Hi Tomasz,

I actually quite like this style.  I was able to understand it after spending some time reading the docs for some of the functions you used.

My problem I guess is being able to write the code this way when the need arises or even just recognising when and where it's an option, both of which to me is considerably harder.

Thanks for the tip.

-John

On 1/29/07, Tomasz Zielonka <tomasz.zielonka@gmail.com> wrote:
On Mon, Jan 29, 2007 at 10:10:47PM +1100, John Ky wrote:
> I've written some code and was wondering if there was a better way to write
> it in terms of readability, brevity and/or efficiency.

This version of mergeForest2 should be more efficient. For even better
efficiency it should use Data.Sequence for efficient concatenation
(instead of ++). I also made it more general. You have to judge
readability yourself.

    import qualified Data.Map as Map

    data ArcData = ArcData
     { name :: String
     } deriving (Show, Eq, Ord) -- derive Ord and Eq

    mergeForest2 :: (Ord k) => [Tree k] -> Forest k
    mergeForest2 =
        map pairToNode .
        Map.toList .
        Map.map mergeForest2 .
        Map.fromListWith (++) .
        map nodeToPair
      where
        nodeToPair (Node x y) = (x, y)
        pairToNode = uncurry Node

Best regards
Tomasz