If you worked with other languages you probably familiar with feature called multi dispatching or multimethods. It is the feature of some object-oriented programming languages in which a function or method can be dynamically dispatched based on the run time (dynamic) type of more than one of its arguments.

For example in C# it will be: public void Multi(D d, A a) { System.Console.WriteLine("DA"); } public void Multi(D d, B b) { System.Console.WriteLine("DB"); } public void Multi(D d, C c) { System.Console.WriteLine("DC"); } public void Multi(E e, A a) { System.Console.WriteLine("EA"); } public void Multi(E e, B b) { System.Console.WriteLine("EB"); } public void Multi(E e, C c) { System.Console.WriteLine("EC"); }

If you like the idea and want to add it to your ruby code check out multidispatch_dsl