monad-skeleton

Monads of program skeleta

https://github.com/fumieval/monad-skeleton

Version on this page:0.1.3.2
LTS Haskell 20.26:0.2
Stackage Nightly 2022-11-17:0.2
Latest on Hackage:0.2

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BSD-3-Clause licensed by Fumiaki Kinoshita
Maintained by Fumiaki Kinoshita
This version can be pinned in stack with:monad-skeleton-0.1.3.2@sha256:46985d046ae0f347d10687569dd0ae64daec3fcfb9cf85fad7f151746fc5b057,1046

Module documentation for 0.1.3.2

Depends on 1 package(full list with versions):
base
Used by 2 packages in lts-8.20(full list with versions):
extensible, objective

monad-skeleton

Build Status Hackage

This package provides Skeleton, an operational monad. 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 :: Interacton 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