package lrs.visitor;
import lrs.*;

public class ToString implements IAlgo
{
   public static final ToString Singleton = new ToString ();

   private ToString ()
   {
   }
   
	/**
	 * @param host empty
	 * @param input  not used
	 * @return 
	 */
	public Object forEmpty(LRStruct host, Object input)
	{
		return "()";
	}

	/**
    * Uses an anonymous inner class helper.
	 * @param host not empty
	 * @param input not used.
	 * @return 
	 */
	public Object forNonEmpty(LRStruct host, Object input)
	{
      return "(" + host.getFirst() + host.getRest().execute (
         new IAlgo ()
         {
	         public Object forEmpty(LRStruct h, Object inp)
	         {
               return ")";
	         }

	         public Object forNonEmpty (LRStruct h, Object inp)
	         {
		         return " " + h.getFirst() + h.getRest ().execute (this, null);
	         }
         }
         , null);
   }
}