ref: a70379d7e4b822f532fb0a8ccdd1624a90b64a68
dir: /test/torus.sl/
(def (maplist f l)
(and l (cons (f l) (maplist f (cdr l)))))
; produce a beautiful, toroidal cons structure
; make m copies of a CDR-circular list of length n, and connect corresponding
; conses in CAR-circular loops
; replace maplist 'identity' with 'copy-tree' for rapdily exploding memory use
(def (torus m n)
(let* ((l (map-int identity n))
(g l)
(prev g))
(dotimes (i (- m 1))
(set! prev g)
(set! g (maplist identity g))
(set-cdr! (last-pair prev) prev))
(set-cdr! (last-pair g) g)
(let ((a l)
(b g))
(dotimes (i n)
(set-car! a b)
(set! a (cdr a))
(set! b (cdr b))))
l))
(def (cyl m n)
(let* ((l (map-int identity n))
(g l))
(dotimes (i (- m 1))
(set! g (maplist identity g)))
(let ((a l)
(b g))
(dotimes (i n)
(set-car! a b)
(set! a (cdr a))
(set! b (cdr b))))
l))
(time (print (torus 100 100)))
;(time (dotimes (i 1) (load "100x100.sl")))
; with ltable
; printing time: 0.415sec
; reading time: 0.165sec
; with ptrhash
; printing time: 0.081sec
; reading time: 0.0264sec