[Python-Dev] PEP 575 (Unifying function/method classes) update

[Ronald Oussoren]

> On 17 Jun 2018, at 11:00, Jeroen Demeyer <J.Demeyer at UGent.be> wrote:
> 
> Hello,
> 
> I have been working on a slightly different PEP to use a new type slot tp_ccalloffset instead the base_function base class. You can see the work in progress here:
> 
> https://github.com/jdemeyer/PEP-ccall
> 
> By creating a new protocol that each class can implement, there is a full decoupling between the features of a class and between the class hierarchy (such coupling was complained about during the PEP 575 discussion). So I got convinced that this is a better approach.
> 
> It also has the advantage that changes can be made more gradually: this PEP changes nothing at all on the Python side, it only changes the CPython implementation. I still think that it would be a good idea to refactor the class hierarchy, but that's now an independent issue.
> 
> Another advantage is that it's more general and easier for existing classes to use the protocol (PEP 575 on the other hand requires subclassing from base_function which may not be compatible with an existing class hierarchy).

This looks interesting. Why did you add a tp_ccalloffset slot to the type with the actual information in instances instead of storing the information in a slot? 

Ronald