups[groupIndex+1];
4489             }
4490 
4491             // Notify GroupTail there is no need to setup group info
4492             // because it will be set here
4493             locals[localIndex] = -1;
4494 
4495             boolean ret = true;
4496             for (int j = 0; j < cmin; j++) {
4497                 if (atom.match(matcher, i, seq)) {
4498                     if (capture) {
4499                         groups[groupIndex] = i;
4500                         groups[groupIndex+1] = matcher.last;
4501                     }
4502                     i = matcher.last;
4503                 } else {
4504                     ret = false;
4505                     break;
4506                 }
4507             }
4508             if (ret) {
4509                 if (type == Qtype.GREEDY) {
4510                     ret = match0(matcher, i, cmin, seq);
4511                 } else if (type == Qtype.LAZY) {
4512                     ret = match1(matcher, i, cmin, seq);
4513                 } else {
4514                     ret = match2(matcher, i, cmin, seq);
4515                 }
4516             }
4517             if (!ret) {
4518                 locals[localIndex] = save0;
4519                 if (capture) {
4520                     groups[groupIndex] = save1;
4521                     groups[groupIndex+1] = save2;
4522                 }
4523             }
4524             return ret;
4525         }
4526         // Aggressive group match
4527         boolean match0(Matcher matcher, int i, int j, CharSequence seq) {
4528             // don't back off passing the starting "j"
4529             int min = j;
4530             int[] groups = matcher.groups;
4531             int save0 = 0;


4737 
4738             info.minLength += minL;
4739             info.maxLength += maxL;
4740             info.maxValid &= maxV;
4741             info.deterministic = false;
4742             return false;
4743         }
4744     }
4745 
4746     /**
4747      * The GroupHead saves the location where the group begins in the locals
4748      * and restores them when the match is done.
4749      *
4750      * The matchRef is used when a reference to this group is accessed later
4751      * in the expression. The locals will have a negative value in them to
4752      * indicate that we do not want to unset the group if the reference
4753      * doesn't match.
4754      */
4755     static final class GroupHead extends Node {
4756         int localIndex;
4757         GroupTail tail;    // for debug/print only, match does not need to know
4758         GroupHead(int localCount) {
4759             localIndex = localCount;
4760         }
4761         boolean match(Matcher matcher, int i, CharSequence seq) {
4762             int save = matcher.locals[localIndex];
4763             matcher.locals[localIndex] = i;
4764             boolean ret = next.match(matcher, i, seq);
4765             matcher.locals[localIndex] = save;
4766             return ret;
4767         }
4768         boolean matchRef(Matcher matcher, int i, CharSequence seq) {
4769             int save = matcher.locals[localIndex];
4770             matcher.locals[localIndex] = ~i; // HACK
4771             boolean ret = next.match(matcher, i, seq);
4772             matcher.locals[localIndex] = save;
4773             return ret;
4774         }
4775     }
4776 
4777     /**


4845         }
4846         boolean match(Matcher matcher, int i, CharSequence seq) {
4847             return loop.matchInit(matcher, i, seq);
4848         }
4849         boolean study(TreeInfo info) {
4850             return loop.study(info);
4851         }
4852     }
4853 
4854     /**
4855      * Handles the repetition count for a greedy Curly. The matchInit
4856      * is called from the Prolog to save the index of where the group
4857      * beginning is stored. A zero length group check occurs in the
4858      * normal match but is skipped in the matchInit.
4859      */
4860     static class Loop extends Node {
4861         Node body;
4862         int countIndex; // local count index in matcher locals
4863         int beginIndex; // group beginning index
4864         int cmin, cmax;
4865         int posIndex;
4866         Loop(int countIndex, int beginIndex) {
4867             this.countIndex = countIndex;
4868             this.beginIndex = beginIndex;
4869             this.posIndex = -1;
4870         }
4871         boolean match(Matcher matcher, int i, CharSequence seq) {
4872             // Avoid infinite loop in zero-length case.
4873             if (i > matcher.locals[beginIndex]) {
4874                 int count = matcher.locals[countIndex];
4875 
4876                 // This block is for before we reach the minimum
4877                 // iterations required for the loop to match
4878                 if (count < cmin) {
4879                     matcher.locals[countIndex] = count + 1;
4880                     boolean b = body.match(matcher, i, seq);
4881                     // If match failed we must backtrack, so
4882                     // the loop count should NOT be incremented
4883                     if (!b)
4884                         matcher.locals[countIndex] = count;
4885                     // Return success or failure since we are under
4886                     // minimum
4887                     return b;
4888                 }
4889                 // This block is for after we have the minimum
4890                 // iterations required for the loop to match
4891                 if (count < cmax) {
4892                     // Let's check if we have already tried and failed
4893                     // at this starting position "i" in the past.
4894                     // If yes, then just return false wihtout trying
4895                     // again, to stop the exponential backtracking.
4896                     if (posIndex != -1 &&
4897                         matcher.localsPos[posIndex].contains(i)) {
4898                         return next.match(matcher, i, seq);
4899                     }
4900                     matcher.locals[countIndex] = count + 1;
4901                     boolean b = body.match(matcher, i, seq);
4902                     // If match failed we must backtrack, so
4903                     // the loop count should NOT be incremented
4904                     if (b)


4905                         return true;
4906                     matcher.locals[countIndex] = count;
4907                     // save the failed position
4908                     if (posIndex != -1) {
4909                         matcher.localsPos[posIndex].add(i);
4910                     }
4911                 }
4912             }
4913             return next.match(matcher, i, seq);
4914         }
4915         boolean matchInit(Matcher matcher, int i, CharSequence seq) {
4916             int save = matcher.locals[countIndex];
4917             boolean ret = false;
4918             if (posIndex != -1 && matcher.localsPos[posIndex] == null) {
4919                 matcher.localsPos[posIndex] = new IntHashSet();
4920             }
4921             if (0 < cmin) {
4922                 matcher.locals[countIndex] = 1;
4923                 ret = body.match(matcher, i, seq);
4924             } else if (0 < cmax) {
4925                 matcher.locals[countIndex] = 1;
4926                 ret = body.match(matcher, i, seq);
4927                 if (ret == false)
4928                     ret = next.match(matcher, i, seq);
4929             } else {
4930                 ret = next.match(matcher, i, seq);
4931             }
4932             matcher.locals[countIndex] = save;
4933             return ret;
4934         }
4935         boolean study(TreeInfo info) {
4936             info.maxValid = false;
4937             info.deterministic = false;
4938             return false;
4939         }
4940     }


5347             int startIndex = (!matcher.transparentBounds) ?
5348                              matcher.from : 0;
5349             int from = Math.max(i - rmaxChars, startIndex);
5350             matcher.lookbehindTo = i;
5351             // Relax transparent region boundaries for lookbehind
5352             if (matcher.transparentBounds)
5353                 matcher.from = 0;
5354             for (int j = i - rminChars;
5355                  !conditionMatched && j >= from;
5356                  j -= j>from ? countChars(seq, j, -1) : 1) {
5357                 conditionMatched = cond.match(matcher, j, seq);
5358             }
5359             //Reinstate region boundaries
5360             matcher.from = savedFrom;
5361             matcher.lookbehindTo = savedLBT;
5362             return !conditionMatched && next.match(matcher, i, seq);
5363         }
5364     }
5365 
5366     /**






























5367      * Handles word boundaries. Includes a field to allow this one class to
5368      * deal with the different types of word boundaries we can match. The word
5369      * characters include underscores, letters, and digits. Non spacing marks
5370      * can are also part of a word if they have a base character, otherwise
5371      * they are ignored for purposes of finding word boundaries.
5372      */
5373     static final class Bound extends Node {
5374         static int LEFT = 0x1;
5375         static int RIGHT= 0x2;
5376         static int BOTH = 0x3;
5377         static int NONE = 0x4;
5378         int type;
5379         boolean useUWORD;
5380         Bound(int n, boolean useUWORD) {
5381             type = n;
5382             this.useUWORD = useUWORD;
5383         }
5384 
5385         boolean isWord(int ch) {
5386             return useUWORD ? CharPredicates.WORD.is(ch)
5387                             : (ch == '_' || Character.isLetterOrDigit(ch));
5388         }
5389 
5390         int check(Matcher matcher, int i, CharSequence seq) {
5391             int ch;
5392             boolean left = false;
5393             int startIndex = matcher.from;
5394             int endIndex = matcher.to;
5395             if (matcher.transparentBounds) {
5396                 startIndex = 0;
5397                 endIndex = matcher.getTextLength();
5398             }
5399             if (i > startIndex) {
5400                 ch = Character.codePointBefore(seq, i);
5401                 left = (isWord(ch) ||
5402                     ((Character.getType(ch) == Character.NON_SPACING_MARK)
5403                      && hasBaseCharacter(matcher, i-1, seq)));
5404             }
5405             boolean right = false;
5406             if (i < endIndex) {


5612                         i += countChars(seq, i, n);
5613                         continue NEXT;
5614                     }
5615                 }
5616                 // Entire pattern matched starting at i
5617                 matcher.first = i;
5618                 boolean ret = next.match(matcher, i + lengthInChars, seq);
5619                 if (ret) {
5620                     matcher.first = i;
5621                     matcher.groups[0] = matcher.first;
5622                     matcher.groups[1] = matcher.last;
5623                     return true;
5624                 }
5625                 i += countChars(seq, i, 1);
5626             }
5627             matcher.hitEnd = true;
5628             return false;
5629         }
5630     }
5631 
5632     @FunctionalInterface
5633     static interface CharPredicate {
5634         boolean is(int ch);
5635 
5636         default CharPredicate and(CharPredicate p) {
5637             return ch -> is(ch) && p.is(ch);
5638         }
5639         default CharPredicate union(CharPredicate p) {
5640             return ch -> is(ch) || p.is(ch);
5641         }
5642         default CharPredicate union(CharPredicate p1,
5643                                     CharPredicate p2 ) {
5644             return ch -> is(ch) || p1.is(ch) || p2.is(ch);
5645         }
5646         default CharPredicate negate() {
5647             return ch -> !is(ch);
5648         }
5649     }
5650 
5651     static interface BmpCharPredicate extends CharPredicate {
5652 
5653         default CharPredicate and(CharPredicate p) {
5654             if(p instanceof BmpCharPredicate)
5655                 return (BmpCharPredicate)(ch -> is(ch) && p.is(ch));
5656             return ch -> is(ch) && p.is(ch);
5657         }
5658         default CharPredicate union(CharPredicate p) {
5659             if (p instanceof BmpCharPredicate)
5660                 return (BmpCharPredicate)(ch -> is(ch) || p.is(ch));
5661             return ch -> is(ch) || p.is(ch);
5662         }
5663         static CharPredicate union(CharPredicate... predicates) {
5664             CharPredicate cp = ch -> {
5665                 for (CharPredicate p : predicates) {
5666                     if (!p.is(ch))
5667                         return false;
5668                 }
5669                 return true;
5670             };
5671             for (CharPredicate p : predicates) {
5672                 if (! (p instanceof BmpCharPredicate))
5673                     return cp;
5674             }
5675             return (BmpCharPredicate)cp;
5676         }
5677     }
5678 
5679     /**
5680      * matches a Perl vertical whitespace
5681      */
5682     static BmpCharPredicate VertWS = cp ->
5683         (cp >= 0x0A && cp <= 0x0D) || cp == 0x85 || cp == 0x2028 || cp == 0x2029;
5684 
5685     /**
5686      * matches a Perl horizontal whitespace
5687      */
5688     static BmpCharPredicate HorizWS = cp ->
5689         cp == 0x09 || cp == 0x20 || cp == 0xa0 || cp == 0x1680 ||
5690         cp == 0x180e || cp >= 0x2000 && cp <= 0x200a ||  cp == 0x202f ||
5691         cp == 0x205f || cp == 0x3000;
5692 
5693     /**
5694      *  for the Unicode category ALL and the dot metacharacter when
5695      *  in dotall mode.
5696      */
5697     static CharPredicate ALL = ch -> true;
5698 
5699     /**
5700      * for the dot metacharacter when dotall is not enabled.
5701      */
5702     static CharPredicate DOT = ch -> (ch != '\n' && ch != '\r'
5703                                           && (ch|1) != '\u2029'
5704                                           && ch != '\u0085');
5705     /**
5706      *  the dot metacharacter when dotall is not enabled but UNIX_LINES is enabled.
5707      */
5708     static CharPredicate UNIXDOT = ch ->  ch != '\n';
5709 
5710     /**
5711      * Indicate that matches a Supplementary Unicode character
5712      */
5713     static CharPredicate SingleS(int c) {
5714         return ch -> ch == c;
5715     }
5716 
5717     /**
5718      * A bmp/optimized predicate of single
5719      */
5720     static BmpCharPredicate Single(int c) {
5721         return ch -> ch == c;
5722     }
5723 
5724     /**
5725      * Case insensitive matches a given BMP character
5726      */
5727     static BmpCharPredicate SingleI(int lower, int upper) {
5728         return ch -> ch == lower || ch == upper;
5729     }
5730 
5731     /**
5732      * Unicode case insensitive matches a given Unicode character
5733      */
5734     static CharPredicate SingleU(int lower) {
5735         return ch -> lower == ch ||
5736                      lower == Character.toLowerCase(Character.toUpperCase(ch));
5737     }
5738 
5739     private static boolean inRange(int lower, int ch, int upper) {
5740         return lower <= ch && ch <= upper;


5741     }
5742 
5743     /**
5744      * Charactrs within a explicit value range
5745      */
5746     static CharPredicate Range(int lower, int upper) {
5747         if (upper < Character.MIN_HIGH_SURROGATE ||
5748             lower > Character.MAX_HIGH_SURROGATE &&
5749             upper < Character.MIN_SUPPLEMENTARY_CODE_POINT)
5750             return (BmpCharPredicate)(ch -> inRange(lower, ch, upper));
5751         return ch -> inRange(lower, ch, upper);
5752     }
5753 
5754    /**
5755     * Charactrs within a explicit value range in a case insensitive manner.
5756     */
5757     static CharPredicate CIRange(int lower, int upper) {
5758         return ch -> inRange(lower, ch, upper) ||
5759                      ASCII.isAscii(ch) &&
5760                      (inRange(lower, ASCII.toUpper(ch), upper) ||
5761                       inRange(lower, ASCII.toLower(ch), upper));































































































































































5762     }
5763 
5764     static CharPredicate CIRangeU(int lower, int upper) {
5765         return ch -> {
5766             if (inRange(lower, ch, upper))
5767                 return true;
5768             int up = Character.toUpperCase(ch);
5769             return inRange(lower, up, upper) ||
5770                    inRange(lower, Character.toLowerCase(up), upper);
5771         };
5772     }
5773 
5774     /**
5775      *  This must be the very first initializer.
5776      */
5777     static final Node accept = new Node();
5778 
5779     static final Node lastAccept = new LastNode();
5780 
5781     /**
5782      * Creates a predicate which can be used to match a string.
5783      *
5784      * @return  The predicate which can be used for matching on a string
5785      * @since   1.8
5786      */
5787     public Predicate<String> asPredicate() {
5788         return s -> matcher(s).find();
5789     }
5790 
5791     /**
5792      * Creates a stream from the given input sequence around matches of this
5793      * pattern.
5794      *
5795      * <p> The stream returned by this method contains each substring of the
5796      * input sequence that is terminated by another subsequence that matches
5797      * this pattern or is terminated by the end of the input sequence.  The
5798      * substrings in the stream are in the order in which they occur in the
5799      * input. Trailing empty strings will be discarded and not encountered in
5800      * the stream.
5801      *