001/*
002 * Copyright (C) 2014 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.graph;
018
019import com.google.common.annotations.Beta;
020import com.google.errorprone.annotations.CanIgnoreReturnValue;
021
022/**
023 * A subinterface of {@link Graph} which adds mutation methods. When mutation is not required, users
024 * should prefer the {@link Graph} interface.
025 *
026 * @author James Sexton
027 * @author Joshua O'Madadhain
028 * @param <N> Node parameter type
029 * @since 20.0
030 */
031@Beta
032@ElementTypesAreNonnullByDefault
033public interface MutableGraph<N> extends Graph<N> {
034
035  /**
036   * Adds {@code node} if it is not already present.
037   *
038   * <p><b>Nodes must be unique</b>, just as {@code Map} keys must be. They must also be non-null.
039   *
040   * @return {@code true} if the graph was modified as a result of this call
041   */
042  @CanIgnoreReturnValue
043  boolean addNode(N node);
044
045  /**
046   * Adds an edge connecting {@code nodeU} to {@code nodeV} if one is not already present.
047   *
048   * <p>If the graph is directed, the resultant edge will be directed; otherwise, it will be
049   * undirected.
050   *
051   * <p>If {@code nodeU} and {@code nodeV} are not already present in this graph, this method will
052   * silently {@link #addNode(Object) add} {@code nodeU} and {@code nodeV} to the graph.
053   *
054   * @return {@code true} if the graph was modified as a result of this call
055   * @throws IllegalArgumentException if the introduction of the edge would violate {@link
056   *     #allowsSelfLoops()}
057   */
058  @CanIgnoreReturnValue
059  boolean putEdge(N nodeU, N nodeV);
060
061  /**
062   * Adds an edge connecting {@code endpoints} (in the order, if any, specified by {@code
063   * endpoints}) if one is not already present.
064   *
065   * <p>If this graph is directed, {@code endpoints} must be ordered and the added edge will be
066   * directed; if it is undirected, the added edge will be undirected.
067   *
068   * <p>If this graph is directed, {@code endpoints} must be ordered.
069   *
070   * <p>If either or both endpoints are not already present in this graph, this method will silently
071   * {@link #addNode(Object) add} each missing endpoint to the graph.
072   *
073   * @return {@code true} if the graph was modified as a result of this call
074   * @throws IllegalArgumentException if the introduction of the edge would violate {@link
075   *     #allowsSelfLoops()}
076   * @throws IllegalArgumentException if the endpoints are unordered and the graph is directed
077   * @since 27.1
078   */
079  @CanIgnoreReturnValue
080  boolean putEdge(EndpointPair<N> endpoints);
081
082  /**
083   * Removes {@code node} if it is present; all edges incident to {@code node} will also be removed.
084   *
085   * @return {@code true} if the graph was modified as a result of this call
086   */
087  @CanIgnoreReturnValue
088  boolean removeNode(N node);
089
090  /**
091   * Removes the edge connecting {@code nodeU} to {@code nodeV}, if it is present.
092   *
093   * @return {@code true} if the graph was modified as a result of this call
094   */
095  @CanIgnoreReturnValue
096  boolean removeEdge(N nodeU, N nodeV);
097
098  /**
099   * Removes the edge connecting {@code endpoints}, if it is present.
100   *
101   * <p>If this graph is directed, {@code endpoints} must be ordered.
102   *
103   * @throws IllegalArgumentException if the endpoints are unordered and the graph is directed
104   * @return {@code true} if the graph was modified as a result of this call
105   * @since 27.1
106   */
107  @CanIgnoreReturnValue
108  boolean removeEdge(EndpointPair<N> endpoints);
109}