1 /*
2 * Copyright (C) 2012 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.google.common.collect;
18
19 import com.google.common.annotations.Beta;
20
21 import java.util.Map;
22
23 import javax.annotation.Nullable;
24
25 /**
26 * A mapping from disjoint nonempty ranges to non-null values. Queries look up the value
27 * associated with the range (if any) that contains a specified key.
28 *
29 * <p>In contrast to {@link RangeSet}, no "coalescing" is done of {@linkplain
30 * Range#isConnected(Range) connected} ranges, even if they are mapped to the same value.
31 *
32 * @author Louis Wasserman
33 * @since 14.0
34 */
35 @Beta
36 public interface RangeMap<K extends Comparable, V> {
37 /**
38 * Returns the value associated with the specified key, or {@code null} if there is no
39 * such value.
40 *
41 * <p>Specifically, if any range in this range map contains the specified key, the value
42 * associated with that range is returned.
43 */
44 @Nullable
45 V get(K key);
46
47 /**
48 * Returns the range containing this key and its associated value, if such a range is present
49 * in the range map, or {@code null} otherwise.
50 */
51 @Nullable
52 Map.Entry<Range<K>, V> getEntry(K key);
53
54 /**
55 * Returns the minimal range {@linkplain Range#encloses(Range) enclosing} the ranges
56 * in this {@code RangeMap}.
57 *
58 * @throws NoSuchElementException if this range map is empty
59 */
60 Range<K> span();
61
62 /**
63 * Maps a range to a specified value (optional operation).
64 *
65 * <p>Specifically, after a call to {@code put(range, value)}, if
66 * {@link Range#contains(Comparable) range.contains(k)}, then {@link #get(Comparable) get(k)}
67 * will return {@code value}.
68 *
69 * <p>If {@code range} {@linkplain Range#isEmpty() is empty}, then this is a no-op.
70 */
71 void put(Range<K> range, V value);
72
73 /**
74 * Puts all the associations from {@code rangeMap} into this range map (optional operation).
75 */
76 void putAll(RangeMap<K, V> rangeMap);
77
78 /**
79 * Removes all associations from this range map (optional operation).
80 */
81 void clear();
82
83 /**
84 * Removes all associations from this range map in the specified range (optional operation).
85 *
86 * <p>If {@code !range.contains(k)}, {@link #get(Comparable) get(k)} will return the same result
87 * before and after a call to {@code remove(range)}. If {@code range.contains(k)}, then
88 * after a call to {@code remove(range)}, {@code get(k)} will return {@code null}.
89 */
90 void remove(Range<K> range);
91
92 /**
93 * Returns a view of this range map as an unmodifiable {@code Map<Range<K>, V>}.
94 * Modifications to this range map are guaranteed to read through to the returned {@code Map}.
95 *
96 * <p>It is guaranteed that no empty ranges will be in the returned {@code Map}.
97 */
98 Map<Range<K>, V> asMapOfRanges();
99
100 /**
101 * Returns a view of the part of this range map that intersects with {@code range}.
102 *
103 * <p>For example, if {@code rangeMap} had the entries
104 * {@code [1, 5] => "foo", (6, 8) => "bar", (10, \u2025) => "baz"}
105 * then {@code rangeMap.subRangeMap(Range.open(3, 12))} would return a range map
106 * with the entries {@code (3, 5) => "foo", (6, 8) => "bar", (10, 12) => "baz"}.
107 *
108 * <p>The returned range map supports all optional operations that this range map supports,
109 * except for {@code asMapOfRanges().iterator().remove()}.
110 *
111 * <p>The returned range map will throw an {@link IllegalArgumentException} on an attempt to
112 * insert a range not {@linkplain Range#encloses(Range) enclosed} by {@code range}.
113 */
114 RangeMap<K, V> subRangeMap(Range<K> range);
115
116 /**
117 * Returns {@code true} if {@code obj} is another {@code RangeMap} that has an equivalent
118 * {@link #asMapOfRanges()}.
119 */
120 @Override
121 boolean equals(@Nullable Object o);
122
123 /**
124 * Returns {@code asMapOfRanges().hashCode()}.
125 */
126 @Override
127 int hashCode();
128
129 /**
130 * Returns a readable string representation of this range map.
131 */
132 @Override
133 String toString();
134 }