Allow for builtin slots to be overriden about grumpy HOT 4 OPEN

I'm all for raising until a reasonable use case presents itself. At least as long as grumpy is in alpha/beta.

from grumpy.

Thanks for the report! This is something that I've fretted a bit about. The real trick is that you have to update the slot on all the subclasses. Here's how CPython does it. Unfortunately, whereas CPython holds the GIL while it does all this work, Grumpy must find some other way to synchronize it, or live with poor consistency guarantees around updating types.

Worse is when you assign to a type's __bases__ attribute. This is not something I can ever imagine a reasonable program doing, but CPython jumps through hoops to support it.

Personally I think it's crazy to support this kind of monkey patching and I'm inclined to raise an exception when people try things like this. But maybe there are legitimate use cases that I'm overlooking. Thoughts and opinions are welcome here.

from grumpy.

I would love to monkeypatch datetime.datetime.now() to be allowed to test time in my billing code...

https://bugs.python.org/issue9528

from grumpy.

You're right that tests are a potentially valid use case for that. Note that normal functions (ones that reside in type(obj).__dict__) can be monkey patched perfectly well. The issue is just the slot functions that don't work quite right, like __add__.

from grumpy.