monad-skeleton
Monads of program skeleta
https://github.com/fumieval/monad-skeleton
| LTS Haskell 20.26: | 0.2 |
| Stackage Nightly 2022-11-17: | 0.2 |
| Latest on Hackage: | 0.2 |
Maintained by Fumiaki Kinoshita
This version can be pinned in stack with:
monad-skeleton-0.2@sha256:1768220a01d010020adfd7a8e435998c8e5e1a6a562866dd54b3af23e08e123f,1053Module documentation for 0.2
- Control
Depends on 1 package(full list with versions):
monad-skeleton
This package provides Skeleton, an operational monad (i.e. free monad that does not require the Functor implementation). The internal encoding
gives O(1) bind and monadic reflection.
Skeleton promotes unit instructions to a monad. It is isomorphic to
MonadView (Skeleton t):
data MonadView t m x where
Return :: a -> MonadView t m a
(:>>=) :: !(t a) -> (a -> m b) -> MonadView t m b
boned :: MonadView t (Skeleton t) a -> Skeleton t a
debone :: Skeleton t a -> MonadView t (Skeleton t) a
GADTs are handy to define instructions:
data Interaction x where
Get :: Interaction String
Put :: String -> Interaction ()
echo :: Skeleton Interaction ()
echo = bone Get >>= bone . Put
Use debone to interpret a computation.
interpret :: Skeleton Interaction a -> IO a
interpret m = case debone m of
Return a -> return a
Get :>>= k -> getLine >>= interpret . k
Put s :>>= k -> putStrLn s >>= interpret . k