/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.operator.learner.igss.hypothesis;

import java.io.Serializable;

import com.rapidminer.example.Attribute;


/** Objects of this class represent a literal in a conjunctive rule.
 * 
 *  @author Dirk Dach 
 *  @version $Id: Literal.java,v 1.3 2008/05/09 19:23:25 ingomierswa Exp $
 */
public class Literal implements Serializable {
	
	private static final long serialVersionUID = 8699112785374243703L;

	/** The attribute tested in this literal.*/
	private Attribute attribute;
	
	/** The value of the attribute for this literal.*/
	private int value;

	/** The literals' index (1.dimension) in the allLiterals[][] array of the class ConjunctiveRule.*/
	private int index;

	/** Counts the total number literals that have been constructed. */
	private static int numberOfLiterals;
	
	/** Constructs a new Literal. */
	public Literal(Attribute a, int v) {
		attribute=a;
		value=v;
		numberOfLiterals++;
	}
	
	/** Constructs a new Literal. */
	public Literal(Attribute a, int v, int i) {
		attribute=a;
		value=v;
		index=i;
		numberOfLiterals++;
	}

	/** Returns the attribute of this literals.*/
	public Attribute getAttribute() {
		return attribute;
	}

	/** Returns the index of the value of this literals' attribute. */
	public int getValue() {
		return value;
	}

	/** Returns the literals' index(1.dimension) in the allLiterals[][] array of the class ConjunctiveRule.*/
	public int getIndex() {
		return index;
	}

	/** Returns true if both attributes and both values are equal. */
	public boolean equals(Object o) {
		if (!(o instanceof Literal))
			return false;
		Literal otherLiteral=(Literal)o;
		if( (this.attribute.equals(otherLiteral.attribute)) && (this.value==otherLiteral.value) )
			return true;
		else 
			return false;
	}
	
	public int hashCode() {
		return this.attribute.hashCode() ^ Integer.valueOf(this.value);
	}
	
	/** Returns a String represenation of this Literal. */
	public String toString() {
		String str=this.attribute.getMapping().mapIndex(value);
		return "("+attribute.getName()+"="+str+")";
	}
}