gistfile1.rb

public
def rec_flatten
  collection ||= []
  return collection if self == []
  if self.class != Array
    return collection << self
  end
  collection + self[0].rec_flatten + self[1..-1].rec_flatten
end


[[3],1,[2],[[[[[[1]],4,[4]]]],2]].rec_flatten 
# => [3, 1, 2, 1, 4, 4, 2]