Dev Call: 7 October 2021

Present

Tim, Florian, Stepan, Mohaned, Matti, Antonio, Simon

Notes

Florian

• hpy_basic example running in Cython.
  • Matti & Stefan Behnel had an "easy" idea for HPy support in Cython. Florian's changes are a bit more invasive.
  • Florian will try to push his changes to a public repo soon so Matti and Stefan can take a look.

Stepan

• HPy_BuildValue PR is open with multiple packing/unpacking specifiers (not all)
• Currently working on debug mode for HPy_UnicodeAsUTF8.
  • We had some discussion around how portable vs efficient the debug mode has to be.
• BEGIN_ALLOW_THREADS is used in psutil, which Stepan has ported
  • We decided to keep it, because it doesn't mean you have to have a GIL.
  • Maybe in the future we can allow extensions to declare they are fully thread-safe and reentrant, so impls without a GIL do not have to take a lock when calling into them
• discussed fast iteration over PyObject** items via the PySequence_Fast* functions
  • we're not going to address this issue now
  • Matti + Stepan suggested we might offer some kind of iteration API
  • Stefan said that passing a function ptr into a `forEach function is bad for the C compiler, and mentioned that GNU R has an API with a buffer that is filled with parts of the sequence and then an explicit loop, which happens to vectorize well.
  • Anto mentioned there was early discussion on this: https://github.com/hpyproject/hpy/blob/master/docs/api.md#specialized-protocols

Matti

• PyPy release in a week will also support 0.0.3
• Cython merge discussion
  • it would be nice if we could merge something that can be called "alpha" at some point for a Cython release
  • maybe when the piconumpy.pyx runs we should propose it

Mohaned

• matplotlib partial porting in progress
• PyArgParseTuple can use custom converters that expect PyObject* - these would need to be ported to HPy for the argument parsing

Anto

• we should define a mixed mode and pure mode compilation, where we disallow Python.h includes completely