gistfile1.hs

import Control.Parallel
import Control.Monad
import Text.Printf

cutoff = 35

fib' :: Int -> Integer
fib' 0 = 0
fib' 1 = 1
fib' n = fib' (n-1) + fib' (n-2)

fib :: Int -> Integer
fib n | n < cutoff = fib' n
      | otherwise  = r `par` (l `pseq` l + r)
    where
      l = fib (n-1)
      r = fib (n-2)

main = forM_ [0..45] $ \i ->
       printf "n=%d => %d\n" i (fib i)