assign_types_to_lines

# File lib/rdoc/markup.rb, line 157
  def assign_types_to_lines(margin = 0, level = 0)
    while line = @lines.next
      if line.blank? then
        line.stamp :BLANK, level
        next
      end

      # if a line contains non-blanks before the margin, then it must belong
      # to an outer level

      text = line.text

      for i in 0...margin
        if text[i] != SPACE
          @lines.unget
          return
        end
      end

      active_line = text[margin..-1]

      # Rules (horizontal lines) look like
      #
      #  ---   (three or more hyphens)
      #
      # The more hyphens, the thicker the rule
      #

      if /^(---+)\s*$/ =~ active_line
        line.stamp :RULE, level, $1.length-2
        next
      end

      # Then look for list entries.  First the ones that have to have
      # text following them (* xxx, - xxx, and dd. xxx)

      if SIMPLE_LIST_RE =~ active_line
        offset = margin + $1.length
        prefix = $2
        prefix_length = prefix.length

        flag = case prefix
               when "*","-" then :BULLET
               when /^\d/   then :NUMBER
               when /^[A-Z]/ then :UPPERALPHA
               when /^[a-z]/ then :LOWERALPHA
               else raise "Invalid List Type: #{self.inspect}"
               end

        line.stamp :LIST, level+1, prefix, flag
        text[margin, prefix_length] = " " * prefix_length
        assign_types_to_lines(offset, level + 1)
        next
      end

      if LABEL_LIST_RE =~ active_line
        offset = margin + $1.length
        prefix = $2
        prefix_length = prefix.length

        next if handled_labeled_list(line, level, margin, offset, prefix)
      end

      # Headings look like
      # = Main heading
      # == Second level
      # === Third
      #
      # Headings reset the level to 0

      if active_line[0] == == and active_line =~ /^(=+)\s*(.*)/
        prefix_length = $1.length
        prefix_length = 6 if prefix_length > 6
        line.stamp :HEADING, 0, prefix_length
        line.strip_leading(margin + prefix_length)
        next
      end

      # If the character's a space, then we have verbatim text,
      # otherwise

      if active_line[0] == SPACE
        line.strip_leading(margin) if margin > 0
        line.stamp :VERBATIM, level
      else
        line.stamp :PARAGRAPH, level
      end
    end
  end