[antlr-interest] mild simplification and tree grammars

[Giampaolo Tomassoni]

> Oops, I see placed the { after the $ earlier, where it should
> be outside the $paramater, like {$parameter}, as in:
> 
> protected
> conditionalExpression[CommonTree TheActualASTRoot]
>     :   QMARK t=expression COMMA f=expression
>             -> ^(ITE {$TheActualASTRoot} $t $f)
>     |
>     ;

Ah, that's it!

Right, it works. Thank you.

I'm a bit astonished with that, then: why a {$var} notation is needed here?
What's the difference with $t and $f, in example?

Giampaolo