On 2021-06-21 8:42 p.m., Steven D'Aprano wrote:
> On Mon, Jun 21, 2021 at 02:54:52PM -0300, Soni L. wrote:
>
> > Quite the opposite. You ask the local module (the one that the code was
> > compiled in), and the module decides whether/when to ask the object itself.
> >
> > In other words, every
> >
> > foo.bar
> >
> > would be sugar for
> >
> > __getattr__(foo, "bar")
> >
> > (where __getattr__ defaults to builtins.getattr) instead of being sugar for
> >
> > <builtins.getattr>(foo, "bar")
>
> All you've done here is push the problem further along -- how does
> `__getattr__` (`__getattribute__`?) decide what to do?
>
> * Why is this extension-aware version per module, instead of a builtin?
>
> * Does that mean the caller has to write it in every module they want to
>   make use of extensions?
>
> * Why do we need a second attribute lookup mechanism instead of having
>   the existing mechanism do the work?
>
> * And most problematic, if we have an extension method on a type, the
>   builtin getattr ought to pick it up.
>
>
> By the way, per-module `__getattr__` already has a meaning, so this name
> won't fly.
>
> https://www.python.org/dev/peps/pep-0562/
>
>

No, you got it wrong. Extension methods don't go *on* the type being
extended. Indeed, that's how they differ from monkeypatching.

The whole point of extension methods *is* to be per-module. You could
shove it in the existing attribute lookup mechanism (aka the
builtins.getattr) but that involves runtime reflection, whereas making a
new, per-module attribute lookup mechanism specifically designed to
support a per-module feature would be a lot better.

Extension methods *do not go on the type*.

And sure, let's call it __opcode_load_attr_impl__ instead. Sounds good?
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