effect-handlers-0.1.0.8: A library for writing extensible algebraic effects and handlers. Similar to extensible-effects but with deep handlers.
This is an extensible effects library for Haskell taking inspiration from the Eff language http://www.eff-lang.org/.
See these papers for the ideas and theory behind the library:
- O. Kammar et al: Handlers in Action! http://homepages.inf.ed.ac.uk/slindley/papers/handlers.pdf
- A. Bauer, M. Pretnar: Programming with Algebraic Effects and Handlers http://arxiv.org/abs/1203.1539
- O Kiselyov, A Sabry, C Swords: Extensible Effects http://dl.acm.org/citation.cfm?id=2503791
Implementation wise it's most close to extensible-effects
http://hackage.haskell.org/package/extensible-effects (also see the Extensible Effects paper) but it implements deep handlers instead of shallow.
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