On Mon, Feb 10, 2020 at 9:50 AM Andrew Barnert via Python-ideas <python-ideas@python.org> wrote: > It’s a well-known problem that async is “contagious”: [...] > > But C# and every other language that’s borrowed the idea has the same > problem, and as far as I know, nobody’s thought of a good answer yet.
Threads don't have that problem: you can use non-thread-aware code with callbacks in your threaded program if you do your own locking. Haskell (GHC) doesn't have that problem: it has fibers that use a programming interface like C#/Python threads, but they're multiplexed by user-mode code within a single OS thread. 16-bit Windows didn't have that problem. Stackless and greenlet don't have that problem. It's a problem that can be solved by just doing the obvious thing, the thing that Python already did with threads: don't define a novel syntax for coroutines, but instead use the syntax that already existed. Async/await syntax is a static type system with two types, may-yield and will-not-yield. There's no provision for writing generic/polymorphic code over those types, so you have to write everything twice. Like any static type system it has some benefits, but I don't think it's worth the cost, especially in Python, which has always eschewed mandatory static typing. I don't know how to fix Python now that it's gone so thoroughly down this path (starting with the yield keyword 18 years ago). But it's not a problem that ever needed to exist. Coroutines aren't that hard. -- Ben _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/ZDQIZ5ORHLOEQO7OD2FTZNYPUSXMUTUU/ Code of Conduct: http://python.org/psf/codeofconduct/
