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Xtext Reader for unnamed Grammar Element [message #638454]

Thu, 11 November 2010 11:15

Helge Mising name

Messages: 17
Registered: October 2010

Junior Member

Hi all,

I read the two threads covering this subject:
(i) http://www.eclipse.org/forums/index.php?t=msg&th=171975& amp;start=0&
(ii) http://www.eclipse.org/forums/index.php?t=msg&goto=54889 1&

but they do not really help me further.

I have a grammar similar to Jeremie's that does not have a name in the top-level element.

CompilationUnit returns CompilationUnit : 
	( 
		( annotations+=Annotations )?
		packageDeclaration+=PackageDeclaration
	)?
	( importDeclarations+=ImportDeclaration )*
	( typeDeclarations+=TypeDeclaration )*
;

Since I want to read Java like code fragments I cannot add a 'name' element there.
Thus, I followed the posts and let the RuntimeModule class override the name provider binding as:

@Override
public Class<? extends IQualifiedNameProvider> bindIQualifiedNameProvider() {
	return CompilationUnitQualifiedNameProvider.class;
}

The implementation of CompilationUnitQualifiedNameProvider returns a name String. Is this all I have to do or did I miss anything? I assume that I have to do something else since my workflow still tells:

Quote:

Could not find any exported element of type 'CompilationUnit' -> Slot 'j' is empty.

and when debugging the name provider it seems, that it is never called.

So, what did I miss? Is there a step-by-step list of what to do in my case?

The DSL generator workflow calls the

fragment = exporting.QualifiedNamesFragment {}

and not the SimpleNamesFragment as in Jeremie's case. Is this the problem? I did not change anything in this DSL generator workflow except allowing for backtracking in the Antlr fragments.
(I use Xtext version 1.0.1)

Best,
Helge

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Re: Xtext Reader for unnamed Grammar Element [message #638469 is a reply to message #638454]

Thu, 11 November 2010 12:28

Alexander Nittka

Messages: 1193
Registered: July 2009

Senior Member

Hi,

as an initial question: Have you tried using the UriBasedReader in the workflow rather than Reader? The former allows for specifying a particular file directly, so that the root element is stored in the model slot.

Alex

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Re: Xtext Reader for unnamed Grammar Element [message #638473 is a reply to message #638469]

Thu, 11 November 2010 12:35

Helge Mising name

Messages: 17
Registered: October 2010

Junior Member

Hi,

I just tried to use the org.eclipse.xtext.mwe.UriBasedReader. It gives the same 'empty slot' message and seems to not call my name provider.

Best,
Helge

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Re: Xtext Reader for unnamed Grammar Element [message #638868 is a reply to message #638473]

Fri, 12 November 2010 20:18

Alexander Nittka

Messages: 1193
Registered: July 2009

Senior Member

Hi,

I just tried it with the following name provider implementation and it works for me

public class MyNameProvider extends DefaultDeclarativeQualifiedNameProvider {
public String qualifiedName(TypeWithoutNameFeature obj) {
return "someName";
}
}

Alex

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Re: Xtext Reader for unnamed Grammar Element [message #642194 is a reply to message #638868]

Tue, 30 November 2010 10:50

Helge Mising name

Messages: 17
Registered: October 2010

Junior Member

Hi,

I did a lot of debugging. I am sure that my name provider is never called. It seems that something is going wrong with registering it. That is, when I debug the RuntimeModule of my language, then the language provider class contains only 'null' and '0' elements. Especially, I would expect the 'qualifiedName' method to appear in the 'publicMethods'.
When debugging the URIBasedReader and particularly the corresponding SlotEntry class, I see that the

Quote:

Could not find any exported element of type 'CompilationUnit' -> Slot 'j' is empty.

message is generated by the 'put(...)' method. There, the model class is correctly assigned to 'eClasses' (see code snippet) but the method 'findEObjectsOfType' returns an empty list since 'resourceDescriptions.getAllResourceDescriptions();' returns an empty collection.

public void put(WorkflowContext ctx, IResourceDescriptions resourceDescriptions, ResourceSet resourceSet) {
		Set<EClass> eClasses = findEClasses(resourceSet, nsURI, type);
		List<EObject> elements = findEObjectsOfType(eClasses, resourceDescriptions, resourceSet);

How do I get my name provider properly registered? Do I have to set anything else, like dependencies to certain plugins, particular switches when running the workflow,... ? May the problem be caused by my setup, since I think that something in the injection process goes wrong? I am using XText (1.0.1) on Java version 1.5.0_24 (32Bit) on Mac OS 10.5.8.

Best,
Helge

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Re: Xtext Reader for unnamed Grammar Element [message #642223 is a reply to message #642194]

Tue, 30 November 2010 13:00

Meinte Boersma

Messages: 434
Registered: July 2009
Location: Leiden, Netherlands

Senior Member

EDIT Never mind, didn't see that you already bound the class in the RuntimeModule.

Xtext blogs: executable models...again? | workshop material | custom scoping with Xtend

[Updated on: Tue, 30 November 2010 13:02]

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Re: Xtext Reader for unnamed Grammar Element [message #642228 is a reply to message #642194]

Tue, 30 November 2010 13:35

Alexander Nittka

Messages: 1193
Registered: July 2009

Senior Member

Hi,

does your name provider extend DefaultDeclarativeQualifiedNameProvider?
Have you set a class breakpoint in order to see if your implementation was bound?
Have you tried using a general type in the qualifiedName-Method (EObject) for making sure that your implementation is used?

As to the binding, your code looks OK. Basically, you should be fine with copying the binding from the AbstractYOURDSLRuntimeModule returning your own implementation.

Alex

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