001/*
002 * Copyright (C) 2007 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.collect;
018
019import com.google.common.annotations.GwtCompatible;
020import com.google.errorprone.annotations.CanIgnoreReturnValue;
021import java.util.Collection;
022import java.util.Comparator;
023import java.util.Map;
024import java.util.Set;
025import java.util.SortedSet;
026import org.checkerframework.checker.nullness.qual.Nullable;
027
028/**
029 * A {@code SetMultimap} whose set of values for a given key are kept sorted; that is, they comprise
030 * a {@link SortedSet}. It cannot hold duplicate key-value pairs; adding a key-value pair that's
031 * already in the multimap has no effect. This interface does not specify the ordering of the
032 * multimap's keys. See the {@link Multimap} documentation for information common to all multimaps.
033 *
034 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods each return a {@link
035 * SortedSet} of values, while {@link Multimap#entries()} returns a {@link Set} of map entries.
036 * Though the method signature doesn't say so explicitly, the map returned by {@link #asMap} has
037 * {@code SortedSet} values.
038 *
039 * <p>See the Guava User Guide article on <a href=
040 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap"> {@code
041 * Multimap}</a>.
042 *
043 * @author Jared Levy
044 * @since 2.0
045 */
046@GwtCompatible
047public interface SortedSetMultimap<K, V> extends SetMultimap<K, V> {
048  // Following Javadoc copied from Multimap.
049
050  /**
051   * Returns a collection view of all values associated with a key. If no mappings in the multimap
052   * have the provided key, an empty collection is returned.
053   *
054   * <p>Changes to the returned collection will update the underlying multimap, and vice versa.
055   *
056   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
057   * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the
058   * {@link Multimap} interface.
059   */
060  @Override
061  SortedSet<V> get(@Nullable K key);
062
063  /**
064   * Removes all values associated with a given key.
065   *
066   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
067   * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the
068   * {@link Multimap} interface.
069   */
070  @CanIgnoreReturnValue
071  @Override
072  SortedSet<V> removeAll(@Nullable Object key);
073
074  /**
075   * Stores a collection of values with the same key, replacing any existing values for that key.
076   *
077   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
078   * returns a {@link SortedSet}, instead of the {@link java.util.Collection} specified in the
079   * {@link Multimap} interface.
080   *
081   * <p>Any duplicates in {@code values} will be stored in the multimap once.
082   */
083  @CanIgnoreReturnValue
084  @Override
085  SortedSet<V> replaceValues(K key, Iterable<? extends V> values);
086
087  /**
088   * Returns a map view that associates each key with the corresponding values in the multimap.
089   * Changes to the returned map, such as element removal, will update the underlying multimap. The
090   * map does not support {@code setValue()} on its entries, {@code put}, or {@code putAll}.
091   *
092   * <p>When passed a key that is present in the map, {@code asMap().get(Object)} has the same
093   * behavior as {@link #get}, returning a live collection. When passed a key that is not present,
094   * however, {@code asMap().get(Object)} returns {@code null} instead of an empty collection.
095   *
096   * <p><b>Note:</b> The returned map's values are guaranteed to be of type {@link SortedSet}. To
097   * obtain this map with the more specific generic type {@code Map<K, SortedSet<V>>}, call {@link
098   * Multimaps#asMap(SortedSetMultimap)} instead.
099   */
100  @Override
101  Map<K, Collection<V>> asMap();
102
103  /**
104   * Returns the comparator that orders the multimap values, with {@code null} indicating that
105   * natural ordering is used.
106   */
107  Comparator<? super V> valueComparator();
108}