Eclipse Community Forums: TMF (Xtext)

Help

Home

Home » Modeling » TMF (Xtext) » strange completion(strange completion behaviour in specific case)

Show: Today's Messages :: Show Polls :: Message Navigator

strange completion [message #844060]

Fri, 13 April 2012 16:39

Michal S

Messages: 74
Registered: July 2011

Member

Hello,
I have little problem, when completion is "too late"...

My grammar:

Model:
	elements += Elements*
;

Elements:
	EntityA|FinalEntity
;
	
EntityA:
	'A' name=ID  '{'
		entityCs+=EntityC+
	'}'	
;

EntityC:
	'C' name=ID  '{'
		entityDs+=EntityD+
	'}'	
;

EntityD:
	'D' name=ID 
;

FinalEntity:
	'X' a=[EntityA] '{'
		assignments += Assignments+
	'}'
;

Assignments:
	AssignmentA|AssignmentB
;

AssignmentA:
	c=[EntityC] refs=DRef? '=' v=INT
;

AssignmentB:
	c=[EntityC] refs=DRef? '==' v=INT
;

DRef:
	'.' d=[EntityD]
;

My scope functions:

IScope scope_Assignments_c(FinalEntity fe, EReference reference){
	return Scopes.scopeFor(fe.getA().getEntityCs());
}

IScope scope_Assignments_c(Assignments asgn, EReference reference){
	EntityA a = EcoreUtil2.getContainerOfType(asgn, FinalEntity.class).getA();
	return Scopes.scopeFor(a.getEntityCs());
}

IScope scope_DRef_d(DRef dref, EReference reference){
	EntityC c = EcoreUtil2.getContainerOfType(dref, Assignments.class).getC();
	return Scopes.scopeFor(c.getEntityDs());
}


IScope scope_DRef_d(Assignments asgn, EReference reference){
	DRef refs = asgn.getRefs();
	if(refs!=null){
		DRef dref = (DRef) refs;
		EntityC c = EcoreUtil2.getContainerOfType(dref, Assignments.class).getC();
		return Scopes.scopeFor(c.getEntityDs());
	}
	return IScope.NULLSCOPE;
}

My model:

A aa {
	C cc {
		D dd 
	}
}

X aa {
	cc.dd = 5
}

Everything works perfect, there is a problem only when I try to complete "dd" in DRef. If I write "." and Ctrl+Space, no completion is offered. If I write one more letter, it offers the completion very well.

What am I doing wrong?

Thank you,
Michal

[Updated on: Fri, 13 April 2012 16:41]

Report message to a moderator

Re: strange completion [message #844112 is a reply to message #844060]

Fri, 13 April 2012 17:51

Christian Dietrich

Messages: 13493
Registered: July 2009

Senior Member

Hi,

the problem is that the model is invalid until there is at least one letter after the .
=> the context is an FinalEntity in this case since neither a AssignmentA nor a AssignmentB can be created

i do not know how to solve this besides chaning the grammar e.g.

Assignments:
	c=[EntityC] refs=DRef? (a?="="|b?="==") v=INT
;


DRef:
	'.' d=[EntityD]
;

	IScope scope_DRef_d(DRef dref, EReference reference){
		EntityC c = EcoreUtil2.getContainerOfType(dref, Assignments.class).getC();
		return Scopes.scopeFor(c.getEntityDs());
	}


	IScope scope_DRef_d(Assignments asn, EReference reference){
		if(asn.getC()!=null){
			return Scopes.scopeFor(asn.getC().getEntityDs());
		}
		return IScope.NULLSCOPE;
	}

~Christian

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/xtext/
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: strange completion [message #844406 is a reply to message #844112]

Sat, 14 April 2012 01:00

Michal S

Messages: 74
Registered: July 2011

Member

Hello Christian,
thank you for your answer.
I was afraid that you give me this solution... It forces me to make changes in the validator, generator, etc., but I will manage Wink

Additional question: I understand, why the context is an FinalEntity. But: Why does it not recognize '.' as it does with normal keyword? (Basically, when any entity is being defined, the model is invalid, isn't it? -> but completion works... There is no other alternative for '.' starting rule in the grammar available at this place.)

Thank you & Best regards,
Michal

Report message to a moderator

Re: strange completion [message #844727 is a reply to message #844406]

Sat, 14 April 2012 09:32

Christian Dietrich

Messages: 13493
Registered: July 2009

Senior Member

I dont know this. you would have to debug the ui parser to see what actually happens. but as said before: you get only contexts that are actually instantiated - and at this point nothing can be instantiated or the already instantiated stuff has to be thrown away.

maybe you could try another solution that may keep a metamodel that is more like your old one:

Refable : EntityC|EntityD;

AssignmentA:
cordd=[Refable] '=' v=INT
;

AssignmentB:
cordd=[Refable] '==' v=INT
;

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/xtext/
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator