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
17package com.google.common.collect;
18
19import com.google.common.annotations.Beta;
20
21import java.util.Map;
22
23import 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
36public 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}
135