org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete/src/org/eclipse/viatra2/gtasm/patternmatcher/incremental/rete/construction/psystem/BasePConstraint.java

/*******************************************************************************
 * Copyright (c) 2004-2010 Gabor Bergmann and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Gabor Bergmann - initial API and implementation
 *******************************************************************************/

package org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem;

import java.util.HashSet;
import java.util.Set;

import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.Buildable;
import org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.RetePatternBuildException;

/**
 * @author Bergmann Gábor
 *
 */
public abstract class BasePConstraint<PatternDescription, StubHandle> implements PConstraint {
	protected PSystem<PatternDescription, StubHandle, ?> pSystem;
	protected Buildable<PatternDescription, StubHandle, ?> buildable;
	private Set<PVariable> affectedVariables;

	/**
	 * @param affectedVariables
	 */
	public BasePConstraint(PSystem<PatternDescription, StubHandle, ?> pSystem, Set<PVariable> affectedVariables) {
		super();
		this.pSystem = pSystem;
		this.buildable = pSystem.getBuildable();
		this.affectedVariables = new HashSet<PVariable>(affectedVariables);
		
		for (PVariable pVariable : affectedVariables) {
			pVariable.refer(this);
		}
		pSystem.registerConstraint(this);
	}
	@Override
	public String toString() {
		return "PC["+getClass().getSimpleName()+":"+toStringRest()+"]";
	}
	protected abstract String toStringRest();

	/* (non-Javadoc)
	 * @see org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PConstraint#getAffectedVariables()
	 */
	@Override
	public Set<PVariable> getAffectedVariables() {
		return affectedVariables;
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PConstraint#replaceVariable(org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PVariable, org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PVariable)
	 */
	@Override
	public void replaceVariable(PVariable obsolete, PVariable replacement) {
		if (affectedVariables.remove(obsolete)) {
			affectedVariables.add(replacement);
			obsolete.unrefer(this);
			replacement.refer(this);
			doReplaceVariable(obsolete, replacement);
		}
	}
	protected abstract void doReplaceVariable(PVariable obsolete, PVariable replacement);
	
	/* (non-Javadoc)
	 * @see org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PConstraint#delete()
	 */
	@Override
	public void delete() {
		for (PVariable pVariable : affectedVariables) {
			pVariable.unrefer(this);
		}
		pSystem.unregisterConstraint(this);
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.viatra2.gtasm.patternmatcher.incremental.rete.construction.psystem.PConstraint#checkSanity()
	 */
	@Override
	public void checkSanity() throws RetePatternBuildException {}
}