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From: "B. Pym" <Nobody447095@here-nor-there.org>
Newsgroups: comp.lang.lisp
Subject: re: Generating code which compiles to a jmphash
Date: Thu, 18 Jul 2024 16:10:44 -0000 (UTC)
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fvmarcoline wrote:

> (defconstant dirs '(up down left right))
> 
> (defun all-moves ()
> 
>   (loop for dir in dirs
>      append
>        (loop for i from 0 to 4
>           collect (list i dir))))
> 
> (defun move-to-int (move)
>   (+ (first move) (* 5 (position (second move) dirs))))
> 
> > (nth 12 (all-moves))
>        => (2 left)
> > (map 'list 'move-to-int (all-moves))
>        => (0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)

Gauche Scheme

(define dirs '(up down left right))
(define dir-table (map cons dirs '(0 5 10 15)))

(define (all-moves)
  (append-map
    (^(dir) (map (^i (list i dir)) (lrange 0 5)))
    dirs))

(define (move-to-int move)
  (+ (car move) (assv-ref dir-table (cadr move))))

(~ (all-moves) 12)
  ===>
(2 left)

(map move-to-int (all-moves))
  ===>
(0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)