scheme (format) question

[Mark Polesky]

\version "2.12.2"

%{

How can I change the following code so that
it returns "2 0.25 0.3333"? That is: return 
integers without decimal point, otherwise 
round to as many decimal places as needed, 
but not more than 4.

%}

#(let ((a 2.0)
       (b 1/4)
       (c 1/3))
   (format #t "~a ~a ~a\n" a b c))

%{

After some experimenting, I found the
following solution, but I'd rather not have
to deal with all the incessant quasiquote
and unquote stuff. Is there a more elegant
solution?

Thanks in advance.
- Mark

%}

#(define (set-precision n)
  (let* ((max-decimals 4)
         (k (expt 10.0 max-decimals)))
   (if (number? n)
       (if (integer? n)
           (inexact->exact n)
           (/ (round (* n k))
              k))
       n)))

#(define (my-format bool string list-of-nums)
  (apply format bool string (map set-precision list-of-nums)))

#(let ((a 2.0)
       (b 1/4)
       (c 1/3))
   (my-format #t "~a ~a ~a\n" `(,a ,b ,c)))