PUBLIC MARKS from nhoizey with tag classes

I find mixins very useful in other languages. In Ruby, any class that implements the each method can utilize the Enumerable mixin. Enumerable is a class containing functions which use the each method including: find, grep, and reject. The functions are mixed into the new class's set of functions. Incidentally, that PHP does not implement mixins natively is not a criticism of PHP. PHP's design goals are different from Ruby's.