/*
 * @(#) Metricable.java - Interface for integer metrics adapters.
 * (c) 2000 Ivan Maidanski <ivmai@chat.ru> http://ivmai.chat.ru
 * Freeware class library sources. All rights reserved.
 **
 * Language: Java [pure]
 * Tested with: JDK v1.1.6
 * Last modified: 2000-12-27 14:25:00 GMT+03:00
 */

/*
 * This software is the proprietary information of the author.
 **
 * Permission to use, copy, and distribute this software and its
 * documentation for non-commercial purposes and without fee is
 * hereby granted provided that this copyright notice appears in all
 * copies.
 **
 * This software should not be modified in any way; any found bug
 * should be reported to the author.
 **
 * The author disclaims all warranties with regard to this software,
 * including all implied warranties of merchantability and fitness.
 * In no event shall the author be liable for any special, indirect
 * or consequential damages or any damages whatsoever resulting from
 * loss of use, data or profits, whether in an action of contract,
 * negligence or other tortuous action, arising out of or in
 * connection with the use or performance of this software.
 */

package ivmai.util;

import java.io.Serializable;

/**
 * Interface for integer metrics adapters.
 **
 * This interface declares a custom function which may evaluate
 * (according to the semantics) an object value. Metrics may also
 * serve as a predicate (filter), just if a non-zero result is
 * interpreted as <CODE>true</CODE>. Metrics may be used in
 * serializable data structures since <CODE>Serializable</CODE>
 * interface is extended.
 **
 * @see ToString
 * @see GComparator
 **
 * @version 2.0
 * @author Ivan Maidanski
 **
 * @since 2.0
 */
public interface Metricable extends Serializable
{

/**
 * The body of the metrics.
 **
 * Evaluates the supplied object. If the object is not instance of
 * the expected type then <CODE>0</CODE> is always returned.
 **
 * @param obj
 * the object (may be <CODE>null</CODE>) to evaluate.
 * @return
 * the integer result of the performed evaluation.
 */
 public abstract int evaluate(Object obj);
}