Ruby Tree Implementation

ruby-tree.rb

class Tree
  # Define instance variables children and node_name
  # and the associated getters and setters
  attr_accessor :children, :node_name

  # Define a constructor with 2 parameters, with the second having a default value
  def initialize(name, children=[])
    @children = children
    @node_name = name
  end

  # Uses code blocks
  def visit_all(&block)
    visit &block
    children.each {|c| c.visit_all &block}
  end

  # Uses code blocks
  def visit(&block)
    block.call self
  end
end

tree = Tree.new("root", [
  Tree.new('child_a'),
  Tree.new('child_b'),
  Tree.new('child_c', [
    Tree.new('child_d', [
      Tree.new('child_e')
    ]),
    Tree.new('child_f')
  ])
])

puts "visit single node"
tree.visit {|node| puts node.node_name}

puts "visit tree"
tree.visit_all {|node| puts node.node_name}

# Output:
# visit single node
# root
# visit tree
# root
# child_a
# child_b
# child_c
# child_d
# child_e
# child_f