Control.Effect.Union

Effects

data Union (r :: [Effect]) m a where

An effect for collecting multiple effects into one effect.

Behind the scenes, Union is the most important effect in the entire library, as the Carrier class is built around handling Unions of effects.

However, even outside of defining novel Carrier instances, Union can be useful as an effect in its own right. Union is useful for effect newtypes -- effects defined through creating a newtype over an existing effect. By making a newtype of Union, it's possible to wrap multiple effects in one newtype.

Not to be confused with Bundle. Unlike Bundle, Union is a proper effect that is given no special treatment by Eff or Effs.

Constructors

Union :: Coercible z m => ElemOf e r -> e z a -> Union r m a

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

Constructors

Here :: ElemOf e (e ': r)

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

Instances

Show (ElemOf e r)

Defined in Control.Effect.Internal.Membership

Methods

showsPrec :: Int -> ElemOf e r -> ShowS

show :: ElemOf e r -> String

showList :: [ElemOf e r] -> ShowS

Actions

unionize :: (Eff (Union b) m, KnownList b) => UnionizeC b m a -> m a

Sends uses of effects in b to a Union b effect.

Derivs (UnionizeC b m) = b ++ Derivs m

unionizeHead :: (HeadEff (Union b) m, KnownList b) => UnionizeHeadC b m a -> m a

Rewrite uses of effects in b into a Union b effect on top of the effect stack.

Derivs (UnionizeC b m) = b ++ StripPrefix '[Union b] Derivs m

Interpretations

runUnion :: forall b m a. (HeadEffs b m, KnownList b) => UnionC b m a -> m a

Run an Union b effect by placing the effects of b on top of the effect stack.

Derivs (UnionC b m) = Union b ': StripPrefix b (Derivs m)

Prims  (UnionC b m) = Prims m

Utilities

inj :: Member e r => e m a -> Union r m a

Inject an effect into a Union containing that effect.

decomp :: RepresentationalEff e => Union (e ': r) m a -> Either (Union r m a) (e m a)

extract :: RepresentationalEff e => Union '[e] m a -> e m a

Extract the only effect of an Union.

weaken :: Union r m a -> Union (e ': r) m a

absurdU :: Union '[] m a -> b

absurdMember :: ElemOf e '[] -> b

membership :: Member e r => ElemOf e r

Carriers

data UnionizeC b m a

Instances

MonadBase b' m => MonadBase b' (UnionizeC b m)

Defined in Control.Effect.Union

Methods

liftBase :: b' α -> UnionizeC b m α

MonadBaseControl b' m => MonadBaseControl b' (UnionizeC b m)

Defined in Control.Effect.Union

Associated Types

type StM (UnionizeC b m) a

Methods

liftBaseWith :: (RunInBase (UnionizeC b m) b' -> b' a) -> UnionizeC b m a

restoreM :: StM (UnionizeC b m) a -> UnionizeC b m a

MonadTrans (UnionizeC b :: (Type -> Type) -> Type -> Type)

Defined in Control.Effect.Union

Methods

lift :: Monad m => m a -> UnionizeC b m a

MonadTransControl (UnionizeC b :: (Type -> Type) -> Type -> Type)

Defined in Control.Effect.Union

Associated Types

type StT (UnionizeC b) a

Methods

liftWith :: Monad m => (Run (UnionizeC b) -> m a) -> UnionizeC b m a

restoreT :: Monad m => m (StT (UnionizeC b) a) -> UnionizeC b m a

Monad m => Monad (UnionizeC b m)

Defined in Control.Effect.Union

Methods

(>>=) :: UnionizeC b m a -> (a -> UnionizeC b m b0) -> UnionizeC b m b0

(>>) :: UnionizeC b m a -> UnionizeC b m b0 -> UnionizeC b m b0

return :: a -> UnionizeC b m a

Functor m => Functor (UnionizeC b m)

Defined in Control.Effect.Union

Methods

fmap :: (a -> b0) -> UnionizeC b m a -> UnionizeC b m b0

(<$) :: a -> UnionizeC b m b0 -> UnionizeC b m a

MonadFix m => MonadFix (UnionizeC b m)

Defined in Control.Effect.Union

Methods

mfix :: (a -> UnionizeC b m a) -> UnionizeC b m a

MonadFail m => MonadFail (UnionizeC b m)

Defined in Control.Effect.Union

Methods

fail :: String -> UnionizeC b m a

Applicative m => Applicative (UnionizeC b m)

Defined in Control.Effect.Union

Methods

pure :: a -> UnionizeC b m a

(<*>) :: UnionizeC b m (a -> b0) -> UnionizeC b m a -> UnionizeC b m b0

liftA2 :: (a -> b0 -> c) -> UnionizeC b m a -> UnionizeC b m b0 -> UnionizeC b m c

(*>) :: UnionizeC b m a -> UnionizeC b m b0 -> UnionizeC b m b0

(<*) :: UnionizeC b m a -> UnionizeC b m b0 -> UnionizeC b m a

MonadIO m => MonadIO (UnionizeC b m)

Defined in Control.Effect.Union

Methods

liftIO :: IO a -> UnionizeC b m a

Alternative m => Alternative (UnionizeC b m)

Defined in Control.Effect.Union

Methods

empty :: UnionizeC b m a

(<|>) :: UnionizeC b m a -> UnionizeC b m a -> UnionizeC b m a

some :: UnionizeC b m a -> UnionizeC b m [a]

many :: UnionizeC b m a -> UnionizeC b m [a]

MonadPlus m => MonadPlus (UnionizeC b m)

Defined in Control.Effect.Union

Methods

mzero :: UnionizeC b m a

mplus :: UnionizeC b m a -> UnionizeC b m a -> UnionizeC b m a

MonadThrow m => MonadThrow (UnionizeC b m)

Defined in Control.Effect.Union

Methods

throwM :: Exception e => e -> UnionizeC b m a

MonadCatch m => MonadCatch (UnionizeC b m)

Defined in Control.Effect.Union

Methods

catch :: Exception e => UnionizeC b m a -> (e -> UnionizeC b m a) -> UnionizeC b m a

MonadMask m => MonadMask (UnionizeC b m)

Defined in Control.Effect.Union

Methods

mask :: ((forall a. UnionizeC b m a -> UnionizeC b m a) -> UnionizeC b m b0) -> UnionizeC b m b0

uninterruptibleMask :: ((forall a. UnionizeC b m a -> UnionizeC b m a) -> UnionizeC b m b0) -> UnionizeC b m b0

generalBracket :: UnionizeC b m a -> (a -> ExitCase b0 -> UnionizeC b m c) -> (a -> UnionizeC b m b0) -> UnionizeC b m (b0, c)

(KnownList b, Eff (Union b) m) => Carrier (UnionizeC b m)

Defined in Control.Effect.Union

Associated Types

type Derivs (UnionizeC b m) :: [Effect]

type Prims (UnionizeC b m) :: [Effect]

Methods

algPrims :: Algebra' (Prims (UnionizeC b m)) (UnionizeC b m) a

reformulate :: Monad z => Reformulation' (Derivs (UnionizeC b m)) (Prims (UnionizeC b m)) (UnionizeC b m) z a

algDerivs :: Algebra' (Derivs (UnionizeC b m)) (UnionizeC b m) a

type StT (UnionizeC b :: (Type -> Type) -> Type -> Type) a

Defined in Control.Effect.Union

type StT (UnionizeC b :: (Type -> Type) -> Type -> Type) a = StT (IdentityT :: (Type -> Type) -> Type -> Type) a

type Derivs (UnionizeC b m)

Defined in Control.Effect.Union

type Derivs (UnionizeC b m) = Append b (Derivs m)

type Prims (UnionizeC b m)

Defined in Control.Effect.Union

type Prims (UnionizeC b m) = Prims m

type StM (UnionizeC b m) a

Defined in Control.Effect.Union

type StM (UnionizeC b m) a = StM m a

type UnionizeHeadC b = CompositionC '[IntroC b '[Union b], UnionizeC b]

data UnionC (l :: [Effect]) m a

Instances

MonadBase b m => MonadBase b (UnionC l m)

Defined in Control.Effect.Union

Methods

liftBase :: b α -> UnionC l m α

MonadBaseControl b m => MonadBaseControl b (UnionC l m)

Defined in Control.Effect.Union

Associated Types

type StM (UnionC l m) a

Methods

liftBaseWith :: (RunInBase (UnionC l m) b -> b a) -> UnionC l m a

restoreM :: StM (UnionC l m) a -> UnionC l m a

MonadTrans (UnionC l :: (Type -> Type) -> Type -> Type)

Defined in Control.Effect.Union

Methods

lift :: Monad m => m a -> UnionC l m a

MonadTransControl (UnionC l :: (Type -> Type) -> Type -> Type)

Defined in Control.Effect.Union

Associated Types

type StT (UnionC l) a

Methods

liftWith :: Monad m => (Run (UnionC l) -> m a) -> UnionC l m a

restoreT :: Monad m => m (StT (UnionC l) a) -> UnionC l m a

Monad m => Monad (UnionC l m)

Defined in Control.Effect.Union

Methods

(>>=) :: UnionC l m a -> (a -> UnionC l m b) -> UnionC l m b

(>>) :: UnionC l m a -> UnionC l m b -> UnionC l m b

return :: a -> UnionC l m a

Functor m => Functor (UnionC l m)

Defined in Control.Effect.Union

Methods

fmap :: (a -> b) -> UnionC l m a -> UnionC l m b

(<$) :: a -> UnionC l m b -> UnionC l m a

MonadFix m => MonadFix (UnionC l m)

Defined in Control.Effect.Union

Methods

mfix :: (a -> UnionC l m a) -> UnionC l m a

MonadFail m => MonadFail (UnionC l m)

Defined in Control.Effect.Union

Methods

fail :: String -> UnionC l m a

Applicative m => Applicative (UnionC l m)

Defined in Control.Effect.Union

Methods

pure :: a -> UnionC l m a

(<*>) :: UnionC l m (a -> b) -> UnionC l m a -> UnionC l m b

liftA2 :: (a -> b -> c) -> UnionC l m a -> UnionC l m b -> UnionC l m c

(*>) :: UnionC l m a -> UnionC l m b -> UnionC l m b

(<*) :: UnionC l m a -> UnionC l m b -> UnionC l m a

MonadIO m => MonadIO (UnionC l m)

Defined in Control.Effect.Union

Methods

liftIO :: IO a -> UnionC l m a

Alternative m => Alternative (UnionC l m)

Defined in Control.Effect.Union

Methods

empty :: UnionC l m a

(<|>) :: UnionC l m a -> UnionC l m a -> UnionC l m a

some :: UnionC l m a -> UnionC l m [a]

many :: UnionC l m a -> UnionC l m [a]

MonadPlus m => MonadPlus (UnionC l m)

Defined in Control.Effect.Union

Methods

mzero :: UnionC l m a

mplus :: UnionC l m a -> UnionC l m a -> UnionC l m a

MonadThrow m => MonadThrow (UnionC l m)

Defined in Control.Effect.Union

Methods

throwM :: Exception e => e -> UnionC l m a

MonadCatch m => MonadCatch (UnionC l m)

Defined in Control.Effect.Union

Methods

catch :: Exception e => UnionC l m a -> (e -> UnionC l m a) -> UnionC l m a

MonadMask m => MonadMask (UnionC l m)

Defined in Control.Effect.Union

Methods

mask :: ((forall a. UnionC l m a -> UnionC l m a) -> UnionC l m b) -> UnionC l m b

uninterruptibleMask :: ((forall a. UnionC l m a -> UnionC l m a) -> UnionC l m b) -> UnionC l m b

generalBracket :: UnionC l m a -> (a -> ExitCase b -> UnionC l m c) -> (a -> UnionC l m b) -> UnionC l m (b, c)

(KnownList l, HeadEffs l m) => Carrier (UnionC l m)

Defined in Control.Effect.Union

Associated Types

type Derivs (UnionC l m) :: [Effect]

type Prims (UnionC l m) :: [Effect]

Methods

algPrims :: Algebra' (Prims (UnionC l m)) (UnionC l m) a

reformulate :: Monad z => Reformulation' (Derivs (UnionC l m)) (Prims (UnionC l m)) (UnionC l m) z a

algDerivs :: Algebra' (Derivs (UnionC l m)) (UnionC l m) a

type StT (UnionC l :: (Type -> Type) -> Type -> Type) a

Defined in Control.Effect.Union

type StT (UnionC l :: (Type -> Type) -> Type -> Type) a = StT (IdentityT :: (Type -> Type) -> Type -> Type) a

type Derivs (UnionC l m)

Defined in Control.Effect.Union

type Derivs (UnionC l m) = Union l ': StripPrefix l (Derivs m)

type Prims (UnionC l m)

Defined in Control.Effect.Union

type Prims (UnionC l m) = Prims m

type StM (UnionC l m) a

Defined in Control.Effect.Union

type StM (UnionC l m) a = StM m a