MSF.hs

data ProbT m a where
  ProbT :: m [(Double, a)] -> ProbT m a -- sum double = 1
  | GaussianDist
      :: Double -- | Mean
      -> Double -- | Width
      -> ProbT m Double
  | ...
return a = [(1, a)]

-- Real system
system :: MSF IO cmd sense

-- Simulation
sim :: Monad m => MSF (ProbT m) cmd (sense, state)

bayesFilter :: MSF (ProbT IO) cmd state
bayesFilter = proc cmd -> do
  realSense <- liftTransS system -< cmd
  (simSense, state) <- sim -< cmd
  arrM guard -< simSense == realSense
  returnA -< state


data ContT m r a = ContT ((a -> m r) -> m r)
data LogicT m r a = LogicT ((a -> m r -> m r) -> m r -> m r)