[swift-users] @noReturn

[Saagar Jha]

By the way, return Never used to be called @noreturn, so you weren't far
off!
On Fri, Mar 24, 2017 at 02:22 Rien via swift-users <swift-users at swift.org>
wrote:

> Excellent!
>
> Love this list ;-)
>
> Regards,
> Rien
>
> Site: http://balancingrock.nl
> Blog: http://swiftrien.blogspot.com
> Github: http://github.com/Balancingrock
> Project: http://swiftfire.nl
>
>
>
>
>
> > On 24 Mar 2017, at 10:12, Philip Erickson <philiperickson at gmail.com>
> wrote:
> >
> > I believe returning Never does what you want, e.g.
> >
> >
> > import Foundation
> >
> > func findReasonAndTerminate() -> Never
> > {
> >    let reason: String = findReason()
> >    fatalError(reason)
> > }
> >
> > func findReason() -> String
> > {
> >       return "some reason"
> > }
> >
> > func buildData() -> Data?
> > {
> >       return nil
> > }
> >
> > guard let data = buildData() else { findReasonAndTerminate() }
> >
> >
> > On Fri, Mar 24, 2017 at 3:02 AM, Rien via swift-users <
> swift-users at swift.org> wrote:
> > Is there any way to mark a function as “no return”?
> >
> > Reason: The compiler generates an error when the else block from a guard
> does not terminate the execution by either a return or a fatalError. I want
> to call out to a function and raise the fatalError in that function.
> >
> > func findReasonAndTerminate() {
> >    let reason: String = ….
> >    fatalError(reason)
> > }
> >
> > main.swift:
> >
> > guard let data = buildData() else { findReasonAndTerminate() }
> >
> >
> > Currently the work around is to add another fatalError like this:
> >
> > guard let data = buildData() else { findReasonAndTerminate(); fatalError
> }
> >
> >
> > but it would be nice to have some attribute like @noReturn:
> >
> > @noReturn
> > func findReasonAndTerminate() { … }
> >
> >
> > Regards,
> > Rien
> >
> > Site: http://balancingrock.nl
> > Blog: http://swiftrien.blogspot.com
> > Github: http://github.com/Balancingrock
> > Project: http://swiftfire.nl
> >
> >
> >
> >
> >
> > _______________________________________________
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> > swift-users at swift.org
> > https://lists.swift.org/mailman/listinfo/swift-users
> >
>
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>
-- 
-Saagar Jha
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