I want to create classes and methods on fly.
It will look something like that:

Program imports module Foo.
Then it:
* calls functions from Foo
* create objects of class Foo::Bar for any Bar
* calls methods of Foo::Bar

1st and 3rd can be done with method_missing
But how can I create classes on fly ?

Where does this message come from and how can I overload this:
NameError: uninitialized constant Bar at Foo