Safe Haskell	None
Language	Haskell2010

Control.Effect.Internal.Membership

Synopsis

data ElemOf (e :: a) (r :: [a]) where
- Here :: ElemOf e (e ': r)
- There :: ElemOf e r -> ElemOf e (_e ': r)
absurdMember :: ElemOf e '[] -> b
sameMember :: forall e e' r. ElemOf e r -> ElemOf e' r -> Maybe (e :~: e')
class Member e r where
- membership :: ElemOf e r

Documentation

data ElemOf (e :: a) (r :: [a]) where Source #

Constructors

Here :: ElemOf e (e ': r)
There :: ElemOf e r -> ElemOf e (_e ': r)

Instances

Show (ElemOf e r) Source #
Instance details Defined in Control.Effect.Internal.Membership Methods showsPrec :: Int -> ElemOf e r -> ShowS # show :: ElemOf e r -> String # showList :: [ElemOf e r] -> ShowS #

sameMember :: forall e e' r. ElemOf e r -> ElemOf e' r -> Maybe (e :~: e') Source #

class Member e r where Source #

A constraint that e is part of the effect row r.

r is typically Derivs m for some m. Member e (Derivs m) allows you to use actions of e with m.

If e occurs multiple times in r, then the first occurence will be used.

If possible, use Eff/s instead.

Methods

Instances

(TypeError (((Text "Unhandled effect: " :<>: ShowType e) :$$: Text "You need to either add or replace an interpreter in your interpretation stack so that the effect gets handled.") :$$: Text "To check what effects are currently handled by your interpretation stack, use `debugEffects' from `Control.Effect.Debug'.") :: Constraint) => Member (e :: a) ([] :: [a]) Source #
Instance details Defined in Control.Effect.Internal.Membership Methods membership :: ElemOf e [] Source #
Member e r => Member (e :: a) (_e ': r :: [a]) Source #
Instance details Defined in Control.Effect.Internal.Membership Methods membership :: ElemOf e (_e ': r) Source #
Member (e :: a) (e ': r :: [a]) Source #
Instance details Defined in Control.Effect.Internal.Membership Methods membership :: ElemOf e (e ': r) Source #