RE: multiple return values

["Karl O. Pinc" <kop@meme.com>]

On 04-Feb-98 Sascha Ziemann wrote:
>Hi,
>
>Guile-GTK needs multiple return values. Does this exist already or are
>there plans to implement it? How about a multi-let or multi-set like
>
>(define (give-two)
>  (list 5 7))
>
>(multi-let (((a b) (give-two)))
>  (display a) ; => 5
>  (display b) ; => 7
>  )

I don't think guile needs multiple return values at all.  The already
existing and very clean way to do it is to use continuation passing
style:

(define (take-two a b)
  (define (give-two)
     (take-two 5 7))
  (display a)
  (display b))

If you don't like the scoping, move give-two outside of take-two's
scope (define (give-two taker) (taker 5 7)) and pass take-two as an
argument to give-two.  And if give-two has to be a thunk, just make
one:

(define (thunk)
  (give-two take-two))

(I don't much like defines, lambda's are more clear, but your's was in
defines so...)