Re: [Haskell-beginners] Trivial function of type (a -> b) -> Maybe a -> Maybe b

On Wed, Jan 13, 2010 at 8:44 AM, Eugen Zagorodniy wrote:

Greetings!

I looked at documentation of Maybe type and suprisingly found no function like

maybize             :: (a -> b) -> Maybe a -> Maybe b maybize f Nothing   =  Nothing maybize f (Just x)  =  Just (f x)

Have you looked at: fmap :: Functor f => (a -> b) -> f a -> f b It will do what you want, and has the bonus of doing the same operation for a lot more structures. Antoine http://haskell.org/ghc/docs/latest/html/libraries/base-4.2.0.0/Prelude.html#...