ref: 5681745bc3eff5ebcaa2986137c1df63ae920a7e
dir: /femtolisp/rule30.lsp/
; -*- scheme -*-
(define (rule30-step b)
(let ((L (ash b -1))
(R (ash b 1)))
(let ((~b (lognot b))
(~L (lognot L))
(~R (lognot R)))
(logior (logand L ~b ~R)
(logand ~L b R)
(logand ~L b ~R)
(logand ~L ~b R)))))
(define (nestlist f zero n)
(if (<= n 0) ()
(cons zero (nestlist f (f zero) (- n 1)))))
(define (string.rep s k)
(cond ((< k 4)
(cond ((<= k 0) "")
((= k 1) (string s))
((= k 2) (string s s))
(else (string s s s))))
((odd? k) (string s (string.rep s (- k 1))))
(else (string.rep (string s s) (/ k 2)))))
(define (pad0 s n) (string (string.rep "0" (- n (length s))) s))
(define (bin-draw s)
(string.map (lambda (c) (case c
(#\1 #\#)
(#\0 #\ )
(else c)))
s))
(for-each (lambda (n)
(begin
(princ (bin-draw (pad0 (number->string n 2) 63)))
(terpri)))
(nestlist rule30-step (uint64 0x0000000080000000) 32))