[Python-ideas] Fwd: Define a method or function attribute outside of a class with the dot operator

Random832 random832 at fastmail.com
Sat Feb 11 15:17:41 EST 2017

On Sat, Feb 11, 2017, at 00:33, Greg Ewing wrote:
> Chris Angelico wrote:
> > Which is why these proposals always seem to gravitate to "anything you
> > can assign to",
> There might be some parsing difficulties with that, e.g.
>     def foo(x)[5](y, z):
>        ...
> That should be acceptable, because foo(x)[5] is something
> assignable, but foo(x) looks like the beginning of the
> definition of a function called foo. I'm not sure whether
> the parser would cope with that.

We could require parentheses to be used anywhere the grammar otherwise
couldn't handle it, like yielding a tuple from a generator expression.

def (whatever)(args):

This does raise the question though of what the function's name/qualname
would be. It's cosmetic, but it's also the only real difference between
def and an assignment *now*, so it's worth considering. In the case
where the last element of the expression is an attribute, the name would
simply be the attribute, but would the class portion of the qualname
(and the name when it's not an attribute) need to depend on the runtime
value of what is being assigned, or would it simply use a string of
exactly "foo(x)[5]"?

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