package list.visitor;
import list.*;

public class ReverseHelp implements IListAlgo
{
    public final static ReverseHelp  Singleton = new ReverseHelp();

    private ReverseHelp()
    {
    }

    /**
     * @param input receives the accumulated list.
     * Returns the accumulated list.
     */
    public Object forEmpty(AList host, Object input)
    {
	return input;
    }
    
    /**
     * @param host receives the list.
     * @param input receives the accumulated list.
     * Helper to Reverse.java.
     * Returns the reverse of the list.
     */
    public Object forNonEmpty(AList host, Object input)
    {
	return host.getRest().execute(this, ListFactory.Singleton.makeNEList(host.getFirst(), (AList)input));
    }
}