[pstricks] New macro addtopsstyle

[Christoph Bersch]

Hi,

for me it would be comfortable to have a macro which adds some 
additional settings to an existing psstyle. Something like

\newpsstyle{Fiber}{linecolor=green}
\addtopsstyle{Fiber}{linewidth=0.1}

-> style Fiber contains both informations

The following code seems to work, but it uses the LaTeX macro 
\g at addto@macro. As I plan to include this into a PSTricks package, the 
question is, if I should rewrite it in plain TeX (don't know how), or if 
use of a LaTeX macro is ok.

\documentclass{article}
\usepackage{pstricks}
\makeatletter
\def\addtopsstyle#1#2{%
    \@ifundefined{pscs@#1}%
       {\newpsstyle{#1}{#2}}%
       {%
         \expandafter\g at addto@macro\csname pscs@#1\endcsname{%
           \def\pset at tempa{#2}%
           \ifx\pst at tempa\@empty\else\psset{#2}\fi%
         }
     }%
}
\makeatother
\newpsstyle{Fiber}{linewidth=0.1}
\begin{document}
\begin{pspicture}(5,5)
   \psline[style=Fiber](0,0)(5,1)
   \addtopsstyle{Fiber}{linecolor=green}
   \psline[style=Fiber](0,1)(5,2)
   \addtopsstyle{Fiber}{linestyle=dotted}
   \psline[style=Fiber](0,2)(5,3)
\end{pspicture}
\end{document}

Christoph