[Haskell-cafe] Either e Monad

Deokhwan Kim dk at ropas.snu.ac.kr
Tue Sep 19 01:55:06 EDT 2006


Dear all,

Where is the Monad instance declaration of Either e?

>From the description of Control.Monad.Error, I deduce that Either e is
an instance of Monad.


http://haskell.org/ghc/docs/latest/html/libraries/mtl/Control-Monad-Error.html

  class Monad m => MonadError e m | m -> e where ...

  Error e => MonadError e (Either e)

But, I cannot find the Monad instance declaration of Either anywhere.

Thanks.

-- 
Deokhwan Kim


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