Network.IRC.Client.Internal.Lens

Types and functions for dealing with optics without depending on the lens library.

This module is NOT considered to form part of the public interface of this library.

Internal lens synonyms

type Lens s t a b = forall f. Functor f => (a -> f b) -> s -> f t

See Control.Lens.Lens.Lens.

type Lens' s a = Lens s s a a

A Simple Lens.

type Getter s a = forall f. (Contravariant f, Functor f) => (a -> f a) -> s -> f s

See Control.Lens.Getter.Getter.

type Getting r s a = (a -> Const r a) -> s -> Const r s

See Control.Lens.Getter.Getting.

type Prism s t a b = forall p f. (Choice p, Applicative f) => p a (f b) -> p s (f t)

See Control.Lens.Prism.Prism.

type Prism' s a = Prism s s a a

A Simple Prism.

Utilities

get :: Getting a s a -> s -> a

Get a value from a lens.

set :: Lens' s a -> a -> s -> s

Set a value in a lens.

modify :: Lens' s a -> (a -> a) -> s -> s

Modify a value in a lens.

preview :: Prism' s a -> s -> Maybe a

Read a value from a prism.

STM

snapshot :: MonadIO m => Getting (TVar a) s (TVar a) -> s -> m a

Atomically snapshot some shared state.

snapshotModify :: MonadIO m => Lens' s (TVar a) -> (a -> STM (a, b)) -> s -> m b

Atomically snapshot and modify some shared state.