Copyright	(C) 2008-2014 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	non-portable (fundeps, MPTCs)
Safe Haskell	Safe
Language	Haskell2010

Control.Comonad.Store

Contents

Description

Synopsis

ComonadStore class

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

Minimal complete definition

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

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)

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)
(Applicative w, Monoid s) => Applicative (StoreT s w)
(ComonadApply w, Semigroup s) => ComonadApply (StoreT s w)
Comonad w => Comonad (StoreT s w)
Typeable (* -> (* -> ) -> -> *) StoreT

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