[didibus]

I don't know that you can really call this a bug? It just seems to be the design choice. Though I agree, it seems odd at first, and appears possibly accidental, it could have been on purpose.

My question to swifters: what if LazyGreeter had another method, say lazyGreet, and you typed it as Greeter? Then you called let greeter : Greeter = LazyGreeter(); greeter.lazyGreet();

Would you expect this to work or fail?

I'd expect it to fail.

In that sense, I assume its simply that extension methods override child overrides. And its just something you need to know. That can even have interesting utility in some scenarios.

[syrrim]

In python, `greeter.lazyGreet()` would succeed, because python only has types at runtime. If you used mypy, you would get a warning for this. No warning would be issued for `greeter.greet()`, but since function dispatch is still done at runtime, this would call `LazyGreeter.greet()`.

I concur that the behaviour is a design decision, not a bug, but I think most programmers would in general prefer design decisions to bring the language closer to python.

[nangtrongvuon]

I’m just a wee lad still dabbling in Swift, but I would say this would work, since the lazyGreet method is separate from the Greeter protocol.