effect-handlers alternatives and similar packages
Based on the "effect" category.
Alternatively, view effect-handlers alternatives based on common mentions on social networks and blogs.
-
effect-monad
Provides 'graded monads' and 'parameterised monads' to Haskell, enabling fine-grained reasoning about effects.
Do you think we are missing an alternative of effect-handlers or a related project?
README
effect-handlers
This is an extensible effects library for Haskell taking inspiration from the Eff language.
See these papers for the ideas and theory behind the library:
- O. Kammar et al: Handlers in Action!
- A. Bauer, M. Pretnar: Programming with Algebraic Effects and Handlers
- O Kiselyov, A Sabry, C Swords: Extensible Effects
Implementation wise it's most close to extensible-effects (also see the Extensible Effects paper) but it implements deep handlers instead of shallow.
What does this library provide?
There is the Eff monad type and modules for pre-implemented effects.
ExceptionIOReaderSearchStateWriter
It is easy to define your own effects and combine them.
Example
Most of the types are inferred, you only need to provide enough to tell the compiler how to specialize some effect handlers (e.g. readerHandler).
import Control.Effects.Cont.Eff
import Control.Effects.Cont.Reader
import Control.Effects.Cont.Exception
program = do
v <- ask
if v < 15
then throw $ show v
else return (v+1)
run n = runPure
. handle exceptionHandler
. handle (readerHandler n)
res :: Integer -> Either String Integer
res n = run n program
Documentation
Haddock docs are available online