Printable data types

[wilbowma]

I want support for making numbers print like numbers. I can redefine #%datum to get numbers to read like numbers, but want vice versa. Some kind of interface to gen:printable?

[stchang]

gen:printable would work for runtime. During typechecking, we're printing stx objects, which do not work with gen:printable. That's why we have the generic type methods. Overloading the resugar-type method might work. Do you have an example in mind?

[wilbowma]

I'd probably want both. I'm working through my demo, and after I define #%datum for the naturals, I type 0 in the REPL and (z) get printed. This is .. okay. Might even be good most of the time. But I'd like to be able to make it print 0.

[stchang]

Ok, gen:print is fine for the repl. Though define-type currently doesnt let you get at the internal struct definition. We should probably open a separate ticket for Turnstile to do that.