% \iffalse meta-comment
%
% File: regstats.dtx
% Version: 2023-04-04 v1.1a
% Info: Counting used registers
%
% Copyright © 2011 - 2023 by
%    H.-Martin Münch <Martin dot Muench at Uni-Bonn dot de>
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either
% version 1.3c of this license or (at your option) any later
% version. This version of this license is in
%    https://www.latex-project.org/lppl/lppl-1-3c.txt
% and the latest version of this license is in
%    https://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions of
% LaTeX version 2005-12-01 or later.
%
% This work has the LPPL maintenance status "maintained".
%
% The Current Maintainer of this work is H.-Martin Münch.
%
% This work consists of the main source file regstats.dtx,
% the README, and the derived files
%    regstats.sty, regstats.pdf,
%    regstats.ins, regstats.drv,
%    regstats-example.tex, regstats-example.pdf,
%    regstats-example.log.
%
% "regstats" is available on CTAN:
% https://ctan.org/pkg/regstats
%
% Also a TDS.ZIP file is provided that contains all the files
% already sorted in a TDS tree:
% https://mirror.ctan.org/install/macros/latex/contrib/regstats.tds.zip
%
%<*ignore>
\begingroup
  \catcode123=1 %
  \catcode125=2 %
  \def\x{LaTeX2e}%
\expandafter\endgroup
\ifcase 0\ifx\install y1\fi\expandafter
         \ifx\csname processbatchFile\endcsname\relax\else1\fi
         \ifx\fmtname\x\else 1\fi\relax
\else\csname fi\endcsname
%</ignore>
%<*install>
\input docstrip.tex
\Msg{*******************************************************************}
\Msg{* Installation                                                    *}
\Msg{* Package: regstats 2023-04-04 v1.1a Counting used registers (HMM)*}
\Msg{*******************************************************************}

\keepsilent
\askforoverwritefalse

\let\MetaPrefix\relax
\preamble

This is a generated file.

Project: regstats
Version: 2023-04-04 v1.1a
Info: Counting used registers

Copyright (C) 2011 - 2023 by
    H.-Martin Muench <Martin dot Muench at Uni-Bonn dot de>

This work may be distributed and/or modified under the
conditions of the LaTeX Project Public License, either
version 1.3c of this license or (at your option) any later
version. This version of this license is in
   https://www.latex-project.org/lppl/lppl-1-3c.txt
and the latest version of this license is in
   https://www.latex-project.org/lppl.txt
and version 1.3c or later is part of all distributions of
LaTeX version 2005-12-01 or later.

This work has the LPPL maintenance status "maintained".

The Current Maintainer of this work is H.-Martin Muench.

This work consists of the main source file regstats.dtx,
the README, and the derived files
   regstats.sty, regstats.pdf,
   regstats.ins, regstats.drv,
   regstats-example.tex, regstats-example.pdf,
   regstats-example.log.

In memoriam
 Claudia Simone Barth + 1996-01-30
 Tommy Muench         + 2014-01-02
 Hans-Klaus Muench    + 2014-08-24

\endpreamble
\let\MetaPrefix\DoubleperCent

\generate{%
  \file{regstats.ins}{\from{regstats.dtx}{install}}%
  \file{regstats.drv}{\from{regstats.dtx}{driver}}%
  \usedir{tex/latex/regstats}%
  \file{regstats.sty}{\from{regstats.dtx}{package}}%
  \usedir{doc/latex/regstats}%
  \file{regstats-example.tex}{\from{regstats.dtx}{example}}%
}

\catcode32=13\relax% active space
\let =\space%
\Msg{************************************************************************}
\Msg{*}
\Msg{* To finish the installation you have to move the following}
\Msg{* file into a directory searched by TeX:}
\Msg{*}
\Msg{*  regstats.sty}
\Msg{*}
\Msg{* To produce the documentation run the file `regstats.drv'}
\Msg{* through (pdf)LaTeX, e.g.}
\Msg{*  pdflatex regstats.drv}
\Msg{*  makeindex -s gind.ist regstats.idx}
\Msg{*  pdflatex regstats.drv}
\Msg{*  makeindex -s gind.ist regstats.idx}
\Msg{*  pdflatex regstats.drv}
\Msg{*}
\Msg{* At least three runs are necessary e.g. to get the}
\Msg{*  references right!}
\Msg{*}
\Msg{* Happy TeXing!}
\Msg{*}
\Msg{************************************************************************}

\endbatchfile
%</install>
%<*ignore>
\fi
%</ignore>
%
% \section{The documentation driver file}
%
% The next bit of code contains the documentation driver file for
% \TeX, i.\,e., the file that will produce the documentation you
% are currently reading. It will be extracted from this file by the
% \texttt{docstrip} programme. That is, run \LaTeX{} on \texttt{docstrip}
% and specify the \texttt{driver} option when \texttt{docstrip}
% asks for options.
%
%    \begin{macrocode}
%<*driver>
\NeedsTeXFormat{LaTeX2e}[2022-11-01]
\ProvidesFile{regstats.drv}[2023-04-04 v1.1a Counting used registers (HMM)]
\documentclass[landscape]{ltxdoc}[2022/06/22]% v2.1i Standard LaTeX documentation class
\usepackage{geometry}[2020/01/02]% v5.9 Page Geometry
\usepackage{holtxdoc}[2019/12/09]% v0.30 Private additional ltxdoc support (HO)
\usepackage[T1]{fontenc}[2021/04/29]% v2.0v Standard LaTeX package
\hypersetup{%
 pdfsubject={Information about used number of TeX registers (HMM)},%
 pdfkeywords={LaTeX, regstats, registers, read, write, language, box, dimen, counter, toks, skip, muskip, math family, insertion},%
 pdfencoding=auto,%
 pdflang={en},%
 breaklinks=true,%
 linktoc=all,%
 pdfstartview=FitH,%
 pdfpagelayout=OneColumn,%
 bookmarksnumbered=true,%
 bookmarksopen=true,%
 bookmarksopenlevel=3,%
 pdfmenubar=true,%
 pdftoolbar=true,%
 pdfwindowui=true,%
 pdfnewwindow=true%
}
\CodelineIndex
\hyphenation{docu-ment}
\makeatletter
\@ifundefined{eTeX}{\gdef\eTeX{\hbox{$\m@th \varepsilon $-\TeX}}}{}
\makeatother
\begin{document}
 \DocInput{regstats.dtx}%
\end{document}
%</driver>
%    \end{macrocode}
% \fi
%
% \GetFileInfo{regstats.drv}
%
% \begingroup
%   \def\x{\#,\$,\^,\_,\~,\ ,\&,\{,\},\%}%
%   \makeatletter
%   \@onelevel@sanitize\x
% \expandafter\endgroup
% \expandafter\DoNotIndex\expandafter{\x}
% \expandafter\DoNotIndex\expandafter{\string\ }
% \begingroup
%   \makeatletter
%     \lccode`9=32\relax
%     \lowercase{%^^A
%       \edef\x{\noexpand\DoNotIndex{\@backslashchar9}}%^^A
%     }%^^A
%   \expandafter\endgroup\x
%
% \DoNotIndex{\\,\@gobble,\@ifclassloaded,\@ifl@t@r,\@ifpackagelater,\@ifpackageloaded,\@ifundefined,\@whilenum,\@percentchar}
% \DoNotIndex{\@tempcnta,\@tempcntb,\AddToHook,\advance,\AfterLastShipout,\Alternative,\arabic,\AtBeginDocument,\AtEndAfterFileList}
% \DoNotIndex{\AtEndDocument,\atveryend,\AtVeryEndDocument,\AtVeryVeryEnd,\begin,\count,\DeclareBoolOption,\divide}
% \DoNotIndex{\csname,\endcsname,\do,\setcounter,\stepcounter,\thenumberreg,\value}
% \DoNotIndex{\documentclass,\end,\eTeX,\fmtversion,\gdef,\hbox,\hologo,\holtxdoc,\hyperref,\ifetex,\IfFileExists}
% \DoNotIndex{\IfFormatAtLeastTF,\ifnum,\IfPackageLoadedTF,\ifpdf,\ifregstats@left,\ifregstats@proof,\ifregstats@timer}
% \DoNotIndex{\iftex,\ifx,\intcalc,\intcalcMod,\jobname,\kvoptions,\left,\listfiles,\luatexfalse,\m@th}
% \DoNotIndex{\makeatletter,\makeatother,\message,\MessageBreak,\multiply,\NeedsTeXFormat}
% \DoNotIndex{\newcommand,\newif,\newline,\options,\PackageError,\PackageInfo,\PackageWarning,\PackageWarningNoLine}
% \DoNotIndex{\pagenumbering,\par,\ProcessKeyvalOptions,\proof,\providecommand,\ProvidesPackage}
% \DoNotIndex{\regcount,\regstats-example.tex,\regstats.dtx,\regstats.sty,\renewcommand,\RequirePackage}
% \DoNotIndex{\regst@tsNoeTeX,\regs@tsmw,\regs@wmst,\regst@ts@st@tistics,\regst@ts@statistics,\regst@ts@timer}
% \DoNotIndex{\regstats@box,\regstats@counter,\regstats@dimen,\regstats@fam,\regstats@firstofone,\regstats@free}
% \DoNotIndex{\regstats@insert,\regstats@language,\regstats@left,\regstats@lft,\regstats@max,\regstats@message}
% \DoNotIndex{\regstats@muskip,\regstats@pl,\regstats@read,\regstats@regstatA,\regstats@regstatB,\regstats@skip}
% \DoNotIndex{\regstats@timerfalse,\regstats@toks,\regstats@used,\regstats@write}
% \DoNotIndex{\section,\SetupKeyvalOptions,\space,\TeX,\textsf,\texttt,\the,\usepackage,\varepsilon}
%
% \title{The \xpackage{regstats} package}
% \date{2023-04-04 v1.1a}
% \author{H.-Martin Münch\\\xemail{Martin.Muench at Uni-Bonn.de}}
%
% \maketitle
%
% \begin{abstract}
% \noindent This \LaTeX{} package allows to count the number of used registers
% (counter, dimen, skip, muskip, box, token, input, output,
% math families, languages, insertions)
% and compare these to the maximum available number of such registers.
% The time needed for a compilation run can be announced.
% \end{abstract}
%
% \bigskip
%
% \noindent Disclaimer for web links: The author is not responsible for any contents
% referred to in this work unless having full knowledge of illegal contents.
% If any damage occurs by the use of information presented there,
% only the author of the respective pages might be liable,
% not the one who has referred to those pages.
%
% \tableofcontents
%
% \section{Introduction}
% \indent This \LaTeX{} package allows to count the number of used registers
% (counter, dimen, skip, muskip, box, token, input, output,
% math families, languages, insertions).
% Therefore the according |\count| is read. While |\count10| should be the number
% of the counters, |\count11| the one of the dimens, and so on, if there is enough
% room for another register of that type, then a new one of that register is used
% and looked at |\the\allocationnumber|. The result for each register is compared
% to the maximum available number of the respective register.\newline
% With option |left| additionally the number of remaining registers of each type
% is given, and with option |timer| the time needed for the compilation run (when
% either \hologo{LuaLaTeX} with |\directlua{starttime = os.clock()}| before
% |\documentclass| or |pdf(la)tex| is used).
%
% \section{Usage}
% \indent Just load the package placing
% \begin{quote}
%   |\usepackage[<|\textit{options}|>]{regstats}|
% \end{quote}
% \noindent at the end of the preamble of your \LaTeXe{} source file. When you
% load packages |\AtBeginDocument|, \xpackage{regstats} should be the last one
% of those packages. The resulting message will be presented at the end of the
% compilation messages at the screen and in the \xfile{log} file.
% \bigskip
%
% The examplefile provides (commented out) |\stressCounter|, |\stressDimen|,
% \dots, and |\stressInsert| to try out how many counters, dimens, \dots, and
% inserts your system can handle.
% \pagebreak
%
% \subsection{Options}
% \DescribeMacro{options}
% \indent The \xpackage{regstats} package takes the following options:
%
% \subsubsection{left}
% \DescribeMacro{left}
% \indent When option \texttt{left} (or \texttt{left=true}) is chosen,
% also the number of remaining registers of each type is given. The default
% is \texttt{left=false}.
%
% \subsubsection{timer}
% \DescribeMacro{timer}
% \indent When option \texttt{timer} (or \texttt{timer=true}) is chosen,
% also the time needed for the compilation run is given. The default
% is \texttt{timer=false}. The used |\pdfelapsedtime| is not available,
% when \hologo{LuaLaTeX} is used instead of |pdf(la)tex| to compile the document.
% In that case at the very beginning of your \xfile{tex} file say\\
% \verb|\directlua{starttime = os.clock()}|\\
% (even before |\documentclass|!), and then the \texttt{timer} option can also
% be used with \hologo{LuaLaTeX}. When neither \hologo{LuaLaTeX} nor \hologo{pdfLaTeX} is used
% to compile the document, the \texttt{timer}(-option) does not work.
%
% \subsubsection{proof}
% \DescribeMacro{proof}
% \indent Option \texttt{proof} is \textbf{obsolete} and should no longer be used.
%
% \section{Alternatives\label{sec:Alternatives}}
% \begin{description}
% \item[-] \xpackage{regcount}, 1999/08/03, v1.0, by \textsc{Jean-Pierre F. Drucbert}~(\textdied),
%   provides the command |\rgcounts|, which can write the numbers of used registers
%   into the \xfile{log} file anywhere (not only at the end) and does this automatically
%   |\AtBeginDocument| and |\AtEndDocument|. The given number of allocated insertions is
%   \emph{wrong}, because these are not numbered $0$, $1$, $2$\ldots,
%   but start at a high number, which is then decreased (and additionally there are jumps,
%   see \hbox{p. \pageref{insertions}).} The package is compatible with the \xpackage{regstats} package
%  (i.\,e.~you can use both packages at the same time in one document) and available at
%   \url{https://ctan.org/pkg/regcount}.
%
% \item[-] One can manually search for the last appearance of
%   |\count|, |\dimen|, |\skip|, |\muskip|, |\box|, |\toks|, |\read| (input),
%   |\write| (output), |\mathgroup| (math family), and |\language|,
%   and find the according number there. This does not provide any information
%   about the number of remaining registers, of course. And it does not work for
%   |\insert|, see \hbox{p. \pageref{insertions}).}
% \end{description}
%
% \bigskip
%
% \noindent You programmed or found another alternative,
% which is available at \url{https://www.CTAN.org/}?
% OK, send an e-mail to me with the name, location at CTAN,
% and a short notice, and I will probably include it in the list above.
%
% \newpage
%
% \section{Example}
%    \begin{macrocode}
%<*example>
%% When compiling with LuaLaTeX (and wanting to use option timer=true),
%% the following line must be uncommented (i.e. remove the "%% ").
%% \directlua{starttime = os.clock()}
\documentclass[british]{article}
\usepackage[left=true,timer=true]{regstats}[2023/04/04]% v1.1a Counting used registers (HMM)
\ifpdf\ifluatex\else
\pdfinfo{
  /Author (H.-Martin Muench)
  /Title (regstats package example)
  /Subject (Example for the regstats package)
  /Keywords (LaTeX;registers;read;write;language;box;dimen;count;toks;muskip;skip;counter;regstats)
}
\fi\fi
%% If you use the hyperref package, use the options of that package
%% to set the pdf information.
%% Do NOT use \pdfinfo AND the hyperref package!

%%\usepackage{etex}
%%\usepackage{morewrites}

\makeatletter
\newcommand{\stressCounter}[1]{%
  \ifnum\the\count10<#1\relax\else\message{Already \the\count10 \space counters used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count10<#1\do%
    {\advance\@tempcnta +1\relax%
     \newcounter{TestCounter\the\@tempcnta} \message{counter \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressDimen}[1]{%
  \ifnum\the\count11<#1\relax\else\message{Already \the\count11 \space dimens used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count11<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newdimen\csname TestDimen\the\@tempcnta\endcsname \message{dimen \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressSkip}[1]{\%
  \ifnum\the\count12<#1\relax\else\message{Already \the\count11 \space skips used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count12<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newskip\csname TestSkip\the\@tempcnta\endcsname \message{skip \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressMuskip}[1]{%
  \ifnum\the\count13<#1\relax\else\message{Already \the\count11 \space muskips used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count13<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newmuskip\csname TestMuskip\the\@tempcnta\endcsname \message{muskip \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressBox}[1]{%
  \ifnum\the\count14<#1\relax\else\message{Already \the\count11 \space boxes used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count14<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newbox\csname TestBox\the\@tempcnta\endcsname \message{box \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressToks}[1]{%
  \ifnum\the\count15<#1\relax\else\message{Already \the\count11 \space toks used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count15<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newtoks\csname TestToks\the\@tempcnta\endcsname \message{toks \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressRead}[1]{%
  \ifnum\the\count16<#1\relax\else\message{Already \the\count11 \space reads used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count16<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newread\csname TestRead\the\@tempcnta\endcsname \message{read \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressWrite}[1]{%
  \ifnum\the\count17<#1\relax\else\message{Already \the\count11 \space writes used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count17<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newwrite\csname TestWrite\the\@tempcnta\endcsname \message{write \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressFam}[1]{%
  \ifnum\the\count18<#1\relax\else\message{Already \the\count11 \space fams used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count18<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newfam\csname TestFam\the\@tempcnta\endcsname \message{fam \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressLanguage}[1]{%
  \ifnum\the\count19<#1\relax\else\message{Already \the\count11 \space languages used.} \fi%
  \@tempcnta=0\relax%
  \@whilenum\the\count19<#1\do%
    {\advance\@tempcnta +1\relax%
     \expandafter\newlanguage\csname TestLanguage\the\@tempcnta\endcsname \message{language \the\allocationnumber ^^J}%
    }%
  }

\newcommand{\stressInsert}[1]{%
 \message{Declaring #1\space ADDITIONAL inserts:}%
 \@tempcnta=0\relax%
 \@whilenum\the\@tempcnta<#1\do%
  {\advance\@tempcnta +1\relax%
   \expandafter\newinsert\csname TestInsert\the\@tempcnta\endcsname%
   \message{insert \the\@tempcnta: \the\allocationnumber^^J}%
  }%
 }
\makeatother

\listfiles
\begin{document}
\pagenumbering{arabic}
\section*{Example for regstats}

This example demonstrates the use of package\newline
\textsf{regstats}, v1.1a as of 2023-04-04.\newline
The used options were \texttt{left=true,timer=true}.\par
\texttt{left=false,timer=false} would be the defaults.\newline

Regarding the use of
\makeatletter%
\ \@ifundefined{eTeX}{\hbox{$\m@th \varepsilon $-\TeX}}{\eTeX}, %
\makeatother%
the \texttt{morewrite} package, the reservation of \texttt{insert}s,
and using more \texttt{math families} please see the documentation!\newline

For the resulting message, please compile \texttt{regstats-example.tex}
and have a look at the end of its \texttt{.log}-file.\newline

Because the compilation time for this example is usually quite short,
option \texttt{timer} is not demonstrated very spectacular.\newline

To test a register type for the number of available registers,
uncomment the respective line below and set the number to an interesting value.


\makeatletter
%%\stressCounter{233}
%%\stressDimen{233}
%%\stressSkip{233}
%%\stressMuskip{255}
%%\stressBox{233}
%%\stressToks{255}
%%\stressRead{15}
%%\stressWrite{14}
%%\stressFam{15}
%%\stressLanguage{255}
%%\stressInsert{20}
\makeatother

\end{document}
%</example>
%    \end{macrocode}
%
% \StopEventually{}
% \newpage
%
% \section{The implementation}
% We start off by checking that we are loading into \LaTeXe{} and
% announcing the name and version of this package.
%
%    \begin{macrocode}
%<*package>
%    \end{macrocode}
%
%    \begin{macrocode}
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{regstats}[2023/04/04 v1.1a Counting used registers (HMM)]

%    \end{macrocode}
%
% A short description of the \xpackage{regstats} package:
%
%    \begin{macrocode}
%% Allows to count the number of used registers
%% (counter, dimen, skip, muskip, box, token, input, output,
%%  math families, languages, insertions)
%% and compare these to the maximum available number of such registers.

%    \end{macrocode}
%
% We need the \xpackage{kvoptions} package:
%
%    \begin{macrocode}
\RequirePackage{kvoptions}% Key value format for package options (HO)

%    \end{macrocode}
%
% We process the options:
%
%    \begin{macrocode}
\SetupKeyvalOptions{family=regstats,prefix=regstats@}
\DeclareBoolOption{left}% \regstats@left
\DeclareBoolOption{timer}
\DeclareBoolOption{proof}% OBSOLETE

\ProcessKeyvalOptions*

%    \end{macrocode}
%
% Option |proof| is \textbf{obsolete}:
%
%    \begin{macrocode}
\ifregstats@proof
  \PackageWarningNoLine{regstats}{Option proof is obsolete. Please do not use it\MessageBreak%
    when loading the regstats package}
\else
  \PackageInfo{regstats}{Option proof is obsolete.\MessageBreak%
    If you used proof=false, please remove this\@gobble}
\fi

%    \end{macrocode}
%
% We need the \pkg{iftex} package (or its predecessors \pkg{ifpdf},
% \pkg{ifetex}, and \pkg{ifluatex}):
%
%    \begin{macrocode}
\IfFileExists{iftex.sty}{\RequirePackage{iftex}}{
  \RequirePackage{ifpdf}
  \RequirePackage{ifetex}
  \RequirePackage{ifluatex}
  }

%    \end{macrocode}
% \pagebreak
%    \begin{macrocode}
\@ifundefined{ifluatex}{\newif\ifluatex \luatexfalse}{\relax}
\@ifundefined{ifetex}{\newif\ifetex \etexfalse}{\relax}

%    \end{macrocode}
%
% Yes, if \hologo{LuaLaTeX} is used without defining |\ifluatex|,
% then we fail safe with assuming \hologo{LuaLaTeX} is not used.
% Otherwise everything (|\else|s and |\fi|s) gets mixed up,
% but \hologo{LuaLaTeX} without |\ifluatex| is really broken.
% Also if |\ifetex| is unknown, we assume that there is no
% \hologo{eTeX} available.
%
% \medskip
%
% Option timer requires some condition:
%
%    \begin{macrocode}
\ifregstats@timer
  \ifpdf \RequirePackage{intcalc}
  \else \PackageError{regstats}{Option timer only works with pdf(la)tex\MessageBreak%
          and with lua(la)tex}{Neither appears to be used here.}
        \regstats@timerfalse
  \fi
\fi

%    \end{macrocode}
%
% The timer:
%
%    \begin{macrocode}
\newcommand{\regst@ts@timer}{\message{^^J}%
  \@tempcnta=0%
%    \end{macrocode}
%
% For \hologo{LuaLaTeX}:
%
%    \begin{macrocode}
  \ifluatex%
    \@tempcnta=%
      \directlua{
        if starttime then
          tex.sprint((os.clock()-starttime)*65536)
        else
          tex.sprint(0)
        end
       }\relax%
%    \end{macrocode}
%
% and for pdf\LaTeX:
%
%    \begin{macrocode}
  \else \ifpdf \@tempcnta=\the\pdfelapsedtime\relax\fi%
  \fi%
%    \end{macrocode}
%
% Checking the result:
%
%    \begin{macrocode}
  \ifnum \the\@tempcnta = 0%
    \ifluatex%
      \PackageError{regstats}{Did you forget to start the timer?}{%
        Before \string\documentclass\space you need to say\MessageBreak%
        \string\directlua{starttime = os.clock()}}%
    \fi%
    \PackageError{regstats}{Could not determine the time used for compilation}{Reason is unknown.}%
  \else%
%    \end{macrocode}
%
% It worked!
% \pagebreak
%
%    \begin{macrocode}
    \xdef\regstatselapsedtime{\the\@tempcnta}%
    \divide \@tempcnta by 65536% scaled-seconds -> seconds
    \xdef\regstatsseconds{\the\@tempcnta}%
    \ifnum \regstatsseconds > 59%
      \xdef\regstatsseconds{\intcalcMod{\the\@tempcnta}{60}}%
      \divide \@tempcnta by 60% seconds -> minutes
    \else%
      \@tempcnta=0% minutes = 0
    \fi%
    \ifnum \regstatsseconds < 10%
      \message{Time elapsed for the last compiler run:^^J%
        about \the\@tempcnta:0\regstatsseconds\space%
        (m:ss; \regstatselapsedtime /65536 s).^^J}%
    \else%
      \message{Time elapsed for the last compiler run:^^J%
        about \the\@tempcnta:\regstatsseconds \space%
        (m:ss; \regstatselapsedtime /65536 s).^^J}%
    \fi%
  \fi%
  }

%    \end{macrocode}
%
% If the |timer|-option was not used, we do not use the timer:
%
%    \begin{macrocode}
\ifregstats@timer\else\renewcommand{\regst@ts@timer}{\relax}\fi

%    \end{macrocode}
%
% Initialisation of some commands:
%
%    \begin{macrocode}
\long\def\regstats@firstofone#1{#1}

\providecommand\IfFormatAtLeastTF{\@ifl@t@r\fmtversion}

\let\regst@tsNoeTeX\relax

\xdef\regstats@lft{}

%    \end{macrocode}
%
% \LaTeXe{} 2011-06-27 changed the |\enddocument| command and thus
% broke the \pkg{atveryend} package, which was then fixed.
% If new \LaTeXe{} and old \xpackage{atveryend} are combined,
% |\AtVeryVeryEnd| will never be called.
% \LaTeXe{} 2020-10-01 introduced a new hook management.
% For \LaTeXe-format 2022-11-01 and newer we use hooks instead of
% loading the \pkg{atveryend} package.
%
%    \begin{macrocode}
\IfFormatAtLeastTF{2022/11/01}{
   \let\regst@ts@statistics\regstats@firstofone% We do not use \AtVeryVeryEnd.
   \newcommand{\regst@ts@st@tistics}[1]{\AddToHook{begindocument}{%
%    \end{macrocode}
%
% The \pkg{morewrites} package allows for more writes (see \hbox{p. \pageref{write}):}
%
%    \begin{macrocode}
     \AddToHook{begindocument/end}{\IfPackageLoadedTF{morewrites}{\def\regs@tsmw{65250}}{%
                                                                  \ifluatex\def\regs@tsmw{124}\else\def\regs@tsmw{16}\fi}%
     \AddToHook{enddocument}{\AddToHook{enddocument/afterlastpage}{\AddToHook{enddocument/afteraux}{%
                                                       \AddToHook{enddocument/info}{\AddToHook{enddocument/end}{#1}}}}}}}}
 }{\RequirePackage{atveryend}
   \let\regst@ts@statistics\AtVeryVeryEnd
   \IfFormatAtLeastTF{2011/06/27}{
      \@ifpackagelater{atveryend}{2011/06/29}{% 2011/06/30, v1.8, or even more recent: OK
       }{% else: older package version, no \AtVeryVeryEnd
         \let\regst@ts@statistics\regstats@firstofone
        }
    }{% else: older fmtversion: also OK
     }
   \newcommand{\regst@ts@st@tistics}[1]{\AtBeginDocument{\AtEndDocument{\AfterLastShipout{\AtVeryEndDocument{%
                                                                                           \AtEndAfterFileList{#1}}}}}}
%    \end{macrocode}
%
% With the |seminar| class or the \pkg{slidesec} package |\AtVeryVeryEnd| must not be used:
%
%    \begin{macrocode}
   \AtBeginDocument{%
     \@ifclassloaded{seminar}{% no \AtVeryVeryEnd
       \let\regst@ts@statistics\regstats@firstofone}{\relax}
     \@ifpackageloaded{slidesec}{% no \AtVeryVeryEnd
       \let\regst@ts@statistics\regstats@firstofone}{\relax}
%    \end{macrocode}
%
% The \pkg{morewrites} package allows for more writes (see \hbox{p. \pageref{write}):}
%
%    \begin{macrocode}
     \@ifpackageloaded{morewrites}{\def\regs@tsmw{32767}}{\ifluatex\def\regs@tsmw{124}\else\def\regs@tsmw{15}\fi}%
%    \end{macrocode}
%
% If neither \eTeX{} is available nor the \pkg{etex} package loaded,
% the number of available registers is drastically reduced:
%
%    \begin{macrocode}
     \ifetex\else%
       \@ifpackageloaded{etex}{\relax}{% else
        \gdef\regst@tsNoeTeX{%
         \PackageWarning{regstats}{Neither eTeX nor the e-TeX-package found.\MessageBreak%
           That can mean that e-TeX was disabled or\MessageBreak%
           that your distribution of TeX does not contain e-TeX\MessageBreak%
           or that you simply forgot to say \string\usepackage{etex}\MessageBreak%
           in the preamble of \jobname.tex.\MessageBreak%
           The number of available counter, dimen, skip,\MessageBreak%
           muskip, box, and toks registers as well as the\MessageBreak%
           number of insertions would be larger when using\MessageBreak%
           eTeX or the e-TeX-package;%
          }%
        }%
       }%
     \fi%
     }
  }

%    \end{macrocode}
% \pagebreak
%    \begin{macrocode}
\regst@ts@st@tistics{%
\regst@ts@statistics{%
  \xdef\regstats@message{\relax}%
%    \end{macrocode}
%
% |\regstats@regstatA| uses three arguments: 1.~the used number of registers
% of some type, 2.~the \textquotedblleft regular\textquotedblright number
% of available registers of that type, 3.~that number in case of extended
% register range (\eTeX). Maximum available minus used registers gives
% the number of free/currently available registers.
%
%    \begin{macrocode}
  \newcommand{\regstats@regstatA}[3]{%
    \ifx\regst@tsNoeTeX\relax \xdef\regstats@max{#3}\else\xdef\regstats@max{#2}\fi%
    \@tempcnta=\regstats@max \relax%
    \advance\@tempcnta by -#1\relax%
    \xdef\regstats@free{\the\@tempcnta}%
    }%
%    \end{macrocode}
%
% |\regstats@regstatB| gives the singular (2nd~argument) or plural (3rd~argument)
% of the name of that register type (1st~argument):
%
%    \begin{macrocode}
  \newcommand{\regstats@regstatB}[3]{%
    \@tempcnta=\regstats@max\relax%
    \advance\@tempcnta by -#1\relax%
    \xdef\regstats@free{\the\@tempcnta}%
    \@tempcnta=#1\relax%
    \ifnum \the\@tempcnta = 0%
      \@tempcnta=2\relax% zero: same as plural
    \fi%
    \ifnum \the\@tempcnta > 1%
      \gdef\regstats@pl{#3}% plural
    \else%
      \gdef\regstats@pl{#2}% singular
    \fi%
%    \end{macrocode}
%
% The number of used registers is given as per cent of the available
% registers of that type:
%
%    \begin{macrocode}
    \@tempcnta=#1\relax%
    \multiply\@tempcnta by 100\relax%
    \@tempcntb=\regstats@max\relax%
    \divide\@tempcnta by\@tempcntb\relax%
    \xdef\regstats@used{\space(\the\@tempcnta\@percentchar\space used)}%
%    \end{macrocode}
%
% If option |left| was chosen, the number of remaining registers of that type is announced:
%
%    \begin{macrocode}
    \ifregstats@left%
      \ifnum \regstats@free > 0\relax%
        \xdef\regstats@lft{, left: \regstats@free}%
      \else%
        \ifnum \regstats@free = 0\relax%
          \xdef\regstats@lft{, left: \regstats@free !!!}%
        \else% \regstats@free < 0
          \xdef\regstats@lft{, left: \regstats@free ??? **********}%
        \fi%
      \fi%
    \fi%
  }%
%    \end{macrocode}
%
% We now just take the current numbers of the various |count|s:
%
%    \begin{macrocode}
  \xdef\regstats@counter{\the\count10}%
  \xdef\regstats@dimen{\the\count11}%
  \xdef\regstats@skip{\the\count12}%
  \xdef\regstats@muskip{\the\count13}%
  \xdef\regstats@box{\the\count14}%
  \xdef\regstats@toks{\the\count15}%
  \xdef\regstats@read{\the\count16}%
  \xdef\regstats@write{\the\count17}%
  \xdef\regstats@fam{\the\count18}%
  \xdef\regstats@language{\the\count19}%
  \xdef\regstats@insert{\the\count20}%
%    \end{macrocode}
%
% |\countdef\insc@unt=20| is a synonym for the insertion counter.\par
% |\countdef\allocationnumber=21| is a synonym for the allocation counter
% |\count21|, which contains the most recently allocated number.
% For example, if |\newdimen{\regstatsdimen}| allocated a new dimen,
% and that dimen uses the $48\textsuperscript{th}$~dimen register, then
% |\count21| contains the $48$.\par
% |\count22| contains $-1$.
% \medskip
%
% We build the |\regstats@message|:
%
%    \begin{macrocode}
  \xdef\regstats@message{\regstats@message\message{^^J}}%
  \xdef\regstats@message{\regstats@message\message{Here is how much of TeX's registers you used^^J}}%
  \xdef\regstats@message{\regstats@message\message{\space (numbers of available registers are estimated!):^^J}}%
%    \end{macrocode}
%
% While |\xdef\regstats@...{\the\count...}| was used above,
% if \eTeX{} is available we use another register of that type
% and look at the register number it received.\par
% Classic \TeX{} has $2^{8}=256$~registers,
% \eTeX{} and \XeTeX{} have $2^{15}=32\,768$~registers,
% and \hologo{LuaLaTeX} has even $2^{15}=65\,536$~registers
% (for |\count|, |\dimen|, |\skip|, |\muskip|, |\box|, and |\toks|).
% There are only 16~|\read|s available.
% |\write|s and |\fam|s were traditionally also 16,
% see page~\pageref{write} (write) and page~\pageref{families} (families) about using more.
% |\lang|s are only 256 available.
% |\insert|s are complicated (see \hbox{p. \pageref{insertions}). --}\ %
% Each |\newlength| needs a skip register.
%
% \medskip
%
% \textbf{The counter registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@counter}{255}{32767}%
  \ifetex\newcounter{regstatscount}\xdef\regstats@counter{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@counter}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@counter\space  counter register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
% \pagebreak
%
% \textbf{The dimen registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@dimen}{255}{32767}%
  \ifetex\newdimen{\regstatsdimen}\xdef\regstats@dimen{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@dimen}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@dimen\space    dimen   register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \textbf{The skip registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@skip}{255}{32767}%
  \ifetex\newskip\regstatsskip\xdef\regstats@skip{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@skip}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@skip\space     skip    register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \textbf{The muskip registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@muskip}{255}{32767}%
  \ifetex\newmuskip\regstatsmuskip\xdef\regstats@muskip{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@muskip}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@muskip\space   muskip  register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \textbf{The box registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@box}{255}{32767}%
  \ifetex\newbox\regstatsbox\xdef\regstats@box{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@box}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@box\space      box     register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \textbf{The toks registers:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@toks}{255}{32767}%
  \ifetex\newtoks\regstatstoks\xdef\regstats@toks{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@toks}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@toks\space     toks    register\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \textbf{The \textquotedblleft read registers\textquotedblright, i.\,e. input streams:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@read}{15}{15}%
  \ifnum \regstats@free > 0\relax\newread\regstatsread\xdef\regstats@read{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@read}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@read\space     input stream\regstats@pl\space (read) %
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \phantomsection\label{write}
% \textbf{The \textquotedblleft write registers\textquotedblright, i.\,e. output streams:}\newline
% Traditionally, there are $16$~available output streams. Lua\TeX{} increases
% this to $124$, and the \pkg{morewrites} package even to $65\,250$ for \LaTeX,
% but not for \hologo{LuaLaTeX}. After write $32\,749\textsuperscript{th}$~write
% on |\write32767|, morewrites additionally uses one count register
% for each new write. And after the $65\,250\textsuperscript{th}$~write
% uses |\count32766|, there is no room for another |\count|,
% and therefore opening further writes fails.
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@write}{15}{\regs@tsmw}%
  \ifnum \regstats@free > 0\relax\newwrite\regstatswrite\xdef\regstats@write{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@write}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@write\space    output stream\regstats@pl\space (write) %
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \phantomsection\label{families}
% \textbf{The \textquotedblleft fam registers\textquotedblright, i.\,e. math families:}\newline
% Traditionally, there are $16$~available math families. \hologo{LuaLaTeX} and \XeLaTeX{}
% increase this to $256$ (at least since the 2015 release of \LaTeXe).
%
% \begin{quotation}
% \TeX{}, or more exactly the 8-bit versions of \TeX, such as \pdfTeX{},
% have a hard limit of~16 on the number of different math font groups
% (\cs{fam} or \cs{mathgroup}) that can be used in a single formula. For each symbol font
% declared (by a package or in the preamble) an extra math group is allocated,
% and the same happens for each math alphabet, (such as \cs{mathbf}) once it
% gets used anywhere in the document. Up to now, these math
% alphabet allocations were permanent, even if they were used only once;
% the result was that in complex documents you
% could easily run out of available math font groups.
% The only remedy for this was to
% define your own math version, which is a complicated and cumbersome process.
%
% This situation has now been improved by the introduction of a new counter
% \texttt{localmathalphabets}: this counter governs how many of
% the math group slots are assigned locally when a new math
% alphabet (and a new math group) is needed.
%
% Once the current formula is finished, every such further (local)
% allocation is undone, giving you a fighting chance of being
% able to use different new math alphabets in the next formula.
%
% The default value of \texttt{localmathalphabets} is 2,
% but if you need more local alphabets because of the complexity of your
% document, you can set this to a higher value such as 4 or~5.
% Setting it even higher is possible, but this would seldom
% be useful because many group slots will be taken up by
% symbol fonts and such slots are always permanently allocated,
% whether used or not.\par
% \hfill{}(Undo math alphabet allocations if necessary, in:
% \LaTeX{} News, Issue 34, 2021-11-15)
% \end{quotation}
%
% So the number of math family groups should have become less relevant.\newline
% |\setcounter{localmathalphabets}{| something larger than 2 |}|
% might help in case of issues. (|\stressFam| in the example file
% still does not find more than 15 (or 255 with \hologo{LuaLaTeX})
% |\fam|s available, because it (intentionally) does not use anything local.
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@fam}{15}{\ifluatex 255 \else 15\fi}%
  \ifnum \regstats@free > 0\relax\newfam\regstatsfam\xdef\regstats@fam{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@fam}{y}{ies}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@fam\space      math famil\regstats@pl\space (fam) %
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
% \pagebreak
%
% \textbf{The \textquotedblleft language registers\textquotedblright, i.\,e. language codes:}
%
%    \begin{macrocode}
  \regstats@regstatA{\regstats@language}{255}{255}%
  \ifnum \regstats@free > 0\relax\newlanguage\regstatslanguage\xdef\regstats@language{\the\allocationnumber}\fi%
  \regstats@regstatB{\regstats@language}{}{s}%
  \xdef\regstats@message{\regstats@message\message{ \regstats@language\space language code\regstats@pl\space%
        out of \regstats@max\regstats@used\regstats@lft ^^J}}%
  %
%    \end{macrocode}
%
% \phantomsection\label{insertions}%
% \textbf{The \textquotedblleft insert registers\textquotedblright, i.\,e. insertions:}\newline
% \textquotedblleft Inserts are given numbers $254$, $253$, etc.,
% since they require a |\count|, |\dimen|, |\skip|, and |\box|
% all with the same number\textquotedblright{} (source2e.pdf,
% File~b: ltplain.dtx Date:~2022-01-25 Version~v2.3h, has bugs, are fixed in dev 2023-04-04 v2.3h (i?)).\newline
% Because counter, dimen, skip, and box registers are also used independently
% from inserts, it can be expected to have no room for a new insert long before
% the 255 inserts are used.\medskip
%
% When testing, the first |\newinsert| registered into |\insert199|,
% followed by |\insert198|, \ldots, |\insert194|, and then apparently some
% |\count|, |\dimen|, |\skip|, or |\box| register was not available for
% |\insert193|. Therefore the |\newinsert| registered into |\insert252|,
% followed by |\insert251|, \ldots, |\insert201|, and then the already
% used insert registers were reached and there was
% |! No room for a new \insert|.\medskip
%
% With \hologo{LuaLaTeX} after |\insert192| the next |\newinsert| registered
% into |\insert252|, followed by |\insert251|, \ldots, |\insert201|,
% and then the next |\newinsert| registered into |\insert65534|,
% followed by |\insert65533|, \ldots, |\insert244|, and then there was
% |! No room for a new \count| -- mark it: |\count|, not |insert|.
% The inserts |\insert252| to |\insert244| seem to have been use twice
% and the inserts |\insert243|ff. not used twice only because no |\count|
% was available for them.\medskip
%
% Historic versions of \LaTeX{} were limited to less registers,
% therefore it was possible to |\usepackage{etex} \reserveinserts{17}|,
% in order to reserve room for up to 17 (or another number given)
% additional insertion classes, that will not be taken away by
% |\newcount|, |\newdimen|, |\newskip|, or |\newbox|.
% For resent \LaTeX-versions this is neither necessary nor recommendable:
% do not use the etex-package.\medskip
%
% When the inserts are needed for floats, the
% \href{https://ctan.org/pkg/morefloats}{morefloats} package can be used
% to \textquotedblleft increased the number of inserts available
% to the float mechanism\textquotedblright{} (\url{https://texfaq.org/FAQ-noroom}%
% \ at 2023-04-02). At the last given url \textquotedblleft No room for a new
% \guillemetright thing\guillemetleft\textquotedblright{} is treated.
%
%    \begin{macrocode}
  \ifx\regst@tsNoeTeX\relax%
    \newinsert\regstatsinsert%
    \xdef\regstats@insert{\the\allocationnumber}%
    \xdef\regstats@max{200}%
    \ifnum \regstats@insert < \regstats@max\relax%
      \xdef\regstats@free{\regstats@insert}%
      \@tempcnta=200\relax%
      \advance\@tempcnta by -\regstats@insert\relax%
      \xdef\regstats@insert{\the\@tempcnta}%
      \regstats@regstatB{\regstats@insert}{}{s}%
      \xdef\regstats@message{\regstats@message\message{ \regstats@insert\space insertion\regstats@pl\space%
            out of \regstats@max\regstats@used\regstats@lft ^^J}}%
    \else%
      \ifnum \regstats@insert = 200\relax%
        \xdef\regstats@message{\regstats@message\message{Number of insertions could not be calculated. ^^J}}%
      \else%
        \ifnum % \regstats@insert > 200 AND %
          \regstats@insert < 253\relax%
          \@tempcnta=253\relax%
          \advance\@tempcnta by -\regstats@insert\relax%
          \@tempcntb=-200\relax%
          \advance\@tempcntb by \regstats@insert\relax%
          \ifluatex%
            \@tempcntb=-65534\relax%
            \advance\@tempcntb by \regstats@insert\relax%
            \xdef\regstats@message{\regstats@message\message{at least \the\@tempcnta\space insertions out of 253 used, %
                                                                                                about 65 000 left ^^J}}%
          \else%
            \xdef\regstats@message{\regstats@message\message{at least \the\@tempcnta\space insertions out of 253 used, %
                                                                                  maybe \the\@tempcntb\space left ^^J}}%
          \fi%
        \else% \regstats@insert > 252, LuaTeX
          \@tempcntb=65534\relax%
          \advance\@tempcntb by -\regstats@insert\relax%
          \advance\@tempcntb by -253\relax%
          \xdef\regstats@message{\regstats@message\message{a lot of insertions out of 65 534 used, %
                                                                                  about \the\@tempcntb\space left ^^J}}%
        \fi%
      \fi%
    \fi%
  \else%
    \xdef\regstats@max{101}%
    \@tempcnta=\regstats@max\relax%
    \advance\@tempcnta by -\regstats@insert\relax%
    \xdef\regstats@insert{\the\@tempcnta}%
    \@tempcnta=\regstats@max\relax%
    \advance\@tempcnta by -\regstats@insert\relax%
    \xdef\regstats@free{\the\@tempcnta}%
    \regstats@regstatB{\regstats@insert}{}{s}%
    \xdef\regstats@message{\regstats@message\message{ \regstats@insert\space insertion\regstats@pl\space out of %
                                                                         \regstats@max\regstats@used\regstats@lft ^^J}}%
    \xdef\regstats@message{\regstats@message\message{* The number of available inserts might be increased by using %
                                                                                          \string\reserveinserts .^^J}}%
  \fi%
%    \end{macrocode}
%
% The construction of the message is now finished, the message is delivered:
%
%    \begin{macrocode}
  \regstats@message%
%    \end{macrocode}
% \pagebreak
%
% A note about morewrites:
%
%    \begin{macrocode}
  \ifluatex%
  \else%
    \def\regs@wmst{16}%
    \ifx\regs@tsmw\regs@wmst\relax%
      \message{The morewrites package was not loaded.^^J}%
      \message{\space With recent LaTeX and morewrites about 32 766 output streams would be available.^^J}%
    \fi%
  \fi%
%    \end{macrocode}
%
% If neither \eTeX{} nor the e-\TeX-package was found,
% the respective warning is given:
%
%    \begin{macrocode}
  \regst@tsNoeTeX%
%    \end{macrocode}
%
% When option |timer| (or |timer=true|) was used, the \xpackage{regstats} package
% additionally gives the time, which was needed for the (last) compilation (run).
% When more than one compilation run is necessary to compile the document,
% the individual times have to be added up manually.
% If~|\pdfelapsedtime| was reset by another package, the result is not correct,
% of course, but unfortunately it is not possible to check for this. You could say
% |\def\pdfresettimer{\relax}| immediately after |\documentclass[...]{...}|
% to prevent this. Better use\\
% |\long\def\pdfresettimer{%|\\
% \ |\PackageError{regstats}{\string\pdfresettimer\space used}}|\\
% to be notified thereof. This redefinition could be implemented in this
% \xpackage{regstats} package, but this would have no effect for the use of
% |\pdfresettimer| before this package is called. Because this package
% should be called as late as immediately before |\begin{document}|, this would mean
% that resetting would be possible during the whole loading of all packages.
%
% |\pdfelapsedtime| is not available when |lua(la)tex| is used instead of
% |pdf(la)tex| to compile the document. In that case at the very beginning
% of your \xfile{tex} file say\\
% \verb|\directlua{starttime = os.clock()}|\\
% (even before |\documentclass|!), and the \texttt{timer} option can also
% be used with \hologo{LuaLaTeX}. When neither |lualatex| nor |pdflatex| is used to
% compile the document, the timer(-option) does not work.
%
%    \begin{macrocode}
  \regst@ts@timer%
  }%
}
%    \end{macrocode}
%    \begin{macrocode}
%</package>
%    \end{macrocode}
% \pagebreak
%
% \section{Installation}
% \subsection{Downloads}
% Everything is available at \url{https://ctan.org},
% but may need additional packages themselves.\\
%
% \DescribeMacro{regstats.dtx}
% For unpacking the |regstats.dtx| file and constructing the documentation
% it is required:
% \begin{description}
% \item[-] \TeX-Format \LaTeXe{}: \url{https://www.CTAN.org/}
%
% \item[-] document class \xpackage{ltxdoc}, 2022/06/22, v2.1i, \url{https://ctan.org/pkg/ltxdoc}
%
% \item[-] package \xpackage{geometry}, 2020/01/02, v5.9, \url{https://ctan.org/pkg/geometry}
%
% \item[-] package \xpackage{holtxdoc}, 2019/12/09, v0.30, \url{https://ctan.org/pkg/holtxdoc}
%
% \item[-] package \xpackage{fontenc}, 2021/04/29, v2.0v, \url{https://ctan.org/pkg/fontenc}
% \end{description}
%
% \DescribeMacro{regstats.sty}
% The |regstats.sty| for \LaTeXe{} (i.\,e.~each document using
% the \xpackage{regstats} package) requires:
% \begin{description}
% \item[-] \TeX Format \LaTeXe{}, \url{https://www.CTAN.org/}
%
% \item[-] package \xpackage{kvoptions}, 2010/12/23, v3.10, \url{http://ctan.org/pkg/kvoptions}
%
% \item[-] package \xpackage{iftex}, \url{http://ctan.org/pkg/iftex}, or, if that is not available,
%   \begin{description}
%   \item[+] package \xpackage{ifpdf}, \url{http://ctan.org/pkg/ifpdf}
%   \item[+] package \xpackage{ifetex}, \url{http://ctan.org/pkg/ifetex}
%   \item[+] package \xpackage{ifluatex}, \url{http://ctan.org/pkg/ifluatex}
%   \end{description}
%
% \item[-] only for old \LaTeX-formats the \xpackage{atveryend} package is used,
%           \url{https://ctan.org/pkg/atveryend}, otherwise that package is not loaded but
%           the new hook management is used.
%
% \item[-] package \xpackage{regstats}, 2023-03-03, v1.1a, \url{https://ctan.org/pkg/regstats}\\
%   (Because you are reading the documentation for the
%    \xpackage{pagecolor} package, it can be assumed that you already
%    have some version of it~-- is it the current one?)
% \end{description}
%
% When option |timer| is used, additionally
% \begin{description}
% \item[-] package \xpackage{intcalc}, \url{https://ctan.org/pkg/intcalc}
% \end{description}
% is needed.\\
%
% \DescribeMacro{regstats-example.tex}
% The |regstats-example.tex| requires the same files as all
% documents using the \xpackage{regstats} package
% (see preceding paragraph |regstats.sty|) and additionally:
% \begin{description}
% \item[-] class \xpackage{article}, 2022/07/02, v1.4n, from \xpackage{classes}: %
%           \url{https://ctan.org/pkg/classes}
% \end{description}
%
% \DescribeMacro{Alternative}
% \DescribeMacro{regcount}
% As possible alternative in section~\ref{sec:Alternatives} there is listed
% \begin{description}
% \item[-] package \xpackage{regcount}, 1999/08/03, v1.0, \url{https://ctan.org/pkg/regcount},
%  which gives the wrong number for insertions, because it uses |\the\count20|,
%  but insertions are \emph{not} allocated from 0 upwards but starting at a higher number moving downward
%  (and having some jumps to other number ranges, see \hbox{p. \pageref{insertions}).}
% \end{description}
%
% \DescribeMacro{Oberdiek}
% \DescribeMacro{holtxdoc}
% \DescribeMacro{kvoptions}
% All packages of the `oberdiek' bundle
% (especially \xpackage{holtxdoc} and \xpackage{kvoptions})
% are also available in a TDS compliant ZIP archive:\newline
% \url{https://mirror.ctan.org/install/macros/latex/contrib/oberdiek.tds.zip}.
% It is probably best to download and use this, because the packages in there
% are quite probably both recent and compatible among themselves.
%
% \DescribeMacro{hyperref}
% \noindent \xpackage{hyperref} is not included in that bundle and needs to be
% downloaded separately,\newline
% \url{https://mirror.ctan.org/install/macros/latex/contrib/hyperref.tds.zip}.
%
% \DescribeMacro{atveryend}
% \noindent \xpackage{atveryend} is only loaded for and used with old \LaTeX-formats,
% otherwise that package is not loaded but the new hook management is used.
% The \xpackage{atveryend} package is available from
% \url{https://mirrors.ctan.org/macros/latex/contrib/atveryend.zip}
%
% \DescribeMacro{intcalc}
% \noindent \xpackage{intcalc} is available from
% \url{https://mirrors.ctan.org/install/macros/latex/contrib/intcalc.tds.zip}.
%
% \DescribeMacro{iftex}
% \DescribeMacro{ifetex}
% \DescribeMacro{ifluatex}
% \DescribeMacro{ifpdf}
% \noindent \xpackage{iftex} is available from
% \url{https://mirrors.ctan.org/install/macros/generic/iftex.tds.zip},
% its predecessors \xpackage{ifetex}, \xpackage{ifluatex}, and \xpackage{ifpdf}
% are no longer officially available for separate download.
%
% \vskip 1cm
%
% \DescribeMacro{Münch}
% A hyperlinked list of my (other) packages can be found at
% \url{https://ctan.org/author/muench-hm}.\\
%
% \subsection{Package, unpacking TDS}
% \paragraph{Package.} This package is available on \url{https://www.CTAN.org}.
% \begin{description}
% \item[\url{https://mirror.ctan.org/macros/latex/contrib/regstats/regstats.dtx}]\ %
%       The source file.
% \item[\url{https://mirror.ctan.org/macros/latex/contrib/regstats/regstats.pdf}]\ %
%       The documentation.
% \item[\url{https://mirror.ctan.org/macros/latex/contrib/regstats/regstats-example.pdf}]\ %
%       The compiled example file.
% \item[\url{https://mirror.ctan.org/macros/latex/contrib/regstats/regstats-example.log}]\ %
%       A \xfile{log} file for the example.
% \item[\url{https://mirror.ctan.org/macros/latex/contrib/regstats/README}]\ %
%       The README file.
% \end{description}
%
% There is also a |regstats.tds.zip| available:
% \begin{description}
% \item[\url{https://mirror.ctan.org/install/macros/latex/contrib/regstats.tds.zip}]\ %
%       Everything in TDS compliant, compiled format.
% \end{description}
% which additionally contains\\
% \begin{tabular}{ll}
% regstats.ins & The installation file.\\
% regstats.drv & The driver to generate the documentation.\\
% regstats.sty & The \xext{sty}le file.\\
% regstats-example.tex & The example file.\\
% regstats-example.log & A \xfile{log} file for the example.
% \end{tabular}
%
% \bigskip
%
% \noindent For required other packages please see the preceding subsection.
%
% \paragraph{Unpacking.} The \xfile{.dtx} file is a self-extracting
% \docstrip{} archive. The files are extracted by running the
% \xext{dtx} through \plainTeX{}:
% \begin{quote}
%   \verb|tex regstats.dtx|
% \end{quote}
%
% About generating the documentation see paragraph~\ref{GenDoc} below.\\
%
% \paragraph{TDS.} Now the different files must be moved into
% the different directories in your installation TDS tree
% (also known as \xfile{texmf} tree):
% \begin{quote}
% \def\t{^^A
% \begin{tabular}{@{}>{\ttfamily}l@{ $\rightarrow$ }>{\ttfamily}l@{}}
%   regstats.sty & tex/latex/regstats/regstats.sty\\
%   regstats.pdf & doc/latex/regstats/regstats.pdf\\
%   regstats-example.tex & doc/latex/regstats/regstats-example.tex\\
%   regstats-example.pdf & doc/latex/regstats/regstats-example.pdf\\
%   regstats-example.log & doc/latex/regstats/regstats-example.log\\
%   regstats.dtx & source/latex/regstats/regstats.dtx\\
% \end{tabular}^^A
% }^^A
% \sbox0{\t}^^A
% \ifdim\wd0>\linewidth
%   \begingroup
%     \advance\linewidth by\leftmargin
%     \advance\linewidth by\rightmargin
%   \edef\x{\endgroup
%     \def\noexpand\lw{\the\linewidth}^^A
%   }\x
%   \def\lwbox{^^A
%     \leavevmode
%     \hbox to \linewidth{^^A
%       \kern-\leftmargin\relax
%       \hss
%       \usebox0
%       \hss
%       \kern-\rightmargin\relax
%     }^^A
%   }^^A
%   \ifdim\wd0>\lw
%     \sbox0{\small\t}^^A
%     \ifdim\wd0>\linewidth
%       \ifdim\wd0>\lw
%         \sbox0{\footnotesize\t}^^A
%         \ifdim\wd0>\linewidth
%           \ifdim\wd0>\lw
%             \sbox0{\scriptsize\t}^^A
%             \ifdim\wd0>\linewidth
%               \ifdim\wd0>\lw
%                 \sbox0{\tiny\t}^^A
%                 \ifdim\wd0>\linewidth
%                   \lwbox
%                 \else
%                   \usebox0
%                 \fi
%               \else
%                 \lwbox
%               \fi
%             \else
%               \usebox0
%             \fi
%           \else
%             \lwbox
%           \fi
%         \else
%           \usebox0
%         \fi
%       \else
%         \lwbox
%       \fi
%     \else
%       \usebox0
%     \fi
%   \else
%     \lwbox
%   \fi
% \else
%   \usebox0
% \fi
% \end{quote}
% If you have a \xfile{docstrip.cfg} that configures and enables \docstrip's
% TDS installing feature, then some files can already be in the right
% place, see the documentation of \docstrip{}.
%
% \subsection{Refresh file name databases}
%
% If your \TeX~distribution (\TeX\,Live, \mikTeX, \dots) relies on
% file name databases, you must refresh these. For example, \TeX\,Live\ users
% run \verb|texhash| or \verb|mktexlsr|.
%
% \subsection{Some details for the interested}
% \paragraph{Unpacking with \LaTeX{}.}
% The \xfile{.dtx} chooses its action depending on the format:
% \begin{description}
% \item[\plainTeX:] Run \docstrip{} and extract the files.
% \item[\LaTeX:] Generate the documentation.
% \end{description}
% If you insist on using \LaTeX{} for \docstrip{} (really,
% \docstrip{} does not need \LaTeX ), then inform the auto-detect routine
% about your intention:
% \begin{quote}
%   \verb|latex \let\install=y\input{regstats.dtx}|
% \end{quote}
% Do not forget to quote the argument according to the demands
% of your shell.
%
% \paragraph{Generating the documentation.\label{GenDoc}}
% You can use both the \xfile{.dtx} or the \xfile{.drv} to generate
% the documentation. The process can be configured by a
% configuration file \xfile{ltxdoc.cfg}. For instance, put the following
% line into this file, if you want to have A4 as paper format:
% \begin{quote}
%   \verb|\PassOptionsToClass{a4paper}{article}|
% \end{quote}
%
% \noindent An example follows how to generate the
% documentation with \pdfLaTeX :
%
% \begin{quote}
%\begin{verbatim}
%pdflatex regstats.dtx
%makeindex -s gind.ist regstats.idx
%pdflatex regstats.dtx
%makeindex -s gind.ist regstats.idx
%pdflatex regstats.dtx
%\end{verbatim}
% \end{quote}
%
% \subsection{Compiling the example}
%
% The example file, \textsf{regstats-example.tex}, can be compiled via\\
% |(pdf)(la)tex regstats-example.tex|\\
% or (after removing the |%% | before |\directlua{starttime = os.clock()}|
% in the line before |\documentclass|\ldots) via\\
% |lua(la)tex regstats-example.tex|.\\
%
% \section{Acknowledgements}
%
% I would like to thank \textsc{Heiko Oberdiek} for providing a lot of
% useful packages (from which I also got everything I know about creating
% a file in \xext{dtx} format, OK, say it: copying),
% \textsc{Jean-Pierre F. Drucbert}~(\textdied) for his \xpackage{regcount} package,
% \textsc{Robin Fairbairns} for pointing me to the \xpackage{regcount} package.
%
% \phantomsection
% \begin{History}\label{History}
%   \begin{Version}{2011/05/14 v1.0a}
%     \item Upload to CTAN.
%   \end{Version}
%   \begin{Version}{2011/05/16 v1.0b}
%     \item Fixed a name clash with \xfile{regcount} package.
%     \item \xfile{regcount} package listed as possible alternative.
%     \item Bug: |skip| and |muskip| mixed up, fixed.
%     \item Counting of skips, math families, and insertions added.
%     \item Bug fix: insertions are numbered high to low.
%     \item Option |proof| added [obsolete now].
%   \end{Version}
%   \begin{Version}{2011/06/08 v1.0c}
%     \item Bug Fix: Number of available |\skip| registers with \eTeX{}.
%     \item Change in \eTeX{}-detection.
%     \item New option |left|.
%   \end{Version}
%   \begin{Version}{2011/06/18 v1.0d}
%     \item Bug Fix: Information about used registers/counters fixed.
%     \item New option |timer|.
%   \end{Version}
%   \begin{Version}{2011/08/22 v1.0e}
%     \item The information about the used registers is now presented even later.
%     \item Quite some details in the documentation.
%     \item Hot fix: \TeX{} 2011/06/27 has changed |\enddocument| and
%             thus broken the |\AtVeryVeryEnd| command/hooking
%             of \xpackage{atveryend} package as of 2011/04/23, v1.7.
%             Until it is fixed, |\AtEndAfterFileList| \emph{was} used.
%   \end{Version}
%   \begin{Version}{2011/08/23 v1.0f}
%     \item The \xpackage{atveryend} package was fixed (2011/06/30, v.1.8).
%             Now \xpackage{regstats} differentiates according to \TeX{} format
%             and \xpackage{atveryend} package version. 2011/06/30, v.1.8
%             should become available at CTAN soon. \xpackage{regstats} also
%             works with the old version, the information is just presented
%             a little bit earlier during compilation, thus theoretically
%             there could be missed some register use after that information,
%             which would be obvious in the \xfile{log}-file.~--
%             [\xpackage{atveryend} is no longer used after v1.0i of regstats,
%              when a recent \LaTeX-format with hook-management is used.]
%   \end{Version}
%   \begin{Version}{2012/01/01 v1.0g}
%     \item Now supports (but does not require) \hologo{LuaLaTeX} for option \texttt{timer}.
%     \item Bug fix: wrong path given in the documentation, fixed.
%     \item Due to the use of temporary counters, no longer a new counter is used
%             (except when option \texttt{proof=true} is chosen, of course). [deprecated now]
%     \item Circumvention of the incompatibility of the \xpackage{atveryend}
%             package with \xclass{seminar} class and \xpackage{slidesec} package
%             introduced.
%     \item Quite some additional changes in the \xfile{dtx} and README files.
%   \end{Version}
%   \begin{Version}{2012/01/07 v1.0h}
%     \item Bug fix: |\ifluatex| undefined without \xpackage{ifluatex} leads to wrong
%             association of |\else|\ldots|\fi|. Fixed by moving |\ifregstats@timer|.
%   \end{Version}
%   \begin{Version}{2012/04/01 v1.0i}
%     \item Bug fix: removed |.| before |on line|.
%     \item Bug fix: removed a |\pagebreak| after the first line of a page
%             from the documentation.
%     \item Bug fix: added a lot of |%|-signs at the end of lines in the code.
%     \item This version has been archived at
%             \url{https://web.archive.org/web/20170107053910/https://mirrors.ctan.org/install/macros/latex/contrib/regstats.tds.zip}.
%   \end{Version}
%   \begin{Version}{2023-04-04 v1.1a}
%     \item No longer uses the \pkg{atveryend} package for new \LaTeX-format but its hook-management.
%     \item No longer uses the \pkg{ltxcmds} package (but it is still loaded by the \xpackage{kvoptions} package).
%     \item No longer uses the deprecated |\BeforeClearDocument|.
%     \item Option proof is now deprecated.
%     \item Converted to UTF-8.
%     \item Added |\stress...| commands to the example.
%     \item Updates to documentation and README.
%   \end{Version}
% \end{History}
%
% \bigskip
%
% When you find a mistake or have a suggestion for an improvement of this package,
% please send an e-mail to the maintainer, thanks! (Please see BUG REPORTS in the README.)
%
% \bigskip
%
% \PrintIndex
%
% \Finale
\endinput