Defining Pet Features and Essentials

[Geoff Canyon]

On Tue, Feb 11, 2014 at 6:59 AM, Ender Nafi Elekcioglu <
endernafi at keehuna.com> wrote:

> Try to calculate a recursive fib(33) under 0.5 second
> {it's 14 seconds on a brand new Macbook Pro Retina, where it's ~100ms. for
> Javascript.}
>

I'll take that bet:

local fibArray

function fib N
   if N = 0 or N = 1 then return N
   if fibArray[N] is empty then put fib(N-2) + fib(N-1) into fibArray[N]
   return fibArray[N]
end fib

on mouseUp
   put the long seconds into T
   get fib(33)
   put it && the long seconds - T
end mouseUp

Puts:

3524578 0.000022

It would be *really* good if LC supported co-routines, tail-recursion
optimization, and native memo-ization of functions, but it's often not hard
to memo-ize manually. Of course in this case recursion is unhelpful to
begin with, but I'm pretending that it's unavoidable since it's the reason
for the example.