post-scarcity/lisp/scratchpad2.lisp
Simon Brooke 64fc43e9fc OK, my idea that long multiplication is like long addition is wrong.
It's still broken, but it's broken because of fundamental misunderstanding which tinkering won't solve.
2019-01-20 23:34:46 +00:00

86 lines
1.4 KiB
Common Lisp

"This demonstrates that although the print representation of three cell bignums blows up, the internal representation is sane"
"We start by adding 8 copies of 2^60 - i.e. the first two-cell integer"
(set! a
(+
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"Then repeatedly add eight copies of the previous generation"
(set! b (+ a a a a a a a a))
(set! c (+ b b b b b b b b))
(set! d (+ c c c c c c c c))
(set! e (+ d d d d d d d d))
(set! f (+ e e e e e e e e))
(set! g (+ f f f f f f f f))
(set! h (+ g g g g g g g g))
(set! i (+ h h h h h h h h))
(set! j (+ i i i i i i i i))
(set! k (+ j j j j j j j j))
(set! l (+ k k k k k k k k))
(set! m (+ l l l l l l l l))
(set! n (+ m m m m m m m m))
(set! o (+ n n n n n n n n))
"p"
(set! p (+ o o o o o o o o))
"q"
(set! q (+ p p p p p p p p))
"r"
(set! r (+ q q q q q q q q))
"s"
(inspect
(set! s (+ r r r r r r r r)))
"t - first three cell integer. Printing blows up here"
(inspect
(set! t (+ s s s s s s s s)))
"u"
(inspect
(set! u (+ t t t t t t t t)))
"v"
(inspect
(set! v (+ u u u u u u u u)))
"w"
(inspect
(set! w (+ v v v v v v v v)))
(inspect
(set! x (+ w w w w w w w w)))
(inspect
(set! y (+ x x x x x x x x)))
(inspect
(set! z (+ y y y y y y y y)))
(inspect
(set! final (+ z z z z z z z z)))