On 2/4/07, Udo Stenzel <[EMAIL PROTECTED]> wrote:
J. Garrett Morris wrote:
Small improvement (Data.Maybe is underappreciated):
> exists str wmap = isJust exists'
> where exists' =
> do x <- Map.lookup (sort str) wmap
> find (== str) (snd x)
This is true. Some time ago I swore off the use of fromRight and
fromLeft in favor of maybe, and have been forgetting about the other
functions in Data.Maybe ever since.
and maybe another improvement, though this is dependent on your tastes:
> exists s wmap = isJust $ Map.lookup (sort s) wmap >>= find (== s) . snd
If you're going to write it all on one line, I prefer to keep things
going the same direction:
exists s wmap = isJust $ find (==s) . snd =<< Map.lookup (sort s) wmap
Normally, from there I would be tempted to look for a points-free
implementation, but in this case I have a strong suspicion that would
simply be unreadable.
/g
--
It is myself I have never met, whose face is pasted on the underside of my mind.
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
