/*
 * Copyright (c) 2021 Goldman Sachs.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompany this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.eclipse.collections.impl.tuple;

import java.util.Map;
import java.util.Objects;

import org.eclipse.collections.api.tuple.Pair;

A PairImpl is a container that holds two related objects. It is the equivalent of an Association in Smalltalk, or an implementation of Map.Entry in the JDK.
/** * A PairImpl is a container that holds two related objects. It is the equivalent of an Association in Smalltalk, or an * implementation of Map.Entry in the JDK. */
class PairImpl<T1, T2> implements Pair<T1, T2> { private static final long serialVersionUID = 1L; private final T1 one; private final T2 two; PairImpl(T1 newOne, T2 newTwo) { this.one = newOne; this.two = newTwo; } @Override public T1 getOne() { return this.one; } @Override public T2 getTwo() { return this.two; } @Override public void put(Map<? super T1, ? super T2> map) { map.put(this.one, this.two); } @Override public PairImpl<T2, T1> swap() { return new PairImpl<>(this.two, this.one); } @Override public boolean equals(Object o) { if (this == o) { return true; } if (!(o instanceof Pair)) { return false; } Pair<?, ?> that = (Pair<?, ?>) o; return Objects.equals(this.one, that.getOne()) && Objects.equals(this.two, that.getTwo()); } @Override public int hashCode() { int result = this.one == null ? 0 : this.one.hashCode(); result = 29 * result + (this.two == null ? 0 : this.two.hashCode()); return result; } @Override public String toString() { return this.one + ":" + this.two; } @Override public Map.Entry<T1, T2> toEntry() { return ImmutableEntry.of(this.one, this.two); } @Override public int compareTo(Pair<T1, T2> other) { int i = ((Comparable<T1>) this.one).compareTo(other.getOne()); if (i != 0) { return i; } return ((Comparable<T2>) this.two).compareTo(other.getTwo()); } }