How to idiomatically extract all fluents present in a formula?

[JoanEspasa]

I'm doing some preprocessing of the preconditions of a problem, and I need to extract all variables present in them. Once I get a grounded action and access its precondition, I have been able to extract its variables by using: pre.environment.free_vars_extractor.get(pre)

It feels a bit strange having to access the environment of the precondition to have access to the walker for then calling the get method. Is there a more idiomatic/clean way of getting these?

Thanks and apologies in advance if there is a more obvious way that I've overlooked!

[Framba-Luca]

Hi @JoanEspasa , for the simplification and substitution we made a "shortcut" (like pre.simplify()), but not for the extraction of variables; this might be a useful shortcut to add even if I am not entirely sure due to the complex and not immediate naming of that functionality.

Currently, the cleanest way to do it is to store the free_vars_extractor of the environment in a variable and call it.

For example:

fve = problem.environment.free_vars_extractor
...
pre_free_variables = fve.get(pre)

[JoanEspasa]

Thanks for clarifying this Framba, it is appreciated :)