[antlr-interest] How to split int a, b:

[Arto Viitanen]

On antlr-interest-request at antlr.org  "Christian Andersson"
<dt05ca4 at student.lth.se> wrote:
> I have this type declaration below:
>
> int a,b;
>
>
> My simple grammar looks like the following:
>
> vardecl
> :type declarator_list ';' ->^(DECL type declarator_list)
> ;
>
> declarator_list
> : ID (',' ID)* ->^(ID)+
> ;
>
> My problem is that I want to split up int a,b; into two
> separate declarations in my AST without moving the declarator_list rule
> up to the vardecl rule.
>   
On a grammar for my language I have:

varDeclaration
    :
    'var'  ID  ( ',' ID )*  ISTYPE typeDenoter
    ( PREDEF expression -> ^(DECL 'var' ID typeDenoter expression)+
    |                   -> ^(DECL 'var' ID typeDenoter)+
    )
    ;

I use -> for ISTYPE and | for PREDEF, so I can use

var a, b -> integer | 3 ;

and

var a, b -> integer ;



So, move the declarator_list up to the vardecl rule and the + after the
tree.

--
Arto Viitanen