[Haskell-cafe] Confusion on the third monad law when using lambda abstractions

Dan Piponi dpiponi at gmail.com
Wed Jun 17 21:24:52 EDT 2009

On Wed, Jun 17, 2009 at 6:08 PM, Jon Strait<jstrait at moonloop.net> wrote:
> ...but if there
> were another monad defined like,
> data MadMaybe a = Nothing | Perhaps | Just a

MadMaybe violates the second law. It's quite unlike a monad.

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