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From: "B. Pym" <Nobody447095@here-nor-there.org>
Newsgroups: comp.lang.lisp
Subject: P16 (**) Drop every N'th element from a list.
Date: Mon, 2 Sep 2024 07:10:35 -0000 (UTC)
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>     Example:
>     * (drop '(a b c d e f g h i k) 3)

Where is "j"?

>     (A B D E G H K)
> "

> (defun drop (list n)
>  (loop
>     :for elt :in list
>     :for i :from 1
>     :for die-elt-die! = (zerop (mod i n))
>     :unless die-elt-die!
>     :collect elt))

Gauche Scheme

(use srfi-1) ;; circular-list

(define (dropnth xs n)
  (filter-map
    (lambda (x b) (and b x))
    xs 
    (cdr (apply circular-list #f (make-list (- n 1) #t)))))

(dropnth '(a b c d e f g h i j k l m) 3)
  ===>
(a b d e g h j k m)