Date: Wed, 14 Apr 2021 11:24:12 +0200 From: Antoine Pitrou <antoine@python.org> Subject: [Python-Dev] Re: Typing syntax and ecosystem

Can you explain why you think C++ typing is based on structural equivalence?

I'd rather not have a detailed discussion of C++ typing on python-dev. My example was Ada style type equivalence by name only, in contrast to Java/C++ style type checking which AFAIK is called "structural equivalence". But if you use another term, it won't matter. My point is that sometimes people have argued that the type checker shouldn't be part of the Python interpreter because we're not sure about the best approach and need to have freedom to experiment. I don't think that is still true. Some type system choices, such as equivalence by name only, have already been effectively ruled out. And there's now so much code already annotated assuming the Java/C++ style that I don't think a different type scheme checking can replace it. We've chosen the type scheme for Python (although there may be some fine details to do) and now we're just working on the implementation aspects. Travelling for a few days, so this is probably a good place to stop on. Thank you everybody for responding. -- cheers, Hugh Fisher