Safe Haskell	None
Language	Haskell2010

Control.Algebra

Contents

Re-exports

Description

The Algebra class is the mechanism with which effects are interpreted.

An instance of the Algebra class defines an interpretation of an effect signature atop a given monad.

Since: 1.0.0.0

Synopsis

class (HFunctor sig, Monad m) => Algebra sig m | m -> sig where
- alg :: sig m a -> m a
run :: Identity a -> a
type Has eff sig m = (Members eff sig, Algebra sig m)
send :: (Member eff sig, Algebra sig m) => eff m a -> m a
data (f :+: g) (m :: * -> *) k
- = L (f m k)
- | R (g m k)
module Control.Effect.Class

Documentation

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

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

Since: 1.0.0.0

Methods

alg :: sig m a -> m a Source #

Construct a value in the carrier for an effect signature (typically a sum of a handled effect and any remaining effects).

Instances

Instances details

Algebra Choose NonEmpty Source #
Instance details Defined in Control.Algebra Methods alg :: Choose NonEmpty a -> NonEmpty a Source #
Algebra Empty Maybe Source #
Instance details Defined in Control.Algebra Methods alg :: Empty Maybe a -> Maybe a Source #
Algebra NonDet [] Source #
Instance details Defined in Control.Algebra Methods alg :: NonDet [] a -> [a] Source #
Algebra sig m => Algebra sig (Alt m) Source #	This instance permits effectful actions to be lifted into the `Alt` monad, which eases the invocation of repeated alternation with `<\|>`: a <\|> b <\|> c <\|> d is equivalent to getAlt (mconcat [a, b, c, d]) Since: 1.0.1.0
Instance details Defined in Control.Algebra Methods alg :: sig (Alt m) a -> Alt m a Source #
Algebra sig m => Algebra sig (Ap m) Source #	This instance permits effectful actions to be lifted into the `Ap` monad given a monoidal return type, which can provide clarity when chaining calls to `mappend`. mappend <$> act1 <> (mappend <$> act2 <> act3) is equivalent to getAp (act1 <> act2 <> act3) Since: 1.0.1.0
Instance details Defined in Control.Algebra Methods alg :: sig (Ap m) a -> Ap m a Source #
Algebra sig m => Algebra sig (IdentityT m) Source #
Instance details Defined in Control.Algebra Methods alg :: sig (IdentityT m) a -> IdentityT m a Source #
Algebra (Lift IO) IO Source #
Instance details Defined in Control.Algebra Methods alg :: Lift IO IO a -> IO a Source #
Algebra (Lift Identity) Identity Source #
Instance details Defined in Control.Algebra Methods alg :: Lift Identity Identity a -> Identity a Source #
Monad m => Algebra (Lift m) (LiftC m) Source #
Instance details Defined in Control.Carrier.Lift Methods alg :: Lift m (LiftC m) a -> LiftC m a Source #
Algebra (Error e) (Either e) Source #
Instance details Defined in Control.Algebra Methods alg :: Error e (Either e) a -> Either e a Source #
Monoid w => Algebra (Writer w) ((,) w) Source #
Instance details Defined in Control.Algebra Methods alg :: Writer w ((,) w) a -> (w, a) Source #
Algebra (Reader r) ((->) r :: Type -> Type) Source #
Instance details Defined in Control.Algebra Methods alg :: Reader r ((->) r) a -> r -> a Source #
(Algebra sig m, Effect sig) => Algebra (Choose :+: sig) (ChooseC m) Source #
Instance details Defined in Control.Carrier.Choose.Church Methods alg :: (Choose :+: sig) (ChooseC m) a -> ChooseC m a Source #
(Algebra sig m, Effect sig) => Algebra (Empty :+: sig) (EmptyC m) Source #
Instance details Defined in Control.Carrier.Empty.Maybe Methods alg :: (Empty :+: sig) (EmptyC m) a -> EmptyC m a Source #
(Algebra sig m, Effect sig) => Algebra (NonDet :+: sig) (NonDetC m) Source #
Instance details Defined in Control.Carrier.NonDet.Church Methods alg :: (NonDet :+: sig) (NonDetC m) a -> NonDetC m a Source #
(MonadIO m, Algebra sig m) => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Printing Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
Algebra sig m => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Ignoring Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
(Algebra sig m, Effect sig) => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Returning Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
(Algebra sig m, Effect sig) => Algebra (Fail :+: sig) (FailC m) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods alg :: (Fail :+: sig) (FailC m) a -> FailC m a Source #
(Algebra sig m, Effect sig) => Algebra (Fresh :+: sig) (FreshC m) Source #
Instance details Defined in Control.Carrier.Fresh.Strict Methods alg :: (Fresh :+: sig) (FreshC m) a -> FreshC m a Source #
(Algebra sig m, Effect sig) => Algebra (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Carrier.Cut.Church Methods alg :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a Source #
(Algebra sig m, Effect sig) => Algebra (Cull :+: (NonDet :+: sig)) (CullC m) Source #
Instance details Defined in Control.Carrier.Cull.Church Methods alg :: (Cull :+: (NonDet :+: sig)) (CullC m) a -> CullC m a Source #
Algebra sig m => Algebra (Reader r :+: sig) (ReaderT r m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: sig) (ReaderT r m) a -> ReaderT r m a Source #
Algebra sig m => Algebra (Reader r :+: sig) (ReaderC r m) Source #
Instance details Defined in Control.Carrier.Reader Methods alg :: (Reader r :+: sig) (ReaderC r m) a -> ReaderC r m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateT s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (State s :+: sig) (StateT s m) a -> StateT s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateT s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (State s :+: sig) (StateT s m) a -> StateT s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Carrier.State.Strict Methods alg :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Carrier.State.Lazy Methods alg :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
(Algebra sig m, Effect sig) => Algebra (Throw e :+: sig) (ThrowC e m) Source #
Instance details Defined in Control.Carrier.Throw.Either Methods alg :: (Throw e :+: sig) (ThrowC e m) a -> ThrowC e m a Source #
(Algebra sig m, Effect sig) => Algebra (Error e :+: sig) (ExceptT e m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Error e :+: sig) (ExceptT e m) a -> ExceptT e m a Source #
(Algebra sig m, Effect sig) => Algebra (Error e :+: sig) (ErrorC e m) Source #
Instance details Defined in Control.Carrier.Error.Either Methods alg :: (Error e :+: sig) (ErrorC e m) a -> ErrorC e m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Writer w :+: sig) (WriterT w m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Writer w :+: sig) (WriterT w m) a -> WriterT w m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Writer w :+: sig) (WriterT w m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Writer w :+: sig) (WriterT w m) a -> WriterT w m a Source #
(Monoid w, Algebra sig m, Effect sig) => Algebra (Writer w :+: sig) (WriterC w m) Source #
Instance details Defined in Control.Carrier.Writer.Strict Methods alg :: (Writer w :+: sig) (WriterC w m) a -> WriterC w m a Source #
(HFunctor eff, HFunctor sig, Reifies s (Handler eff m), Monad m, Algebra sig m) => Algebra (eff :+: sig) (InterpretC s eff m) Source #
Instance details Defined in Control.Carrier.Interpret Methods alg :: (eff :+: sig) (InterpretC s eff m) a -> InterpretC s eff m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) a -> RWST r w s m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) a -> RWST r w s m a Source #

run :: Identity a -> a Source #

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

Since: 1.0.0.0

type Has eff sig m = (Members eff sig, Algebra sig m) Source #

m is a carrier for sig containing eff.

Note that if eff is a sum, it will be decomposed into multiple Member constraints. While this technically allows one to combine multiple unrelated effects into a single Has constraint, doing so has two significant drawbacks:

Due to a problem with recursive type families, this can lead to significantly slower compiles.
It defeats ghc’s warnings for redundant constraints, and thus can lead to a proliferation of redundant constraints as code is changed.

send :: (Member eff sig, Algebra sig m) => eff m a -> m a Source #

Construct a request for an effect to be interpreted by some handler later on.

Re-exports

data (f :+: g) (m :: * -> *) k infixr 4 Source #

Higher-order sums are used to combine multiple effects into a signature, typically by chaining on the right.

Constructors

L (f m k)
R (g m k)

Instances

Instances details

Algebra NonDet [] Source #
Instance details Defined in Control.Algebra Methods alg :: NonDet [] a -> [a] Source #
Member l r => Member l (l' :+: r) Source #	Right-recursion: if `t` is a member of `r`, we can inject it into `r` in O(n), followed by lifting that into `l :+: r` in O(1).
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. l m a -> (l' :+: r) m a Source #
Member l (l :+: r) Source #	Left-occurrence: if `t` is at the head of a signature, we can inject it in O(1).
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. l m a -> (l :+: r) m a Source #
Member t (l1 :+: (l2 :+: r)) => Member t ((l1 :+: l2) :+: r) Source #	Left-recursion: if `t` is a member of `l1 :+: l2 :+: r`, then we can inject it into `(l1 :+: l2) :+: r` by injection into a right-recursive signature, followed by left-association.
Instance details Defined in Control.Effect.Sum Methods inj :: forall (m :: Type -> Type) a. t m a -> ((l1 :+: l2) :+: r) m a Source #
Algebra (Error e) (Either e) Source #
Instance details Defined in Control.Algebra Methods alg :: Error e (Either e) a -> Either e a Source #
Generic1 ((f :+: g) m :: Type -> Type) Source #
Instance details Defined in Control.Effect.Sum Associated Types type Rep1 ((f :+: g) m) :: k -> Type # Methods from1 :: forall (a :: k). (f :+: g) m a -> Rep1 ((f :+: g) m) a # to1 :: forall (a :: k). Rep1 ((f :+: g) m) a -> (f :+: g) m a #
(Effect f, Effect g) => Effect (f :+: g) Source #
Instance details Defined in Control.Effect.Sum Methods thread :: (Functor ctx, Monad m) => ctx () -> (forall x. ctx (m x) -> n (ctx x)) -> (f :+: g) m a -> (f :+: g) n (ctx a) Source #
(HFunctor f, HFunctor g) => HFunctor (f :+: g) Source #
Instance details Defined in Control.Effect.Sum Methods hmap :: Functor m => (forall x. m x -> n x) -> (f :+: g) m a -> (f :+: g) n a Source #
(Algebra sig m, Effect sig) => Algebra (Choose :+: sig) (ChooseC m) Source #
Instance details Defined in Control.Carrier.Choose.Church Methods alg :: (Choose :+: sig) (ChooseC m) a -> ChooseC m a Source #
(Algebra sig m, Effect sig) => Algebra (Empty :+: sig) (EmptyC m) Source #
Instance details Defined in Control.Carrier.Empty.Maybe Methods alg :: (Empty :+: sig) (EmptyC m) a -> EmptyC m a Source #
(Algebra sig m, Effect sig) => Algebra (NonDet :+: sig) (NonDetC m) Source #
Instance details Defined in Control.Carrier.NonDet.Church Methods alg :: (NonDet :+: sig) (NonDetC m) a -> NonDetC m a Source #
(MonadIO m, Algebra sig m) => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Printing Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
Algebra sig m => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Ignoring Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
(Algebra sig m, Effect sig) => Algebra (Trace :+: sig) (TraceC m) Source #
Instance details Defined in Control.Carrier.Trace.Returning Methods alg :: (Trace :+: sig) (TraceC m) a -> TraceC m a Source #
(Algebra sig m, Effect sig) => Algebra (Fail :+: sig) (FailC m) Source #
Instance details Defined in Control.Carrier.Fail.Either Methods alg :: (Fail :+: sig) (FailC m) a -> FailC m a Source #
(Algebra sig m, Effect sig) => Algebra (Fresh :+: sig) (FreshC m) Source #
Instance details Defined in Control.Carrier.Fresh.Strict Methods alg :: (Fresh :+: sig) (FreshC m) a -> FreshC m a Source #
(Algebra sig m, Effect sig) => Algebra (Cut :+: (NonDet :+: sig)) (CutC m) Source #
Instance details Defined in Control.Carrier.Cut.Church Methods alg :: (Cut :+: (NonDet :+: sig)) (CutC m) a -> CutC m a Source #
(Algebra sig m, Effect sig) => Algebra (Cull :+: (NonDet :+: sig)) (CullC m) Source #
Instance details Defined in Control.Carrier.Cull.Church Methods alg :: (Cull :+: (NonDet :+: sig)) (CullC m) a -> CullC m a Source #
Algebra sig m => Algebra (Reader r :+: sig) (ReaderT r m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: sig) (ReaderT r m) a -> ReaderT r m a Source #
Algebra sig m => Algebra (Reader r :+: sig) (ReaderC r m) Source #
Instance details Defined in Control.Carrier.Reader Methods alg :: (Reader r :+: sig) (ReaderC r m) a -> ReaderC r m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateT s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (State s :+: sig) (StateT s m) a -> StateT s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateT s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (State s :+: sig) (StateT s m) a -> StateT s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Carrier.State.Strict Methods alg :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
(Algebra sig m, Effect sig) => Algebra (State s :+: sig) (StateC s m) Source #
Instance details Defined in Control.Carrier.State.Lazy Methods alg :: (State s :+: sig) (StateC s m) a -> StateC s m a Source #
(Algebra sig m, Effect sig) => Algebra (Throw e :+: sig) (ThrowC e m) Source #
Instance details Defined in Control.Carrier.Throw.Either Methods alg :: (Throw e :+: sig) (ThrowC e m) a -> ThrowC e m a Source #
(Algebra sig m, Effect sig) => Algebra (Error e :+: sig) (ExceptT e m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Error e :+: sig) (ExceptT e m) a -> ExceptT e m a Source #
(Algebra sig m, Effect sig) => Algebra (Error e :+: sig) (ErrorC e m) Source #
Instance details Defined in Control.Carrier.Error.Either Methods alg :: (Error e :+: sig) (ErrorC e m) a -> ErrorC e m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Writer w :+: sig) (WriterT w m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Writer w :+: sig) (WriterT w m) a -> WriterT w m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Writer w :+: sig) (WriterT w m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Writer w :+: sig) (WriterT w m) a -> WriterT w m a Source #
(Monoid w, Algebra sig m, Effect sig) => Algebra (Writer w :+: sig) (WriterC w m) Source #
Instance details Defined in Control.Carrier.Writer.Strict Methods alg :: (Writer w :+: sig) (WriterC w m) a -> WriterC w m a Source #
(HFunctor eff, HFunctor sig, Reifies s (Handler eff m), Monad m, Algebra sig m) => Algebra (eff :+: sig) (InterpretC s eff m) Source #
Instance details Defined in Control.Carrier.Interpret Methods alg :: (eff :+: sig) (InterpretC s eff m) a -> InterpretC s eff m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) a -> RWST r w s m a Source #
(Algebra sig m, Effect sig, Monoid w) => Algebra (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) Source #
Instance details Defined in Control.Algebra Methods alg :: (Reader r :+: (Writer w :+: (State s :+: sig))) (RWST r w s m) a -> RWST r w s m a Source #
(Functor (f m), Functor (g m)) => Functor ((f :+: g) m) Source #
Instance details Defined in Control.Effect.Sum Methods fmap :: (a -> b) -> (f :+: g) m a -> (f :+: g) m b # (<$) :: a -> (f :+: g) m b -> (f :+: g) m a #
(Foldable (f m), Foldable (g m)) => Foldable ((f :+: g) m) Source #
Instance details Defined in Control.Effect.Sum Methods fold :: Monoid m0 => (f :+: g) m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> (f :+: g) m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> (f :+: g) m a -> m0 # foldr :: (a -> b -> b) -> b -> (f :+: g) m a -> b # foldr' :: (a -> b -> b) -> b -> (f :+: g) m a -> b # foldl :: (b -> a -> b) -> b -> (f :+: g) m a -> b # foldl' :: (b -> a -> b) -> b -> (f :+: g) m a -> b # foldr1 :: (a -> a -> a) -> (f :+: g) m a -> a # foldl1 :: (a -> a -> a) -> (f :+: g) m a -> a # toList :: (f :+: g) m a -> [a] # null :: (f :+: g) m a -> Bool # length :: (f :+: g) m a -> Int # elem :: Eq a => a -> (f :+: g) m a -> Bool # maximum :: Ord a => (f :+: g) m a -> a # minimum :: Ord a => (f :+: g) m a -> a # sum :: Num a => (f :+: g) m a -> a # product :: Num a => (f :+: g) m a -> a #
(Traversable (f m), Traversable (g m)) => Traversable ((f :+: g) m) Source #
Instance details Defined in Control.Effect.Sum Methods traverse :: Applicative f0 => (a -> f0 b) -> (f :+: g) m a -> f0 ((f :+: g) m b) # sequenceA :: Applicative f0 => (f :+: g) m (f0 a) -> f0 ((f :+: g) m a) # mapM :: Monad m0 => (a -> m0 b) -> (f :+: g) m a -> m0 ((f :+: g) m b) # sequence :: Monad m0 => (f :+: g) m (m0 a) -> m0 ((f :+: g) m a) #
(Eq (f m k), Eq (g m k)) => Eq ((f :+: g) m k) Source #
Instance details Defined in Control.Effect.Sum Methods (==) :: (f :+: g) m k -> (f :+: g) m k -> Bool # (/=) :: (f :+: g) m k -> (f :+: g) m k -> Bool #
(Ord (f m k), Ord (g m k)) => Ord ((f :+: g) m k) Source #
Instance details Defined in Control.Effect.Sum Methods compare :: (f :+: g) m k -> (f :+: g) m k -> Ordering # (<) :: (f :+: g) m k -> (f :+: g) m k -> Bool # (<=) :: (f :+: g) m k -> (f :+: g) m k -> Bool # (>) :: (f :+: g) m k -> (f :+: g) m k -> Bool # (>=) :: (f :+: g) m k -> (f :+: g) m k -> Bool # max :: (f :+: g) m k -> (f :+: g) m k -> (f :+: g) m k # min :: (f :+: g) m k -> (f :+: g) m k -> (f :+: g) m k #
(Show (f m k), Show (g m k)) => Show ((f :+: g) m k) Source #
Instance details Defined in Control.Effect.Sum Methods showsPrec :: Int -> (f :+: g) m k -> ShowS # show :: (f :+: g) m k -> String # showList :: [(f :+: g) m k] -> ShowS #
type Rep1 ((f :+: g) m :: Type -> Type) Source #
Instance details Defined in Control.Effect.Sum type Rep1 ((f :+: g) m :: Type -> Type) = D1 ('MetaData ":+:" "Control.Effect.Sum" "fused-effects-1.0.0.1-inplace" 'False) (C1 ('MetaCons "L" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 (f m))) :+: C1 ('MetaCons "R" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 (g m))))

module Control.Effect.Class