Switch returns Switch:
	'Switch'
	'{'
	('id' id=EInt)?
	'currentPosition' currentPosition=Position
	('connectsTo' '(' connectsTo+=[TrackElement|STRING] ("," connectsTo+=[TrackElement|STRING])* ')')?
[b]	('positions' '(' positions+=[SwitchPosition|STRING] ("," positions+=[SwitchPosition|STRING])* ')')?[/b]
	'}';

SwitchPosition returns SwitchPosition:
	'SwitchPosition'
	'{'
	('id' id=EInt)?
	'position' position=Position
[b]	'switch' switch=[Switch|STRING][/b]
	'}';

RailwayContainer {
	semaphores{
		Semaphore{
			id 0 
			signal GO
		}
	}
	routes{
		Route {
			id 1
			entry '0'
			exit '0'
			definedBy{
				Sensor{
					id 9
				},
				Sensor{
					id 8
				}
			}
		}		
	}
}

class MyDslRuntimeModule extends AbstractMyDslRuntimeModule {
	
	override bindIQualifiedNameProvider() {
		MyQNP
	}
	
}

package org.xtext.example.mydsl1;

import org.eclipse.xtext.naming.DefaultDeclarativeQualifiedNameProvider;
import org.eclipse.xtext.naming.QualifiedName;

import railway.Semaphore;

public class MyQNP extends DefaultDeclarativeQualifiedNameProvider {
	
	public QualifiedName qualifiedName(Semaphore s) {
		return QualifiedName.create(Integer.toString(s.getId()));
	}

}