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 javax.annotation.Nullable;
027
028/**
029 * A {@code SetMultimap} whose set of values for a given key are kept sorted;
030 * that is, they comprise a {@link SortedSet}. It cannot hold duplicate
031 * key-value pairs; adding a key-value pair that's already in the multimap has
032 * no effect. This interface does not specify the ordering of the multimap's
033 * keys. See the {@link Multimap} documentation for information common to all
034 * multimaps.
035 *
036 * <p>The {@link #get}, {@link #removeAll}, and {@link #replaceValues} methods
037 * each return a {@link SortedSet} of values, while {@link Multimap#entries()}
038 * returns a {@link Set} of map entries. Though the method signature doesn't say
039 * so explicitly, the map returned by {@link #asMap} has {@code SortedSet}
040 * values.
041 *
042 * <p>See the Guava User Guide article on <a href=
043 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">
044 * {@code Multimap}</a>.
045 *
046 * @author Jared Levy
047 * @since 2.0
048 */
049@GwtCompatible
050public interface SortedSetMultimap<K, V> extends SetMultimap<K, V> {
051  // Following Javadoc copied from Multimap.
052
053  /**
054   * Returns a collection view of all values associated with a key. If no
055   * mappings in the multimap have the provided key, an empty collection is
056   * returned.
057   *
058   * <p>Changes to the returned collection will update the underlying multimap,
059   * and vice versa.
060   *
061   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
062   * key, this method returns a {@link SortedSet}, instead of the
063   * {@link java.util.Collection} specified in the {@link Multimap} interface.
064   */
065  @Override
066  SortedSet<V> get(@Nullable K key);
067
068  /**
069   * Removes all values associated with a given key.
070   *
071   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
072   * key, this method returns a {@link SortedSet}, instead of the
073   * {@link java.util.Collection} specified in the {@link Multimap} interface.
074   */
075  @CanIgnoreReturnValue
076  @Override
077  SortedSet<V> removeAll(@Nullable Object key);
078
079  /**
080   * Stores a collection of values with the same key, replacing any existing
081   * values for that key.
082   *
083   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given
084   * key, this method returns a {@link SortedSet}, instead of the
085   * {@link java.util.Collection} specified in the {@link Multimap} interface.
086   *
087   * <p>Any duplicates in {@code values} will be stored in the multimap once.
088   */
089  @CanIgnoreReturnValue
090  @Override
091  SortedSet<V> replaceValues(K key, Iterable<? extends V> values);
092
093  /**
094   * Returns a map view that associates each key with the corresponding values
095   * in the multimap. Changes to the returned map, such as element removal, will
096   * update the underlying multimap. The map does not support {@code setValue()}
097   * on its entries, {@code put}, or {@code putAll}.
098   *
099   * <p>When passed a key that is present in the map, {@code
100   * asMap().get(Object)} has the same behavior as {@link #get}, returning a
101   * live collection. When passed a key that is not present, however, {@code
102   * asMap().get(Object)} returns {@code null} instead of an empty collection.
103   *
104   * <p><b>Note:</b> The returned map's values are guaranteed to be of type
105   * {@link SortedSet}. To obtain this map with the more specific generic type
106   * {@code Map<K, SortedSet<V>>}, call
107   * {@link Multimaps#asMap(SortedSetMultimap)} instead.
108   */
109  @Override
110  Map<K, Collection<V>> asMap();
111
112  /**
113   * Returns the comparator that orders the multimap values, with {@code null}
114   * indicating that natural ordering is used.
115   */
116  Comparator<? super V> valueComparator();
117}