class RDoc::Markup::ToBs

def accept_heading(heading)
  use_prefix or @res << ' ' * @indent
  @res << @headings[heading.level][0]
  @in_b = true
  @res << attributes(heading.text)
  @in_b = false
  @res << @headings[heading.level][1]
  @res << "\n"
end

def accept_list_item_start(list_item)
  type = @list_type.last
  case type
  when :NOTE, :LABEL then
    bullets = Array(list_item.label).map do |label|
      attributes(label).strip
    end.join "\n"
    bullets << ":\n" unless bullets.empty?
    @prefix = ' ' * @indent
    @indent += 2
    @prefix << bullets + (' ' * @indent)
  else
    bullet = type == :BULLET ? '*' :  @list_index.last.to_s + '.'
    @prefix = (' ' * @indent) + bullet.ljust(bullet.length + 1)
    width = bullet.length + 1
    @indent += width
  end
end

def annotate(tag)
  case tag
  when '+b' then @in_b = true
  when '-b' then @in_b = false
  when '+_' then @in_em = true
  when '-_' then @in_em = false
  end
  ''
end

def convert_regexp_handling(target)
  convert_string super
end

def convert_string(string)
  return string unless @in_b or @in_em
  chars = if @in_b then
            string.chars.map do |char| "#{char}\b#{char}" end
          elsif @in_em then
            string.chars.map do |char| "_\b#{char}" end
          end
  chars.join
end

def init_tags
  add_tag :BOLD, '+b', '-b'
  add_tag :EM,   '+_', '-_'
  add_tag :TT,   '', ''   # we need in_tt information maintained
end

def initialize(markup = nil)
  super
  @in_b  = false
  @in_em = false
end