HPy support

[koubaa]

Hello!

Supporting HPy - an alternative for the CPython C API could offer some benefits for cinder. Some python libraries have branches which support the HPy API - and while it is slower by default when used as a shim on top of the standard CPython implementation - it removes implementation details from the CPython C API, which buys options to make different choices (JIT, garbage collector, etc) like those made here in cinder. CPython extension modules that target the HPy API would Just Work with any python runtime that supports HPy - which means you don't have to change your C API to match changes from 3.9+.

[itamaro]

thanks for bringing this up @koubaa ! this is something @tekknolagi mentioned recently as well.

iiuc HPy support isn't really relevant to the cinder/3.8 branch, but would be relevant once we complete the cinder/3.10 port.
since cinder is mostly compatible with cpython C APIs, I believe full HPy support should be attainable once cinder/3.10 becomes our main branch in a couple of months.

[tekknolagi]

I am very interested in poking at this after our 3.10 upgrade

[dmarx]

bumping since apparently 3.10 upgrade is complete