Sent from my iPad
> On May 10, 2016, at 5:41 PM, Timothy Wood <[email protected]> wrote: > > >> On May 10, 2016, at 2:01 PM, Chris Lattner via swift-evolution >> <[email protected]> wrote: >> That said, I’m not sure I understand the concrete use-cases. When is this >> concept important? When is “Self” not good enough? > > From my old mail on the subject: > >> I would love to see a way to get the type of the "enclosing thing at compile >> time”. In my particular case, I’m using the type as a generic parameter to >> tag a created resource with something like: >> >> class Client: PropertyOwner { >> let intProperty = Client.property(“name”, Int(0)) >> } >> >> where PropertyOwner has a static property<Owner, DataType>(...) >> >> With `Self` meaning the static version of the thing being compiled, I could >> at least write: >> >> class Client: PropertyOwner { >> let intProperty = Self.property(“name”, Int(0)) >> } >> >> which would have the benefit of being harder to mess up due to copy-pasting >> between different PropertyOwner implementors. > > > and > >> I was thinking about the syntax a bit further and it seems like the >> capability that would be added is like #file, in that it does some >> compile-time textual replacement. So, perhaps #Self would work? >> >> Also, along these lines, I would find use for call-site interpolation like >> #file has. I could then do a free function version of my property() call >> that was something like: >> >> func property(ownerType: PropertyOwner.Type = #Self, ...) { } >> >> which would only be callable from w/in things conforming to or subclassing >> PropertyOwner. Ahh, this is different than what I have been talking about as it statically evaluates at the call site rather than the declaration site. Sorry, I think I missed your earlier post. One question about this - how would it work if this method was called in a lexical con txt without an enclosing type declaration? Would that be an error or would it just require a parameter to be passed? If we call what I am talking about Type and we also want this behavior we should call it #Type as it would be the static type at the call site. But they are separate ideas and should be separate proposals. > > > -tim >
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