Comments on: Factorial and Memoizing

By: Lanny Ripple

Lanny Ripple — Tue, 17 Aug 2010 19:00:07 +0000

Also

my $fact := (1, [\*] 1..*);
say $fact[0..10].perl;

(1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800)

By: colomon

colomon — Wed, 11 Aug 2010 08:31:17 +0000

Brill!

By: RobertS

RobertS — Wed, 11 Aug 2010 07:45:55 +0000

This works for me:

my $fact = [\*] 1,1..*;
say $fact.munch(20).perl;

(1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6.402373705728e+15, 1.21645100408832e+17)

By: Pm

Pm — Wed, 11 Aug 2010 07:00:01 +0000

Note that it would need to be parenthesized, because of item assignment:

my $fact = (1, [\*] 1..*);

It still doesn’t work (yet?), because itemizing the Parcel tends to make it eager, so we end up evaluating an infinite list. But the following does work:

my $fact = (1, [\*] 1..100);

which at least gets you to 100 factorial, and doesn’t take forever to do it.

By: colomon

colomon — Tue, 10 Aug 2010 16:41:52 +0000

I tried that first and it failed.

By: Eddward

Eddward — Tue, 10 Aug 2010 16:32:37 +0000

I don’t have perl6 installed at work. Would the following work?

my $fact = 1, [\*] 1..*;