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From: "B. Pym" <No_spamming@noWhere_7073.org>
Newsgroups: comp.lang.scheme
Subject: Re: (Mastermind) puzzle (with 3 digits) -- Elegant (readable) code Sought
Date: Sun, 26 May 2024 08:11:11 -0000 (UTC)
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On 3/1/2024, Andreas Eder wrote:

> I would write it without the second define using a named let:
> 
> (define (range n)
>   (let go ((n n) (a '()))
>     (if (< n 0)
>         a
>         (go (1- n) (cons n a)))))

Looks good.

Using "do":

(define (range n)
  (do ((i n (- i 1))
       (a '() (cons i a)))
    ((< i 0) a)))


Using "unfold-right" in Gauche Scheme:

(use srfi-1)

Gauche doesn't have "1-".

(define (1- n) (- n 1))

(define (range n) (unfold-right negative? values 1- n)) 

(range 9)
  ===>
(0 1 2 3 4 5 6 7 8 9)