package lrs.visitor;
import lrs.*;
/**
* Shares the host's tail with the input LRStruct.
*/
public class ShareRest implements IAlgo
{
	public final static ShareRest Singleton = new ShareRest ();

	private ShareRest()
	{
	}

	/**
    * Does nothing.
	 * @param host an empty LRStruct.
	 * @param input a non-empty LRStruct
	 * @return null.
	 */
	public Object nullCase(LRStruct host, Object input)
	{
    //((LRStruct)input).setRest (new LRStruct ());
		return null;
	}

	/**
    * Sets the input's tail to the host's tail.
	 * @param host a non-empty LRStruct.
	 * @param input a non-empty LRStruct.
	 * @return null.
	 */
	public Object nonNullCase(LRStruct host, Object input)
	{
      ((LRStruct)input).setRest (host.getRest ());
		return null;
	}
}