# File lib/rdoc/text.rb, line 190
  def to_html text
    if Object.const_defined? :Encoding then
      html = ''.encode text.encoding

      encoded = RDoc::Text::TO_HTML_CHARACTERS[text.encoding]
    else
      html = ''
      encoded = {
        :close_dquote => '”',
        :close_squote => '’',
        :copyright    => '©',
        :ellipsis     => '…',
        :em_dash      => '—',
        :en_dash      => '–',
        :open_dquote  => '“',
        :open_squote  => '‘',
        :trademark    => '®',
      }
    end

    s = StringScanner.new text
    insquotes = false
    indquotes = false
    after_word = nil

    until s.eos? do
      case
      when s.scan(/<(tt|code)>.*?<\/\1>/) then # skip contents of tt
        html << s.matched.gsub('\\\\', '\\')
      when s.scan(/<(tt|code)>.*?/) then
        warn "mismatched <#{s[1]}> tag" # TODO signal file/line
        html << s.matched
      when s.scan(/<[^>]+\/?s*>/) then # skip HTML tags
        html << s.matched
      when s.scan(/\\(\S)/) then # unhandled suppressed crossref
        html << s[1]
        after_word = nil
      when s.scan(/\.\.\.(\.?)/) then
        html << s[1] << encoded[:ellipsis]
        after_word = nil
      when s.scan(/\(c\)/) then
        html << encoded[:copyright]
        after_word = nil
      when s.scan(/\(r\)/) then
        html << encoded[:trademark]
        after_word = nil
      when s.scan(/---/) then
        html << encoded[:em_dash]
        after_word = nil
      when s.scan(/--/) then
        html << encoded[:en_dash]
        after_word = nil
      when s.scan(/&quot;|"/) then
        html << encoded[indquotes ? :close_dquote : :open_dquote]
        indquotes = !indquotes
        after_word = nil
      when s.scan(/``/) then # backtick double quote
        html << encoded[:open_dquote]
        after_word = nil
      when s.scan(/''/) then # tick double quote
        html << encoded[:close_dquote]
        after_word = nil
      when s.scan(/'/) then # single quote
        if insquotes
          html << encoded[:close_squote]
          insquotes = false
        elsif after_word
          # Mary's dog, my parents' house: do not start paired quotes
          html << encoded[:close_squote]
        else
          html << encoded[:open_squote]
          insquotes = true
        end

        after_word = nil
      else # advance to the next potentially significant character
        match = s.scan(/.+?(?=[<\\.("'`&-])/) #"

        if match then
          html << match
          after_word = match =~ /\w$/
        else
          html << s.rest
          break
        end
      end
    end

    html
  end