Control.Comonad.Store

ComonadStore class

class Comonad w => ComonadStore s w | w -> s where

Methods

pos :: w a -> s

peek :: s -> w a -> a

peeks :: (s -> s) -> w a -> a

seek :: s -> w a -> w a

seeks :: (s -> s) -> w a -> w a

experiment :: Functor f => (s -> f s) -> w a -> f a

Instances

ComonadStore s w => ComonadStore s (IdentityT w)

(ComonadStore s w, Monoid m) => ComonadStore s (TracedT m w)

ComonadStore s w => ComonadStore s (EnvT e w)

Comonad w => ComonadStore s (StoreT s w)

The Store comonad

type Store s = StoreT s Identity

store :: (s -> a) -> s -> Store s a

Create a Store using an accessor function and a stored value

runStore :: Store s a -> (s -> a, s)

The StoreT comonad transformer

data StoreT s w a

Constructors

StoreT (w (s -> a)) s

Instances

ComonadEnv e w => ComonadEnv e (StoreT t w)

Comonad w => ComonadStore s (StoreT s w)

ComonadTraced m w => ComonadTraced m (StoreT s w)

ComonadTrans (StoreT s)

ComonadHoist (StoreT s)

Functor w => Functor (StoreT s w)

(Typeable s, Typeable1 w) => Typeable1 (StoreT s w)

(Applicative w, Monoid s) => Applicative (StoreT s w)

(ComonadApply w, Semigroup s) => ComonadApply (StoreT s w)

Comonad w => Comonad (StoreT s w)

(Typeable s, Typeable1 w, Typeable a) => Typeable (StoreT s w a)

runStoreT :: StoreT s w a -> (w (s -> a), s)

Re-exported modules

module Control.Comonad

module Control.Comonad.Trans.Class