[Haskell-beginners] IO action on a list of [IO a]

Manfred Lotz manfred.lotz at arcor.de
Sat Oct 6 20:11:33 CEST 2012


On Sat, 06 Oct 2012 16:56:36 +0200
koomi <koomi at hackerspace-bamberg.de> wrote:

> On 06.10.2012 16:16, Manfred Lotz wrote:
> > Hi all,
> > I want to do an IO action on a list of [IO a] like this:
> >
> > myfor :: (a -> IO () ) -> [IO a] -> IO ()
> > myfor _ [] = return ()
> > myfor f (x:xs) = do
> >    x' <- x
> >    f x'
> >    myfor f xs
> >      
> >
> >
> > Is there a library function doing just this?
> >
> >
> >
> You could do: mapM_ (\x -> x >>= f) xs
> 

Yep, that works nicely. Thanks.


-- 
Manfred





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