001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3.tuple;
018
019import java.util.Objects;
020
021/**
022 * A mutable triple consisting of three {@link Object} elements.
023 *
024 * <p>Not #ThreadSafe#</p>
025 *
026 * @param <L> the left element type.
027 * @param <M> the middle element type.
028 * @param <R> the right element type.
029 * @since 3.2
030 */
031public class MutableTriple<L, M, R> extends Triple<L, M, R> {
032
033    /**
034     * The empty array singleton.
035     * <p>
036     * Consider using {@link #emptyArray()} to avoid generics warnings.
037     * </p>
038     *
039     * @since 3.10
040     */
041    public static final MutableTriple<?, ?, ?>[] EMPTY_ARRAY = {};
042
043    /** Serialization version */
044    private static final long serialVersionUID = 1L;
045
046    /**
047     * Returns the empty array singleton that can be assigned without compiler warning.
048     *
049     * @param <L> the left element type.
050     * @param <M> the middle element type.
051     * @param <R> the right element type.
052     * @return the empty array singleton that can be assigned without compiler warning.
053     * @since 3.10
054     */
055    @SuppressWarnings("unchecked")
056    public static <L, M, R> MutableTriple<L, M, R>[] emptyArray() {
057        return (MutableTriple<L, M, R>[]) EMPTY_ARRAY;
058    }
059
060    /**
061     * Obtains a mutable triple of three objects inferring the generic types.
062     *
063     * <p>This factory allows the triple to be created using inference to
064     * obtain the generic types.</p>
065     *
066     * @param <L> the left element type.
067     * @param <M> the middle element type.
068     * @param <R> the right element type.
069     * @param left  the left element, may be null.
070     * @param middle  the middle element, may be null.
071     * @param right  the right element, may be null.
072     * @return a triple formed from the three parameters, not null.
073     */
074    public static <L, M, R> MutableTriple<L, M, R> of(final L left, final M middle, final R right) {
075        return new MutableTriple<>(left, middle, right);
076    }
077
078    /**
079     * Obtains a mutable triple of three non-null objects inferring the generic types.
080     *
081     * <p>This factory allows the triple to be created using inference to
082     * obtain the generic types.</p>
083     *
084     * @param <L> the left element type.
085     * @param <M> the middle element type.
086     * @param <R> the right element type.
087     * @param left  the left element, may not be null.
088     * @param middle  the middle element, may not be null.
089     * @param right  the right element, may not be null.
090     * @return a triple formed from the three parameters, not null.
091     * @throws NullPointerException if any input is null.
092     * @since 3.13.0
093     */
094    public static <L, M, R> MutableTriple<L, M, R> ofNonNull(final L left, final M middle, final R right) {
095        return of(Objects.requireNonNull(left, "left"), Objects.requireNonNull(middle, "middle"), Objects.requireNonNull(right, "right"));
096    }
097
098    /** Left object. */
099    public L left;
100    /** Middle object. */
101    public M middle;
102
103    /** Right object. */
104    public R right;
105
106    /**
107     * Create a new triple instance of three nulls.
108     */
109    public MutableTriple() {
110    }
111
112    /**
113     * Create a new triple instance.
114     *
115     * @param left  the left value, may be null.
116     * @param middle  the middle value, may be null.
117     * @param right  the right value, may be null.
118     */
119    public MutableTriple(final L left, final M middle, final R right) {
120        this.left = left;
121        this.middle = middle;
122        this.right = right;
123    }
124
125    /**
126     * {@inheritDoc}
127     */
128    @Override
129    public L getLeft() {
130        return left;
131    }
132
133    /**
134     * {@inheritDoc}
135     */
136    @Override
137    public M getMiddle() {
138        return middle;
139    }
140
141    /**
142     * {@inheritDoc}
143     */
144    @Override
145    public R getRight() {
146        return right;
147    }
148
149    /**
150     * Sets the left element of the triple.
151     *
152     * @param left  the new value of the left element, may be null.
153     */
154    public void setLeft(final L left) {
155        this.left = left;
156    }
157
158    /**
159     * Sets the middle element of the triple.
160     *
161     * @param middle  the new value of the middle element, may be null.
162     */
163    public void setMiddle(final M middle) {
164        this.middle = middle;
165    }
166
167    /**
168     * Sets the right element of the triple.
169     *
170     * @param right  the new value of the right element, may be null.
171     */
172    public void setRight(final R right) {
173        this.right = right;
174    }
175}
176