#4159: move Monad and MonadFix instances for Either from mtl to base

wren ng thornton wren at community.haskell.org
Thu Jul 1 17:14:45 EDT 2010

Ross Paterson wrote:
> The proposal is to move the Monad and MonadFix instances for Either
> (currently in the mtl package) to Control.Monad.Instances and
> Control.Monad.Fix respectively (both in the base package).  The Monad
> instance is still an orphan, to retain Haskell 98 compatibility, but the
> MonadFix instance is together with its class.  The Error constraint is
> removed from both instances, and the default definition of fail is used.

+1 btw.

Live well,

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