Folks,

We are extremely happy to announce the control-monad-failure and safe-failure packages for error handling.

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

Instances are provided for several concrete representations of failure handling: Maybe, Either, ErrorT, Control.Exception.Throw, and [].

safe-failure is a fork of Neil Mitchell's Safe package providing MonadFailure versions of several partial functions
in the Prelude, which instead of failing with a runtime error fail with Failure.

> head :: MonadFailure HeadFailure m => [a] -> m a

This is a joint release from the authors of the attempt and the control-monad-exception packages,
and accompanying releases of those packages have been made making them adopt the MonadFailure interface.
We have also created a wiki page explaining our reasons for following this path in:

 http://www.haskellwiki.org/Failure


Thanks,
Jose Iborra, Nicolas Pouillard and Michael Snoyman