3.9: Remove docstring shenanigans from events

[AstraLuma]

Python 3.9.0 changed the way docstrings are searched, which I believe means we no longer need the dynamic type shenanigans in xonsh.events.

[scopatz]

Oh, that would be nice!

[jnoortheen]

@AstraLuma could you explain what has been changed a bit?

[AstraLuma]

From the 3.9 changes:

The documentation string is now shown not only for class, function, method etc, but for any object that has its own doc attribute. (Contributed by Serhiy Storchaka in bpo-40257.)

[jnoortheen]

Ok. I don't see dropping 3.8 anytime soon. Though I find this following pattern very easier to read and reason with.

# any new event can create an empty function with the correct signature
def autovox_policy(path: "Path") -> "str|Path|None":
    """
    Register a policy with autovox.
    Parameters
    -----------
    ...
    """

# we can then use this register function to wrap `EventManager.doc`
    def register(self, func):
        """
            wraps ``EventManager.doc``

        Parameters
        ----------
        func
            extract name and doc from the function
        """

        name = func.__name__
        doc = inspect.getdoc(func)
        sign = inspect.signature(func)
        return self.doc(name, f"{name}{sign}\n\n{doc}")

I have this locally and planning to create a PR later.

[AstraLuma]

Yeah, I thought about doing a function-based version of event definition as well. But the existing system was already established and I didn't think the incremental improvement over it was worth it.

[jnoortheen]

I want to create an entrypoint based xontrib loading mechanism. Where I want to remove any global access. It would be helpful in that time.

[AstraLuma]

Not all event handlers come from xontribs.