On 2/4/07, Udo Stenzel
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.