An example which comes to mind is how Racket handles tests: they're generally written in "sub-modules" of whatever they're testing, and hence they have access t

An example which comes to mind is how Racket handles tests: they're generally written in "sub-modules" of whatever they're testing, and hence they have access to "private" (AKA un-exported) definitions. https://blog.racket-lang.org/2012/06/submodules.html https://blog.racket-lang.org/2012/06/submodules.html Framing discussions around "classes and methods" is a rather narrow-minded view, which ignores lots of potential solutions.