| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Control.Effect.Type.WriterPrim
Synopsis
- data WriterPrim o :: Effect where
- WriterPrimTell :: o -> WriterPrim o m ()
- WriterPrimListen :: m a -> WriterPrim o m (o, a)
- WriterPrimPass :: m (o -> o, a) -> WriterPrim o m a
- threadWriterPrim :: forall o t m a. (MonadTrans t, ThreadsEff t (ListenPrim o), Monad m) => ((forall x. WriterPrim o m x -> m x) -> t m (o -> o, a) -> t m a) -> (forall x. WriterPrim o m x -> m x) -> WriterPrim o (t m) a -> t m a
- threadWriterPrimViaClass :: forall o t m a. (Monoid o, MonadTrans t, Monad m) => (RepresentationalT t, forall b. MonadWriter o b => MonadWriter o (t b)) => (forall x. WriterPrim o m x -> m x) -> WriterPrim o (t m) a -> t m a
- algListenPrimIntoWriterPrim :: Algebra' (ListenPrim o ': p) m a -> (m (o -> o, a) -> m a) -> Algebra' (WriterPrim o ': p) m a
Effects
data WriterPrim o :: Effect where Source #
A primitive effect that may be used for
interpreters of connected Tell,
Listen, and Pass effects.
This combines Tell and
Listen and Pass.
This may be relevant if there are monad transformers that may only lift
pass if they also have access to
listen and tell.
WriterPrim is only used as a primitive effect.
If you define a Carrier that relies on a novel
non-trivial monad transformer t, then you need to make
a Monoid o => ThreadsEff t (WriterPrim o)threadWriterPrim and threadWriterPrimViaClass can help you with that.
The following threading constraints accept WriterPrim:
Constructors
| WriterPrimTell :: o -> WriterPrim o m () | |
| WriterPrimListen :: m a -> WriterPrim o m (o, a) | |
| WriterPrimPass :: m (o -> o, a) -> WriterPrim o m a |
Instances
Threading utilities
threadWriterPrim :: forall o t m a. (MonadTrans t, ThreadsEff t (ListenPrim o), Monad m) => ((forall x. WriterPrim o m x -> m x) -> t m (o -> o, a) -> t m a) -> (forall x. WriterPrim o m x -> m x) -> WriterPrim o (t m) a -> t m a Source #
Construct a valid definition of threadEff for a
ThreadsEff t (WriterPrim o)WriterPrimPass should be lifted.
This relies on an existing ThreadsEff t (ListenPrim o)
threadWriterPrimViaClass :: forall o t m a. (Monoid o, MonadTrans t, Monad m) => (RepresentationalT t, forall b. MonadWriter o b => MonadWriter o (t b)) => (forall x. WriterPrim o m x -> m x) -> WriterPrim o (t m) a -> t m a Source #
A valid definition of threadEff for a
Monoid o => ThreadsEff (WriterPrim o) tt lifts MonadWriter w
Combinators for Algebras
algListenPrimIntoWriterPrim :: Algebra' (ListenPrim o ': p) m a -> (m (o -> o, a) -> m a) -> Algebra' (WriterPrim o ': p) m a Source #
Rewrite an Algebra where the topmost effect is ListenPrim into
an Algebra where the topmost effect is WriterPrim by providing
an implementation of WriterPrimPass.