Oh! Yeah, my bad... You are correct; I'd started thinking like I was on -evolution instead of -users.
> On Oct 19, 2017, at 1:29 PM, Itai Ferber <ifer...@apple.com> wrote: > > Mm, the point I’m trying to get at here is that JSON is inherently untyped > while Swift is strongly typed, and the two don’t line up. > It doesn’t really make sense to ask to decode an existential because there’s > not enough type information to influence what you get back. > > On 19 Oct 2017, at 13:20, David Sweeris wrote: > > I think if you can figure that out, you’re halfway to letting protocols > conform to themselves. > > (Syntactically, I would probably say that something like “Codable.Self” would > read well, but I think that already means something. Maybe the answer will > become clearer when we rework the reflection APIs?) > > Sent from my iPhone > > On Oct 19, 2017, at 13:13, Itai Ferber <ifer...@apple.com > <mailto:ifer...@apple.com>> wrote: > >> Even then, that wouldn’t necessarily help in the general case. If you decode >> {"key" : 1} as [String : Codable], what concrete type would 1 have? Int? >> Double? Int8? (Arguments can be made for any one of these, but the key here >> is that it is inherently ambiguous and there isn’t necessarily a good >> answer.) >> >> On 19 Oct 2017, at 12:57, David Sweeris wrote: >> >> On Oct 19, 2017, at 12:50 PM, David Baraff via swift-users >> <swift-users@swift.org <mailto:swift-users@swift.org>> wrote: >> >> Yes; this is a case where anywhere in the code base I want to just say >> struct MyNewType : Codable { >> // add codable datatypes >> } >> >> and don’t want/can’t always go to the centralized place to add it in. >> Is there some extension-like trick I can pull off that lets me spread the >> implementation out over different files/libraries? >> >> Ah, ok. >> >> No, I don't think you'll be able to do that until/unless Swift gets more >> macro/metaprogramming features. Maybe if protocols ever get to conform to >> themselves? That's a common request, but implementing it is apparently >> beyond tricky. I'm pretty sure somebody's working on it, but "bigger fish" >> and all that... >> >> - Dave Sweeris >> >
_______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
