Copyright	(c) Michael Szvetits 2020
License	BSD3 (see the file LICENSE)
Maintainer	typedbyte@qualified.name
Stability	stable
Portability	portable
Safe Haskell	None
Language	Haskell2010

Control.Effect.Embed

Contents

Embed Effect
Interpretations

Description

The embed effect for integrating arbitrary monads into the effect system.

Synopsis

class Monad m => Embed n m where
- embed :: n a -> m a
data Transformation n t m a
runEmbed :: (forall b. n b -> t b) -> (Embed n `Via` Transformation n t) m a -> m a

Embed Effect

class Monad m => Embed n m where Source #

An effect that integrates a monad n into the computation m.

Methods

embed :: n a -> m a Source #

Monadic actions in n can be lifted into m via embed.

embed is like liftIO, but not limited to IO. In fact, liftIO can be realized using embed by specializing n to IO.

Instances

Instances details

Monad m => Embed m m Source #
Instance details Defined in Control.Effect.Embed Methods embed :: m a -> m a Source #
Lift (Embed n) t m => Embed n (Via eff t m) Source #
Instance details Defined in Control.Effect.Embed Methods embed :: n a -> Via eff t m a Source #
Handle (Embed n) t m => Embed n (Via (Embed n) t m) Source #
Instance details Defined in Control.Effect.Embed Methods embed :: n a -> Via (Embed n) t m a Source #
Embed t m => Embed n (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods embed :: n a -> Transformation n t m a Source #

Interpretations

data Transformation n t m a Source #

The transformation interpreter of the embed effect. This type implements the Embed type class by transforming the integrated monad n into another integrated monad t via natural transformation.

When interpreting the effect, you usually don't interact with this type directly, but instead use one of its corresponding interpretation functions.

Instances

Instances details

MonadBase b m => MonadBase b (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods liftBase :: b α -> Transformation n t m α #
MonadBaseControl b m => MonadBaseControl b (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Associated Types type StM (Transformation n t m) a # Methods liftBaseWith :: (RunInBase (Transformation n t m) b -> b a) -> Transformation n t m a # restoreM :: StM (Transformation n t m) a -> Transformation n t m a #
Embed t m => Embed n (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods embed :: n a -> Transformation n t m a Source #
MonadTrans (Transformation n t) Source #
Instance details Defined in Control.Effect.Embed Methods lift :: Monad m => m a -> Transformation n t m a #
MonadTransControl (Transformation n t) Source #
Instance details Defined in Control.Effect.Embed Associated Types type StT (Transformation n t) a # Methods liftWith :: Monad m => (Run (Transformation n t) -> m a) -> Transformation n t m a # restoreT :: Monad m => m (StT (Transformation n t) a) -> Transformation n t m a #
Monad m => Monad (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods (>>=) :: Transformation n t m a -> (a -> Transformation n t m b) -> Transformation n t m b # (>>) :: Transformation n t m a -> Transformation n t m b -> Transformation n t m b # return :: a -> Transformation n t m a #
Functor m => Functor (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods fmap :: (a -> b) -> Transformation n t m a -> Transformation n t m b # (<$) :: a -> Transformation n t m b -> Transformation n t m a #
Applicative m => Applicative (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods pure :: a -> Transformation n t m a # (<>) :: Transformation n t m (a -> b) -> Transformation n t m a -> Transformation n t m b # liftA2 :: (a -> b -> c) -> Transformation n t m a -> Transformation n t m b -> Transformation n t m c # (>) :: Transformation n t m a -> Transformation n t m b -> Transformation n t m b # (<*) :: Transformation n t m a -> Transformation n t m b -> Transformation n t m a #
MonadIO m => MonadIO (Transformation n t m) Source #
Instance details Defined in Control.Effect.Embed Methods liftIO :: IO a -> Transformation n t m a #
type StT (Transformation n t) a Source #
Instance details Defined in Control.Effect.Embed type StT (Transformation n t) a
type StM (Transformation n t m) a Source #
Instance details Defined in Control.Effect.Embed type StM (Transformation n t m) a

runEmbed Source #

Arguments

:: (forall b. n b -> t b)	The natural transformation from monad `n` to monad `t`.
-> (Embed n `Via` Transformation n t) m a	The program whose embed effect should be handled.
-> m a	The program with its embed effect handled.

Runs the embed effect by transforming the integrated monad n into another integrated monad t.