[Haskell-cafe] async simplify code

[gbwey9]

Thanks! That is exactly what I was looking for.
Grant


On Sun, Jul 6, 2014 at 5:54 AM, Sjoerd Visscher <sjoerd at w3future.com> wrote:

> You can use the Concurrently newtype wrapper for this, then you can use
> the Applicative and Alternative type classes.
>
> dostuff :: Int -> Concurrently (String, Int)
> dostuff n = Concurrently $ do
>   ..
>
> let aborcd  =  (\x y -> [x, y]) <$> dostuff 6 <*> dostuff 12
>            <|> (\x y -> [x, y]) <$> dostuff 8 <*> dostuff 10
> fromMaybe [] <$> timeout (1000000 * 20) (runConcurrently aborcd)
>
> or even
>
> let aborcd = traverse dostuff [6, 12] <|> traverse dostuff [8, 10]
>
> Sjoerd
>
> On 06 Jul 2014, at 06:17, Michael Snoyman <michael at snoyman.com> wrote:
>
> >
> >
> >
> > On Sat, Jul 5, 2014 at 3:58 AM, grant weyburne <gbwey9 at gmail.com> wrote:
> > Hi Cafe,
> >
> > Is there any way to simplify this async code to somehow merge the
> withAsync code
> > into the STM code? Looking at the code for tstABorCD it is not easy to
> see that
> > it is really just (A&&B)||(C&&D). Here is the code:
> >
> > http://lpaste.net/106945
> >
> > Thanks for any pointers,
> > Grant
> >
> >
> >
> > The code as-is doesn't actually look too bad to me. But it *might* be a
> bit easier to read if instead of withAsync, waitSTM, and registerDelay, you
> used race, concurrently, and timeout. That might look something like this
> (untested):
> >
> > let toList (x, y) = [x, y]
> >     ab = toList <$> concurrently (doStuff 6) (doStuff 12)
> >     cd = toList <$> concurrently (doStuff 8) (doStuff 10)
> > res <- timeout (1000000 * 20) $ race ab cd
> > return $ maybe [] (either id id) res
> >
> > Michael
> > _______________________________________________
> > Haskell-Cafe mailing list
> > Haskell-Cafe at haskell.org
> > http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>
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