marray.rb

class MArray < Array
  def self.wrap(value)
    new([value])
  end 
  
  def self.empty
    new([])
  end
  
  def +(other)
    MArray.new(super(other))
  end
  
  def join
    MArray.new(reduce([]) { |result, array| result << array })
  end 
  
  def pass(&block)
    MArray.new(map(&block)).join
  end 
end