[Haskell-cafe] A function for Maybes (RESOLVED)
newhoggy at gmail.com
Thu Jan 25 20:47:37 EST 2007
On 1/26/07, Brandon S. Allbery KF8NH <allbery at ece.cmu.edu> 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 at kf8nh.com
> system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
> electrical and computer engineering, carnegie mellon university KF8NH
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