[Shootout-list] harmonic sum for ghc and perl

[Einar Karttunen]

Greg Buchholz <sleepingsquirrel@yahoo.com> writes:
>     Attached are implementations of the harmonic sum benchmark for GHC
> and Perl.  The benchmark description should probably mention that the
> results should be rounded to 9 decimal places.

Here is a faster one for GHC - gives a 5x increase.
Compile with ghc -O2 -fexcess-precision a.hs -o a

import System(getArgs)
import Numeric

main = do [n] <- getArgs
          putStrLn $ showFFloat (Just 9) (loop (read n) 0 0) ""

loop :: Int -> Double -> Double -> Double
loop 0 _ sum = sum
loop i d sum = loop (i-1) d' (sum + (1/d')) where d' = d+1


- Einar Karttunen