org.eclipse.ocl.internal.evaluation.IterationTemplateExists Maven / Gradle / Ivy

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/**
 * 
 *
 * Copyright (c) 2005, 2007 IBM Corporation and others.
 * 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:
 *   IBM - Initial API and implementation
 *
 * 
 *
 * $Id: IterationTemplateExists.java,v 1.3 2009/09/01 20:11:22 ewillink Exp $
 */

package org.eclipse.ocl.internal.evaluation;

import java.util.List;

import org.eclipse.ocl.EvaluationEnvironment;
import org.eclipse.ocl.EvaluationVisitor;
import org.eclipse.ocl.expressions.Variable;

/**
 *
 */
public final class IterationTemplateExists
		extends IterationTemplate {
	
	private IterationTemplateExists(
			EvaluationVisitor v) {
		super(v);
	}
	
	public static
	IterationTemplate
	getInstance(EvaluationVisitor v) {
		return new IterationTemplateExists(v);
	}
	
	@Override
    protected Object evaluateResult(List> iterators, String resultName, Object body) {
		EvaluationEnvironment env = getEvalEnvironment();
		
		// check for undefined result:
		// the current result value cannot be true since the short-circuit
		// "isDone" mechanism below would have caused the evaluation to stop.
		// If the body result is undefined then the entire expression's value
		// is invalid
		if ((body == null) || (body == getInvalid())) {
			setDone(true);
			return getInvalid();
		}
		
		Boolean currVal = (Boolean)env.getValueOf(resultName);
		Boolean bodyVal = (Boolean)body;
		
		boolean resultVal = currVal.booleanValue() || bodyVal.booleanValue();
		if (resultVal)
			setDone(true);
		return resultVal ? Boolean.TRUE : Boolean.FALSE;
	}
}