[Haskell-cafe] instance Alternative (Either [a])

Corentin Dupont corentin.dupont at gmail.com
Mon May 19 15:31:20 UTC 2014

Hi guys!
I'd like to implement the instance in the subject:
instance Alternative (Either [a])

However the instance in Control.Monad.Trans.Error.Error gets in the way...
I cannot use this one, it works only with Strings.
My use case is that the Either handle in the Right a final value, or else
in the Left a list of things "left to do" to compute the value.
How can I do?

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