broken Monad Either instance?

Christian Maeder Christian.Maeder at
Wed Nov 30 13:55:09 CET 2011

Yes, thanks, this works and is worth knowing.
It looks a bit ugly but is shorter than making a new monad.

Prelude Control.Monad.Identity Control.Monad.Error>
   runIdentity . runErrorT $ fail "bla" :: Either String ()
Left "bla"


Am 30.11.2011 11:39, schrieb Erik Hesselink:
> ErrorT from mtl still has a 'fail' implementation that returns a Left.
> Erik

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