/* SimpleSet
 *
 * The PEA tool set is a collection of tools for
 * Phase Event Automata (PEA). See
 * http://csd.informatik.uni-oldenburg.de/projects/peatools.html
 * for more information.
 * 
 * Copyright (C) 1999-2002 Jochen Hoenicke.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program 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 Lesser General Public License
 * along with this program; see the file COPYING.LESSER.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: SimpleSet.java 227 2006-10-19 07:29:43Z jfaber $
 */

package de.uni_freiburg.informatik.ultimate.lib.pea.util;

import java.util.AbstractSet;
import java.util.Iterator;

public class SimpleSet<T> extends AbstractSet<T> implements Cloneable {
	T[] elementObjects;
	int count = 0;
	
	public SimpleSet() {
		this(2);
	}
	
	@SuppressWarnings("unchecked")
	public SimpleSet(final int initialSize) {
		elementObjects = (T[]) new Object[initialSize];
	}
	
	@Override
	public int size() {
		return count;
	}
	
	@Override
	@SuppressWarnings("unchecked")
	public boolean add(final T element) {
		if (element == null) {
			throw new IllegalArgumentException();
		}
		
		for (int i = 0; i < count; i++) {
			if (element.equals(elementObjects[i])) {
				return false;
			}
		}
		
		if (count == elementObjects.length) {
			final T[] newArray = (T[]) new Object[(count + 1) * 3 / 2];
			System.arraycopy(elementObjects, 0, newArray, 0, count);
			elementObjects = newArray;
		}
		elementObjects[count++] = element;
		return true;
	}
	
	@Override
	@SuppressWarnings("unchecked")
	public Object clone() {
		try {
			final SimpleSet<T> other = (SimpleSet<T>) super.clone();
			other.elementObjects = elementObjects.clone();
			return other;
		} catch (final CloneNotSupportedException ex) {
			throw new InternalError("Clone?");
		}
	}
	
	@Override
	public Iterator<T> iterator() {
		return new Iterator<T>() {
			int pos = 0;
			
			@Override
			public boolean hasNext() {
				return pos < count;
			}
			
			@Override
			public T next() {
				return elementObjects[pos++];
			}
			
			@Override
			public void remove() {
				if (pos < count) {
					System.arraycopy(elementObjects, pos,
							elementObjects, pos - 1, count - pos);
				}
				count--;
				pos--;
			}
		};
	}
}