\haddockmoduleheading{Simple}
\label{module:Simple}
\haddockbeginheader
{\haddockverb\begin{verbatim}
module Simple (
    foo
  ) where\end{verbatim}}
\haddockendheader

\begin{haddockdesc}
\item[\begin{tabular}{@{}l}
foo\ ::\ t
\end{tabular}]\haddockbegindoc
This is foo.
\par

\end{haddockdesc}