Xtext ScopeProvider: Accessing context object leads to errors

Question

Every time I try to access the context object in the ScopeProvider , I'll get a "cyclic resolution of lazy links" error or my ScopeProvider will be fully ignored and the default scope is used.

Heres a small example grammar:

grammar org.xtext.example.mydsl.MyDsl with org.eclipse.xtext.common.Terminals

generate myDsl "http://www.xtext.org/example/mydsl/MyDsl"

Model:
    (greetings+=Greeting)*
    (farewells+=Farewell)*;

Greeting:
    'Hello' name=ID '!';

Farewell:
    'Bye' name=[Greeting] '.';

This is the ScopeProvider:

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

def scope_Farewell_name(Farewell context,EReference reference){
    System.out.println(context.name);
    return IScope::NULLSCOPE
}
}

Is there something wrong in my approach?

Why I want to access the context:

Im trying to create an Editor for the GLSL shading language. Ill need to distinguish between a struct member and a field selection operator: Example:

struct Test{
vec4 x;
};

Test s;
s.x.x=5.0;

The first x is the struct member and the 2nd one is the x-coordinate of the vector.

Answer 1

Hi xtext does Indexing and linking in separate phases. Thus you are not allowed to access cross refs in the name provider. You can use NodeModelUtil.findNodesForFeature to retrieve the link text in the nameprovider