MonadMorphIO [Re: Move MonadIO to base]

[Ross Paterson]

On Fri, Apr 23, 2010 at 05:16:28PM +0200, Bas van Dijk wrote:
> Ideally mtl and transformers will depend on this package and provide
> the necessary instances in the same modules as where their data types
> are defined so avoiding orphaned instances.

It's also possible to avoid orphan instances by having this package
depend on both mtl and transformers (with qualified imports) and define
instances for their types in the same module as the class.