[Python-ideas] Fixing class scope brainstorm

[Joao S. O. Bueno]

>
> Honestly that sounds way too complex. In my ideal world, only functions
> defined with 'def' are methods whose __get__ auto-binds the first argument
> (unless @classmethod or @staticmethod is present), and do not get to "see"
> the class scope. This is how you define methods after all. Lambdas used at
> class scope do not get this benefit, and they see the class scope as just
> another closure; ditto for comprehensions and genexprs.
>
> I don't think that the "is the call delayed" idea is the proper way to
> distinguish the two cases here. IMO the key concept is "is it used to define
> a method". I betcha if you see a lambda here it's because there's some
> calculation going on whose result will be stored as a class variable.


Nevertheless, treating lambdas differently from "def functions" in this context
alone can be complicated. Even if not the most intuitive thing on writing code,
everywhere else lambda s can't even be distinguished from "regular
functions" once
created. And I have created a lot of "one line methods"  as lambdas
over the years.
(that is a lot of code that would be broke with no reason). Even
calling "type" with a
couple "lambda" expressionsin the namespace parameter is something
very useful, and
might be crippled if lambda's can't be methods at all (although that
is a different context,
I don't think things should be changed at this point)


But there are two different things about lambdas in class bodies:

- enabling a lambda to "see" the outer class scope: that is ok, as it
would just make
things simpler, and won't break existing code, as this ability did not
exist before.

- preventing a lambda to become a method though its `__get__`: this breakes
stuff. As it is not incompatible with a lambda that can "see" the
class scope, I see no reason for doing that
(code might not work if a lambda with cell classes pointing to the class body,
but my feeling is that it would just work correctly if such cells are
permitted to start with)


  js
 -><-