/*
* Copyright 2014 the original author or authors.
*
* 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 org.gradle.internal;
import com.google.common.base.Function;
public final class Pair<L, R> {
public final L left;
public final R right;
private Pair(L left, R right) {
this.left = left;
this.right = right;
}
public L getLeft() {
return left;
}
public R getRight() {
return right;
}
public L left() {
return left;
}
public R right() {
return right;
}
public static <L, R> Pair<L, R> of(L left, R right) {
return new Pair<L, R>(left, right);
}
public <T> Pair<T, Pair<L, R>> pushLeft(T t) {
return of(t, this);
}
public <T> Pair<Pair<L, R>, T> pushRight(T t) {
return of(this, t);
}
public <T> Pair<Pair<T, L>, R> nestLeft(T t) {
return of(of(t, left), right);
}
public <T> Pair<L, Pair<T, R>> nestRight(T t) {
return of(left, of(t, right));
}
public <T> Pair<T, R> mapLeft(Function<? super L, ? extends T> function) throws Exception {
return of(function.apply(left), right);
}
public <T> Pair<L, T> mapRight(Function<? super R, ? extends T> function) throws Exception {
return of(left, function.apply(right));
}
public <T> T map(Function<? super Pair<L, R>, ? extends T> function) throws Exception {
return function.apply(this);
}
public static <L, T extends Pair<L, ?>> Function<T, L> unpackLeft() {
return new Function<T, L>() {
@Override
public L apply(T tuple) {
return tuple.left;
}
};
}
public static <R, T extends Pair<?, R>> Function<T, R> unpackRight() {
return new Function<T, R>() {
@Override
public R apply(T tuple) {
return tuple.right;
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
Pair<?, ?> pair = (Pair<?, ?>) o;
return !(left != null ? !left.equals(pair.left) : pair.left != null) && !(right != null ? !right.equals(pair.right) : pair.right != null);
}
@Override
public int hashCode() {
int result = left != null ? left.hashCode() : 0;
result = 31 * result + (right != null ? right.hashCode() : 0);
return result;
}
@Override
public String toString() {
return "Pair[" + left + "," + right + ']';
}
}