[Haskell-cafe] Re: Applicative but not Monad

[Tom Davie]

On 10/31/09, Heinrich Apfelmus <apfelmus at quantentunnel.de> wrote:
> The only possible monad instance would be
>
>    return x = Const mempty
>    fmap f (Const b) = Const b
>    join (Const b)   = Const b

Your join doesn't seem to have the right type... Unless I'm missing something.

Bob