/**********************************************************************
 * Copyright (c) 2007 IBM Corporation.
 * 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 Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ptp.pldt.mpi.analysis.analysis;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class Util {
	
	public static List Intersect(List A, List B){
		if(A == null || B == null) return null;
		List list = new ArrayList();
		for(Iterator i = A.iterator(); i.hasNext();){
			Object o = i.next();
			if(B.contains(o)) list.add(o);
		}
		return list;
	}
	
	public static boolean equals(List A, List B){
		if(A == null && B == null) return true;
		if(A == null && B != null) return false;
		if(A != null && B == null) return false;
		if(A.size() != B.size()) return false;
		for(Iterator i = A.iterator(); i.hasNext();){
			if(!B.contains(i.next())) return false;
		}
		return true;
	}
	
	public static List Union(List A, List B){
		if(A == null) return B;
		if(B == null) return A;
		List list = new ArrayList(A);
		for(Iterator i = B.iterator(); i.hasNext();){
			Object o = i.next();
			if(!list.contains(o)) list.add(o);
		}
		return list;
	}
	
	public static List Union(List A, List B, List C){
		return Union(Union(A, B), C);
	}
	
	/* 
	 * @ return: A - B 
	 */
	public static List Minus(List A, List B){
		if(B.isEmpty()) return A;
		List list = new ArrayList();
		for(Iterator i = A.iterator(); i.hasNext();){
			Object o = i.next();
			if(!B.contains(o)) list.add(o);
		}
		return list;
	}
	
	/* to = Union(to, from) */
	public static void addAll(List to, List from){
		if(from == null) return;
		if(from.size() == 0) return;
		for(Iterator i = from.iterator(); i.hasNext();){
			String s = (String)i.next();
			if(!to.contains(s))
				to.add(s);
		}
	}
	
	public static List copy(List oldlist){
		List list = new ArrayList();
		for(Iterator i = oldlist.iterator(); i.hasNext();){
			list.add(i.next());
		}
		return list;
	}
}