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 * https://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
18 package org.apache.commons.collections4;
19
20 import java.util.Comparator;
21 import java.util.SortedMap;
22
23 /**
24 * Defines a map that allows bidirectional lookup between key and values and retains both keys and values in sorted order.
25 * <p>
26 * Implementations should allow a value to be looked up from a key and a key to be looked up from a value with equal performance.
27 * </p>
28 *
29 * @param <K> The type of the keys in the map
30 * @param <V> The type of the values in the map
31 * @since 3.0
32 */
33 public interface SortedBidiMap<K, V> extends OrderedBidiMap<K, V>, SortedMap<K, V> {
34
35 /**
36 * Gets a view of this map where the keys and values are reversed.
37 * <p>
38 * Changes to one map will be visible in the other and vice versa. This enables both directions of the map to be accessed equally.
39 * </p>
40 * <p>
41 * Implementations should seek to avoid creating a new object every time this method is called. See {@code AbstractMap.values()} etc. Calling this method on
42 * the inverse map should return the original.
43 * </p>
44 * <p>
45 * Implementations must return a {@code SortedBidiMap} instance, usually by forwarding to {@code inverseSortedBidiMap()}.
46 * </p>
47 *
48 * @return An inverted bidirectional map.
49 */
50 @Override
51 SortedBidiMap<V, K> inverseBidiMap();
52
53 /**
54 * Gets the comparator used for the values in the value-to-key map aspect.
55 *
56 * @return Comparator<? super V>.
57 */
58 Comparator<? super V> valueComparator();
59 }