Re: proposing a simpler mechanism
Thomas Bushnell BSG 13 Nov 2009 20:02 UTC
On Fri, 2009-11-13 at 11:55 -0800, Arthur A. Gleckler wrote:
> > Case-lambda is not a part of standard scheme. If you mean srfi-16,
> > notice the way the reference implementation works. It defines a
> > procedure with a formals list that looks like this:
>
> Case-lambda is part of R6RS.
Thanks for the correction; I'm surprised, but not surprised. In any
case, my comments are the same. If the implementation in r6rs is any
guide, then what--*exactly*--is the arity supposed to be, if it's not
something metaphysical?
I was asked "what's the arity of read?". I'll ask, what's the arity of
foo:
(define foo
(case-lambda
((x) (list x))))
And what's the arity of bar:
(define (bar . args) args)
If you tell me that the arity of foo is 1, and the arity of bar is "any
number", then the example definiton of case-lambda in r6rs must be
incorrect.
Thomas