Re: [Haskell-cafe] rebinding >>= for restricted monads

On 12/17/06, David Roundy wrote:

Hello fellow haskellers,

I am wondering if anyone has an idea whether I'd run into trouble if I rebound >>= in order to provide a more restricted monad. My idea is to define a class:

. . .

which seems rather heavy. Can anyone think of syntax-light way to allow my hypothesized rebound do-notation to also work with ordinary monads?

You could try something like this:

import Prelude hiding (Monad (..)) import qualified Prelude (Monad (..)) as P

class WitnessMonad wm where ...

data M m w w' c = M (m c)

instance P.Monad m => WitnessMonad (M m) where ...

Then if everything works out, you should end up with M IO and such as WitnessMonads.