Example of stepping/running an Wire with constant dt

SHO.hs

{-# LANGUAGE Arrows #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE NoMonomorphismRestriction #-}

module Main (main) where

import Control.Wire
import FRP.Netwire.Move
import Control.Arrow
import Prelude hiding ((.), id, mapM_)
import Data.Foldable
import Control.Category
import Control.Monad.Fix

dt :: Double
dt = 0.01

sho :: (HasTime Double s, MonadFix m) => Wire s () m a Double
sho = proc _ -> do
    rec let a = -0.5 * x
        v <- integral 0 -< a
        x <- integral 1 -< v
    returnA -< x

stepShow :: Int -> Wire (Timed Double ()) () IO () Double -> IO ()
stepShow 0 _ = return ()
stepShow n a = do
    (ds, _) <- stepSession (countSession dt <*> pure ())
    (r, a') <- stepWire a ds (Right ())
    mapM_ print r
    stepShow (n-1) a'

main :: IO ()
main = stepShow 1001 sho