do we want to use decorators to "hide" compatibility checks?

[sergpolly]

from one of the discussions about our new "checks" someone mentioned "decorators" ...
Are we looking to do something like below:

I think this would be very very cool and improve readability of the code

[Phlya]

Yeah I think I mentioned this, and that's what I meant! Indeed I think it would be cool.

[sergpolly]

will leave some relevant info here:
https://learning-python.com/rangetest.html

so, what not so trivial is to extract values of some specific arguments that were passed to one of our functions, i.e.:

@check_cooler_balanced
def expected_cis(
    clr,
    view_df=None,
    intra_only=True,
    smooth=True,
    aggregate_smoothed=True,
    smooth_sigma=0.1,
    clr_weight_name="weight",
    ignore_diags=2
...
)

in this case hypothetical check_cooler_balanced would need to "intercept" only relevant arguments passed to epected_cis - i.e. clr and clr_weight_name - from *args and **kwargs passed to expected_cis ...

• "intercepting" clr can be easy, as it is positional , and we could agree that it would always be the first one or whatrever (still important to note that it could be passed via *args, or **kwargs still ! expected_cis(myclr) vs expected_cis(clr=myclr))
• "intercepting" clr_weight_name isn't so easy - as it could be passed as args or kwargs, or skipped altogether (since it has a default) - then you'd have to make sure it was skipped and apply its default for the checker
• users might not obey the original function signature and then it'll fall apart - how exactly ?

some relevant bit for introspecting functions:

import inspect
argspec = inspect.getfullargspec(func)

assert "clr" in argspec.args
assert "clr_weight_name" in argspec.args

# catching strictly positional argument
if "clr" not in kwargs:
    _arg_index = argspec.args.index("clr")
    _val_passed = args[_arg_index]
    clr = _val_passed
else:
    clr = kwargs["clr"]

# last n-defaults !
argspec.defaults
...

there is also that https://www.python.org/dev/peps/pep-3102/ - that @mimakaev brought up some time ago (enforcing kwargs form for some arguments)

[sergpolly]

this is mega https://stackoverflow.com/questions/57314496/how-to-intercept-and-preproccess-arguments-with-decorators