class HTML::Document

def initialize(text, strict=false, xml=false)
  tokenizer = Tokenizer.new(text)
  @root = Node.new(nil)
  node_stack = [ @root ]
  while token = tokenizer.next
    node = Node.parse(node_stack.last, tokenizer.line, tokenizer.position, token, strict)
    node_stack.last.children << node unless node.tag? && node.closing == :close
    if node.tag?
      if node_stack.length > 1 && node.closing == :close
        if node_stack.last.name == node.name
          if node_stack.last.children.empty?
            node_stack.last.children << Text.new(node_stack.last, node.line, node.position, "")
          end
          node_stack.pop
        else
          open_start = node_stack.last.position - 20
          open_start = 0 if open_start < 0
          close_start = node.position - 20
          close_start = 0 if close_start < 0
          msg = <<EOF.strip
ring attempt to close #{node_stack.last.name} with #{node.name}
ened at byte #{node_stack.last.position}, line #{node_stack.last.line}
osed at byte #{node.position}, line #{node.line}
tributes at open: #{node_stack.last.attributes.inspect}
xt around open: #{text[open_start,40].inspect}
xt around close: #{text[close_start,40].inspect}
          strict ? raise(msg) : warn(msg)
        end
      elsif !node.childless?(xml) && node.closing != :close
        node_stack.push node
      end
    end
  end
end