Modulefused-effects-1.1.2.7Haskell2010

Control.Carrier.Accum.IORef

A carrier for Accum effects. This carrier performs its append operations strictly and thus avoids the space leaks inherent in lazy writer monads. These appends are left-associative; as such, [] is a poor choice of monoid for computations that entail many calls to add. The Seq or DList monoids may be a superior choice. This carrier also uses an IORef to store its accumulator, which allows it a MonadUnliftIO instance, but precludes backtracking when run in conjunction with Control.Effect.NonDet.

1 type
3 values

Packagefused-effects-1.1.2.7
Exports4
LanguageHaskell2010
LicenceBSD-3-Clause
SourceIORef.hs

Accum carrier

4 declarations

valuerunAccum :: MonadIO m => w -> AccumC w m a -> m (w, a)

Run an Accum effect with a Semigroup-based log.

runAccum w0 (pure a) = pure (w0, a)

runAccum w0 (add w) = pure (w0 <> w, ())

runAccum w0 (add w >> look) = pure (w0 <> w, w0 <> w)

valueexecAccum :: MonadIO m => w -> AccumC w m a -> m w

Run a Accum effect with a Semigroup-based log, producing the final log and discarding the result value.

execAccum w = fmap fst . runAccum w

valueevalAccum :: MonadIO m => w -> AccumC w m a -> m a

Run a Accum effect with a Semigroup-based log, producing the result value and discarding the final log.

evalAccum w = fmap snd . runAccum w

newtypenewtype AccumC w (m :: Type -> Type) a

Constructors

AccumC
- runAccumC :: ReaderC (IORef w) m a

Instances11MonadTrans, Monad, Functor, MonadFix, MonadFail, Applicative, …

MonadTrans (AccumC w)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
Monad m => Monad (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
Functor m => Functor (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
MonadFix m => MonadFix (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
MonadFail m => MonadFail (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
Applicative m => Applicative (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
Alternative m => Alternative (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
(Alternative m, Monad m) => MonadPlus (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
MonadIO m => MonadIO (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
MonadUnliftIO m => MonadUnliftIO (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef
(Algebra sig m, Semigroup w, MonadIO m) => Algebra (Accum w :+: sig) (AccumC w m)Defined in fused-effects-1.1.2.7 · Control.Carrier.Accum.IORef

Accum effect

0 declarations

module Control.Effect.Accum