MealyDataflow.hs

data Validity = Invalid | Valid deriving (Eq, Show, Generic, NFData)
data Readiness = NotReady | Ready deriving (Eq, Show, Generic, NFData)
asValid x = if x then Valid else Invalid
asReady x = if x then Ready else NotReady

data DFIO a = DFIO { valid :: Validity, ready :: Readiness, val :: a } deriving (Eq, Show, Generic, NFData)
dfio iV oR dat = DFIO (asValid iV) (asReady oR) dat
pending placeholder = DFIO Invalid NotReady placeholder
done result = DFIO Valid Ready result

isValid DFIO{..} = valid == Valid
isReady DFIO{..} = ready == Ready

mealyDF' :: HiddenClockReset dom gated sync
         => (s -> DFIO i -> (s, DFIO o))
         -> s
         -> DataFlow dom Bool Bool i o
mealyDF' f s = liftDF (\i iV oR -> let dfo = mealy f s $ dfio <$> iV <*> oR <*> i
                                   in (fmap val dfo, fmap isValid dfo, fmap isReady dfo))