How many of these "levels" (not to confuse them with actual classes) exist in javascript? Only the first one?
(that said, I guess the fourth one (metaclasses) isn't a clear yes/no, since OO is very different in js)
(that said, I guess the fourth one (metaclasses) isn't a clear yes/no, since OO is very different in js)
metaclasses isn't really a major optimization hazard, it effectively boils down to hijacking the "class" syntax to instead run some custom code. It's used by things like dataclasses and the Django ORM to use class syntax to make a little DSL.