Seven Languages in Seven Weeks - Ruby. tree.rb: Create a nested tree object using a hash as an input

tree.rb

class Tree
  attr_accessor :children, :node_name
  
  def initialize(tree)
    tree.each { |name, branches|
      @node_name = name
      @children = []
      branches.each_slice(1) { |branch|
        @children.push(Tree.new(branch))
      }
    }
  end
  
  def visit_all(&block)
    visit &block
    children.each {|c| c.visit_all &block}
  end
  
  def visit(&block)
    block.call self
  end
end

ruby_tree = Tree.new({
  :grandad => {
    :dad => {
      :me => {},
      :sister => {}
    },
    :uncle => {
      :cousin => {}
    }
  }
})

puts "Visiting a node"
ruby_tree.visit {|node| puts node.node_name}
puts

puts "visiting entire tree"
ruby_tree.visit_all {|node| puts node.node_name}