[REBOL] Re: language shoot-out :-)
From: joel:neely:fedex at: 5-Nov-2002 7:15
Hi, Tom,
Could you please post the code which you used to generate that
output? It doesn't match what I'm getting at all!
Here's my test harness ...
8<----------------------------------------------------------------------
ackermann: make object! [
curr_depth: max_depth: tot_evals: 0
ack: func [m [integer!] n [integer!] /local result] [
max_depth: max max_depth curr_depth: curr_depth + 1
tot_evals: tot_evals + 1
result: either m = 0 [
n + 1
][
either n = 0 [
ack m - 1 1
][
ack m - 1 ack m n - 1
]
]
curr_depth: curr_depth - 1
result
]
run: func [][
repeat i 8 [
curr_depth: max_depth: tot_evals: 0
if error? try [
print [i ack 3 i max_depth tot_evals]
][
print [
"Failure at depth" curr_depth "/" max_depth
"after" tot_evals
]
]
]
]
]
8<----------------------------------------------------------------------
... and I get these results ...
>> ackermann/run
1 13 15 106
2 29 31 541
3 61 63 2432
4 125 127 10307
5 253 255 42438
6 509 511 172233
Failure at depth 709 / 709 after 250362
Failure at depth 709 / 709 after 249577
(on w95, but YMMVDOP!)
-jn-
Tom Conlin wrote:
> I would geuss ack 3 7 blows up close to where ack 3 8 does
>
> %ack 3 8
> ...
> 323990
> 323991
> 323992
> 323993
> 323994
> 323995
> ** Internal Error: Stack overflow
> ** Near: ack (x - 1) 1
>
> On Mon, 4 Nov 2002, Carl at REBOL wrote:
>
> > How deep is the stack at 7?
> >
--
; Joel Neely joeldotneelyatfedexdotcom
REBOL [] do [ do func [s] [ foreach [a b] s [prin b] ] sort/skip
do function [s] [t] [ t: "" foreach [a b] s [repend t [b a]] t ] {
| e s m!zauafBpcvekexEohthjJakwLrngohOqrlryRnsctdtiub} 2 ]
