We seem to have a plethora of PEPs where we really ought to have one (or none?).
Traditionally when writing a new piece of software, one gathered requirements before implementing the code. Let us return to that venerable tradition.
IMO, mailing lists are a terrible way to do software design, but a good way to gather requirements as it makes less likely that someone will be forgotten.
So, let us gather the requirements for a new calling API.
Here are my starting suggestions:
1. The new API should be fully backwards compatible and shouldn't break the ABI 2. The new API should be used internally so that 3rd party extensions are not second class citizens in term of call performance. 3. The new API should not prevent 3rd party extensions having full introspection capabilities, supporting keyword arguments or another feature supported by Python functions. 4. The implementation should not exceed D lines of code delta and T lines of code in total size. I would suggest +200 and 1000 for D and T respectively (or is that too restrictive?). 5. It should speed up CPython for the standard benchmark suite. 6. It should be understandable.
What am I missing? Comments from the maintainers of Cython and other similar tools would be appreciated.