Action.java

/*
 * 
 * Copyright 2012 lexergen.
 * This file is part of lexergen.
 * 
 * lexergen 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.
 * 
 * lexergen 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 lexergen.  If not, see <http://www.gnu.org/licenses/>.
 *  
 * lexergen:
 * A tool to chunk source code into tokens for further processing in a compiler chain.
 * 
 * Projectgroup: bi, bii
 * 
 * Authors: Johannes Dahlke
 * 
 * Module:  Softwareprojekt Übersetzerbau 2012 
 * 
 * Created: Apr. 2012 
 * Version: 1.0
 *
 */

package de.fuberlin.bii.regextodfaconverter.directconverter.lrparser;

import de.fuberlin.bii.regextodfaconverter.directconverter.AutomatEventHandler;
import de.fuberlin.bii.regextodfaconverter.directconverter.lrparser.grammar.Symbol;
import de.fuberlin.bii.regextodfaconverter.directconverter.lrparser.grammar.Terminal;
import de.fuberlin.bii.regextodfaconverter.directconverter.lrparser.itemset.Closure;
import de.fuberlin.bii.regextodfaconverter.directconverter.lrparser.itemset.Lr0Closure;
import de.fuberlin.bii.utils.Test;

/**
 * Aktion für den Parser
 * 
 * @author Johannes Dahlke
 *
 * @param <Element>
 */
@SuppressWarnings("rawtypes")
public abstract class Action<Element extends Symbol, SpecializedClosure extends Closure> implements AutomatEventHandler<Element, SpecializedClosure> {
	
	private Action alternativeAction = null; 
	
	public Action() {
		super();
	}
	
	/**
	 * Fügt der Aktion eine alternative Aktion hinzu. Diese wird dann gewählt, wenn der {@link ItemAutomat}
	 * keine passende Reduce-Regel mehr anwenden kann und einen erneuten Anlauf nimmt. 
	 * 
	 * @param theAlternativeAction
	 */
	public void addAlternative( Action theAlternativeAction) {
		if ( Test.isUnassigned( this.alternativeAction))
			this.alternativeAction = theAlternativeAction;
		else
			if ( !this.alternativeAction.equals( theAlternativeAction))
			  this.alternativeAction.addAlternative( theAlternativeAction);
	}
	
	/**
	 * Test auf Vorhandensein einer alternativen Aktion.
	 * 
	 * @return
	 */
	public boolean hasAlternative() {
		return Test.isAssigned( alternativeAction);
	}
	
	/**
	 * Akzessor auf die alternative Aktion
	 * @return
	 */
	public Action getAlternative() {
		return alternativeAction;
	}

	
}