Katz reviews some work that seeks to “decorate” a Person class to include teacher traits. A factory that creates a Person proxy decorated with Teacher properties is considered as an approach. But it is criticized. Yehuda writes:
...this code, by tacking close to vocabulary created to describe Java patterns, rebuilds functionality that exists natively in Ruby. It would be equivalent to creating a Hash of Procs in Ruby when a Class would do.
Correct use of Ruby can provide built-in support for modular patterns, Katz writes, adding, "we don’t see enough usage of them," and provides some examples. http://yehudakatz.com/2010/02/15/abstractqueryfactoryfactories-and-alias_method_chain-the-ruby-way/