Re: Retrieving the string name of token

[Hans Aberg]

On 7 Mar 2006, at 16:55, Frans Englich wrote:

> > > sometimes I really feel like writing rules like this:
> > >
> > > Rule: (A | B) C D
> > >
> > > Which would allow A C D or B C D. What is the reason to that such
> > > constructs
> > > are not possible?
> >
> > Simply because nobody has implemented it. I think some grads at
> > Berkeley made a Bison version with such constructs.
>
> Interesting. So who knows, it will be interesting to see if  
> something pops up
> at somepoint.

If somebody gets interested in implementing it. It should not be too  
difficult, at this point, as Bison itself has a .y grammar, making  
grammar extensions fairly easy, and the method used to implement this  
kind of extensions is merely by introducing some new hidden  
variables, in a similar way empty rules are implemented.

  Hans Aberg