[pstricks] Check for file version of pstricks-add.tex

[Herbert Voss]

Christoph Bersch schrieb:
> for my package I need a pstricks-add.tex version >= 2.81. Is there a way
> to check for this (\RequirePackage does not work, as I want to use a
> certain version of the _.tex_ file) and alternatively define the macro
> in my package?
>
> \ifversion>=2.81
> % include pstricks-add.tex
> \else
> % use the corresponding code part
> \fi
>
> Is this possible and is this a good idea? I need the macro \nlput (the
> related code contains only 24 lines).
>   
there are different possibilities:

\providecommand\nlput....
...
}
\usepackage{pstricks-add}

or check, if \nlput exists.

Herbert

\documentclass{article}
\usepackage{pstricks-add}
\makeatletter
\@ifundefined{nlput}{%
\typeout{\string\nlput{...} not defined!}
\typeout{pstricks-add: v.\fileversion}
\def\psLDNode(#1)(#2)#3#4{%
% #1: node A  #2: node B  #3: dimen measured from A  #4: node name
  \pst at getcoor{#1}\pst at tempA%
  \pst at getcoor{#2}\pst at tempB%
  \pssetlength\pst at dimp{#3}%
  \pnode(!%
    \pst at tempA /YA exch \pst at number\psyunit div def
    /XA exch \pst at number\psxunit div def
    \pst at tempB /YB exch \pst at number\psyunit div def
    /XB exch \pst at number\psxunit div def
    /dx XB XA sub def
    /dy YB YA sub def
    /angle dy dx Atan def
    /linelength \pst at number\pst at dimp \pst at number\psunit div def
    XA linelength angle cos mul add YA linelength angle sin mul add ){#4}%
}
\def\nlput{\pst at object{nlput}}
\def\nlput at i(#1)(#2)#3#4{%
  \begin at SpecialObj
  \psLDNode(#1)(#2){#3}{temp at lnput}
  \pcline[linestyle=none](#1)(temp at lnput)%
  \ncput[npos=1]{#4}%
  \end at SpecialObj
}%
}{}
\makeatother

\begin{document}

foo \nlput(0,0)(3,3){1cm}{A}%
\psdots(0,0)(A)(3,3)
\end{document}