| /* |
| * Copyright (C) 2007 Google Inc. |
| * |
| * 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 static com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.io.Serializable; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** An ordering that uses the natural order of the values. */ |
| @GwtCompatible(serializable = true) |
| @SuppressWarnings("unchecked") // TODO: the right way to explain this?? |
| final class NaturalOrdering |
| extends Ordering<Comparable> implements Serializable { |
| static final NaturalOrdering INSTANCE = new NaturalOrdering(); |
| |
| public int compare(Comparable left, Comparable right) { |
| checkNotNull(right); // left null is caught later |
| if (left == right) { |
| return 0; |
| } |
| |
| @SuppressWarnings("unchecked") // we're permitted to throw CCE |
| int result = left.compareTo(right); |
| return result; |
| } |
| |
| @SuppressWarnings("unchecked") // TODO: the right way to explain this?? |
| @Override public <S extends Comparable> Ordering<S> reverse() { |
| return (Ordering) ReverseNaturalOrdering.INSTANCE; |
| } |
| |
| // Override to remove a level of indirection from inner loop |
| @SuppressWarnings("unchecked") // TODO: the right way to explain this?? |
| @Override public int binarySearch( |
| List<? extends Comparable> sortedList, Comparable key) { |
| return Collections.binarySearch((List) sortedList, key); |
| } |
| |
| // Override to remove a level of indirection from inner loop |
| @Override public <E extends Comparable> List<E> sortedCopy( |
| Iterable<E> iterable) { |
| List<E> list = Lists.newArrayList(iterable); |
| Collections.sort(list); |
| return list; |
| } |
| |
| // preserving singleton-ness gives equals()/hashCode() for free |
| private Object readResolve() { |
| return INSTANCE; |
| } |
| |
| @Override public String toString() { |
| return "Ordering.natural()"; |
| } |
| |
| private NaturalOrdering() {} |
| |
| private static final long serialVersionUID = 0; |
| } |