Control.Effect

Documentation

class Effect m where

Specifies "parametric effect monads" which are essentially monads but annotated by a type-level monoid formed by Plus and Unit

Minimal complete definition

return, (>>=)

Associated Types

type Unit m :: k

Effect of a trivially effectful computation |

type Plus m f g :: k

Cominbing effects of two subcomputations |

type Inv m f g :: Constraint

Inv provides a way to give instances of Effect their own constraints for >>=

Methods

return :: a -> m (Unit m) a

Effect-parameterised version of return. Annotated with the 'Unit m' effect, denoting pure compuation

(>>=) :: Inv m f g => m f a -> (a -> m g b) -> m (Plus m f g) b

Effect-parameterise version of >>= (bind). Combines two effect annotations f and g on its parameter computations into Plus

(>>) :: Inv m f g => m f a -> m g b -> m (Plus m f g) b

Instances

Effect * Counter

Effect * IMaybe

Effect * Vector

Effect Nat Counter

Monad m => Effect * (Monad m)

Effect [*] Reader

Effect [*] Reader

Effect [*] State

Effect [*] WriteOnce

Effect [*] Writer

Effect (Maybe *) Update

Effect (Morph * *) T

fail :: t

class Subeffect m f g where

Specifies subeffecting behaviour

Methods

sub :: m f a -> m g a

Instances

Subset s t => Subeffect [*] Reader s t

If s is a subset of t then, s is a subeffect of t

Superset s t => Subeffect [*] Writer s t