Am Samstag, 25. Oktober 2008 12:34 schrieb Glurk:
The lambdabot on #haskell has a plugin named "pointless" that can transform this into a definition that doesn't mention x and xs anymore. I think it will propose
howMany = (length .) . matches
And with
matches x xs = filter (x==) xs
matches x = filter (x==)
matches = filter . (==)
we have
howMany = (length .) . filter . (==)
howMany = curry (length . uncurry matches)
Thanks apfelmus,
unfortunately, none of those suggested changes seem to work ! I get errors like :-
Unresolved top-level overloading *** Binding : howMany2 *** Outstanding context : Eq b
I'm using WinHugs - do you get them to work in some other environment ?
Did you give a type signature for these? Then you would of course have to include the context Eq b, since (==) is used. If you don't give any type signatures, all above versions should work in all environments, otherwise it would be a serious bug.
Thanks ! :)