Re: [Haskell-cafe] Building a monoid, continuation-passing style

David Menendez wrote:

I'm reminded of the parameterized monad of continuations that Oleg mentioned a few years back.

http://www.haskell.org/pipermail/haskell/2007-December/020034.html

This is all very interesting, thank you both for the pointers! I was trying to get rid of the newtypes but couldn't think of how to do that. I can't believe the solution now is as simple as (m -> r) -> a. There's hardly any code left, now. The fact that it all exists already is nice on the one hand and sad on the other. :-) I will have to look into parametrized monads and parametrized applicatives. Thanks again, Martijn.