23 Oct
2010
23 Oct
'10
7:57 p.m.
On 10/23/10 7:52 PM, wren ng thornton wrote:
I'd argue that neither usage is "primary", and therefore the best solution is actually to have three classes (neutral, additive, and multiplicative) with two functors (additive->neutral, multiplicative->neutral) to connect them[1].[...]
[1] the Exp/Log isomorphism between additive and multiplicative are not considered here, as there are good arguments both for using newtypes and for not using them.
Of course, I mean "functor" in the category theoretic sense (monoid homomorphisms, in this case). Not in the type class sense, per se (though all newtypes are/can be Functors). -- Live well, ~wren