fused-effects-0.5.0.0: A fast, flexible, fused effect system.

Safe HaskellNone
LanguageHaskell2010

Control.Effect.Cut

Contents

Synopsis

Cut effect

data Cut m k Source #

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

Constructors

Cutfail 
Call (m a) (a -> m k) 
Instances
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' :: 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
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 #

fail :: String -> 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
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
Member sub sub Source # 
Instance details

Defined in Control.Effect.Sum

Methods

inj :: sub m a -> sub m a Source #

prj :: 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 :: sub m a -> (sub' :+: sup) m a Source #

prj :: (sub' :+: sup) m a -> Maybe (sub m a) Source #

Member sub (sub :+: sup) Source # 
Instance details

Defined in Control.Effect.Sum

Methods

inj :: sub m a -> (sub :+: sup) m a Source #

prj :: (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.