[swift-users] 'Error' is ambiguous for type lookup in this context

Shawn Erickson shawnce at gmail.com
Wed Sep 7 23:22:05 CDT 2016


You are implementing function defined in the WCSessionDelegate so that your
AppDelegate can be called by WCSession as things happen. It calls your
implementation and supplies it with an error is one exists (e.g. an error
happened).

It doesn't make sense for this function (the one you implement) to throw
since you aren't returning an error to the caller (WCSession) but instead
potentially getting an error from the caller (WCSession).

-Shawn

On Wed, Sep 7, 2016 at 8:53 PM Zhao Xin <owenzx at gmail.com> wrote:

> I also have a question on this API
> ‚Äč`func session(_ session: WCSession, activationDidCompleteWith
> activationState: WCSessionActivationState, error: Error?)`. Why did it use
> `throws`? The other APIs, which use NSError in Objective-C, change to
> throws in Swift counterpart.
>
> Zhaoxin
>
> On Thu, Sep 8, 2016 at 10:52 AM, Shawn Erickson <shawnce at gmail.com> wrote:
>
>> For one RealmSwift should likely consider changing their enum cases to
>> use lowerCamelCase like Swift 3 did. Also at some point it should consider
>> the changes to NSError / Swift.Error bridging.
>>
>> -Shawn
>>
>> On Wed, Sep 7, 2016 at 7:18 PM Zhao Xin via swift-users <
>> swift-users at swift.org> wrote:
>>
>>> When I use RealmSwift in my project, I got an alert " 'Error' is
>>> ambiguous for type lookup in this context".
>>>
>>> import UIKit
>>>
>>> import UserNotifications
>>>
>>> import WatchConnectivity
>>>
>>> import RealmSwift
>>>
>>>
>>> extension AppDelegate:WCSessionDelegate {
>>>
>>>     func session(_ session: WCSession, activationDidCompleteWith
>>> activationState: WCSessionActivationState, error: Error?) {
>>>
>>>
>>>     }
>>>  }
>>>
>>>
>>> I think the reason is that in Swift, Error is a protocol. And in
>>> RealmSwift, there is a `case Error(NSError)` in `public enum
>>> RealmCollectionChange<T>`.
>>>
>>>
>>> I managed to eliminate the alert buy change `Error?` to `Swift.Error?`.
>>> Are there any other ways to fix this?
>>>
>>>
>>> Zhaoxin
>>> _______________________________________________
>>> swift-users mailing list
>>> swift-users at swift.org
>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>
>>
>
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