package clist;

import clist.visitor.ICLVisitor;

class NullNode extends ANode
{
	/** @SBGen Singleton Variable   */
	public final static NullNode Singleton = new NullNode ();

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

	/**
	 * @param parent 
	 * @return 
	 */
	Object clockwiseDat(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no data");
	}

	/**
	 * @param parent 
	 * @return 
	 */
	Object counterwiseDat(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no data");
	}

	/**
	 * @param dat 
	 * @param parent 
	 */
	void insertClockwise(Object dat, CLList parent)
	{
      new DatNode (dat, parent, parent);
	}

	/**
	 * @param dat 
	 * @param parent 
	 */
	void insertCounterwise(Object dat, CLList parent)
	{
      new DatNode (dat, parent, parent);
	}

	/**
	 * @param parent 
	 * @return 
	 */
	Object remClockwise(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no data");
	}

	/**
	 * @param parent 
	 * @return 
	 */
	Object remCounterwise(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no data");
	}

	/**
	 * @param parent 
	 * @return 
	 */
	CLList clockwiseTail(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no clockwise tail");
	}

	/**
	 * @param parent 
	 * @return 
	 */
	CLList counterwiseTail(CLList parent)
	{
		throw new java.util.NoSuchElementException ("Null Node has no counter clockwise tail.");
	}

	/**
	 * @param algo 
	 * @param start 
	 * @param input 
	 * @param parent 
	 * @return 
	 */
	Object execClockwise(ICLVisitor algo, CLList start, Object input, CLList parent)
	{
		return algo.nullCase(parent, start, input);
	}

	/**
	 * @param algo 
	 * @param start 
	 * @param input 
	 * @param parent 
	 * @return 
	 */
	Object execCounterwise(ICLVisitor algo, CLList start, Object input, CLList parent)
	{
		return algo.nullCase(parent, start, input);
	}

	/**
	 * @param cllist 
	 */
	void setClockwiseParent(CLList cllist)
	{
      // do nothing.
	}

	/**
	 * @param cllist 
	 */
	void setCounterwiseParent(CLList cllist)
	{
      // do nothing.
	}
}