[racket] syntax-parse questions
On Apr 12, 2011, at 5:38 PM, Ryan Culpepper wrote:
>
> There are two kinds of ~optional: one is for head patterns and the other is for ellipsis-head patterns. The #:name keyword is only allowed in the latter case.
ok, makes sense.
> Ah, sorry, the docs are incomplete for #:defaults; I'll fix that. If the ellipsis depth is not 0 (for example, 'key' has a depth of 1), you must specify the depth too. I think this is what you want: [...]
Yes, that does the job perfectly!
> I wish I'd made #:defaults take patterns on the left-hand sides instead.
Indeed, that's the first thing I tried! (conversely, I would never have guessed the current syntax)
> I'll see if I can add something like that before the upcoming release.
that'd be great,
> Hope that helps,
it does, thanks a lot.
-- Éric