#
# Simple visitor: show how calculate the depth of a tree
#
class DepthTreeNodeVisitor < TreeNodeVisitor

  attr_reader :depth

  def initialize
    super
    @depth = 0
  end

  def enter_tree_node( treeNode )
    @depth += 1
  end

  def exit_tree_node( treeNode )
    @depth -= 1
  end

  def visit_leaf_node( leafNode )
  end

end