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From: HenHanna <HenHanna@devnull.tb>
Newsgroups: comp.lang.lisp
Subject: Re: Descending
Date: Tue, 23 Jul 2024 12:27:39 -0700
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On 6/7/2024 3:57 AM, B. Pym wrote:
> 
> 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
> 

(i've added some spaces)

the good ol'  Flatten ?