effin
Version 0.2.1.3 revision 0 uploaded by AnthonyVandikas.
Package meta
- Synopsis
- A Typeable-free implementation of extensible effects
- Description
This package implements extensible effects, and alternative to monad transformers. The original paper can be found at http://okmij.org/ftp/Haskell/extensible/exteff.pdf. The main differences between this library and the one described in the paper are that this library does not use the Typeable type class, does not require that effects implement the Functor type class, and has a simpler API for handling effects.
For example, the following code implements a handler for exceptions:
newtype Exception e = Throw e runException :: Effect (Exception e :+ es) a -> Effect es (Either e a) runException = eliminate (\x -> return (Right x)) (\(Throw e) k -> return (Left e))Compare this to the corresponding code in extensible-effects (http://hackage.haskell.org/package/extensible-effects):
runExc :: Typeable e => Eff (Exc e :> r) a -> Eff r (Either e a) runExc = loop . admin where loop (Val x) = return (Right x) loop (E u) = handleRelay u loop (\(Exc e) -> return (Left e))In particular, effect implementors are not required to do any recursion, thereby making effect handlers more composeable.
- Author
- Anthony Vandikas
- Bug reports
- n/a
- Category
- Control, Effect
- Copyright
- (c) 2014 Anthony Vandikas
- Homepage
- https://github.com/YellPika/effin
- Maintainer
- yellpika@gmail.com
- Package URL
- n/a
- Stability
- n/a