1 /*

     2  * Copyright (c) 2010, 2013, 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 jdk.nashorn.internal.runtime.regexp;

    27 

    28 import jdk.nashorn.internal.runtime.ParserException;

    29 

    30 import static java.util.regex.Pattern.CASE_INSENSITIVE;

    31 import static java.util.regex.Pattern.MULTILINE;

    32 import static java.util.regex.Pattern.UNICODE_CASE;

    33 

    34 import java.util.regex.Matcher;

    35 import java.util.regex.Pattern;

    36 import java.util.regex.PatternSyntaxException;

    37 

    38 /**

    39  * Default regular expression implementation based on java.util.regex package.

    40  *

    41  * Note that this class is not thread-safe as it stores the current match result

    42  * and the string being matched in instance fields.

    43  */

    44 public class DefaultRegExp extends RegExp {

    45 

    46     /** Java regexp pattern to use for match. We compile to one of these */

    47     private Pattern pattern;

    48 

    49     /** The matcher */

    50     private RegExpMatcher matcher;

    51 

    52     /**

    53      * Construct a Regular expression from the given {@code source} and {@code flags} strings.

    54      *

    55      * @param source RegExp source string

    56      * @param flags RegExp flag string

    57      * @throws ParserException if flags is invalid or source string has syntax error.

    58      */

    59     public DefaultRegExp(final String source, final String flags) throws ParserException {

    60         super(source, flags);

    61 

    62         int intFlags = 0;

    63 

    64         if (isIgnoreCase()) {

    65             intFlags |= CASE_INSENSITIVE | UNICODE_CASE;

    66         }

    67         if (isMultiline()) {

    68             intFlags |= MULTILINE;

    69         }

    70 

    71         try {

    72             RegExpScanner parsed;

    73 

    74             try {

    75                 parsed = RegExpScanner.scan(source);

    76             } catch (final PatternSyntaxException e) {

    77                 // refine the exception with a better syntax error, if this

    78                 // passes, just rethrow what we have

    79                 Pattern.compile(source, intFlags);

    80                 throw e;

    81             }

    82 

    83             if (parsed != null) {

    84                 this.pattern = Pattern.compile(parsed.getJavaPattern(), intFlags);

    85                 this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead();

    86             }

    87         } catch (final PatternSyntaxException e2) {

    88             throwParserException("syntax", e2.getMessage());

    89         }

    90     }

    91 

    92     @Override

    93     public RegExpMatcher match(final String str) {

    94         if (pattern == null) {

    95             return null; // never matches or similar, e.g. a[]

    96         }

    97 

    98         RegExpMatcher currentMatcher = this.matcher;

    99 

   100         if (currentMatcher == null || matcher.getInput() != str) {

   101             currentMatcher = new DefaultMatcher(str);

   102             this.matcher  = currentMatcher;

   103         }

   104 

   105         return currentMatcher;

   106     }

   107 

   108     class DefaultMatcher implements RegExpMatcher {

   109         final String input;

   110         final Matcher defaultMatcher;

   111 

   112         DefaultMatcher(final String input) {

   113             this.input = input;

   114             this.defaultMatcher = pattern.matcher(input);

   115         }

   116 

   117         @Override

   118         public boolean search(final int start) {

   119             return defaultMatcher.find(start);

   120         }

   121 

   122         @Override

   123         public String getInput() {

   124             return input;

   125         }

   126 

   127         @Override

   128         public int start() {

   129             return defaultMatcher.start();

   130         }

   131 

   132         @Override

   133         public int start(final int group) {

   134             return defaultMatcher.start(group);

   135         }

   136 

   137         @Override

   138         public int end() {

   139             return defaultMatcher.end();

   140         }

   141 

   142         @Override

   143         public int end(final int group) {

   144             return defaultMatcher.end(group);

   145         }

   146 

   147         @Override

   148         public String group() {

   149             return defaultMatcher.group();

   150         }

   151 

   152         @Override

   153         public String group(final int group) {

   154             return defaultMatcher.group(group);

   155         }

   156 

   157         @Override

   158         public int groupCount() {

   159             return defaultMatcher.groupCount();

   160         }

   161     }

   162 

   163 }