Re: MonadPlus instance for ContT

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Edward Kmett writes:

Because there are many monads for which you do not want this construction!

It isn't what you mean when you use mappend on [a] for sure! It is also different from the behavior for Monad, and it rules out those and many many other perfectly valid uses by overlap.

Thanks for the clarification, Edward! Very good points. -- John Wiegley FP Complete Haskell tools, training and consulting http://fpcomplete.com johnw on #haskell/irc.freenode.net