[XeTeX] Counter reset problem

[Ross Moore]

Hello Karljürgen,

On 19/09/2009, at 4:02 AM, Karljurgen Feuerherm wrote:

> Hello all,
>
> I have set up a counter and environment (using XeLaTeX) as follows:
>
> \newcounter{examples}[chapter]
>
> \newenvironment{examples}
>  {\begin{list}%
>   {\textsc{Example} \arabic{examples}.} %
>   {\setlength{\labelsep}{10pt} %
>    \setlength{\itemindent}{10pt} %
>    \setlength{\leftmargin}{0pt} %
>    \setlength{\labelwidth}{0pt} %
>    \usecounter{examples}%
>   } %
>  } %
>  {\end{list}}
>
> The idea is to let the examples counter run through each chapter  
> and only reset at the next chapter. For some reason, it resets  
> itself in environment changes (for example after enumerates, at  
> each new section...).

No, it resets itself for every use of the {examples}
environment.
This is because of how \usecounter expands;
viz.

\usecounter #1->\@nmbrlisttrue \def \@listctr {#1}\setcounter {#1}\z@
#1<-examples


That  \setcounter {#1}\z@   is resetting to zero.

You'll need a second counter or macro to retain the
value of your 'examples' counter at the end of each
environment.


e.g.

\newcounter{examples}[chapter]
\newcounter{runningexample}[chapter]

\newenvironment{examples}{%
  \begin{list}%
   {\textsc{Example}~\arabic{examples}.}%
   {\usecounter{examples}%
    \setcounter{examples}{\value{runningexample}}%
    \setlength{\labelsep}{10pt}%
    \setlength{\itemindent}{10pt}%
    \setlength{\leftmargin}{0pt}%
    \setlength{\labelwidth}{0pt}%
   }%
  } %
  {\end{list}%
   \setcounter{runningexample}{\value{examples}}%
  }

Note also that I've suppressed the extra spaces after '}'
that your coding was inserting (to no great harm though).


>
> What am I doing wrong?

With the 'runningexample' counter as above,
the following example works fine, so far as I can tell.


\begin{document}
%\maketitle
\chapter{One}

\begin{examples}
\item First example
\item Second example
\item Third example
\end{examples}

\begin{enumerate}
\item something else
\end{enumerate}

\begin{examples}
\item Another First example
\item Another Second example
\item Another Third example
\end{examples}


\chapter{Two}

\begin{examples}
\item First example
\item Second example
\item Third example
\end{examples}

\begin{enumerate}
\item more other things
\end{enumerate}

\begin{examples}
\item Another First example
\item Another Second example
\item Another Third example
\end{examples}


\end{document}

>
> Thanks
>
> K
>
> Karljürgen G. Feuerherm, PhD
> Department of Archaeology and Classical Studies
> Wilfrid Laurier University



Hope this helps,

	Ross

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Ross Moore                                       ross at maths.mq.edu.au
Mathematics Department                           office: E7A-419
Macquarie University                             tel: +61 (0)2 9850 8955
Sydney, Australia  2109                          fax: +61 (0)2 9850 8114
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