binary tree and nodes

binary_tree.rb

class Node
  attr_accessor :data, :left, :right

  def initialize(data)
    @left  = nil
    @right = nil
    @data  = data
  end

  include Comparable

  def <=>(node)
    data <=> node.data
  end
 
  def nodes
    result = []
    result.concat(@left.nodes) if @left
    result << self
    result.concat(@right.nodes) if @right

    result
  end

  def insert(new_node)
    if new_node < self
      if @left
        @left.insert(new_node)
      else
        @left = new_node
      end
    else
      if @right
        @right.insert(new_node)
      else
        @right = new_node
      end
    end
  end
  
  def to_s
    [left, data, right].join(" ")
  end
end


class BinaryTree
  attr_accessor :root
  def insert(new_node)
    if @root
      @root.insert(new_node)
    else # if root (first node in tree) does not exist
      @root = new_node #assign the new_node to root instance variable
    end
  end

  def nodes
    @root.nodes
  end

  #def to_s
   # self.root.to_s.squeeze(" ").strip
  #end
end

@tree = BinaryTree.new

%w(Dan Barry Ted Daniel Alice Andy Sally).each do |name|
 @tree.insert(Node.new(name))
end


puts @tree.nodes