Safe Haskell	None
Language	Haskell2010

Control.Effect.Cut

Contents

Cut effect
Cut carrier
Re-exports

Synopsis

data Cut m k
- = Cutfail
- | forall a. Call (m a) (a -> m k)
cutfail :: (Carrier sig m, Member Cut sig) => m a
call :: (Carrier sig m, Member Cut sig) => m a -> m a
cut :: (Alternative m, Carrier sig m, Member Cut sig) => m ()
runCut :: Alternative m => CutC m a -> m a
runCutAll :: (Alternative f, Applicative m) => CutC m a -> m (f a)
newtype CutC m a = CutC {
- runCutC :: forall b. (a -> m b -> m b) -> m b -> m b -> m b
}
class (HFunctor sig, Monad m) => Carrier sig m | m -> sig
class Member (sub :: (* -> *) -> * -> *) sup
run :: PureC a -> a

Cut effect

data Cut m k Source #

Cut effects are used with NonDet to provide control over backtracking.

Constructors

Cutfail
forall a. Call (m a) (a -> m k)

Instances

Instances details

Effect Cut Source #
Instance details Defined in Control.Effect.Cut Methods handle :: (Functor f, Monad m) => f () -> (forall x. f (m x) -> n (f x)) -> Cut m a -> Cut n (f a) Source #
HFunctor Cut Source #
Instance details Defined in Control.Effect.Cut Methods fmap' :: forall (f :: Type -> Type) a b. Functor (Cut f) => (a -> b) -> Cut f a -> Cut f b Source # hmap :: Functor m => (forall x. m x -> n x) -> Cut m a -> Cut n a Source #
Functor m => Functor (Cut m) Source #
Instance details Defined in Control.Effect.Cut Methods fmap :: (a -> b) -> Cut m a -> Cut m b # (<$) :: a -> Cut m b -> Cut m a #
(Carrier sig m, Effect sig) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods eff :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a Source #

cutfail :: (Carrier sig m, Member Cut sig) => m a Source #

Fail the current branch, and prevent backtracking within the nearest enclosing call (if any).

Contrast with empty, which fails the current branch but allows backtracking.

run (runNonDet (runCut (cutfail <|> pure a))) === []

run (runNonDet (runCut (pure a <|> cutfail))) === [a]

call :: (Carrier sig m, Member Cut sig) => m a -> m a Source #

Delimit the effect of cutfails, allowing backtracking to resume.

run (runNonDet (runCut (call (cutfail <|> pure a) <|> pure b))) === [b]

cut :: (Alternative m, Carrier sig m, Member Cut sig) => m () Source #

Commit to the current branch, preventing backtracking within the nearest enclosing call (if any) on failure.

run (runNonDet (runCut (pure a <|> cut *> pure b))) === [a, b]

run (runNonDet (runCut (cut *> pure a <|> pure b))) === [a]

run (runNonDet (runCut (cut *> empty <|> pure a))) === []

Cut carrier

runCut :: Alternative m => CutC m a -> m a Source #

Run a Cut effect within an underlying Alternative instance (typically another Carrier for a NonDet effect).

run (runNonDetOnce (runCut (pure a))) === Just a

runCutAll :: (Alternative f, Applicative m) => CutC m a -> m (f a) Source #

Run a Cut effect, returning all its results in an Alternative collection.

newtype CutC m a Source #

Constructors

CutC
Fields runCutC :: forall b. (a -> m b -> m b) -> m b -> m b -> m b A higher-order function receiving three parameters: a function to combine each solution with the rest of the solutions, an action to run when no results are produced (e.g. on `empty`), and an action to run when no results are produced and backtrcking should not be attempted (e.g. on `cutfail`).

Instances

Instances details

MonadTrans CutC Source #
Instance details Defined in Control.Effect.Cut Methods lift :: Monad m => m a -> CutC m a #
Monad (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods (>>=) :: CutC m a -> (a -> CutC m b) -> CutC m b # (>>) :: CutC m a -> CutC m b -> CutC m b # return :: a -> CutC m a #
Functor (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods fmap :: (a -> b) -> CutC m a -> CutC m b # (<$) :: a -> CutC m b -> CutC m a #
MonadFix m => MonadFix (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods mfix :: (a -> CutC m a) -> CutC m a #
MonadFail m => MonadFail (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods fail :: String -> CutC m a #
Applicative (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods pure :: a -> CutC m a # (<>) :: CutC m (a -> b) -> CutC m a -> CutC m b # liftA2 :: (a -> b -> c) -> CutC m a -> CutC m b -> CutC m c # (>) :: CutC m a -> CutC m b -> CutC m b # (<*) :: CutC m a -> CutC m b -> CutC m a #
MonadIO m => MonadIO (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods liftIO :: IO a -> CutC m a #
Alternative (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods empty :: CutC m a # (<\|>) :: CutC m a -> CutC m a -> CutC m a # some :: CutC m a -> CutC m [a] # many :: CutC m a -> CutC m [a] #
MonadPlus (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods mzero :: CutC m a # mplus :: CutC m a -> CutC m a -> CutC m a #
(Carrier sig m, Effect sig) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods eff :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a Source #

Re-exports

class (HFunctor sig, Monad m) => Carrier sig m | m -> sig Source #

The class of carriers (results) for algebras (effect handlers) over signatures (effects), whose actions are given by the eff method.

Minimal complete definition

eff

Instances

Instances details

Carrier Pure PureC Source #
Instance details Defined in Control.Effect.Carrier Methods eff :: Pure PureC a -> PureC a Source #
(HFunctor eff, Carrier sig m, Member eff sig) => Carrier sig (InterposeC eff m) Source #
Instance details Defined in Control.Effect.Interpose Methods eff :: sig (InterposeC eff m) a -> InterposeC eff m a Source #
Monad m => Carrier (Lift m) (LiftC m) Source #
Instance details Defined in Control.Effect.Lift Methods eff :: Lift m (LiftC m) a -> LiftC m a Source #
(Carrier sig m, MonadIO m) => Carrier (Resource :+: sig) (ResourceC m) Source #
Instance details Defined in Control.Effect.Resource Methods eff :: (Resource :+: sig) (ResourceC m) a -> ResourceC m a Source #
(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (NonDetC m) Source #
Instance details Defined in Control.Effect.NonDet Methods eff :: (NonDet :+: sig) (NonDetC m) a -> NonDetC m a Source #
(Carrier sig m, Effect sig) => Carrier (NonDet :+: sig) (OnceC m) Source #
Instance details Defined in Control.Effect.Cull Methods eff :: (NonDet :+: sig) (OnceC m) a -> OnceC m a Source #
(Carrier sig m, Effect sig) => Carrier (Fresh :+: sig) (FreshC m) Source #
Instance details Defined in Control.Effect.Fresh Methods eff :: (Fresh :+: sig) (FreshC m) a -> FreshC m a Source #
(Carrier sig m, Effect sig) => Carrier (Fail :+: sig) (FailC m) Source #
Instance details Defined in Control.Effect.Fail Methods eff :: (Fail :+: sig) (FailC m) a -> FailC m a Source #
(Carrier sig m, Effect sig) => Carrier (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Effect.Cut Methods eff :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a Source #
(Carrier sig m, Effect sig) => Carrier (Cull :+: (NonDet :+: sig)) (CullC m) Source #
Instance details Defined in Control.Effect.Cull Methods eff :: (Cull :+: (NonDet :+: sig)) (CullC m) a -> CullC m a Source #
(Carrier sig m, Effect sig) => Carrier (Trace :+: sig) (TraceByReturningC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByReturningC m) a -> TraceByReturningC m a Source #
Carrier sig m => Carrier (Trace :+: sig) (TraceByIgnoringC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByIgnoringC m) a -> TraceByIgnoringC m a Source #
(MonadIO m, Carrier sig m) => Carrier (Trace :+: sig) (TraceByPrintingC m) Source #
Instance details Defined in Control.Effect.Trace Methods eff :: (Trace :+: sig) (TraceByPrintingC m) a -> TraceByPrintingC m a Source #
(HFunctor eff, Carrier sig m) => Carrier (eff :+: sig) (InterpretC eff m) Source #
Instance details Defined in Control.Effect.Interpret Methods eff :: (eff :+: sig) (InterpretC eff m) a -> InterpretC eff m a Source #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Strict Methods eff :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
(Carrier sig m, Effect sig) => Carrier (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Effect.State.Lazy Methods eff :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
Carrier sig m => Carrier (Reader r :+: sig) (ReaderC r m) Source #
Instance details Defined in Control.Effect.Reader Methods eff :: (Reader r :+: sig) (ReaderC r m) a -> ReaderC r m a Source #
(Carrier sig m, Effect sig, RandomGen g) => Carrier (Random :+: sig) (RandomC g m) Source #
Instance details Defined in Control.Effect.Random Methods eff :: (Random :+: sig) (RandomC g m) a -> RandomC g m a Source #
(Carrier sig m, Effect sig) => Carrier (Error e :+: sig) (ErrorC e m) Source #
Instance details Defined in Control.Effect.Error Methods eff :: (Error e :+: sig) (ErrorC e m) a -> ErrorC e m a Source #
Carrier sig m => Carrier (Resumable err :+: sig) (ResumableWithC err m) Source #
Instance details Defined in Control.Effect.Resumable Methods eff :: (Resumable err :+: sig) (ResumableWithC err m) a -> ResumableWithC err m a Source #
(Carrier sig m, Effect sig) => Carrier (Resumable err :+: sig) (ResumableC err m) Source #
Instance details Defined in Control.Effect.Resumable Methods eff :: (Resumable err :+: sig) (ResumableC err m) a -> ResumableC err m a Source #
(Monoid w, Carrier sig m, Effect sig) => Carrier (Writer w :+: sig) (WriterC w m) Source #
Instance details Defined in Control.Effect.Writer Methods eff :: (Writer w :+: sig) (WriterC w m) a -> WriterC w m a Source #
(HFunctor eff, Carrier sig m, Effect sig) => Carrier (eff :+: sig) (InterpretStateC eff s m) Source #
Instance details Defined in Control.Effect.Interpret Methods eff :: (eff :+: sig) (InterpretStateC eff s m) a -> InterpretStateC eff s m a Source #

class Member (sub :: (* -> *) -> * -> *) sup Source #

Minimal complete definition

inj, prj

Instances

Instances details

Member sub sub Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> sub m a Source # prj :: forall (m :: Type -> Type) a. sub m a -> Maybe (sub m a) Source #
Member sub sup => Member sub (sub' :+: sup) Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> (sub' :+: sup) m a Source # prj :: forall (m :: Type -> Type) a. (sub' :+: sup) m a -> Maybe (sub m a) Source #
Member sub (sub :+: sup) Source #
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. sub m a -> (sub :+: sup) m a Source # prj :: forall (m :: Type -> Type) a. (sub :+: sup) m a -> Maybe (sub m a) Source #

run :: PureC a -> a Source #

Run an action exhausted of effects to produce its final result value.