| /* |
| * Copyright (C) 2007 The Guava 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 com.google.common.collect; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import java.io.Serializable; |
| import java.util.Comparator; |
| import java.util.Iterator; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** An ordering which sorts iterables by comparing corresponding elements pairwise. */ |
| @GwtCompatible(serializable = true) |
| final class LexicographicalOrdering<T> extends Ordering<Iterable<T>> implements Serializable { |
| final Comparator<? super T> elementOrder; |
| |
| LexicographicalOrdering(Comparator<? super T> elementOrder) { |
| this.elementOrder = elementOrder; |
| } |
| |
| @Override |
| public int compare(Iterable<T> leftIterable, Iterable<T> rightIterable) { |
| Iterator<T> left = leftIterable.iterator(); |
| Iterator<T> right = rightIterable.iterator(); |
| while (left.hasNext()) { |
| if (!right.hasNext()) { |
| return LEFT_IS_GREATER; // because it's longer |
| } |
| int result = elementOrder.compare(left.next(), right.next()); |
| if (result != 0) { |
| return result; |
| } |
| } |
| if (right.hasNext()) { |
| return RIGHT_IS_GREATER; // because it's longer |
| } |
| return 0; |
| } |
| |
| @Override |
| public boolean equals(@NullableDecl Object object) { |
| if (object == this) { |
| return true; |
| } |
| if (object instanceof LexicographicalOrdering) { |
| LexicographicalOrdering<?> that = (LexicographicalOrdering<?>) object; |
| return this.elementOrder.equals(that.elementOrder); |
| } |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| return elementOrder.hashCode() ^ 2075626741; // meaningless |
| } |
| |
| @Override |
| public String toString() { |
| return elementOrder + ".lexicographical()"; |
| } |
| |
| private static final long serialVersionUID = 0; |
| } |