Model:
	declarations+=Declarations*
	expressions+=Expression*
	strangeThing+=StangeThing*
	;
	
	
Declarations:
'declaration' name=ID '{'  '}'
;

Expression:
'expression' name=ID 'using' declaration=[Declarations] '{'
'}'
;

StangeThing:
	"strange" "thing" "for" declaration=[Declarations] "with" expr=[Expression]
;

public class MyDslResourceDescriptionStrategy extends DefaultResourceDescriptionStrategy {
	
	@Override
	public boolean createEObjectDescriptions(EObject eObject, IAcceptor<IEObjectDescription> acceptor) {
		if (eObject instanceof Expression) {
			Map<String, String> data = new HashMap<>();
			data.put("DEF", NodeModelUtils.findNodesForFeature(eObject, MyDslPackage.Literals.EXPRESSION__DECLARATION).get(0).getText());
			IEObjectDescription d = EObjectDescription.create(getQualifiedNameProvider().getFullyQualifiedName(eObject), eObject, data );
			acceptor.accept(d);
		}
		return super.createEObjectDescriptions(eObject, acceptor);
	}

}

class MyDslScopeProvider extends org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider {

	def IScope scope_StrangeThing_expr(StrangeThing ctx, EReference ref) {
		val name = ctx.declaration.name
		val locals = <Declarations>newArrayList
		// todo collect locals manually
		// ...
		Scopes.scopeFor(locals, new FilteringScope(delegateGetScope(ctx,ref),[
			name == getUserData("DEF")
		]))
	}

}

val locals = EcoreUtil2.getContainerOfType(ctx, Model).expressions.filter[declaration == ctx.declaration]
		

StangeThing:
	"strange" "thing" "for" declaration=[Declarations] "with" expr=[Expression]
;

Model:
	declarations+=Declarations*
	expressions+=Expression*
	;
	
Declarations:
'declaration' name=ID '{'  '}'
;

Expression:
'expression' name=ID 'using' declaration=[Declarations] '{'
'}'
;

    IResourceDescriptions descriptions = resourceDescriptionsProvider.getResourceDescriptions(declVar.eResource());
    IResourceDescription resourceDescription = descriptions.getResourceDescription(resource.getURI());
    IContainer yyyy = manager.Containers(resourceDescription, descriptions);