[antlr-interest] Newbie Question
Jim Idle
jimi at temporal-wave.com
Mon Mar 16 16:43:54 PDT 2009
Behdad Forghani wrote:
> Hello,
>
> I am trying to built AST from a rule with an optional part.
> The rule is:
>
> type :
> builtinType constraint?;
>
>
> I want the constraint node to be the child of builtinType. So, I add:
>
> type :
> builtinType constraint?->^(builtinType constraint?);
>
That should be fine, unless the constraint has more than one node
itself, which I am guessing is your issue. You probably really want an
imaginary token here:
tokens {
BUILTINTYPE;
}
type :
builtinType constraint?->^(BUILTINTYPE builtinType constraint?);
;
Jim
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