Control.Effect.WriteOnceWriter

Documentation

put :: a -> WriteOnce '[a] ()

Write a value of type a

data WriteOnce (w :: [*]) a

Provides a kind of writer monad, which can only write an item once (no accumulation), an effect system as a list of the items that have been written

Constructors

W

Fields

• runWriteOnce :: (a, List w)

Instances

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

type Unit [*] WriteOnce

type Unit [*] WriteOnce = [] *

type Plus [*] WriteOnce s t

type Plus [*] WriteOnce s t = (:++) s t

type Inv [*] WriteOnce s t

type Inv [*] WriteOnce s t = ()