[swift-evolution] Guaranteed closure execution

[Andrew Bennett]

Sorry I missed that scrolling back through the history, that proposal looks
great. It doesn't look like it has been submitted as a pull request to
swift-evolution yet though.

On Sunday, 10 April 2016, Gwendal Roué <gwendal.roue at gmail.com> wrote:

> Felix Cloutier already wrote one:
> https://github.com/zneak/swift-evolution/blob/master/proposals/00xx-noescape-once.md
>
> Do you think it needs to be rewritten?
>
> Gwendal Roué
>
> Le 10 avr. 2016 à 14:56, Andrew Bennett <cacoyi at gmail.com
> <javascript:_e(%7B%7D,'cvml','cacoyi at gmail.com');>> a écrit :
>
> Hi, not beyond this thread that I have seen. I think it's worth you
> summarizing this thread in a formal proposal and putting it up for
> discussion or submitting it as a PR :)
>
> On Sunday, 10 April 2016, Gwendal Roué <swift-evolution at swift.org
> <javascript:_e(%7B%7D,'cvml','swift-evolution at swift.org');>> wrote:
>
>> Hello all,
>>
>> I was wondering if this topic had evolved in anyway since its original
>> introduction.
>>
>> @noescape(once) would still be a useful addition to the language!
>>
>> Gwendal Roué
>>
>>
>>
>> Le 3 févr. 2016 à 22:21, Félix Cloutier via swift-evolution <
>> swift-evolution at swift.org> a écrit :
>>
>> I updated the proposal to address some concerns. It can be found at:
>> https://github.com/zneak/swift-evolution/blob/master/proposals/00xx-noescape-once.md
>>
>> Things that changed:
>>
>>
>>    - It now says that the closure must be called on code paths where the
>>    function throws;
>>    - you can have multiple @noescape(once) parameters but they can't
>>    make assumptions from one another.
>>
>>
>> I'm not 100% convinced that forcing a call on code paths that throw is
>> always desirable. I've changed it because Chris's support probably means
>> that the feature has better chances of making it, but I'm not convinced
>> yet. If throwing allows me to return without calling the closure, I can
>> write this:
>>
>> do {
>> let foo: Int
>> try withLock(someLock, timeout: 0.5) {
>> foo = sharedThing.foo
>> }
>> } catch {
>> print("couldn't acquire lock fast enough")
>> }
>>
>> which would be kind of messy if instead, the closure needed a parameter
>> to tell whether the lock was acquired or not when it runs.
>>
>> Félix
>>
>> _______________________________________________
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>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>>
>>
>
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