Do you have an example for kind-classes? Keean.
On 9 January 2015 at 07:46, Jonathan S. Shapiro <[email protected]> wrote: > On Thu, Jan 8, 2015 at 11:26 PM, Keean Schupke <[email protected]> wrote: > >> The alternative here is to push int2 into a dynamic scoping stack for >> this instance so it overrides int1. This is probably more useful as it >> allows local changed to type-class resolution. >> > That was pretty much the intention of my original example, except I'm not > sure why you say this is a *dynamic* scoping thing. My intent was that the > "using" construct should operate on the instance environment in much the > way that the "let" construct operates on the binding environment, and that > instance resolution should proceed according to the customary lexical > resolution rules by resolving required instances at the call site against > the instance environment. > > But I'm still failing to see why this renders anything incoherent. An > instance is acting here as something very like a type parameter to the > called procedure. By virtue of its presence, it induces a type-driven > specialization of the procedure that is called. > > At the tail end of your "record lifting" email you note that instances > only have to be coherent where they are implicit. If so, then it sounds > like we are in agreement that explicit instance overrides which induce > quasitype-driven specialization do not entail any coherence problems. Are > we? > > I do agree that records and type classes seem suspiciously similar, but I > wonder how that intuition will hold up as we start talking about kind > classes... > > > shap > > _______________________________________________ > bitc-dev mailing list > [email protected] > http://www.coyotos.org/mailman/listinfo/bitc-dev > >
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