On Nov 5, 2007 8:11 PM, Alex Young
{--------------------------------------------------} module Main where
import Random import System.Environment import List import Monad
randMax = 32767 unitRadius = randMax * randMax
rand :: IO Int rand = getStdRandom (randomR (0, randMax))
randListTail accum 0 = accum randListTail accum n = randListTail (rand : accum) (n - 1)
I can't believe that nobody has pointed this out yet. I think we were all focused on your weird usage of the IO monad... Anyway, you do not want to use tail recursion in this case. Here you have to evaluate everything before you can return the first element, because we don't know that you're going to return accum when you get down to zero... you might return 1:accum or something. When you're returning a list, it's best not to use tail recursion because we can get the initial elements of the list lazily. randList 0 = [] randList n = rand : randList (n-1) Is a much better implementation in Haskell. But that's usually just spelled "replicate n rand". :-) Luke