Control.Effect.Internal.Intercept

Documentation

data Intercept (e :: Effect) :: Effect where

An effect for intercepting actions of a first-order effect.

Even for this library, proper usage of this effect is very complicated. When properly used, this can be a very useful helper effect, allowing you write interpretations for a class of higher-order effects that wouldn't otherwise be possible.

For more information, see the wiki.

Constructors

Intercept :: Coercible z m => (forall x. e z x -> m x) -> m a -> Intercept e m a

Instances

(FirstOrder e, Eff (Unravel (InterceptB e)) m) => Handler InterceptH (Intercept e) m

Defined in Control.Effect.Internal.Intercept

Methods

effHandler :: EffHandler (Intercept e) m

data InterceptCont (e :: Effect) :: Effect where

A variant of InterceptCont that is significantly more powerful, allowing you to capture the continuation of the program at each use-site of an effect, as well as aborting execution of the parameter computation early.

Constructors

InterceptCont :: Coercible z m => InterceptionMode -> (forall x. (x -> m a) -> e z x -> m a) -> m a -> InterceptCont e m a

Instances

(FirstOrder e, Member e (Derivs m), Eff (Unravel (InterceptB e)) m) => Handler InterceptH (InterceptCont e) m

Defined in Control.Effect.Internal.Intercept

Methods

effHandler :: EffHandler (InterceptCont e) m

data InterceptionMode

Constructors

InterceptOne

InterceptAll

data InterceptB e a where

Constructors

InterceptB :: (forall q x. (x -> a) -> e q x -> a) -> InterceptB e a

Instances

(FirstOrder e, Carrier m, Threaders '[SteppedThreads] m p) => PrimHandler InterceptH (Unravel (InterceptB e)) (SteppedC e m)

Defined in Control.Effect.Internal.Intercept

Methods

effPrimHandler :: EffPrimHandler (Unravel (InterceptB e)) (SteppedC e m)

interceptB :: forall e m q a. (FirstOrder e, Eff (Unravel (InterceptB e)) m) => (forall x. (x -> m a) -> e q x -> m a) -> m a -> m a

newtype InterceptContC e m a

Constructors

InterceptContC

Fields

• unInterceptContC :: IntroC '[InterceptCont e, Intercept e] '[Unravel (InterceptB e)] (InterpretC InterceptH (InterceptCont e) (InterpretC InterceptH (Intercept e) (InterpretPrimC InterceptH (Unravel (InterceptB e)) (SteppedC e m)))) a

Instances

MonadBase b m => MonadBase b (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

liftBase :: b α -> InterceptContC e m α

MonadTrans (InterceptContC e)

Defined in Control.Effect.Internal.Intercept

Methods

lift :: Monad m => m a -> InterceptContC e m a

Monad (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

(>>=) :: InterceptContC e m a -> (a -> InterceptContC e m b) -> InterceptContC e m b

(>>) :: InterceptContC e m a -> InterceptContC e m b -> InterceptContC e m b

return :: a -> InterceptContC e m a

Functor (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

fmap :: (a -> b) -> InterceptContC e m a -> InterceptContC e m b

(<$) :: a -> InterceptContC e m b -> InterceptContC e m a

MonadFail m => MonadFail (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

fail :: String -> InterceptContC e m a

Applicative (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

pure :: a -> InterceptContC e m a

(<*>) :: InterceptContC e m (a -> b) -> InterceptContC e m a -> InterceptContC e m b

liftA2 :: (a -> b -> c) -> InterceptContC e m a -> InterceptContC e m b -> InterceptContC e m c

(*>) :: InterceptContC e m a -> InterceptContC e m b -> InterceptContC e m b

(<*) :: InterceptContC e m a -> InterceptContC e m b -> InterceptContC e m a

MonadIO m => MonadIO (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

liftIO :: IO a -> InterceptContC e m a

MonadThrow m => MonadThrow (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

throwM :: Exception e0 => e0 -> InterceptContC e m a

MonadCatch m => MonadCatch (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Methods

catch :: Exception e0 => InterceptContC e m a -> (e0 -> InterceptContC e m a) -> InterceptContC e m a

(FirstOrder e, Carrier m, Member e (Derivs m), Threaders '[SteppedThreads] m p) => Carrier (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

Associated Types

type Derivs (InterceptContC e m) :: [Effect]

type Prims (InterceptContC e m) :: [Effect]

Methods

algPrims :: Algebra' (Prims (InterceptContC e m)) (InterceptContC e m) a

reformulate :: Monad z => Reformulation' (Derivs (InterceptContC e m)) (Prims (InterceptContC e m)) (InterceptContC e m) z a

algDerivs :: Algebra' (Derivs (InterceptContC e m)) (InterceptContC e m) a

type Derivs (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

type Derivs (InterceptContC e m) = Derivs (IntroC '[InterceptCont e, Intercept e] '[Unravel (InterceptB e)] (InterpretC InterceptH (InterceptCont e) (InterpretC InterceptH (Intercept e) (InterpretPrimC InterceptH (Unravel (InterceptB e)) (SteppedC e m)))))

type Prims (InterceptContC e m)

Defined in Control.Effect.Internal.Intercept

type Prims (InterceptContC e m) = Prims (IntroC '[InterceptCont e, Intercept e] '[Unravel (InterceptB e)] (InterpretC InterceptH (InterceptCont e) (InterpretC InterceptH (Intercept e) (InterpretPrimC InterceptH (Unravel (InterceptB e)) (SteppedC e m)))))

data InterceptH

Instances

(FirstOrder e, Member e (Derivs m), Eff (Unravel (InterceptB e)) m) => Handler InterceptH (InterceptCont e) m

Defined in Control.Effect.Internal.Intercept

Methods

effHandler :: EffHandler (InterceptCont e) m

(FirstOrder e, Eff (Unravel (InterceptB e)) m) => Handler InterceptH (Intercept e) m

Defined in Control.Effect.Internal.Intercept

Methods

effHandler :: EffHandler (Intercept e) m

(FirstOrder e, Carrier m, Threaders '[SteppedThreads] m p) => PrimHandler InterceptH (Unravel (InterceptB e)) (SteppedC e m)

Defined in Control.Effect.Internal.Intercept

Methods

effPrimHandler :: EffPrimHandler (Unravel (InterceptB e)) (SteppedC e m)

runInterceptCont :: forall e m a p. (FirstOrder e, Carrier m, Member e (Derivs m), Threaders '[SteppedThreads] m p) => InterceptContC e m a -> m a

Run Intercept e, InterceptCont e and e effects, provided that e is first-order and also part of the remaining effect stack.

There are three very important things to note here:

• e must be first-order.
• Any action of e made by a handler run after runInterceptCont won't get be intercepted. What this means is that you typically want to run the handler for e immediately after runInterceptCont.
• This imposes the very restrictive primitive effect Unravel. Most notably, neither StateThreads nor WriterThreads accepts it. Because of that, this module offers various alternatives of several common State and Tell interpreters with threading constraints that do accept Unravel.

Derivs (InterceptContC e m) = InterceptCont e ': Intercept e ': e ': Derivs m

Prims  (InterceptContC e m) = Unravel (InterceptB e) ': Prims m

runStateStepped :: forall s m a p. (Carrier m, Threaders '[SteppedThreads] m p) => s -> SteppedC (State s) m a -> m (s, a)

A variant of runState with a SteppedThreads threading constraint instead of a StateThreads threading constraint.

runTellListStepped :: forall o m a p. (Carrier m, Threaders '[SteppedThreads] m p) => SteppedC (Tell o) m a -> m ([o], a)

A variant of runTell with a SteppedThreads threading constraint instead of a StateThreads threading constraint.

runTellStepped :: forall w m a p. (Monoid w, Carrier m, Threaders '[SteppedThreads] m p) => SteppedC (Tell w) m a -> m (w, a)

A variant of runTell with a SteppedThreads threading constraint instead of a StateThreads threading constraint.

data ListenSteppedH

Instances

Eff (ListenPrim w) m => Handler ListenSteppedH (Listen w) m

Defined in Control.Effect.Internal.Intercept

Methods

effHandler :: EffHandler (Listen w) m

(Monoid w, Carrier m, Threaders '[SteppedThreads] m p) => PrimHandler ListenSteppedH (ListenPrim w) (SteppedC (Tell w) m)

Defined in Control.Effect.Internal.Intercept

Methods

effPrimHandler :: EffPrimHandler (ListenPrim w) (SteppedC (Tell w) m)

newtype ListenSteppedC w m a

Constructors

ListenSteppedC

Fields

• unListenSteppedC :: ReinterpretC ListenSteppedH (Listen w) '[ListenPrim w] (InterpretPrimC ListenSteppedH (ListenPrim w) (SteppedC (Tell w) m)) a

Instances

MonadBase b m => MonadBase b (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

liftBase :: b α -> ListenSteppedC w m α

MonadTrans (ListenSteppedC w)

Defined in Control.Effect.Internal.Intercept

Methods

lift :: Monad m => m a -> ListenSteppedC w m a

Monad (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

(>>=) :: ListenSteppedC w m a -> (a -> ListenSteppedC w m b) -> ListenSteppedC w m b

(>>) :: ListenSteppedC w m a -> ListenSteppedC w m b -> ListenSteppedC w m b

return :: a -> ListenSteppedC w m a

Functor (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

fmap :: (a -> b) -> ListenSteppedC w m a -> ListenSteppedC w m b

(<$) :: a -> ListenSteppedC w m b -> ListenSteppedC w m a

MonadFail m => MonadFail (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

fail :: String -> ListenSteppedC w m a

Applicative (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

pure :: a -> ListenSteppedC w m a

(<*>) :: ListenSteppedC w m (a -> b) -> ListenSteppedC w m a -> ListenSteppedC w m b

liftA2 :: (a -> b -> c) -> ListenSteppedC w m a -> ListenSteppedC w m b -> ListenSteppedC w m c

(*>) :: ListenSteppedC w m a -> ListenSteppedC w m b -> ListenSteppedC w m b

(<*) :: ListenSteppedC w m a -> ListenSteppedC w m b -> ListenSteppedC w m a

MonadIO m => MonadIO (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

liftIO :: IO a -> ListenSteppedC w m a

MonadThrow m => MonadThrow (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

throwM :: Exception e => e -> ListenSteppedC w m a

MonadCatch m => MonadCatch (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Methods

catch :: Exception e => ListenSteppedC w m a -> (e -> ListenSteppedC w m a) -> ListenSteppedC w m a

(Monoid w, Carrier m, Threaders '[SteppedThreads] m p) => Carrier (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

Associated Types

type Derivs (ListenSteppedC w m) :: [Effect]

type Prims (ListenSteppedC w m) :: [Effect]

Methods

algPrims :: Algebra' (Prims (ListenSteppedC w m)) (ListenSteppedC w m) a

reformulate :: Monad z => Reformulation' (Derivs (ListenSteppedC w m)) (Prims (ListenSteppedC w m)) (ListenSteppedC w m) z a

algDerivs :: Algebra' (Derivs (ListenSteppedC w m)) (ListenSteppedC w m) a

type Derivs (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

type Derivs (ListenSteppedC w m) = Derivs (ReinterpretC ListenSteppedH (Listen w) '[ListenPrim w] (InterpretPrimC ListenSteppedH (ListenPrim w) (SteppedC (Tell w) m)))

type Prims (ListenSteppedC w m)

Defined in Control.Effect.Internal.Intercept

type Prims (ListenSteppedC w m) = Prims (ReinterpretC ListenSteppedH (Listen w) '[ListenPrim w] (InterpretPrimC ListenSteppedH (ListenPrim w) (SteppedC (Tell w) m)))

runListenStepped :: forall w m a p. (Monoid w, Carrier m, Threaders '[SteppedThreads] m p) => ListenSteppedC w m a -> m (w, a)

A variant of runListen with a SteppedThreads threading constraint instead of a StateThreads threading constraint.

Derivs (ListenSteppedC w m) = Listen w ': Tell w ': Derivs m

Prims (ListenSteppedC w m) = ListenPrim w ': Derivs m

newtype ReifiedFOHandler e m

Constructors

ReifiedFOHandler (forall q x. e q x -> m x)

newtype InterceptRC (e :: Effect) m a

Constructors

InterceptRC

Fields

• unInterceptRC :: ReaderT (ReifiedFOHandler e m) m a

Instances

MonadBase b m => MonadBase b (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

liftBase :: b α -> InterceptRC e m α

MonadBaseControl b m => MonadBaseControl b (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Associated Types

type StM (InterceptRC e m) a

Methods

liftBaseWith :: (RunInBase (InterceptRC e m) b -> b a) -> InterceptRC e m a

restoreM :: StM (InterceptRC e m) a -> InterceptRC e m a

MonadTrans (InterceptRC e)

Defined in Control.Effect.Internal.Intercept

Methods

lift :: Monad m => m a -> InterceptRC e m a

Monad m => Monad (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

(>>=) :: InterceptRC e m a -> (a -> InterceptRC e m b) -> InterceptRC e m b

(>>) :: InterceptRC e m a -> InterceptRC e m b -> InterceptRC e m b

return :: a -> InterceptRC e m a

Functor m => Functor (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

fmap :: (a -> b) -> InterceptRC e m a -> InterceptRC e m b

(<$) :: a -> InterceptRC e m b -> InterceptRC e m a

MonadFix m => MonadFix (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

mfix :: (a -> InterceptRC e m a) -> InterceptRC e m a

MonadFail m => MonadFail (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

fail :: String -> InterceptRC e m a

Applicative m => Applicative (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

pure :: a -> InterceptRC e m a

(<*>) :: InterceptRC e m (a -> b) -> InterceptRC e m a -> InterceptRC e m b

liftA2 :: (a -> b -> c) -> InterceptRC e m a -> InterceptRC e m b -> InterceptRC e m c

(*>) :: InterceptRC e m a -> InterceptRC e m b -> InterceptRC e m b

(<*) :: InterceptRC e m a -> InterceptRC e m b -> InterceptRC e m a

MonadIO m => MonadIO (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

liftIO :: IO a -> InterceptRC e m a

Alternative m => Alternative (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

empty :: InterceptRC e m a

(<|>) :: InterceptRC e m a -> InterceptRC e m a -> InterceptRC e m a

some :: InterceptRC e m a -> InterceptRC e m [a]

many :: InterceptRC e m a -> InterceptRC e m [a]

MonadPlus m => MonadPlus (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

mzero :: InterceptRC e m a

mplus :: InterceptRC e m a -> InterceptRC e m a -> InterceptRC e m a

MonadThrow m => MonadThrow (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

throwM :: Exception e0 => e0 -> InterceptRC e m a

MonadCatch m => MonadCatch (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

catch :: Exception e0 => InterceptRC e m a -> (e0 -> InterceptRC e m a) -> InterceptRC e m a

MonadMask m => MonadMask (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Methods

mask :: ((forall a. InterceptRC e m a -> InterceptRC e m a) -> InterceptRC e m b) -> InterceptRC e m b

uninterruptibleMask :: ((forall a. InterceptRC e m a -> InterceptRC e m a) -> InterceptRC e m b) -> InterceptRC e m b

generalBracket :: InterceptRC e m a -> (a -> ExitCase b -> InterceptRC e m c) -> (a -> InterceptRC e m b) -> InterceptRC e m (b, c)

(FirstOrder e, Carrier m, Threads (ReaderT (ReifiedFOHandler e m)) (Prims m)) => Carrier (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

Associated Types

type Derivs (InterceptRC e m) :: [Effect]

type Prims (InterceptRC e m) :: [Effect]

Methods

algPrims :: Algebra' (Prims (InterceptRC e m)) (InterceptRC e m) a

reformulate :: Monad z => Reformulation' (Derivs (InterceptRC e m)) (Prims (InterceptRC e m)) (InterceptRC e m) z a

algDerivs :: Algebra' (Derivs (InterceptRC e m)) (InterceptRC e m) a

type Derivs (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

type Derivs (InterceptRC e m) = Intercept e ': (e ': Derivs m)

type Prims (InterceptRC e m)

Defined in Control.Effect.Internal.Intercept

type Prims (InterceptRC e m) = Unlift (ReaderT (ReifiedFOHandler e m) m) ': Prims m

type StM (InterceptRC e m) a

Defined in Control.Effect.Internal.Intercept

type StM (InterceptRC e m) a = StM (ReaderT (ReifiedFOHandler e m) m) a

runInterceptR :: forall e m a p. (FirstOrder e, Member e (Derivs m), Carrier m, Threaders '[ReaderThreads] m p) => InterceptRC e m a -> m a

Run Intercept e and e effects, provided e is first-order and part of the effect stack.

runInterceptR differs from runInterceptCont in four different ways:

• It doesn't handle InterceptCont.
• It has the significantly less restrictive threading constraint ReaderThreads instead of SteppedThreads
• It imposes the significantly more restrictive primitive effect Unlift instead of Unravel.
• It is significantly faster.

There are some interpreters -- such as bracketToIO and concToIO -- that runInterceptCont can't be used together with in any capacity due to its SteppedThreads threading constraint. In these cases, runInterceptR can be used instead.

Derivs (InterceptRC e m) = Intercept e ': e ': 'Derivs m'

Prims  (InterceptRC e m) = Unlift (ReaderT (ReifiedFOHandler e m)) ': 'Derivs m'