Safe Haskell	None
Language	Haskell2010

Polysemy.View

Contents

Synopsis

data View v m a where
- See :: View v m v
see :: forall v r. MemberWithError (View v) r => Sem r v
viewToState :: forall v s r a. Member (State s) r => (s -> Sem r v) -> Sem (View v ': r) a -> Sem r a
viewToInput :: forall v i r a. Member (Input i) r => (i -> v) -> Sem (View v ': r) a -> Sem r a

Effect

data View v m a where Source #

A View is an expensive computation that should be cached.

Constructors

See :: View v m v

Instances

type DefiningModule (View :: k1 -> k2 -> k1 -> Type) Source #
Instance details Defined in Polysemy.View type DefiningModule (View :: k1 -> k2 -> k1 -> Type) = "Polysemy.View"

Actions

see :: forall v r. MemberWithError (View v) r => Sem r v Source #

viewToState :: forall v s r a. Member (State s) r => (s -> Sem r v) -> Sem (View v ': r) a -> Sem r a Source #

Get a View as an exensive computation over an underlying State effect. This View is only invalidated when the underlying State changes.

viewToInput :: forall v i r a. Member (Input i) r => (i -> v) -> Sem (View v ': r) a -> Sem r a Source #

Transform a View into an Input.