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/*-
 *  * Copyright 2016 Skymind, 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 org.datavec.api.io;


import org.datavec.api.writable.Writable;

/**
 * A {@link Writable} which is also {@link Comparable}.
 *
 * WritableComparables can be compared to each other, typically 
 * via Comparators. Any type which is to be used as a 
 * key in the Hadoop Map-Reduce framework should implement this
 * interface.
 *
 * Example:
 * 
 *     public class MyWritableComparable implements WritableComparable {
 *       // Some data
 *       private int counter;
 *       private long timestamp;
 *
 *       public void write(DataOutput out) throws IOException {
 *         out.writeInt(counter);
 *         out.writeLong(timestamp);
 *       }
 *
 *       public void readFields(DataInput in) throws IOException {
 *         counter = in.readInt();
 *         timestamp = in.readLong();
 *       }
 *
 *       public int compareTo(MyWritableComparable w) {
 *         int thisValue = this.value;
 *         int thatValue = ((IntWritable)o).value;
 *         return (thisValue < thatValue ? -1 : (thisValue==thatValue ? 0 : 1));
 *       }
 *     }
 * 

 */
public interface WritableComparable extends Writable, Comparable {
}