[swift-evolution] Name disambiguation of computed property/function with same type defined in extensions

Jordan Rose jordan_rose at apple.com
Wed Jun 8 20:04:39 CDT 2016


> On Jun 8, 2016, at 12:02, Thorsten Seitz via swift-evolution <swift-evolution at swift.org> wrote:
> 
>> 
>> Am 07.06.2016 um 22:27 schrieb L Mihalkovic <laurent.mihalkovic at gmail.com <mailto:laurent.mihalkovic at gmail.com>>:
>> 
>>> 
>>> On Jun 7, 2016, at 9:47 PM, Thorsten Seitz <tseitz42 at icloud.com <mailto:tseitz42 at icloud.com>> wrote:
>>> 
>>> 
>>> 
>>> Am 07.06.2016 um 20:11 schrieb L Mihalkovic via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>>:
>>> 
>>>> T1 =======
>>>> import Lib1
>>>> var str = func2()	// lib1
>>>> 
>>>> T2 =======
>>>> import Lib1
>>>> import func Lib2.func2
>>>> var str = func2()	// lib2
>>> 
>>> Shouldn't func2() be ambiguous here? It is imported from Lib1 and from Lib2.
>>> 
>>> -Thorsten 
>> 
>> 
>> no, that is precisely the point .. it works!!  I am able to override whatever my laziness brought into scope from Lib1 (caused by my * import) with a meticulously chosen implementation from Lib2. It is brilliant. extensions on the other hand work differently (although something could undoubtedly be done about them, I cannot entirely convince myself that it is time well spent. It would be if that could be a stepping stone form something else (which I have not been able to identify so far).
> 
> So it is dependent on the order of the imports? That’s rather fragile IMO and I would prefer having to solve clashes explicitly independent of import order, e.g. by having to hide the version from Lib1:
> 
> import Lib1 hiding func2  // strawman syntax
> import func Lib2.func2

It doesn’t depend on the order, but it does consider naming a specific top-level value to be a “better” choice than importing the whole module, on the grounds that you wouldn’t have written it that way otherwise.

(I’ve been lukewarm on the entire feature of selective imports for a while since there are often a lot of helpers in the same module (think UITableView and UITableViewDataSource). We do seem to be gravitating towards making helper things nested, though (see SE-0086 <https://github.com/apple/swift-evolution/blob/master/proposals/0086-drop-foundation-ns.md>).)

This is getting a little off-topic from the problem of disambiguating members, though.

Jordan

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160608/4aad52fc/attachment.html>


More information about the swift-evolution mailing list