On Mon, 2009-01-19 at 10:59 -0800, Iavor Diatchki wrote:
Hello, The multitude of newtypes in the Monoid module are a good indication that the Monoid class is not a good fit for the class system
I would say rather that the class system is not a good fit for Monoid. Proposals for local instances, multiple instances, instance import/export control, etc. come up quite frequently on this list; the phenomena in question are not restricted to Monoid.
I usually avoid using the "newtype" trick as I find it inconvenient: usually the newtype does not have the same operations as the underlying type and so it cannot be used directly, and if you are going to wrap thing just when you use the class methods,
OTOH, I think you mean here `when you use class methods and when you use overloaded functions'. jcc