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 package org.apache.commons.text.diff;
18
19 /**
20 * Command representing the keeping of one object present in both sequences.
21 * <p>
22 * When one object of the first sequence {@code equals} another objects in
23 * the second sequence at the right place, the {@link EditScript edit script}
24 * transforming the first sequence into the second sequence uses an instance of
25 * this class to represent the keeping of this object. The objects embedded in
26 * these type of commands always come from the first sequence.
27 * </p>
28 *
29 * @see StringsComparator
30 * @see EditScript
31 *
32 * @param <T> object type
33 * @since 1.0
34 */
35 public class KeepCommand<T> extends EditCommand<T> {
36
37 /**
38 * Constructs a new instance of KeepCommand.
39 *
40 * @param object the object belonging to both sequences (the object is a
41 * reference to the instance in the first sequence which is known
42 * to be equal to an instance in the second sequence)
43 */
44 public KeepCommand(final T object) {
45 super(object);
46 }
47
48 /**
49 * Accepts a visitor. When a {@code KeepCommand} accepts a visitor, it
50 * calls its {@link CommandVisitor#visitKeepCommand visitKeepCommand} method.
51 *
52 * @param visitor the visitor to be accepted
53 */
54 @Override
55 public void accept(final CommandVisitor<T> visitor) {
56 visitor.visitKeepCommand(getObject());
57 }
58 }