Re: FYI: default %printer/%destructor

[Hans Aberg]

On 21 Nov 2006, at 23:41, Joel E. Denny wrote:

> > The problem is that EBNF is so fundamental, it is important to  
> > find a good
> > notation of it.
>
> Bison will already need an alternative for {}.

The proposal I made does not use "{ }", except in Bison actions.

> > > There are only so many characters on the
> > > keyboard.
> >
> > Well, Unicode has some 100000 plus characters, and one might  
> > substitute
> > poor-mans-ASCII for some of them.
>
> Do you have a specific proposal in mind?

I already gave one: using U+2192 '→', which in ASCII looks like "->".

> > > I suspect that using [] in a grammar to mean optional is not  
> > > nearly as
> > > common.
> >
> > I think it is quite common, in fact.
>
> I don't mean to say it isn't.  I mean to say that it's less common  
> than
> (), and we have to pick something.

I think "[ ]" for optional looks good. 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.

  Hans Aberg