Descending

Ken Tilton wrote:

I am having trouble coding a list traversal segment.
 eg list:
>
(a (b) (c (e (h i)) (f (j))) (d (g)))
>
I want to traverse this list in "preorder" and get the following
output:
>
a b c e h i f j d g
>
anyone have a code segment to this?
>
thanks....
>
Chris.

 
Will this work?:
 
(defun dump (list-or-atom)
   (if (listp list-or-atom)
      (dolist (loa list-or-atom)
          (dump loa))
      (format t "~s " list-or-atom)))

Gauche Scheme:

(define (dump list-or-atom)
  (cond ((null? list-or-atom) )
        ((list? list-or-atom)
          (begin
            (dump (car list-or-atom))
            (dump (cdr list-or-atom))))
        (#t (format #t ":~s " list-or-atom))))

(dump '(a (b) (c (e (h i)) (f (j))) (d (g))))
  ===>
:a :b :c :e :h :i :f :j :d :g #t