On Fri, Oct 8, 2021 at 1:45 PM S Pradeep Kumar <gohan...@gmail.com> wrote: > The Callable type is also usable as an expression, like in type aliases > `IntOperator = (int, int) -> int` and `cast((int) -> int, f)` calls. > > **Question 1**: Are there concerns we should keep in mind about such a syntax > proposal? >
Either I'm reading this wrongly, or this is oddly inconsistent with tuples. With a tuple, it's the comma that defines it; with function parameters here, it looks like the parentheses are mandatory, and they are what define it? Which of these will be valid? x = int -> int y = int, int -> int # tuple containing (int, Callable) or function taking two args? z = (int,) -> int Given the examples you've shown, my intuition is that it should match def statement syntax - namely, the args are always surrounded by parentheses, a trailing comma is legal but meaningless, and it has nothing to do with tuple display. It would be very convenient for one-arg functions to be able to be defined the way x is, and I suspect people will try it, but it introduces annoying ambiguities. There are parallel proposals to support a lambda syntax like "x => x.spam" as equivalent to "lambda x: x.spam", so I'm curious what the rules would be for the two types of arrows, and whether they'd be consistent with each other. ChrisA _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/KIQQEIOC2D4INNAAIYWC6HH7GXPZWLXH/ Code of Conduct: http://python.org/psf/codeofconduct/
