class Kramdown::Converter::Latex

def convert_codeblock(el, opts)
  if !el.value
    @doc.warnings << "Cannot convert codeblock with entity references"
    return ''
  end
  show_whitespace = el.options[:attr] && el.options[:attr]['class'].to_s =~ /\bshow-whitespaces\b/
  lang = el.options[:attr] && el.options[:attr]['lang']
  if show_whitespace || lang
    result = "\\lstset{showspaces=%s,showtabs=%s}\n" % (show_whitespace ? ['true', 'true'] : ['false', 'false'])
    result += "\\lstset{language=#{lang}}\n" if lang
    result += "\\lstset{basicstyle=\\ttfamily\\footnotesize}\\lstset{columns=fixed,frame=tlbr}\n"
    "#{result}\\begin{lstlisting}\n#{el.value}\n\\end{lstlisting}"
  else
    "\\begin{verbatim}#{el.value}\\end{verbatim}\n"
  end
end