30 Apr
2005
30 Apr
'05
9:33 p.m.
In article <4f386ed173562cddfbf16258f3b57a37@alum.mit.edu>, Jan-Willem Maessen <jmaessen@alum.mit.edu> wrote:
And the binary operation in a Magma has *no* properties. My feeling is that there MonadPlus must have *some* set of properties in order to be useful---otherwise it's just an ad-hoc mechanism to call a pile of different binary operations "mplus". I think most people would agree that's undesiriable, and the only confusion is which properties must hold.
I claim "monoid" is a point of agreement, at least.
I think Left Zero is too. I'd be very interested in what people feel constitutes a real MonadPlus: my own preference is Monoid, Left Zero, and Left Distribution. -- Ashley Yakeley, Seattle WA