>It is only used in the `program-arity function`, which is not called anywhere in the Guile repository (and calling it with valid inputs results in an error due to the `program-arities` being undefined).
This is untrue, it (i.e. program-arities) is also used in the manual.
Fair point.
>Removing those functions is simple, but the `arity:` accessors have more users, […]
It shouldn’t be removed, rather a replacement should be provided somewhere.
Regardless of the changes to the VM, compiled procedures still exist, and by definition that’s what a ‘program’ is, so ‘programs’ still exist, and hence many of the procedures in that module still make sense, including program-arities. In particular, arity information is still recorded (in .guile.arities), so it should be made / kept accessible somewhere.
I agree that this information should be available. I should have explicated my assumption that the similarly-named function "find-program-arities" was a suitable replacement. It is defined in "system/vm/debug.scm" and references .guile.arities. I will interrogate this assumption more thoroughly before submitting a patch, the email was meant as an early notification that this is something that I'm starting to look at in case someone else is already looking at it. I am fine with changing the direction of the patch if that turns out to make sense (perhaps by turning program-arities an alias for find-program-arities).