permute.scm

(define (random-permutate lst)
  (let* ([len (length lst)]
         [i (rand len)]
         [j (let loop ((number (rand len)))
              (if (= number i)
                  (loop (rand len))
                  number))]
         [vec (list->vector lst)])
    (vector-swap! vec i j)
    (vector->list vec)))