[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: proposing a simpler mechanism



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