[Haskell-beginners] maybe in IO

[Mike Ledger]

With Data.Foldable, it's quite nice:

check x assoc = lookup x assoc `for_` \f -> putStrLn ("found " ++ f)

On Fri, Aug 2, 2013 at 1:45 AM, Michael Orlitzky <michael at orlitzky.com>wrote:

> On 08/01/2013 11:00 AM, vold wrote:
> > I've defined a function similar to
> >
> > check x assoc = let found = lookup x assoc in
> >                     when (isJust found) $ putStrLn $ "found " ++
> fromJust found
> >
> > which I've used several times from within the IO monad. Is there a more
> > compact way of doing this?
> >
>
> maybe (return ()) (putStrLn . ("found " ++)) found
>
> is the best I could do.
>
>
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