| /* |
| * Copyright 2000-2014 JetBrains s.r.o. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package com.intellij.openapi.util; |
| |
| import com.intellij.util.Function; |
| import org.jetbrains.annotations.NotNull; |
| |
| public class Pair<A, B> { |
| public final A first; |
| public final B second; |
| |
| @NotNull |
| public static <A, B> Pair<A, B> create(A first, B second) { |
| //noinspection DontUsePairConstructor |
| return new Pair<A, B>(first, second); |
| } |
| |
| @NotNull |
| public static <A, B> Function<A, Pair<A, B>> createFunction(final B value) { |
| return new Function<A, Pair<A, B>>() { |
| public Pair<A, B> fun(A a) { |
| return create(a, value); |
| } |
| }; |
| } |
| |
| public static <T> T getFirst(Pair<T, ?> pair) { |
| return pair != null ? pair.first : null; |
| } |
| |
| public static <T> T getSecond(Pair<?, T> pair) { |
| return pair != null ? pair.second : null; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private static final Pair EMPTY = create(null, null); |
| |
| @SuppressWarnings("unchecked") |
| public static <A, B> Pair<A, B> empty() { |
| return EMPTY; |
| } |
| |
| public Pair(A first, B second) { |
| this.first = first; |
| this.second = second; |
| } |
| |
| public final A getFirst() { |
| return first; |
| } |
| |
| public final B getSecond() { |
| return second; |
| } |
| |
| public final boolean equals(Object o) { |
| return o instanceof Pair && Comparing.equal(first, ((Pair)o).first) && Comparing.equal(second, ((Pair)o).second); |
| } |
| |
| public int hashCode() { |
| int result = first != null ? first.hashCode() : 0; |
| result = 31 * result + (second != null ? second.hashCode() : 0); |
| return result; |
| } |
| |
| public String toString() { |
| return "<" + first + "," + second + ">"; |
| } |
| } |