/*
* Copyright (c) 2007-2010 Concurrent, Inc. All Rights Reserved.
*
* Project and contact information: http://www.cascading.org/
*
* This file is part of the Cascading project.
*
* Cascading is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Cascading is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Cascading. If not, see <http://www.gnu.org/licenses/>.
*/
package cascading.tuple;
import java.util.Comparator;
/**
* The Comparison interface allows specific underlying type mechanisms to additionally return relevant
* {@link Comparator} implementations when required internally.
* <p/>
* In the case of Hadoop, {@link org.apache.hadoop.io.serializer.Serialization} implementations that present
* alternative serialization implementations for custom types manged by {@link Tuple}s should also
* implement the {@link #getComparator(Class)} method.
* <p/>
* During runtime Cascading can identify and use the correct Comparator during grouping operations if it was
* not given explicitly on the {@link Fields#setComparator(Comparable, java.util.Comparator)} family of methods.
* <p/>
* See the class {@link cascading.tuple.hadoop.BytesSerialization} for an example.
* <p/>
* see cascading.tuple.hadoop.BytesSerialization
*/
public interface Comparison<T>
{
Comparator<T> getComparator( Class<T> type );
}