#!/usr/bin/env ruby
require 'pp'

a = ['one',['two','three'],[['four','five','six']], [[['seven','eight','nine','ten']]]]

class Array
  alias_method :old_flatten, :flatten
  def flatten(depth=nil)
    if depth.nil?
      ret = old_flatten
    else
      if depth == 0
        ret = self
      else
        depth -= 1
        ret = []
        each do |x|
          if x.kind_of? Array
            ret += x.flatten(depth)
          else
            ret << x
          end
        end
      end
    end
    ret
  end
end

puts "flatten it one level"
pp a.flatten(1)

puts "flatten it to two"
pp a.flatten(2)

puts "flatten it to 100"
pp a.flatten(100)