From: Joel VanderWerf <vjoel@...>
Date: 2004-11-16T08:26:07+09:00
Subject: Re: "The Ruby Way" and adding methods to base classes in libraries

Tim Bates wrote:
> Joel VanderWerf wrote:
> 
>>> So, what's the right way to handle this situation?
>>
>>
>>
>> You could define this method in a module and use Object#extend to give 
>> that functionality to particular arrays.
> 
> 
> The other way to deal with this would be to create a new class that 
> inherits from Array:
> 
> class SuperSetArray < Array     # or some other, better name
>   def first_superset_of(*arrays)
>     arrays.detect do |array|
>         self.detect do |element|
>             not array.include?(element) ? false : true
>         end
>     end
>   end
> end

This is useful, but when an Array gets returned from, say, collect, it's 
not of this class, so you may still want to extend with a module that 
defines the same method.