Re: FYI: default %printer/%destructor

[Paul Eggert]

"Joel E. Denny" <address@hidden> writes:

> I suspect that using [] in a grammar to mean optional is not nearly as 
> common.

It's pretty common, I'm afraid.  It's in the ISO standard for EBNF,
for example.

http://www.cl.cam.ac.uk/~mgk25/iso-ebnf.html

Characters unused by ISO EBNF include .:!+_%@&#$<>/\^`~.

I sort of liked the notation a.b to denote the b component of a, as
it's a common notation in many languages.  But I admit I haven't been
following this discussion too closely.