SingletonIterator.java

/*******************************************************************************
 * Copyright (c) 2013 Stephen F. Siegel, University of Delaware.
 * 
 * This file is part of SARL.
 * 
 * SARL 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 3 of the License, or (at your
 * option) any later version.
 * 
 * SARL 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 Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with SARL. If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package edu.udel.cis.vsl.sarl.util;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Simple implementation of Iterator for iterating over a sequence consisting of
 * a single element.
 * 
 * @author siegel
 * 
 * @param <E>
 *            type of the element
 */
public class SingletonIterator<E> implements Iterator<E> {

	private E thing;

	private boolean hasNext = true;

	public SingletonIterator(E thing) {
		this.thing = thing;
	}

	@Override
	public boolean hasNext() {
		return hasNext;
	}

	@Override
	public E next() {
		if (hasNext) {
			hasNext = false;
			return thing;
		}
		throw new NoSuchElementException();
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException();
	}
}