On Apr 13, 2014, at 12:48 AM, Stefan Behnel <stefan...@behnel.de> wrote:
> Stefan Behnel, 12.04.2014 19:11: > > So, what I've learned from seven years of Cython is that static typing in > signatures is actually less interesting than you might think at first > sight. It might be ok for documentation purposes, although its verboseness > makes that also a bit questionable. You raise a valid point that type hinting a dict instead of a Mapping is likely to create an overly limiting API. This sort of error is however quite easy to fix forward. To counter, we’ve had multiple data points during the summit suggesting that duck typing is not really that often used in production code. In other words, after initial prototyping and testing, an API of a callable gets settled and is later used with a very limited number of types. Of course, fuzzy terms like “often”, “seldom”, and “limited” suggest that we don’t have hard data here. That being said, there is a clear need to improve our ability to lint code, refactor code easier, and document the contracts better. This has been voiced by various conference attendees and the consensus is tremendous. Moreover, this need has been proven by owners of large codebases like Google, Facebook, and Microsoft by creating optionally typed variants of known dynamic languages (namely Dart, Hack and TypeScript). For Python specifically the existence of prototypes like Mypy, obiwan, or pytypedecl shows that there is growing interest in standardizing this functionality. Therefore, I'm drafting a PEP for opt-in type hints with optional checks at runtime and by static analysis. Will post the initial form in the upcoming days, and then we can go paint that bike shed. I'm aware that great care here is needed for the outcome to feel Pythonic and not overwhelming. Don't worry before you get your hands on the draft, though. -- Best regards, Łukasz Langa WWW: http://lukasz.langa.pl/ Twitter: @llanga IRC: ambv on #python-dev _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
