[swift-evolution] Keyword for protocol conformance

[Charles Srstka]

> On Aug 23, 2016, at 2:33 PM, Robert Widmann via swift-evolution <swift-evolution at swift.org> wrote:
> 
> 2016/08/22 14:30、David Cordero via swift-evolution <swift-evolution at swift.org <mailto:swift-evolution at swift.org>> のメッセージ:
> 
>> 
>> The problem:
>> At the moment, looking at the code of a class or a struct implementing a protocol, it is hard to know what methods are actually implementing the protocol and what other methods are just part of the code of the class or struct.
>> 
> 
> That seems like a feature, not a bug.  Why should I as an author care whether a method contributes to a protocol conformance or not if the compiler can tell me that kind of information itself?

Being able to reason about your code, what it does, and what it’s for is undesirable?

>> ```
>> protocol MyProtocol {
>>     func myMethod() -> String
>> }
>> 
>> class MyClass: MyProtocol {
>> 
>>     conform func myMethod() -> String {
>>         return "Yuhuuu,I am conforming \\o//"
>>     }
>> 
>>     func whatever() {
>>         print("I am a boring method and I don't conform anything")
>>     }
>> }
>> ```
>> 
>> It would be something similar to the current keyword `override` but for protocols. 
>> 
>> Apart from improving code readability, It would allow the detection, in compilation time, of errors due to code evolution. For example redundant methods that no longer conform anything once the requirement is removed from the protocol for whatever reason.
> 
> If you make a breaking change to a protocol like this, you should have gone through a deprecation cycle to indicate to your clients the appropriate changes you're going to make to the protocol.  This aspect of the change seems to if not encourage, highlight, bad behavior.

What if it’s your own code and all the callers are internal? What if you’re still developing the protocol and haven’t released the API interface yet?

Charles

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20160823/e611c268/attachment.html>