Re: FYI: default %printer/%destructor

[Hans Aberg]

On 22 Nov 2006, at 15:44, Joel E. Denny wrote:

> > The proposal I made does not use "{ }", except in Bison actions.
>
> Sorry, I was thinking of ISO EBNF.

I looked at that one a long time ago, and I think it was strange in  
some respects, though I do not immediately recall what. Better to  
design a grammar ones own.

> > > Do you have a specific proposal in mind?
> >
> > I already gave one: using U+2192 '→', which in ASCII looks like "- 
> > >".
>
> First, given you've still chosen an ASCII representation, I don't  
> see the
> benefit of Unicode here.

Or vice versa: choosing a Unicode representation makes ASCII  
unnecessary, ecept for those poor guys that do not have an UTF-8  
editor. But then for this latter, one might make separate Unicode- 
ASCII translators.

> Second, I don't see how this addresses the issue
> we're discussing anyway: names for semantic values and locations.

Overuse of tokens may cause grammar conflicts.

> > You seem to have made your mind about
> > these variables, and want to adapt the other stuff around it. I  
> > wonder if this
> > is wise: if clashes can be avoided that way, the combination might be
> > cumbersome.
>
> I tried considering alternatives, but I think it may be a lost cause.
> More importantly, when it comes to EBNF, I'm not sure it's worthwhile.
> Do you know of someone who's actually going to contribute EBNF  
> support to
> Bison?

It has popped up from time in Help-Bison, and the last time Akim  
seemed to be interested, given that Bison already has all the  
features making an implementation easy: a .y grammar, and implicit  
grammar variables, already used for the implementation of rule-mid- 
actions. Therefore, I wrote this EBNF proposal in Bug-Bison.

  Hans Aberg