Re: Enum for token '0', EOF

[Akim Demaille]

Le 8 juil. 06 à 17:08, Joel E. Denny a écrit :

> On Sat, 8 Jul 2006, Frans Englich wrote:
>
> > No, I don't have a need to put END in my grammar nor give it a  
> > semantic value,
>
> I can't think of a need either.  The results look buggy with the  
> current
> implementation, so maybe Bison should report an error for this usage.

A friend of mine was using END in his grammars in a very specific
place (he was making error recovery right before END), that's why
I didn't disable it.  Sure, it's wrong to play with it, but quickly
enough you have a grammar that generates an empty language if you
play too hard, so I didn't care about adding a safety net.

> > but I need to signal it in my hand written tokenizer(and it is  
> > messy to cast
> > 0 to the yytokentype enum).
>
> I'm guessing this feature was originally intended for no more than  
> just
> that (and giving the end token a user-friendly string alias).

No it was not.  The original motivation was truly to provide a string
alias while sticking to the existing interface for the other tokens.