package scheme2.visitor;

import scheme2.AListFW;
import scheme2.IListAlgo;

public class GetSum implements IListAlgo
{
	/** @SBGen Singleton Variable   */
	public final static GetSum Singleton = new GetSum ();

	/** @SBGen Constructor   */
	private GetSum()
	{
	}

	/**
	 * @param host 
	 * @param input not used.
	 * @return 
	 */
	public Object forEmpty(AListFW host, Object input)
	{
		return new Integer (0);  // Empty Range Axiom!
	}

	/**
	 * @param host 
	 * @param input not used. 
	 * @return 
	 */
	public Object forNonEmpty(AListFW host, Object input)
	{
		return host.getRest ().execute (new HelpGetSum (((Integer)host.getFirst()).intValue ()), null);
	}
}