From: Moses Hohman <mmhohman@...>
Date: 2004-11-16T05:23:51+09:00
Subject: "The Ruby Way" and adding methods to base classes in libraries

I have a question about practical experience with adding methods to 
base classes in libraries. Say I'm writing a library and in a method of 
that library, I need a method like "first_superset_of", which acts on 
an array of arrays, and returns the first such array that is a superset 
of a second array argument's elements, i.e.

def first_superset_of(arrays, elements)
	arrays.detect do |array|
		elements.detect do |element|
			not array.include?(element) ? false : true
		end
	end
end
private :first_superset_of

Now, it's not very object-oriented to add this as a private method in a 
class that is not an array or an enumerable or whatever and then call 
it on two arguments. It seems more the ruby way to actually add a 
method called first_superset_of (and maybe a method called subset_of? 
for the second inner loop in there) to Enumerable or to Array, and then 
use that method that way. However, adding this method might clash with 
another added method in another library that a user might be using, if 
the author of that other library also created a method on Array or 
Enumerable with the same name.

So, what's the right way to handle this situation?

thanks in advance for any comments,

Moses