104 lines
2.8 KiB
Java
104 lines
2.8 KiB
Java
/*
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* Copyright (C) 2007 The Guava Authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.common.collect;
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import static com.google.common.base.Preconditions.checkNotNull;
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import java.io.Serializable;
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import java.util.Iterator;
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import com.google.common.annotations.GwtCompatible;
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/** An ordering that uses the reverse of the natural order of the values. */
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@GwtCompatible(serializable = true)
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@SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??
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final class ReverseNaturalOrdering extends Ordering<Comparable> implements Serializable {
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static final ReverseNaturalOrdering INSTANCE = new ReverseNaturalOrdering();
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@Override
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public int compare(Comparable left, Comparable right) {
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checkNotNull(left); // right null is caught later
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if (left == right) {
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return 0;
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}
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return right.compareTo(left);
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}
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@Override
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public <S extends Comparable> Ordering<S> reverse() {
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return Ordering.natural();
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}
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// Override the min/max methods to "hoist" delegation outside loops
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@Override
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public <E extends Comparable> E min(E a, E b) {
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return NaturalOrdering.INSTANCE.max(a, b);
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}
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@Override
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public <E extends Comparable> E min(E a, E b, E c, E... rest) {
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return NaturalOrdering.INSTANCE.max(a, b, c, rest);
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}
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@Override
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public <E extends Comparable> E min(Iterator<E> iterator) {
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return NaturalOrdering.INSTANCE.max(iterator);
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}
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@Override
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public <E extends Comparable> E min(Iterable<E> iterable) {
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return NaturalOrdering.INSTANCE.max(iterable);
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}
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@Override
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public <E extends Comparable> E max(E a, E b) {
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return NaturalOrdering.INSTANCE.min(a, b);
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}
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@Override
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public <E extends Comparable> E max(E a, E b, E c, E... rest) {
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return NaturalOrdering.INSTANCE.min(a, b, c, rest);
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}
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@Override
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public <E extends Comparable> E max(Iterator<E> iterator) {
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return NaturalOrdering.INSTANCE.min(iterator);
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}
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@Override
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public <E extends Comparable> E max(Iterable<E> iterable) {
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return NaturalOrdering.INSTANCE.min(iterable);
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}
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// preserving singleton-ness gives equals()/hashCode() for free
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private Object readResolve() {
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return INSTANCE;
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}
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@Override
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public String toString() {
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return "Ordering.natural().reverse()";
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}
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private ReverseNaturalOrdering() {
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}
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private static final long serialVersionUID = 0;
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}
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