25 Jan
2007
25 Jan
'07
9:22 a.m.
On Jan 25, 2007, at 9:15 , John Ky wrote:
Is there a built-in function that already does this?
foo :: (a -> b) -> Maybe a -> Maybe b foo f m | isNothing m = Nothing | otherwise = Just (f (fromJust m))
Nothing specific to Maybe, because the more general liftM (over monads) or fmap (over functors) already does it. -- brandon s. allbery [linux,solaris,freebsd,perl] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH