>From what I understand, enums normally are represented internally by an offset >— that is their truth. With RawRepresentable enums, you are saying “no, I want >the truth to be something else”. But it seems that they are still represented >internally by an offset, so you can’t reorder a RawRepresentable enum’s cases >and maintain ABI compatibility either.
So what you are saying about the order of cases being an intrinsic part of an enum does make sense. I’m not sure if can still lead to confusing / fragile code though. Patrick > On 2 Jun 2016, at 10:17 PM, Leonardo Pessoa <[email protected]> wrote: > > There are several ways to solve this, which IMO is a basic functionality of > enums, writing code that is currently possible and works. But that's the > issue, you still have to write code to have a basic functionally. I don't > remember not being able to do this out-of-the-box in any language I worked > with. > > L > From: Patrick Smith <mailto:[email protected]> > Sent: 02/06/2016 02:07 AM > To: Brent Royal-Gordon <mailto:[email protected]> > Cc: Leonardo Pessoa <mailto:[email protected]>; swift-evolution > <mailto:[email protected]> > Subject: Re: [swift-evolution] Working with enums by name > > Great points Brent. I think the ValuesEnumerable method would be the most > straight forward. Also, the number of cases are likely only going to be in > range of 6–20, so iterating would be fine I think. People can create > something like `Dictionary(Planet.allValues.enumerated().lazy.map{ ($1, $0) > })` (I think that’s right) if they really need. > > > > On 2 Jun 2016, at 2:40 PM, Brent Royal-Gordon via swift-evolution > > <[email protected]> wrote: > > > > Or the `ValuesEnumerable` proposal would give you a convenient, though > > slightly slow, way to do two-way lookup by order: > > > > enum Planet: String, ValuesEnumerable { > > var order: Int { > > return Planet.allValues.index(of: self)! > > } > > init(order: Int) { > > self = Planet.allValues[order] > > } > > case mercury, venus, … > > } >
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