Ah, yes, you are right, I didn’t think of configuring delegates when the 
delegate ist set.

-Thorsten


> Am 22.04.2016 um 19:04 schrieb David Waite <[email protected]>:
> 
> Sure, but I personally want to configure delegates early, when the delegate 
> is set.
> 
> It may be inappropriate to send a synthetic message through (e.g. give me the 
> table row height for arbitrary index -1 so I can detect if you have 
> overridden behavior)
> 
> A default implementation may help the caller, but some API do consider a 
> non-default implementation to be a flag in itself.
> 
> I don’t think you can meet current objective-c usage and meaning of optional 
> protocols by collapsing the flag into default method behavior. This would 
> cause problems when porting the objective-c caller of the delegate interface 
> to swift.
> 
> -DW
> 
>> On Apr 22, 2016, at 10:01 AM, Thorsten Seitz <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> We could require optional methods which would return T to instead return 
>> OptionalResult<T> which is essentially an enum with values 'unimplemented' 
>> and 'implemented(T)', i.e. essentially the same as Optional but as a 
>> separate type to avoid confusion when the real result would be 'T?'.
>> 
>> Default implementations would answer 'unimplemented'.
>> 
>> This would require the caller to handle the unimplemented default case 
>> explicitly.
>> 
>> -Thorsten 
> 

_______________________________________________
swift-evolution mailing list
[email protected]
https://lists.swift.org/mailman/listinfo/swift-evolution

Reply via email to