| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Effectful.Writer.Dynamic
Description
The dynamically dispatched variant of the Writer effect.
Note: unless you plan to change interpretations at runtime, it's recommended to use one of the statically dispatched variants, i.e. Effectful.Writer.Static.Local or Effectful.Writer.Static.Shared.
Synopsis
- data Writer w :: Effect where
- runWriterLocal :: Monoid w => Eff (Writer w ': es) a -> Eff es (a, w)
- execWriterLocal :: Monoid w => Eff (Writer w ': es) a -> Eff es w
- runWriterShared :: Monoid w => Eff (Writer w ': es) a -> Eff es (a, w)
- execWriterShared :: Monoid w => Eff (Writer w ': es) a -> Eff es w
- tell :: (HasCallStack, Writer w :> es) => w -> Eff es ()
- listen :: (HasCallStack, Writer w :> es) => Eff es a -> Eff es (a, w)
- listens :: (HasCallStack, Writer w :> es) => (w -> b) -> Eff es a -> Eff es (a, b)
Effect
data Writer w :: Effect where Source #
Provide access to a write only value of type w.
Instances
| type DispatchOf (Writer w) Source # | |
Defined in Effectful.Writer.Dynamic | |
Handlers
Local
runWriterLocal :: Monoid w => Eff (Writer w ': es) a -> Eff es (a, w) Source #
Run the Writer effect and return the final value along with the final
output (via Effectful.Writer.Static.Local).
execWriterLocal :: Monoid w => Eff (Writer w ': es) a -> Eff es w Source #
Run a Writer effect and return the final output, discarding the final
value (via Effectful.Writer.Static.Local).
Shared
runWriterShared :: Monoid w => Eff (Writer w ': es) a -> Eff es (a, w) Source #
Run the Writer effect and return the final value along with the final
output (via Effectful.Writer.Static.Shared).
execWriterShared :: Monoid w => Eff (Writer w ': es) a -> Eff es w Source #
Run the Writer effect and return the final output, discarding the final
value (via Effectful.Writer.Static.Shared).
Operations
tell :: (HasCallStack, Writer w :> es) => w -> Eff es () Source #
Append the given output to the overall output of the Writer.