Support Python 3.12

[tbennun]

To add support for Python 3.12:

• What's new in Python 3.12? Are there any modified AST features or any added syntactic features?
• Does Python 3.12 work with the current test suite (change github workflows)?
• Modify setup.py as necessary to add support in the next release
• Release a major version (v0.15)

[tbennun]

@BenWeber42 @phschaad could we add this to the next release, which should be a major release?

[phschaad]

Sure, we'll make sure to include it, thanks

[tbennun]

I'm answering my own comments in the top message:

• Nothing new that would affect AST parsing in 3.12 (new f-strings should be supported as-is)
• Testing is in progress
• Done in Python 3.12 #1386
• Someone needs to release a version if point (2) works

[alexnick83]

• Nothing new that would affect AST parsing in 3.12 (new f-strings should be supported as-is)

There is a new type statement, which I suppose should be added to the disallowed statements (it is used to define types; I don't think there is currently any use in a DaCeProgram). I also see a lot of deprecation warnings (to be enforced in Python 3.14), so we may as well prepare early. Working on it ...

[tbennun]

Instead of disallowing them we might want to skip those as they’re noops.

[alexnick83]

After doing some testing, I decided to disallow the type statement (ast.TypeAlias). My justification is the following:

Consider the following DaCe program using the new type statement:

    @dace.program
    def type_statement():
        type Scalar[T] = T
        A: Scalar[dace.float32] = 0
        return A

Without any changes to the frontend, the above program will fail because Scalar has not been defined. If I make a visitor method for ast.TypeAlias that returns None, there will be a warning about the type annotation but the program will run. However, the output will be [0], i.e. an integer. Compare this to the following DaCe program, which will correctly return [0.], i.e., a floating point number:

    @dace.program
    def type_statement():
        A: dace.float32 = 0
        return A

Therefore, I believe that considering the type statement a no-op will only result in "minor" errors for users that use the type statement, which will be difficult to debug. I think the best course of action is to explicitly disallow the statement until we are ready to properly support it.

[BenWeber42]

I'm also in favor of disallowing for now. Searching ast module for 3.12, there are more changes. New classes:

• ast.TypeAlias
• ast.TypeVar
• ast.ParamSpec
• ast.TypeVarTuple

And some classes got a type_params attribute (ast.FunctionDef, ast.ClassDef, ast.AsyncFunctionDef).
The new typing features seem quite nice (https://peps.python.org/pep-0695/), but I'm not sure what it means for how we've handled typing in DaCe's python front-end so far.

[tbennun]

On second thought, I agree with you both.

[phschaad]

I will make sure to handle the release with @BenWeber42 before the next dace meeting.