| Copyright | (c) Edward Kmett & Sjoerd Visscher 2011 |
|---|---|
| License | BSD3 |
| Maintainer | ekmett@gmail.com |
| Stability | experimental |
| Safe Haskell | Safe-Inferred |
| Language | Haskell2010 |
Control.Comonad.Representable.Store
Description
This is a generalized Store Comonad, parameterized by a Representable Functor.
The representation of that Functor serves as the index of the store.
This can be useful if the representable functor serves to memoize its contents and will be inspected often.
Synopsis
- type Store g = StoreT g Identity
- store :: Representable g => (Rep g -> a) -> Rep g -> Store g a
- runStore :: Representable g => Store g a -> (Rep g -> a, Rep g)
- data StoreT g w a = StoreT (w (g a)) (Rep g)
- storeT :: (Functor w, Representable g) => w (Rep g -> a) -> Rep g -> StoreT g w a
- runStoreT :: (Functor w, Representable g) => StoreT g w a -> (w (Rep g -> a), Rep g)
- class Comonad w => ComonadStore s (w :: Type -> Type) | w -> s where
Documentation
type Store g = StoreT g Identity Source #
A memoized store comonad parameterized by a representable functor g, where
the representatation of g, Rep g is the index of the store.
Arguments
| :: Representable g | |
| => (Rep g -> a) | computation |
| -> Rep g | index |
| -> Store g a |
Construct a store comonad computation from a function and a current index.
(The inverse of runStore.)
Arguments
| :: Representable g | |
| => Store g a | a store to access |
| -> (Rep g -> a, Rep g) | initial state |
Unwrap a store comonad computation as a function and a current index.
(The inverse of store.)
A store transformer comonad parameterized by:
g- A representable functor used to memoize results for an indexRep gw- The inner comonad.
Instances
class Comonad w => ComonadStore s (w :: Type -> Type) | w -> s where Source #
Methods
peek :: s -> w a -> a Source #
peeks :: (s -> s) -> w a -> a Source #
seek :: s -> w a -> w a Source #
seeks :: (s -> s) -> w a -> w a Source #
experiment :: Functor f => (s -> f s) -> w a -> f a Source #