> On Dec 23, 2015, at 3:35 PM, Joe Groff via swift-evolution
> <swift-evolution@swift.org> wrote:
>
>>
>> On Dec 23, 2015, at 10:16 AM, Andrew Duncan via swift-evolution
>> <swift-evolution@swift.org> wrote:
>>
>> In fact, I feel the same way too. I have definite views about indefinite
>> pronouns. When I am teaching, I studiously avoid “it”, “this”, and “that”:
>> at any given instant half the students have wandering minds, and if they
>> miss the referent, they get lost. My old HyperTalk habits must be
>> resurfacing with “it”. :)
>>
>> I still think the use case is valuable as a (natural IMHO) generalization of
>> guard, and feel the annoyance of having the bound variable show up three
>> times and outlast the guard, when I don’t want to use or even see it.
>> Brent’s suggestion removes the second objection and alleviates the first;
>> I’ll see that, but ask if we can raise it. The pitch is:
>>
>> guard case let .Succeed(m) = returnsResult() else let r {
>> return r
>> }
>>
>> Improvement! The question is: can we reduce this by one or two ‘r’s?
>
> A slight generalization would be to allow for an arbitrary pattern in the
> `else` clause:
>
> guard case let .Succeed(m) = returnsResult() else case let .Failure(r) {
> return r
> }
>
> with the requirement that the "guard" and "else" patterns form an exhaustive
> match when taken together. That feels nicer than special-case knowledge of
> two-case enums, though I admit it punishes what's likely to be a common case.
I thought a bit about that. Would it make sense to support multiple else blocks?
guard case let .Succeed(m) = returnsResult()
else if case .Failure("Temporary Failure") {
return retry()
}
else case let .Failure(r) {
return r
}
--
Brent Royal-Gordon
Architechies
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