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From: "B. Pym" <Nobody447095@here-nor-there.org>
Newsgroups: comp.lang.lisp,comp.lang.scheme
Subject: Re: Translating circular Haskell code to lisp
Date: Fri, 30 Aug 2024 17:09:35 -0000 (UTC)
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Pascal Costanza wrote:

> > I don't need a general purpose transformation, just some guidelines to
> > follow when I see code like this.
> 
> General guideline: Look for a solution that uses LOOP. ;)
> 
> (defun diff3 (list)
>    (let ((avg (loop for element in list
>                     sum element into sum
>                     count t into length
>                     finally (return (/ sum length)))))
>      (loop for element in list
>            collect (- element avg))))

Gauche Scheme

(define (diff3 lst)
  (let ((len 0) (sum 0))
    (dolist (x lst) (inc! len) (inc! sum x))
    (map (cute  - <> (/ sum len)) lst)))

(diff3 '(1 2 3 4 5))
  ===>
(-2 -1 0 1 2)