[Chicken-users] Re: crazy behaviour in csi!

[Jens Axel Søgaard]

Sunnan wrote:
> Thanks, I guess I was stressed, and forgot that unknown macros can
> already be defined. The error message just looked so weird.
>
> I was pretty sleep-deprived at the time.
>
> I hadn't looked at srfi-31 before. I thought I knew most of the srfis.
> This one was pretty disappointing.
>
> (define (...) 10)
> ; They want to write:
> ((rec (F N) 
>       (if (zero? N) 1 
> 	  (* N (F (- N 1))))) (...))
>
> ;; instead of:
> (let f ((n (...)))
>   (if (zero? n) 1
>       (* n (f (- n 1)))))
> ;; it's the exact same number of characters!

Almost - note that REC returns the recursive
function, so you need to return the function
in the let:

  ((let f ((n (...)))
     (if (zero? n) 1
         (* n (f (- n 1))))
     f)
    (...))

--
Jens Axel Søgaard