package scheme2;

class EmptyListFW extends AListFW
{
   public final static EmptyListFW Singleton = new EmptyListFW ();

   private EmptyListFW()
   {
   }
   
  public Object getFirst()
  {
    throw new java.util.NoSuchElementException ("Empty has no element.");
  }

  public AListFW getRest()
  {
    throw new java.util.NoSuchElementException ("Empty has no tail.");
  }

  /**
	 * @param input 
	 */
	public Object execute(IListAlgo algo, Object input)
   {
      return algo.forEmpty (this, input);
   }
}