EcoreUtil2.indexOf((List)container.eContainer().eGet(container.eContainingFeature()), container, 0);

override void doGenerate(Resource resource, IFileSystemAccess2 fsa, IGeneratorContext context) {
		fsa.generateFile('greetings.txt', '''
		«FOR g : resource.allContents.filter(Greeting).toIterable»
		«g.indexOf» «g.name»
		«ENDFOR»
		''')
	}
	
	def int indexOf(EObject o) {
		ECollections.indexOf(o.eContainer.eGet(o.eContainingFeature) as List<Greeting>, o, 0)
	}