PEP 563 compatiblity

[bswck]

Current string-check argument parsing is pretty naive and doesn't work for postponed annotations.
https://peps.python.org/pep-0563/

[bswck]

Example:

Having

# foo.py
from autocommand import autocommand

@autocommand(__name__)
def main(arg: int):
    pass

the python -m foo m command correctly reports an error:

usage: foo.py [-h] arg
foo.py: error: argument arg: invalid int value: 'm'

However, adding from __future__ import annotations on top of the module breaks this and skips validation:

Having

# foo-ann.py
from __future__ import annotations
from autocommand import autocommand

@autocommand(__name__)
def main(arg: int):
    pass

the python -m foo-ann m command works just fine.

[bswck]

Note

It was a known issue:

autocommand/src/autocommand/autoparse.py

Lines 60 to 61 in acff23e

	If you provide an annotation that is somehow both a string and a callable,
	the behavior is undefined.

[bswck]

Related to #30.

[Lucretiel]

I'm confused by that PEP; this is just a major breaking change being shipped to a future minor release of Python?

[Lucretiel]

PEP 563 appears to have been superseded, due to backwards compatibility issues, so I'm closing this for now. Feel free to re-open if PEP is restored.

[bswck]

PEP 563 appears to have been superseded, due to backwards compatibility issues, so I'm closing this for now. Feel free to re-open if PEP is restored.

Strong -1 on this one. It indeed has been superseded by PEP 649, but PEP 649 is to come in Python 3.13 that hasn't yet even been released. A correct conclusion would be that PEP 563 would no longer be supported by October 2028. Until 2028, please consider supporting PEP 563, because

• hundrends of thousands of Python projects rely on the PEP, if not more and I need autocommand to support that PEP for Expand type hints across projects jaraco/skeleton#98,
• I am going to submit a PR for this,
• there is more than 4 years yet left for PEP 563 to be no longer supported.

@Lucretiel, could you please reopen? I'm not able to do it myself.