// Path: src/main/java/org/deri/cqels/data/Mapping.java
// public interface Mapping extends Map<Var, Long>{
// 	
// 
// 	public long get(Var var); 
// 	
// 	public void from(OpRouter router);
// 	
// 	public OpRouter from();
// 	
// 	public ExecContext getCtx();
// 	
// 	public Iterator<Var> vars();
// 	
// 	public void addParent(Mapping parent);
// 	
// 	public boolean hasParent();
// 	
// 	public boolean isCompatible(Mapping mapping);
// }


import org.deri.cqels.data.Mapping;
package org.deri.cqels.engine.iterator;



public class NullMappingIter extends MappingIter {
	private static NullMappingIter instance;
	public NullMappingIter() {
		super(null);
	}
	
	public static NullMappingIter instance() {
		if(instance==null) instance=new NullMappingIter(); 
		return instance;
	}
	
	@Override
	protected void closeIterator() {
		// TODO Auto-generated method stub

	}

	@Override
	protected boolean hasNextMapping() {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
// Path: src/main/java/org/deri/cqels/data/Mapping.java
// public interface Mapping extends Map<Var, Long>{
// 	
// 
// 	public long get(Var var); 
// 	
// 	public void from(OpRouter router);
// 	
// 	public OpRouter from();
// 	
// 	public ExecContext getCtx();
// 	
// 	public Iterator<Var> vars();
// 	
// 	public void addParent(Mapping parent);
// 	
// 	public boolean hasParent();
// 	
// 	public boolean isCompatible(Mapping mapping);
// }


// Path: src/main/java/org/deri/cqels/engine/iterator/NullMappingIter.java
import org.deri.cqels.data.Mapping;

package org.deri.cqels.engine.iterator;



public class NullMappingIter extends MappingIter {
	private static NullMappingIter instance;
	public NullMappingIter() {
		super(null);
	}
	
	public static NullMappingIter instance() {
		if(instance==null) instance=new NullMappingIter(); 
		return instance;
	}
	
	@Override
	protected void closeIterator() {
		// TODO Auto-generated method stub

	}

	@Override
	protected boolean hasNextMapping() {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
	protected Mapping moveToNextMapping() {