class Hash
  def depth
      a = self.to_a
      d = 1
      while (a.flatten!(1).map! {|e| (e.is_a? Hash) ? e.to_a.flatten(1) : (e.is_a? Array) ? e : nil}.compact!.size > 0)
          d += 1
      end
      d
  end

  def compact(opts={})
    inject({}) do |new_hash, (k,v)|
      if !v.nil?
        new_hash[k] = opts[:recurse] && v.class == Hash ? v.compact(opts) : v
      end
      new_hash
    end
  end
end

class Array
  def depth
    a = self.to_a
    return 0 unless a.is_a?(Array)
    return 1 + depth(a[0])
  end
end