Model Python interpreter separate from version

[jaraco]

While writing up #508, I had another idea.

Perhaps this project should consider decoupling the interpreter from the version (model "implementation" as PyPy or CPython and "version" as "3.9[-dev]"). Right now, the two concerns are mashed together into a single "version" variable.

If instead the values were allowed to be separate, it would allow for the implementation to be used in the matrix. It could also allow for things like version: latest to indicate the latest available version. I'd love to have this setting in my config:

strategy:
  matrix:
    python:
    - 3.9
    - "3.10"
    include:
    - implementation: PyPy
      version: latest

[vsafonkin]

Hi @jaraco, thank you for your suggestions! We will take a look at this.

[henryiii]

PyPy has two versions, the interpreter version (pypy3.9) and the actual PyPy version. The PyPy version and CPython version don't overlap, and only a subset of versions are supported - your example above would break if you tried to use 3.10 + PyPy at the moment. I'm not sure this would really help, think of pypy3.9 and 3.9 might really be the best way to do it - minus the actual PyPy version, which IIRC isn't handled very well yet. I don't know, just something to think about. Maybe implementation: pypy3.9 would make sense? Though then you'd never be able to share version numbers in a matrix (though as I point out above, usually you can't anyway, the last couple versions will be CPython only).

[dmitry-shibanov]

Hello everyone. For now I'm going to close the issue because we're not planing to add a separate field for the interpreter. We'd like to stick with approach to use the one python-version field to install Python or PyPy.