Hi everyone,
I built a DSL with XBase expressions. In order to create my own simple types, I added to the grammar something like that :
Typedef : 'alias' name=ID type=JvmTypeReference
Entity : 'entity' name=ID '{'
(vardefs += EntVarDef)*
'}';
EntVarDef : type = [Typedef] name=ID ;
I can then write things like :
alias text java.lang.String
alias geom my.own.GeomClass
entity Foo {
text fooId
geom geometry
}
And with a JvmModelInferrer generating a class for every entity, it works great.
Now I would like to be able to reuse a declared entity as being the type for an entity internal variable. In other words, I'd like to be able to append to that model someting like this :
entity Bar {
text BarId
Foo fooVar
}
I could do that if I was allowed to write this in the grammar :
EntVarDef : type = [Typedef] | [Entity] name=ID;
But I am not allowed to do so. I tried to subtype JvmTypeReference but I am not allowed to do so either.
I tried several other things so far, like subtyping :
EntVarDef : type = [VarType|ID] name=ID;
VarType : Typedef | Entity
Which looks to be ok for validation but I run into problems when trying to write the JvmModelInferrer (how to give a JvmReferenceType to the toField() method ?)
I also tried a solution like this :
Typedef returns JvmTypeReference : 'alias' name=ID type=JvmTypeReference
...
EntVarDef : type = JvmTypeReference name=ID ;
and it allows me to reuse a declared entity but I do not have access to my alias types any more.
Well, in your opinion, what best way should I explore further to obtain the expected behavior ?
I advance, thank you for your help.
[Updated on: Thu, 07 March 2013 04:36] by Moderator
Home