[pstricks] Bookkeeping in pspicture environment

[Christoph Bersch]

Hi,

in the next pst-optexp version I want to integrate some kind of 
bookkeeping for named objects. The names are defined with a parameter 
'compname'. The names are registered in a global list and before every 
new definition it is checked if the name was already used.

Now this bookkeeping should be local in every pspicture environment. I 
thought of doing this by redefining \pspicture as follows:

\let\old at pspicture\pspicture
\def\pspicture{\let\@complist\@empty\old at pspicture}%

A working example would then be

\documentclass{article}
\usepackage{pst-xkey}
\usepackage{pstricks}
\makeatletter
\let\old at pspicture\pspicture
\def\pspicture{\let\@complist\@empty\old at pspicture}%
\define at key[psset]{}{compname}{%
    \edef\pst at temp{#1}%
    \ifx\pst at temp\@empty\else
       \@expandtwoargs\in@{,#1,}{,\@complist,}%
       \ifin@
          \PackageWarning{}%
             {^^Jcompname '#1' already used.^^J}%
       \else
	 % Use definition of \XKV at addtolist@x with an \xdef instead
	 % of \edef in order to keep the bookkeeping global
          \xdef\@complist{\@complist\ifx\@complist\@empty\else,\fi#1}%
       \fi
    \fi
}%
\makeatother
\begin{document}
\begin{pspicture}(5,5)
   \psset{compname=Name}
\end{pspicture}
\begin{pspicture}(5,5)
   \psset{compname=Name}
%  \psset{compname=Name}
\end{pspicture}
\end{document}

This seems to work... The problem does not raise any PackageWarning, 
only when uncommenting the last \psset{...} it is raised, as expected.

Are there any problems to be expected with my solution or do you have a 
better suggestion how to solve this issue?

Thank you,
Christoph