package collections;

import java.util.NoSuchElementException;

/** A simple stack definition; restrictive in that you cannot
 * access arbitrary stack elements.
 *
 * @author Terence Parr
 * <a href=http://www.MageLang.com>MageLang Institute</a>
 */
public interface Stack {
    public void push(Object o);
    public Object pop() throws NoSuchElementException;
    public int height();
}