Haven't used PHP in more than a decade so I looked up the documentation. The most relevant parts I could find were "Classes and Objects" and "Namespaces". After a rough review, I'd say that the it is possible that PHP inner classes provide one of the most rudimentary components of "type theoretic modules" in a partial and likely broken way. I don't mean this as a diss at PHP—it's just hard to do it right.

Namespaces also provide something similar to "type theoretic modules" but they provide only the very most prosaic, simple, and unimportant function: namely, namespacing.