[Haskell-cafe] ANNOUNCE: control-monad-failure and safe-failure

Nicolas Pouillard nicolas.pouillard at gmail.com
Tue Nov 17 04:46:16 EST 2009

Excerpts from Kalman Noel's message of Tue Nov 17 07:47:14 +0100 2009:
> Michael Snoyman schrieb:
> > control-monad-failure provides a basic notion of failure which does not
> > commit to any concrete representation.
> > It is just a version of the MonadError class without the annoying bits.
> > 
> >> class MonadFailure e m where failure :: e -> m a 
> Why is it called "MonadFailure" (specifically, what's the "Monad" bit doing 
> there)?

Because of 'Monad m' being a superclass of 'MonadFailure e m'.

Here is the class:
class Monad m => MonadFailure e m where
  failure :: e -> m a

Nicolas Pouillard

More information about the Haskell-Cafe mailing list