1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17
18package java.util.regex;
19
20/**
21 * Holds the results of a successful match of a {@link Pattern} against a
22 * given string. Typically this is an instance of {@link Matcher}, but
23 * since that's a mutable class it's also possible to freeze its current
24 * state using {@link Matcher#toMatchResult}.
25 */
26public interface MatchResult {
27
28    /**
29     * Returns the index of the first character following the text that matched
30     * the whole regular expression.
31     */
32    int end();
33
34    /**
35     * Returns the index of the first character following the text that matched
36     * a given group. See {@link #group} for an explanation of group indexes.
37     */
38    int end(int group);
39
40    /**
41     * Returns the text that matched the whole regular expression.
42     */
43    String group();
44
45    /**
46     * Returns the text that matched a given group of the regular expression.
47     *
48     * <p>Explicit capturing groups in the pattern are numbered left to right in order
49     * of their <i>opening</i> parenthesis, starting at 1.
50     * The special group 0 represents the entire match (as if the entire pattern is surrounded
51     * by an implicit capturing group).
52     * For example, "a((b)c)" matching "abc" would give the following groups:
53     * <pre>
54     * 0 "abc"
55     * 1 "bc"
56     * 2 "b"
57     * </pre>
58     *
59     * <p>An optional capturing group that failed to match as part of an overall
60     * successful match (for example, "a(b)?c" matching "ac") returns null.
61     * A capturing group that matched the empty string (for example, "a(b?)c" matching "ac")
62     * returns the empty string.
63     */
64    String group(int group);
65
66    /**
67     * Returns the number of groups in the results, which is always equal to
68     * the number of groups in the original regular expression.
69     */
70    int groupCount();
71
72    /**
73     * Returns the index of the first character of the text that matched the
74     * whole regular expression.
75     */
76    int start();
77
78    /**
79     * Returns the index of the first character of the text that matched a given
80     * group. See {@link #group} for an explanation of group indexes.
81     */
82    int start(int group);
83}
84