[Haskell-cafe] Either e Monad

[Albert Lai]

Deokhwan Kim <dk at ropas.snu.ac.kr> writes:

> Where is the Monad instance declaration of Either e?

It is in Control.Monad.Error as well.  Strange: the doc doesn't state it.
I found out in ghci using:

:module +Control.Monad.Error
:info Either

The relevant result is:

instance Error e => Monad (Either e)
        -- Imported from Control.Monad.Error