[reactive] Fwd: First steps in FRP

[Álvaro García Pérez]

Hi,

I've found Sasha's example

> import FRP.Reactive
> import FRP.Reactive.LegacyAdapters
> import Control.Concurrent
> type BellMachine = Event () -> Event ()
> doorBell :: BellMachine
> doorBell = id
> runMachine :: BellMachine -> IO ()
> runMachine machine = do
>   -- get button press
>   clock <- makeClock
>   (buttonPressed, buttonPressedSink) <- makeEvent clock
>   forkIO $ buttonPresses buttonPressedSink
>   adaptE (fmap bell $ machine buttonPressed)
>   -- run the machine
>   where bell = const $ print "beep!"
>         buttonPresses sink = sequence_ $ repeat $ (getChar >> sink ())
> main = runMachine doorBell

and it fits my purposes, but notice that the values collected from the
makeEvent function must be in reverse order, at least with reactive-0.11.

> (buttonPressedSink, buttonPressed) <- makeEvent clock

Regards,

Alvaro.

---------- Mensaje reenviado ----------
De: Álvaro García Pérez <agarcia at babel.ls.fi.upm.es>
Fecha: 8 de junio de 2009 11:57
Asunto: First steps in FRP
Para: reactive at haskell.org


Hello,

I'm new to FRP and I'm trying to write a simple program adapting the events
to IO. I've read the tutorial "Introducing Reactive: Events" but it's not
very clear how to do it. Can someone send me an example? I would like to
capture events from IO (let's say, keyboard strokes) and print text in the
console. I'm using the last version of the reactive package.

Thanks,

Alvaro.
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