Getting input into Netwire programs

Question

I\'m getting started with Netwire version 5.

I have no problem writing all the wires I want to transform my inputs into my outputs.

Now the time has come to writ

Answer 1

I just solved this in an Arrow way, so this might be more composible. You can read my posts if you like. Kleisli Arrow in Netwire 5? and Console interactivity in Netwire?. The second post has a complete interactive program

First, you need this to lift Kleisli functions (That is, anything a -> m b):

mkKleisli :: (Monad m, Monoid e) => (a -> m b) -> Wire s e m a b
mkKleisli f = mkGen_ $ \a -> liftM Right $ f a

Then, assuming you want to get characters from terminal, you can lift hGetChar by doing this:

inputWire :: Wire s () IO () Char
inputWire = mkKleisli $ \_ -> hGetChar stdin

I haven't tested this runWire function (I just stripped code off from my previous posts), but it should run your wires:

runWire :: (Monad m) => Session m s -> Wire s e m () () -> m ()
runWire s w = do
  (ds, s') <- stepSession s
  -- | You don't really care about the () returned
  (_, w') <- stepWire w ds (Right ())
  runWire s' w'

You can compose the input wire wherever you like like any other Wires or Arrows. In my example, I did this (don't just copy, other parts of the program are different):

mainWire = proc _ -> do 
  c <- inputWire -< ()
  q <- quitWire -< c
  outputWire -< c
  returnA -< q

Or, one-liner:

mainWire = inputWire >>> (quitWire &&& outputWire) >>> arr (\(q,_) -> q)