libobject.java

Mandarax是一个规则引擎的纯Java实现。它支持多类型的事实和基于反映的规则

/*
 * Copyright (C) 1999-2004 <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</a>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.mandarax.lib;

import org.mandarax.kernel.*;


/**
 * Abstract super class mandarax lib predicates and functions.
 * Equals and hashCode are defined here: all instamnces of a class are considered equal,
 * usually only one instance per class should exist. However, when deserializing 
 * functions/mandarax, multiple instances might exist and will be considered equal.
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 * @since 1.9.1
 */
public abstract class LibObject {
    /**
     * Get the hashcode for the respective object.
     * @return an integer
     */
    public int hashCode() {
    	return getClass().hashCode();
    }
    /**
     * Compare objects.
     * @param obj another object
     * @return a boolean
     */
    public boolean equals(Object obj) {
    	return obj!=null && getClass()==obj.getClass();
    }
    /**
     * Indicates whether a predicate is a predicate from the lib.
     * @param p a predicate
     * @return a boolean
     */
    public static boolean isLibPredicate(Predicate p) {
    	return p!=null && (p instanceof AbstractPredicate || p instanceof Cut);
    }
}