From: Olivier Renaud <o.renaud@...>
Date: 2007-03-26T05:28:42+09:00
Subject: Re: splitting an array into sub_arrays ...need advice

Note that partition_by is a simple method with no dependencies. So, you can 
just copy/paste this method in your code from facets.rubyforge.org online 
documentation. Here it is :

module Enumerable
  def partition_by
    r = Hash.new{ |h,k| h[k]=[] }
    each do |e|
      r[ yield(e) ] << e
    end
    return r
  end
end

And then :

require 'enumerator'
start_array.partition_by {|ary| ary[1..2]}.to_enum(:each_value).to_a

-- 
Olivier Renaud