Deep Reverse

deep_reverse.scm

; 2.27

(define (deep-reverse list)
  (define (iter-list reversed-list unprocessed-remaining)
    (if (null? unprocessed-remaining)
        reversed-list
        (iter-list (cons (if (list? (car unprocessed-remaining))
                            (deep-reverse (car unprocessed-remaining))
                            (car unprocessed-remaining))
                             reversed-list) (cdr unprocessed-remaining))
    ))
  (iter-list null list)
  )

(deep-reverse (list 3 4 (list 5 6)))                  ;--->((6 5) 4 3)
(deep-reverse (list 3 4 (list 5 6 (list 7 8 9))))     ;--->(((9 8 7) 6 5) 4 3)
(deep-reverse (list 3 4 (list 5 (list 6 (list 7)))))  ;--->((((7) 6) 5) 4 3)