Kwartz::Node ^(Class)

for visitor pattern

ex.

  ## find a expression node which token is '?'
  condop_node = expr_node.find { |node| node.token == '?' }

ex.

  ## get expression node which token is '?', and it's parent
  condop_node, parent_node = expr_node.find_with_parent {
     |node| node.token == '?'
  }

for debug

for translator

ex.

 expression_node.traverse { |node| p node.token }

ex.

 expression_node.traverse_with_depth { |node, depth|
   indent = ' ' * depth
   print indent
   p node.token
 }

ex.

 condop_node = nil
 parent_node = nil
 expression_node.traverse_with_parent { |node, depth, parent|
   if node.token == '?'
    condop_node = node
    parent_ndoe = parent
    break
   end
 }