[antlr-interest] Re: changing a token type at the parser level

[Chris Black]

--- In antlr-interest at yahoogroups.com, Mark Lentczner <markl at g...> wrote:
> > Unfortunately, whenever I have an empty rule like:
> >
> > empty: ;
> >
> > in my parser, the generated java does not compile since it comlains
> > about an unreachable catch block since an empty rule will not throw a
> > RecognitionException:
> 
> > Any ideas?
> How'z'bout:
> 
> empty options{defaultErrorHandler=false;}: ;
> 
> See:
> 	http://www.antlr.org/doc/options.html#defaultErrorHandler
> 
> Sorry I didn't catch that...
> 
> 	- Mark
> 

Oddly enough I was looking at that option a few weeks ago...

What I ended up doing was:

optionalField: f:FIELD { ## = #[ABSENT,"absent empty tok"]; }
| { ## = #[ABSENT,"absent empty tok"]; }

Which works fine.

Thanks for your help!
Chris



 
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