[texhax] Creating stared versions of macros

[Morten Høgholm]

On Thu, 30 Dec 2004 12:36:20 +0100, Stefan Björk <stefan at raggmunk.nu>  
wrote:

>> instead of RTFM -- try to look inside your favorite packages or clases
>
> I tried (pstricks) but that was even more confusing. :-)

That particular one is pretty hairy!

This small example should perhaps make it a little clearer:
%%%%%%%%%%%
\documentclass{minimal}
\makeatletter
\newcommand*\testa{%
   \@ifstar
     {Star version, two mandatory arguments:
      \testa at star}
     {No star, one mandatory and one optional argument:
      \testa at nostar}%
}

\newcommand*\testa at star[2]{%
   Arg~1:~``#1'', arg~2:~``#2''.%
}
\newcommand*\testa at nostar[2][Default]{%
   Arg~1:~``#1'', arg~2:~``#2''.%
}
\makeatother
\begin{document}
   \testa*{First}{Second}

   \testa[Optional]{Mandatory}

   \testa{Mandatory only}
\end{document}
%%%%%%%%%%%

This kind of trickery will be a lot easier in the (near) future with the  
xparse package. You can get it from  
<http://www.latex-project.org/code/experimental/xbase.tgz> if you want to  
look at it.
-- 
Morten Høgholm