Introspection: macro: introduce a PythonTypeHint struct

[Tpt]

Allows to build static type hint or manipulate the ones from PyO3 traits

Makes type hint manipulation code much nicer

[Tpt]

Aside: I am not sure the PythonTypeHint struct name is great because it covers more usages than type hints like decorators. A big renaming to something like PythonExpression affecting also the TypeHint type in pyo3::inspect and po3_introspection might make sense.

[davidhewitt]

Thanks! Indeed makes code much easier to read.

Aside: I am not sure the PythonTypeHint struct name is great because it covers more usages than type hints like decorators. A big renaming to something like PythonExpression affecting also the TypeHint type in pyo3::inspect and po3_introspection might make sense.

I am tempted by this, I was thinking similarly. Only drawback is that there are some enum variants such as "union" which seem more specifically type hint related. (In a full "expression" I think the union would be some kind of ast of | operators?)

[Tpt]

Only drawback is that there are some enum variants such as "union" which seem more specifically type hint related. (In a full "expression" I think the union would be some kind of ast of | operators?)

Indeed. If we do such change we would imho change the variant to be more focus on Python syntax (and maybe align with the python ast module). My feeling is that we care here more about the Python syntax and not the really the semantic (the main use case of the AST being to rewrite imports) so having a unified syntax-focused representation might make sense.

If you agree, I can do an MR draft going into this direction to see how it feels (having this MR merged before would help because it means less places to update).

[davidhewitt]

Sounds good to me 👍