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Date: Fri, 7 Jun 2024 10:57:15 -0000 (UTC)
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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