It's better practice to include a module versus opening up a class and adding methods (because it's easier to see where the method was introduced, to step around it, get access to `super`, etc)

Note: your definition of `constantize` is different from Rails — so including rocx and Rails might lead to some weird bugs.

I wonder if a _library_ should ever do core_ext... Extending the language is something that a team of developers can agree to do (as in idioms) because they're consciously adopting a dialect, but if this library gets used by teams we don't know and in projects we aren't imagining.... monkey-patching String may be more surprising than relying on ActiveSupport!