[antlr-interest] rewrite smth like "type: (primitive|complex) multiplicity?"

[Felix Dorner]

Hey,

I have a grammar rule for specifying the type of a variable.

vardef : Identifier ':' type;
type : (PrimitiveType | complexType) ('['IntegerLiteral']')?;

PrimitiveType : 'int' | 'boolean';
complexType : Identifier ('*' Identifier)* -> Identifier+;

I'd like the trees for vardefs like this, i.e. introduce an additional 
type subtree.

(VAR i  (TYPE int 4))
(VAR j  (TYPE int))
(VAR k (TYPE abc def ghi 5))

To achieve this I try something like:

type : ... -> ^(TYPE (PrimitiveType | ComplexType) IntegerLiteral? // or
type: (e=...) ->^(TYPE $e.tree IntegerLiteral?

but this does not work. I can't find another solution but to respecify 
the type rule like this:

type : primitiveType ('['IntegerLiteral']'?) ->  ^(TYPE primitiveType  
IntegerLiteral?)
        | complexType ('[IntegerLiteral']' )?-> ^(TYPE complexType 
IntegerLiteral?)

I bet there are solutions with more style? Thanks,
Felix