[swift-users] try? priority

[Zhao Xin]

I encountered similar issue today too.

My code was like

if try? bookmarkPlistURL.checkResourceIsReachable() ?? false {

    ....

}


And the IDE (Xcode) wrongly suggests me to change try? to try!, which I did
and my app crashed when `throws`. The only right approach is to change code
to


if (try? bookmarkPlistURL.checkResourceIsReachable()) ?? false {


Besides, if you chose to use an indicator, Xcode would kindly tell you the
`?? false` part would never run.


let foo = try? bookmarkPlistURL.checkResourceIsReachable() ?? false // Left
side of nil coalescing operator '??' has non-optional type 'Bool', so the
right side is never used


So the behavior is on purpose? I just want to learn if anyone can tell me
why?


Zhaoxin

On Thu, Aug 4, 2016 at 10:38 PM, J.E. Schotsman via swift-users <
swift-users at swift.org> wrote:

> I was surprised when I got a compiler error for this code:
>
> if try? MyThrowingFunction() != nil {…}     (MyThrowingFunction does not
> return an optional value)
>
> This compiles:
>
> if (try? MyThrowingFunction) != nil {…}     (Xcode 7.3.1)
>
> Shouldn’t try? have higher priority than != here?
>
> Please disregard if this is changed in Swift 3
>
> Jan E.
> _______________________________________________
> swift-users mailing list
> swift-users at swift.org
> https://lists.swift.org/mailman/listinfo/swift-users
>
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