I agree it’s overkill for what I’m really looking for, which is a simple way to get a Bool result from testing an enum against a specific case, without looking at the associated values.
Andy > On Jan 18, 2017, at 10:15 AM, Tony Allevato <tony.allev...@gmail.com> wrote: > > FWIW, I'm not convinced that making enum values look like structs with > optional properties for the union of all their cases is a good idea. It's > certainly not something I would want added to all of my enums by default, and > it feels IMO like it's just an awkward hack around the fact that pattern > matching is a bit verbose in some scenarios because Swift doesn't provide a > case-expression to let you test/bind as part of a larger expression. > > > On Wed, Jan 18, 2017 at 10:08 AM Andy Chou via swift-evolution > <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: > That’s an interesting proposal. Here’s a link for reference: > https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160926/027287.html > > <https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20160926/027287.html> > > The one thing is the proposed syntax doesn’t handle enum cases without > payloads. I think that could be handled by an optional Void, so this comment > in the original proposal: > > > Only enum cases with a payload can be used with this syntax (it would make > > no sens for cases without a payload). > > Would be changed to allow for empty payloads turning into Void?. For example: > >> enum Result { >> case success(Int) >> case failure >> } >> >> let r: Result = foo() >> >> let x: Int? = r.success >> let y: Void? = r.failure >> >> assert(r.success == Optional(42)) >> assert(r.failure == nil) > I think it’s a reasonable compromise, though I still think it’s a bit awkward > for the common case. Looks like this is being postponed for now, so we’ll > have to live with the alternatives. > > Andy > > >> On Jan 18, 2017, at 12:20 AM, Anton Zhilin <antonyzhi...@gmail.com >> <mailto:antonyzhi...@gmail.com>> wrote: >> >> AFAICS, Andy needs not default implementations of Equatable, but >> cases-as-optional-properties—this topic has also been discussed on the list. >> >> enum Result { >> case success(Int) >> case failure(String) >> } >> >> let r: Result = foo() >> >> let x: Int? = r.success >> let y: String? = r.failure >> >> assert(r.success == Optional(42)) >> assert(r.failure == nil) > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org <mailto:swift-evolution@swift.org> > https://lists.swift.org/mailman/listinfo/swift-evolution > <https://lists.swift.org/mailman/listinfo/swift-evolution>
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