> On Jun 1, 2016, at 12:53 PM, Paul Cantrell via swift-evolution
> <[email protected]> wrote:
>
> Indeed, you’re quite right: verified that I get “Mars” even when the enum is
> in a framework.
>
> It took a little digging to get back what I was thinking of: it’s when the
> enum value is inside some other data structure that you get an annoyingly
> fully qualified name:
>
> enum CoinSide {
> case heads
> case tails
> }
>
> enum CoinState {
> case inAir
> case landed(showing: CoinSide)
> }
>
> print(CoinState.inAir) // → "inAir"
>
> // …but…
>
> print(CoinState.landed(showing: .heads)) // → "landed(CoinSide.heads)"
>
> print([CoinSide.heads: 1]) // → "[CoinSide.heads: 1]"
>
> This is the case I was thinking of where the module name comes into play.
> Drop those enums into a framework, and you’ll get
> "landed(MyFramework.CoinSide.heads)". Ugh!
This seems to be more of namespace “import” issue than a problem with enums
specifically. Declaring enums within another entity is a useful. I take
advantage of qualified naming to make short, possibly non-unique enum names.
>
> So what if you want those second two to print out as "landed(heads)" and
> "[heads: 1]”? This does not work:
>
> enum CoinSide: CustomStringConvertible {
> case heads
> case tails
>
> var description: String {
> return String(self) // infinite recursion
> }
> }
>
> There’s no automatically implemented description (or debugDescription)
> property we can delegate to. The conversion of .heads → "heads" is
> apparently runtime magic that we lose access to as soon as we implement
> CustomStringConvertible or CustomDebugStringConvertible, and therefore AFAIK
> there's no way to do this other than switching on all the cases:
>
> enum CoinSide: CustomStringConvertible {
> case heads
> case tails
>
> var description: String {
> switch(self) {
> case heads: return "heads"
> case tails: return "tails"
> }
> }
> }
>
> Is is true that there’s no better way? Is there some
> CustomVerboseDebugStringConvertible protocol we can override to change only
> the "MyFramework.CoinSide.heads" form?
>
> If indeed there is no better way, it seems like a really good case for having
> the synthesized .caseName property. Even if there is a
> CustomVerboseDebugStringConvertible to override in the particular case above,
> being able to customize an enum’s description but still use the enum case
> name in that description seems like a compelling use case as well.
>
> Cheers, P
>
>> On Jun 1, 2016, at 10:47 AM, Leonardo Pessoa <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Paul, in all my tests for this thread printing the enum value only
>> produced the enum value's name ("Mars" in your example). The proposal
>> of having a .caseName (or should it better be .caseValue to cover
>> enums with associated values? any other suggestions?) will prevent
>> that changes to this behaviour crash apps in the future as this should
>> always produce the same result even if the string representation
>> changes.
>>
>> L
>>
>> On 1 June 2016 at 12:15, Paul Cantrell via swift-evolution
>> <[email protected] <mailto:[email protected]>> wrote:
>>> IIRC, string interpolation prepends the module name if the enum belongs to
>>> a module: “MyLib.Mars” instead of just “Mars”. It’s also been a source of
>>> compiler crashes, at least in the past.
>>>
>>> Those two factors forced me into this ugliness:
>>> https://github.com/bustoutsolutions/siesta/blob/master/Source/ResourceObserver.swift#L106-L115
>>>
>>> <https://github.com/bustoutsolutions/siesta/blob/master/Source/ResourceObserver.swift#L106-L115>
>>>
>>> A clean, documented, supported way of exposing the enum case name that the
>>> runtime clearly already has available seems sensible — and should be
>>> independent of the raw type.
>>>
>>> Cheers, P
>>>
>>>> On Jun 1, 2016, at 5:10 AM, Charlie Monroe via swift-evolution
>>>> <[email protected]> wrote:
>>>>
>>>> This is, however, kind of a hack IMHO that relies on the compiler behavior
>>>> that isn't well documented.
>>>>
>>>> For example, this:
>>>>
>>>> enum Planet {
>>>> case Earth
>>>> case Mars
>>>> }
>>>>
>>>> "\(Planet.Mars)" // This is "Mars"
>>>>
>>>>
>>>> Works as well. You don't need to have the represented value to be String.
>>>>
>>>> Note that this:
>>>>
>>>> - works both when you have a plain enum, or enum Planet: Int, or whatever
>>>> raw value kind
>>>> - does not work (!) when declared as @objc - then the result is "Planet".
>>>>
>>>>> On Jun 1, 2016, at 9:52 AM, Patrick Smith via swift-evolution
>>>>> <[email protected]> wrote:
>>>>>
>>>>> I had no idea you could do this!!
>>>>>
>>>>>> On 1 Jun 2016, at 12:32 PM, Brent Royal-Gordon via swift-evolution
>>>>>> <[email protected]> wrote:
>>>>>>
>>>>>> Who said anything about repeating the name?
>>>>>>
>>>>>> Welcome to Apple Swift version 2.2 (swiftlang-703.0.18.8
>>>>>> clang-703.0.30). Type :help for assistance.
>>>>>> 1> enum Planet: String { case mercury, venus, earth, mars, jupiter,
>>>>>> saturn, uranus, neptune }
>>>>>> 2> Planet.mercury.rawValue
>>>>>> $R0: String = "mercury"
>>>>>
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