Control.Effect

Documentation

class Effect (m :: k -> * -> *) 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 :: k) (g :: k) :: k

Cominbing effects of two subcomputations |

type Inv m (f :: k) (g :: k) :: 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 Nat Counter

Associated Types

type Unit Counter (m :: Counter -> * -> *) :: k

type Plus Counter (m :: Counter -> * -> *) (f :: Counter) (g :: Counter) :: k

type Inv Counter (m :: Counter -> * -> *) (f :: Counter) (g :: Counter) :: Constraint

Methods

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

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

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

Effect [*] State

Associated Types

type Unit State (m :: State -> * -> *) :: k

type Plus State (m :: State -> * -> *) (f :: State) (g :: State) :: k

type Inv State (m :: State -> * -> *) (f :: State) (g :: State) :: Constraint

Methods

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

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

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

Effect [*] Reader

Associated Types

type Unit Reader (m :: Reader -> * -> *) :: k

type Plus Reader (m :: Reader -> * -> *) (f :: Reader) (g :: Reader) :: k

type Inv Reader (m :: Reader -> * -> *) (f :: Reader) (g :: Reader) :: Constraint

Methods

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

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

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

Effect [*] WriteOnce

Associated Types

type Unit WriteOnce (m :: WriteOnce -> * -> *) :: k

type Plus WriteOnce (m :: WriteOnce -> * -> *) (f :: WriteOnce) (g :: WriteOnce) :: k

type Inv WriteOnce (m :: WriteOnce -> * -> *) (f :: WriteOnce) (g :: WriteOnce) :: Constraint

Methods

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

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

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

Effect [Mapping Symbol *] Reader

Associated Types

type Unit Reader (m :: Reader -> * -> *) :: k

type Plus Reader (m :: Reader -> * -> *) (f :: Reader) (g :: Reader) :: k

type Inv Reader (m :: Reader -> * -> *) (f :: Reader) (g :: Reader) :: Constraint

Methods

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

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

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

Effect [Mapping Symbol *] Writer

Associated Types

type Unit Writer (m :: Writer -> * -> *) :: k

type Plus Writer (m :: Writer -> * -> *) (f :: Writer) (g :: Writer) :: k

type Inv Writer (m :: Writer -> * -> *) (f :: Writer) (g :: Writer) :: Constraint

Methods

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

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

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

Effect (Maybe *) Update

Associated Types

type Unit Update (m :: Update -> * -> *) :: k

type Plus Update (m :: Update -> * -> *) (f :: Update) (g :: Update) :: k

type Inv Update (m :: Update -> * -> *) (f :: Update) (g :: Update) :: Constraint

Methods

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

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

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

Effect * Counter

Associated Types

type Unit Counter (m :: Counter -> * -> *) :: k

type Plus Counter (m :: Counter -> * -> *) (f :: Counter) (g :: Counter) :: k

type Inv Counter (m :: Counter -> * -> *) (f :: Counter) (g :: Counter) :: Constraint

Methods

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

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

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

Effect * IMaybe

Associated Types

type Unit IMaybe (m :: IMaybe -> * -> *) :: k

type Plus IMaybe (m :: IMaybe -> * -> *) (f :: IMaybe) (g :: IMaybe) :: k

type Inv IMaybe (m :: IMaybe -> * -> *) (f :: IMaybe) (g :: IMaybe) :: Constraint

Methods

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

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

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

Effect * Vector

Associated Types

type Unit Vector (m :: Vector -> * -> *) :: k

type Plus Vector (m :: Vector -> * -> *) (f :: Vector) (g :: Vector) :: k

type Inv Vector (m :: Vector -> * -> *) (f :: Vector) (g :: Vector) :: Constraint

Methods

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

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

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

Monad m => Effect * (Monad m)

Associated Types

type Unit (Monad m) (m :: Monad m -> * -> *) :: k

type Plus (Monad m) (m :: Monad m -> * -> *) (f :: Monad m) (g :: Monad m) :: k

type Inv (Monad m) (m :: Monad m -> * -> *) (f :: Monad m) (g :: Monad m) :: Constraint

Methods

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

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

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

Effect (Morph * *) T

Associated Types

type Unit T (m :: T -> * -> *) :: k

type Plus T (m :: T -> * -> *) (f :: T) (g :: T) :: k

type Inv T (m :: T -> * -> *) (f :: T) (g :: T) :: Constraint

Methods

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

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

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

fail :: a

class Subeffect (m :: k -> * -> *) f g where

Specifies subeffecting behaviour

Minimal complete definition

sub

Methods

sub :: m f a -> m g a

Instances

Submap s t => Subeffect [Mapping Symbol *] Reader s t

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

Methods

sub :: s t a -> s g a

Supermap s t => Subeffect [Mapping Symbol *] Writer s t

Methods

sub :: s t a -> s g a