import java.util.Iterator;

// An example True-Iterator implemented using the IteratorHelper class.
// This class implements the Iterator interface but does not support the
// remove method.
public class Range implements Runnable, Iterator<Integer> {

	private int low;
	private int high;

	private IteratorHelper<Integer> ih;

	// Constructor.
	public Range(int low, int high) {
		this.low = low;
		this.high = high;
		ih = new IteratorHelper<Integer>(this);
		ih.start();
	}

	// Checks if we have reached the end of the iterator.
	public boolean hasNext() {
		return !ih.done();
	}

	// Gives the next element. If no such element exists it throws
	// NoSuchElementException.
	public Integer next() {
		return ih.get();
	}
	
	// Not supported.
	public void remove() {
		throw new UnsupportedOperationException();
	}

	// Implements the method of the Runnable interface.
	public void run() {
		for (int i = low; i <= high; i++) {
			ih.yield(new Integer(i));
		}
	}

}