[Haskell-cafe] Control.Monad.Error deprecated?

[Francesco Ariis]

On Sun, Sep 14, 2014 at 12:40:56PM -0700, Karl Voelker wrote:
> I just discovered that Control.Monad.Error [1] has recently become
> deprecated in favor of Control.Monad.Except [2], and I am curious about
> what motivated the change. Can anyone explain?

I discovered it recently too, in a search for a package similar to ``either``
but which didn't rely on template-haskell.

Not a maintainer, so just a wild guess: maybe it is because the new module
hasn't got the ``class Error`` (and people wanted to get rid of it) and
general less hairiness?

The commits/changelog don't contain other info:

https://github.com/ekmett/mtl/commits/master/Control/Monad/Except.hs