[antlr-interest] How to rewrite rule with optional terms?

[Terence Parr]

On May 26, 2008, at 1:10 PM, fridi70 at gmx.de wrote:

> Hi,
>
> if have a grammar like this:
>
> op: queryOp ('>' INT)?;
>

trySomething like:

op : queryOp ('>' INT -> ^('>' queryOp INT) | ->^('>' queryOp  
INT["0"])) ;

> INT: DIGIT+;
>
> fragment
> DIGIT: '0'..'9';
>
>
> I want to rewrite the rule op in a manner that it adds '>' and '0'  
> as children to the root if '>0' is missing.
>
> How can I achieve this? Thanks in advance, fridi
>
> -- 
> Psssst! Schon vom neuen GMX MultiMessenger gehört?
> Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger