plugins/org.eclipse.gmf.xpand.migration/src/org/eclipse/gmf/internal/xpand/expression/TypesComparator.java

/*
 * <copyright>
 *
 * Copyright (c) 2005-2006 Sven Efftinge 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:
 *     Sven Efftinge - Initial API and implementation
 *
 * </copyright>
 */
package org.eclipse.gmf.internal.xpand.expression;

import java.util.Comparator;
import java.util.List;

import org.eclipse.emf.ecore.EClassifier;
import org.eclipse.gmf.internal.xpand.BuiltinMetaModel;

public final class TypesComparator implements Comparator<List<? extends EClassifier>> {
    /**
     * 
     * returns -1 if the second list of types is not assignable to the first
     * list of types returns 0 if the second list of types exactly matches the
     * first list of types returns 1 if the second list of types is assignable
     * to the first list of types
     */
    public int compare(final List<? extends EClassifier> types1, final List<? extends EClassifier> types2) {
        if ((types1 == null) || (types2 == null)) {
			throw new NullPointerException();
		}
        if (types1.size() != types2.size()) {
			return -1;
		}
        boolean directMatch = true;
        for (int i = 0, x = types1.size(); i < x; i++) {
            final EClassifier type1 = types1.get(i);
            final EClassifier type2 = types2.get(i);
            if (BuiltinMetaModel.isAssignableFrom(type1, type2)) {
                if (!type1.equals(type2)) {
                    directMatch = false;
                }
            } else {
				return -1;
			}
        }
        if (directMatch) {
			return 0;
		} else {
			return 1;
		}
    }

}