1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu)
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21package proguard.util;
22
23/**
24 * This StringParser can create StringMatcher instances for regular expressions
25 * matching names. The regular expressions are interpreted as comma-separated
26 * lists of names, optionally prefixed with '!' negators.
27 * If a name with a negator matches, a negative match is returned, without
28 * considering any subsequent entries in the list.
29 * Names can contain the following wildcards:
30 * '?'  for a single character, and
31 * '*'  for any number of characters.
32 *
33 * @author Eric Lafortune
34 */
35public class NameParser implements StringParser
36{
37    // Implementations for StringParser.
38
39    public StringMatcher parse(String regularExpression)
40    {
41        int           index;
42        StringMatcher nextMatcher = new EmptyStringMatcher();
43
44        // Look for wildcards.
45        for (index = 0; index < regularExpression.length(); index++)
46        {
47            // Is there a '*' wildcard?
48            if (regularExpression.charAt(index) == '*')
49            {
50                // Create a matcher for the wildcard and, recursively, for the
51                // remainder of the string.
52                nextMatcher =
53                    new VariableStringMatcher(null,
54                                              null,
55                                              0,
56                                              Integer.MAX_VALUE,
57                                              parse(regularExpression.substring(index + 1)));
58                break;
59            }
60
61            // Is there a '?' wildcard?
62            else if (regularExpression.charAt(index) == '?')
63            {
64                // Create a matcher for the wildcard and, recursively, for the
65                // remainder of the string.
66                nextMatcher =
67                    new VariableStringMatcher(null,
68                                              null,
69                                              1,
70                                              1,
71                                              parse(regularExpression.substring(index + 1)));
72                break;
73            }
74        }
75
76        // Return a matcher for the fixed first part of the regular expression,
77        // if any, and the remainder.
78        return index != 0 ?
79            (StringMatcher)new FixedStringMatcher(regularExpression.substring(0, index), nextMatcher) :
80            (StringMatcher)nextMatcher;
81    }
82
83
84    /**
85     * A main method for testing name matching.
86     */
87    public static void main(String[] args)
88    {
89        try
90        {
91            System.out.println("Regular expression ["+args[0]+"]");
92            NameParser parser  = new NameParser();
93            StringMatcher  matcher = parser.parse(args[0]);
94            for (int index = 1; index < args.length; index++)
95            {
96                String string = args[index];
97                System.out.print("String             ["+string+"]");
98                System.out.println(" -> match = "+matcher.matches(args[index]));
99            }
100        }
101        catch (Exception ex)
102        {
103            ex.printStackTrace();
104        }
105    }
106}
107