Thanks -John On 1/26/07, Brandon S. Allbery KF8NH wrote:

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