Question

I have a module Foo, that it is the namespace for many classes like Foo::Bar, Foo::Baz and so on.

Is there an way to return all class names namespaced by Foo?

Answer 1

Foo.constants

returns all constants in Foo. This includes, but is not limited to, classnames. If you want only class names, you can use

Foo.constants.select {|c| Foo.const_get(c).is_a? Class}

If you want class and module names, you can use is_a? Module instead of is_a? Class.