% \iffalse
% This is the shortlst package
% Copyright 1998 by Mogens Lemvig Hansen
% Run this file through LaTeX and read the documentation in shortlst.dvi
% \fi
% \CheckSum{366}
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
% \def\fileversion{1.1} \def\filedate{1998/11/27} \def\docdate{\filedate}
% \title{The \textsf{shortlst} Package\thanks{This file describes version
%   \fileversion, \filedate, which is a bug-fix release containing no new
%   functionality since version 1.0.}}
% \author{\copyright\ Mogens Lemvig Hansen\\mlhansen@uniserve.com}
% \date{\docdate}
% \maketitle
% \begin{abstract}
%    The \textsf{shortlst} package provides environments similar
%    to \textsf{itemize} and \textsf{enumerate} designed especially
%    for lists of short items.
% \end{abstract}
%
% \tableofcontents
%
% \section{The Basics}
% When you have a list of short items, the regular \textsf{itemize}
% environment leaves
% \begin{itemize}
% \item a lot
% \item of
% \item white
% \item space.
% \end{itemize}
% The obvious alternative is to use a \textsf{tabular}, but tables are
% difficult to type and harder to edit if you decide to interchange two items.
% \DescribeEnv{shortitemize}
% This package allows you to type input very similar to \textsf{itemize}
% input.
% \begin{verbatim}
% \begin{shortitemize}
% \item the \textsf{itemize} environment
% \item leaves
% \item a lot
% \item of
% \item white space
% \end{shortitemize}
% \end{verbatim}
% The code above yields output like\footnote{All ``output'' in this document
% is simulated since you probably did not install the \textsf{shortlst}
% package before \LaTeX ing the documentation.  The \emph{real} output is
% nicer\dots} this:
% \newlength\mlh
% \begin{quote}\raggedright\setlength\mlh{65pt}
% \makebox[2\mlh][l]{$\bullet$\hspace{\labelsep}the \textsf{itemize}
%   environment}\ignorespaces
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}leaves}\\
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}a lot}\ignorespaces
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}of}\ignorespaces
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}white space}
% \end{quote}
% Above, \LaTeX\ decided that the first item needs twice as much space as the
% other items.  You may give an optional argument to the \textsf{shortitemize}
% environment specifying the width of the default allotment of space.
% \begin{verbatim}
% \begin{shortitemize}[the \textsf{itemize} environment]
% \end{verbatim}
% Now each item gets as much space as the first.
% \begin{quote}\raggedright
% \settowidth\mlh{the \textsf{itemize} environment}%
% \addtolength\mlh{2\labelsep}\addtolength\mlh\labelwidth
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}the \textsf{itemize}
%   environment}%
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}leaves}\\%
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}a lot}%
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}of}\\%
% \makebox[\mlh][l]{$\bullet$\hspace{\labelsep}white space}%
% \end{quote}
%
% You may not put any list environment inside a
% \textsf{shortitemize} environment---but a \textsf{shortitemize} environment
% can be (part of) an item of a regular list environment.
% If you put a \textsf{shortitemize} environment inside a regular
% \textsf{itemize} environment, \textsf{shortitemize} will use the next level
% of labels.
% \DescribeMacro{\item}
% You may use the optional argument to \verb:\item: to override
% the label---just as for the regular \textsf{itemize} environment.
%
% \DescribeEnv{shortenumerate}
% The \textsf{shortlst} package also provides a \textsf{shortenumerate}
% environment.  You may use \textsf{shortenumerate} in the same way as
% \textsf{shortitemize}, \emph{mutatis mutandis}.
% \begin{verbatim}
% \begin{enumerate}
% \item An item.
% \item This item contains a sub-list:
%       \begin{shortenumerate}
%       \item One
%       \item[\%] One and a half
%       \item Two
%       \item \label{here}Three
%       \end{shortenumerate}
% \item Back in the outer list.
% \end{enumerate}
% \end{verbatim}
% The code above yields this output:
% \begin{enumerate}
% \item An item.
% \item \label{here}This item contains a sub-list:
%       \begin{quote}\raggedright\setlength\mlh{1.2in}
% \makebox[\mlh][l]{(a)\hspace{\labelsep}One}%
% \makebox[\mlh][l]{\%\hspace{\labelsep}One and a half}%
% \makebox[\mlh][l]{(b)\hspace{\labelsep}Two}%
% \makebox[\mlh][l]{(c)\hspace{\labelsep}Three}%
%       \end{quote}
% \item Back in the outer list.
% \end{enumerate}
% Now you may use \verb:\ref{here}: to refer to item \ref{here}(c) in the
% usual manner.
%
% \DescribeEnv{runenumerate}
% Some lists do not deserve a displayed paragraph.  For such you may use the
% \textsf{runenumerate} environment.
% \begin{verbatim}
% You have three choices:
% \begin{runenumerate}
% \item wash you hands,
% \item postpone it until tomorrow, or
% \item \label{choice}stay dirty.
% \end{runenumerate}
% I choose \ref{choice}!
% \end{verbatim}
% Here is then the output:
% \begin{quotation}\setlength\mlh{1em plus .5em minus .5em}
% You have three choices:
% \mbox{1.\hspace\labelsep}wash you hands,\hspace\mlh
% \mbox{2.\hspace\labelsep}postpone it until tomorrow, or\hspace\mlh
% \mbox{3.\hspace\labelsep}stay dirty.\hspace\mlh
% I choose 3!
% \end{quotation}
% The main advantage of the \textsf{runenumerate} environment is the automatic
% (and nested) numbering and cross references.
% \DescribeEnv{runitemize}
% For completeness, the \textsf{shortlst} package also provides a
% \textsf{runitemize} environment.
%
% \section{The Parameters}
%
% \DescribeMacro{\runitemsep}
% The length \verb:\runitemsep: stores the space
% between items of a \textsf{runenumerate} or \textsf{runitemize}
% environment.  Here is the default value:
% \begin{verbatim}
% \setlength{\runitemsep}{1em plus .5em minus .5em}
% \end{verbatim}
%
% \DescribeMacro{\labelsep}
% All four environments, \textsf{shortitemize}, \textsf{shortenumerate},
% \textsf{runitemize}, and \textsf{runenumerate} use \verb:\labelsep: (from
% the \LaTeX\ kernel, see \cite[p.~113]{LaTeXbook}, \cite[p.~62]{companion},
% or \cite{ltlists}) for the space between the label and
% the item itself.  The two short-list environments use the same space as the
% minimal space between one item and the next label.
%
% \DescribeMacro{\labelwidth}
% The labels of the \textsf{shortitemize} and \textsf{shortenumerate}
% environments may overlap the previous item if the length \verb:\labelwidth:
% (from the \LaTeX\ kernel, see \cite[p.~113]{LaTeXbook},
% \cite[p.~62]{companion}, or \cite{ltlists}) is too small.
%
% \DescribeMacro{\shortitemwidth}
% Instead of giving optional arguments to each \textsf{shortitemize} and
% \textsf{shortitemize} environment, you may change the length
% \verb:\shortitemwidth:, which stores the default width of each item (without
% the label and a bit of space on each side).
% \begin{verbatim}
% \setlength{\shortitemwidth}{65pt}
% \end{verbatim}
% Inside a \textsf{shortitemize} or \textsf{shortenumerate} environment
% \verb:\shortitemwidth: is the width of the optional argument to the
% environment.  Thus you may use
% \verb:\parbox[t]{\shortitemwidth}{:\meta{paragraph}\verb:}: to typeset a
% long item.
% \begin{verbatim}
% \begin{shortenumerate}[A little paragraph]
% \item A short item
% \item \parbox[t]{\shortitemwidth}{A little paragraph
%       that\footnote{To parbox} will be too long to fit on one line
%       no matter what\strut.}
% \item Another short
% \item \newlength{\mylength}%
%       \setlength{\mylength}{2\shortitemwidth}%
%       \addtolength{\mylength}{2\labelsep}%
%       \addtolength{\mylength}{\labelwidth}%
%       \begin{minipage}[t]{\mylength}
%         A little paragraph that\footnote{To minipage}
%         will be too long to fit on one line no matter what.
%       \end{minipage}
% \item Bla
% \item Bla
% \end{shortenumerate}
% \end{verbatim}
% The \verb:\strut: on the last line of the \verb:\parbox: improves the
% spacing between the \verb:\parbox: and the following line.
% \begin{quote}
% \raggedright
% \newlength\mylength
% \settowidth\mylength{A little paragraph}
% \setlength\mlh{100pt}
% \makebox[\mlh][l]{1.\hspace\labelsep A short item}^^A
% \makebox[\mlh][l]{2.\hspace\labelsep \parbox[t]{\mylength}{A little
% paragraph that\footnotemark{} will be too long to fit on one line
% no matter what.\strut}}\footnotetext{To parbox}^^A
% \makebox[\mlh][l]{3.\hspace\labelsep Another short}\\
% \makebox[2\mlh][l]{4.\hspace\labelsep
%       \begin{minipage}[t]{180pt}
%               A little paragraph that\footnote{To minipage}
%               will be too long to fit on one line
%               no matter what.
%       \end{minipage}}^^A
% \makebox[\mlh][l]{5.\hspace\labelsep Bla}\\
% \makebox[\mlh][l]{6.\hspace\labelsep Bla}^^A
% \end{quote}
%
%
% \section{The Limitations}
% \begin{itemize}
% \item The \textsf{shortitemize} and \textsf{shortenumerate} environments
% cannot contain any list environment.  These include \textsf{shortitemize},
% \textsf{shortenumerate}, \textsf{itemize}, \textsf{enumerate},
% \textsf{description}, \textsf{quote}, \textsf{quotation}, \textsf{verse},
% \textsf{center}, \textsf{flushleft}, \textsf{flushright},
% \textsf{verbatim}\footnote{But \texttt{\bslash verb} is ok.},
% \textsf{tabbing}, \textsf{trivlist}, \textsf{list}, and all environments
% made with \verb:\newtheorem:.
%
% \item All four environments handle footnotes\footnote{In the case of
% \textsf{shortitemize} and \textsf{shortenumerate} due to a technique found
% in the \textsf{tabularx} package by David Carlisle
% \cite[code lines 121--127]{tabularx}.};
% however, the \textsf{shortitemize} and \textsf{shortenumerate} environments
% do not handle other types of floats.
%
% \item The \textsf{shortitemize} and \textsf{shortenumerate} environments
% cannot handle items that are longer than one line; use \verb:\parbox: or the
% \textsf{minipage} environment---with the implications that has on footnotes.
%
% \item The \textsf{shortlst} package does not define a version of the
% \textsf{description} environment because I do not know what it should do.
%
% \item You cannot use the \verb:\label: command if your
% \textsf{shortenumerate} or \textsf{runenumerate} environment is nested
% inside a \textsf{tabularx} environment.
%
% \item All four environments defined by the \textsf{shortlst} package make
% (parts of) paragraphs not boxes.  If you want your list centred, you must
% therefore include it in a \verb:\parbox: (or \textsf{minipage}) and centre
% the box.
%
% \end{itemize}
%
%
% \section{The Alternatives}
% \begin{description}
% \item[multiple columns]
% You may use the regular \textsf{itemize} and \textsf{enumerate} environments
% in a multi-column format.  The \textsf{multicol} package \cite{multicol}
% creates multiple columns very nicely.  The items end up ordered vertically
% where this package orders them horizontally.
%
% \item[\textsf{tabular}]
% You can put your items in a table---but such are difficult to edit and you
% do not get automatic numbering and cross references.
%
% \item[\textsf{multienum}]
% The \textsf{multienum} package \cite{multienum} provides an environment
% similar to \textsf{shortenumerate}.  However, the input syntax is more
% similar to \textsf{tabular} than to \textsf{enumerate}.
%
% \item[\textsf{paralist}]
% The \textsf{paralist} package \cite{paralist} provides environments
% similar to \textsf{runitemize} and \textsf{runenumerate} except that
% nesting inside \textsf{itemize} or \textsf{enumerate} is not considered.
%
% \end{description}

%
%
% \section{The Copyright}
% \begin{itemize}
% \item
%%      You may use this software.
% \item
%%      You may copy this software and the documentation for your own use.
% \item
%%      You may distribute the file \texttt{shortlst.dtx} to others provided
%%      you do not make a profit doing so.
% \item
%%      You may modify my code and the documentation---including incorporating
%%      it into your own work---provided you do not make a profit on my work
%%      or allow others to.
% \end{itemize}
%
%
% \section{The Installation}
% \begin{itemize}
% \item Run the file \texttt{shortlst.dtx} through \LaTeX\ (thrice to resolve
% cross references\footnote{If you want an index you must run MakeIndex
% (\texttt{makeindex -s gind.ist shortlst}) between the second and third
% \LaTeX{} run.}).
% \begin{verbatim}
% latex shortlst.dtx
% \end{verbatim}
% \item Run the file \texttt{shortlst.ins} which now exists through \LaTeX.
% \begin{verbatim}
% latex shortlst.ins
% \end{verbatim}
% \item You now have to decide what to do with several files.
% \begin{itemize}
% \item You may now have to move the file \texttt{shortlst.sty} to some
% directory where \LaTeX\ can find it; \texttt{texmf/tex/latex/misc} would be
% the natural choice~\cite{tds}.
% \item Move the documentation, \texttt{shortlst.dvi}, to
% \texttt{texmf/doc/latex/misc}.
% \item You may discard the source file, \texttt{shortlst.dtx}, or store it in
% the directory \texttt{texmf/source/latex/misc}.
% \item Discard all remaining \texttt{shortlst.*} files.
% \end{itemize}
% \end{itemize}
%
%\StopEventually{
% \bibliographystyle{is-plain}
% ^^A\bibliography{tex}
% \begin{thebibliography}{1}
%
% \bibitem{ltlists}
% Johannes Braams, David Carlisle, Alan Jeffrey, Leslie Lamport, Frank
%   Mittelbach, Tobias Oetiker, Chris Rowley, and Rainer Sch{\"{o}}pf.
% \newblock {\em ltlists.dtx}.
% \newblock CTAN, 1997/02/21 edition, 1997.
%
% \bibitem{tabularx}
% David Carlisle.
% \newblock {\em The \textsf{tabularx} Package}.
% \newblock CTAN, 1997/09/18 v2.05 edition, 1997.
%
% \bibitem{ltboxes}
% David Carlisle, Leslie Lamport, Frank Mittelbach, and Chris Rowley.
% \newblock {\em ltboxes.dtx}.
% \newblock CTAN, 1998/06/05 edition, 1998.
%
% \bibitem{companion}
% Michel Goossens, Frank Mittelbach, and Alexander Samarin.
% \newblock {\em The {\LaTeX} Companion}.
% \newblock Addison-Wesley, 1994.
% \newblock ISBN 0-201-54199-8.
%
% \bibitem{multienum}
% Dennis Kletzing.
% \newblock {\em A Multienumerate Package}.
% \newblock CTAN.
% \newblock The author does not provide a version number.
%
% \bibitem{LaTeXbook}
% Leslie Lamport.
% \newblock {\em {\LaTeX}, A Document Preparation System, User's Guide and
%   Reference Manual}.
% \newblock Addison-Wesley, second edition, 1994.
% \newblock ISBN 0-201-52983-1.
%
% \bibitem{multicol}
% Frank Mittelbach.
% \newblock {\em An environment for multicolumn output}.
% \newblock CTAN, 1997/12/16 v1.5p edition, 1997.
%
% \bibitem{paralist}
% Bernd Schandl.
% \newblock {\em \textsf{paralist}, Enumerate and Itemize as and within
%   Paragraphs}.
% \newblock CTAN, 1998/10/11 v1.0 edition.
%
% \bibitem{tds}
% {TUG Working Group on a {\TeX} Directory Structure (TWG-TDS)}.
% \newblock {\em A Directory Structure for {\TeX} Files}.
% \newblock CTAN, version 0.9995, january 26, 1998 edition, 1998.
%
% \end{thebibliography}
% \PrintIndex
%}
%
%
% \section{The Driver}
% The following few lines of code allow \LaTeX\ to generate
% the \texttt{.sty} file and the documentation from this source.
% First, a \textsf{filecontents} environment creates the installation script,
% \texttt{shortlst.ins}, for \textsc{DocStrip}.
%    \begin{macrocode}
%<*docstrip>
\begin{filecontents}{shortlst.ins}
\input docstrip.tex
\preamble
   The shortlst Package
   Copyright 1998 by Mogens Lemvig Hansen
   mlhansen@uniserve.com
\endpreamble
%    \end{macrocode}
% I think that \texttt{shortlst.sty} should go into the directory
% \texttt{tex/latex/misc}; however, \textsc{DocStrip} will not heed my advise
% unless your configuration file, \texttt{docstrip.cfg}, allows it to.
%    \begin{macrocode}
\usedir{tex/latex/misc}
\generate{\file{shortlst.sty}{\from{shortlst.dtx}{package}}}
\endbatchfile
\end{filecontents}
%</docstrip>
%    \end{macrocode}
% Then the driver to typeset the documentation.
%    \begin{macrocode}
%<*docdriver>
\documentclass{ltxdoc}[1996/01/11]
\CodelineIndex%\EnableCrossrefs
\begin{document} \DocInput{shortlst.dtx} \end{document}
%</docdriver>
%    \end{macrocode}
%
%
% \section{The Implementation}
%
% Declare the package name.  I made this package with the December 1997
% version of \LaTeX; it may work with earlier versions.
%    \begin{macrocode}
%<*package>
\NeedsTeXFormat{LaTeX2e}[1997/12/01]
\ProvidesPackage{shortlst}
         [1998/11/27 version 1.1]
%    \end{macrocode}
%
% \subsection{The run-in lists}
% \begin{macro}{\runitemsep}
% Run-in items are separated by the length \verb:\runitemsep:.  The same
% amount of space is also placed before the first item and after the last.
%    \begin{macrocode}
\newlength\runitemsep
\setlength\runitemsep{1em plus .5em minus .5em}
%    \end{macrocode}
% \end{macro}
%
% \begin{environment}{runitemize}
% The \textsf{runitemize} environment first checks if the current level of
% nesting of \textsf{itemize}-like environments is shallow enough to proceed.
%    \begin{macrocode}
\newenvironment{runitemize}{%
   \ifnum \@itemdepth >\thr@@\@toodeep\else
   \advance\@itemdepth\@ne
%    \end{macrocode}
% Define the default label, \verb:\@itemlabel:, as \verb:\labelitem:\meta{i}
% which expand to the bullet, dash, etc.\ used by \textsf{itemize}.
%    \begin{macrocode}
   \edef\@itemitem{labelitem\romannumeral\the\@itemdepth}%
   \def\@itemlabel{\csname\@itemitem\endcsname}%
%    \end{macrocode}
% The regular \verb:\item: command calls \verb:\@item:, so make it use a
% custom version.
%    \begin{macrocode}
   \let\@item\run@item
%    \end{macrocode}
% Disable \verb:\par: inside the \textsf{runitemize} environment, ignore
% spaces following the \verb:\begin{runitemize}:, and close the \verb:\ifnum:
% at the beginning of this definition.
%    \begin{macrocode}
   \let\par\relax
   \ignorespaces\fi}
%    \end{macrocode}
% At the end of the \textsf{runitemize} environment you must remove the space
% (if any) between the last item and the \verb:\end{runitemize}:; replace it
% by \verb:\runitemsep: amount of space.   Then ignore spaces following the
% \verb:\end{runitemize}:.
%    \begin{macrocode}
   {\unskip\hspace\runitemsep\ignorespacesafterend}
%    \end{macrocode}
% \end{environment}
%
% \begin{environment}{runenumerate}
% The definition of the \textsf{runenumerate} environment is similar to that
% of the \textsf{runitemize} environment.
%    \begin{macrocode}
\newenvironment{runenumerate}{%
   \ifnum \@enumdepth >\thr@@\@toodeep\else
   \advance\@enumdepth\@ne
%    \end{macrocode}
% The call to \verb:\usecounter{enum:\meta{i}\verb:}: sets \verb:\if@nmbrlist:
% true and defines \verb:\@listctr: as \verb:enum:\meta{i} which is the
% counter used by the \textsf{enumerate} environment at this level.
%    \begin{macrocode}
   \edef\@enumctr{enum\romannumeral\the\@enumdepth}%
   \usecounter{\@enumctr}%
%    \end{macrocode}
% Define the default label, \verb:\@itemlabel:, as \verb:\labelenum:\meta{i}.
%    \begin{macrocode}
   \def\@itemlabel{\csname label\@enumctr \endcsname}%
   \let\@item\run@item
   \let\par\@empty
   \ignorespaces\fi}
   {\unskip\hspace\runitemsep\ignorespacesafterend}
%    \end{macrocode}
% \end{environment}
%
% \begin{macro}{\run@item}
% The regular \verb:\item: command checks if it has an optional argument,
% stores the answer in \verb:\if@noitemarg:, and calls \verb:\@item: or
% \verb:\@item[\@itemlabel]: as appropriate.  The \verb:\run@item: command is
% the custom version of \verb:\@item: for the run-in list environments.
%
% First remove the space (if any) between the last item and this one; replace
% it by \verb:\runitemsep: amount of space.  However, this could be the first
% item of a list which is the first object in a paragraph.  In that case, just
% begin a new paragraph.
%    \begin{macrocode}
\def\run@item[#1]{%
   \ifhmode\unskip\hspace\runitemsep\else\leavevmode\fi
%    \end{macrocode}
% If the \verb:\item: had no optional argument and if this is a numbered list,
% increment the counter.
%    \begin{macrocode}
   \if@noitemarg
      \@noitemargfalse
      \if@nmbrlist\refstepcounter{\@listctr}\fi
   \fi
%    \end{macrocode}
% Set the label.
%    \begin{macrocode}
   \mbox{#1}\kern\labelsep\ignorespaces}
%    \end{macrocode}
% \end{macro}
%
% \subsection{The short-lists}
% \begin{macro}{\shortitemwidth}
% The idea is to typeset each item in a box of width
% ``a multiple of a fixed length.''  \TeX\ will then stack the boxes so that
% they line up nicely.
% The default ``fixed length'' is $\verb:\shortitemwidth: + \verb:\labelwidth:
% + 2\verb:\labelsep:$ (one \verb:\labelsep: between the label and the item;
% another \verb:\labelsep: between this item and the next label).
% The default value is rather arbitrary.
%    \begin{macrocode}
\newlength\shortitemwidth
\setlength\shortitemwidth{65pt}
%    \end{macrocode}
% \end{macro}
%
% \begin{environment}{shortitemize}
% The default value of the optional argument to the \textsf{shortitemize}
% environment is a box of width \verb:\shortitemwidth:.
%    \begin{macrocode}
\newenvironment{shortitemize}[1][\hbox to \shortitemwidth{\hfil}]{%
%    \end{macrocode}
% Check the level of nesting and define the default label as for
% \textsf{runitemize} above.
%    \begin{macrocode}
   \ifnum \@itemdepth >\thr@@\@toodeep\let\endsh@rtitem\relax\else
   \ifx\item\sh@rtitem\sh@rtnesterr\let\endsh@rtitem\relax\else
   \advance\@itemdepth\@ne
   \edef\@itemitem{labelitem\romannumeral\the\@itemdepth}%
%    \end{macrocode}
% Measure the width of the optional argument.
% Since short-list environments
% cannot be nested anyway, you may store the value locally in
% \verb:\shortitemwidth:.
%    \begin{macrocode}
   \settowidth\shortitemwidth{#1}%
%    \end{macrocode}
%
% Use the \textsf{list} environment to create a displayed paragraph for the
% short-list.
% If the end-user has mismatched environments, \LaTeX\ should not mention a
% \textsf{list} environment from the workings of this code, so use
% \verb:\list: and \verb:\endlist: instead of \verb:\begin{list}: and
% \verb:\end{list}:.
%
% In the \textsf{itemize} environment labels stick out in the margin; to get
% things to line up here, it is easier to move the left margin instead.
%    \begin{macrocode}
   \list{}{\addtolength\leftmargin\itemindent
           \addtolength\leftmargin{-\labelwidth}%
           \addtolength\leftmargin{-\labelsep}%
%    \end{macrocode}
% You cannot have any indentation inside the \textsf{shortitemize}
% environment.
%    \begin{macrocode}
           \setlength\itemindent\z@}%
%    \end{macrocode}
% The \verb:\item: command gets the \textsf{list} environment started.  Then
% it is safe to set up a custom version of \verb:\item:
% \changes{1.1}{98/11/27}{Fixed the ragged right.}
% and a \verb:\raggedright: style right-hand margin.
% The \verb:\endsh@rtitem: command is explained below.
%    \begin{macrocode}
   \item\relax
   \@rightskip\@flushglue \rightskip\@rightskip
   \let\endsh@rtitem\noindent
   \let\item\sh@rtitem
   \def\@itemlabel{\csname\@itemitem\endcsname}%
   \fi\fi\ignorespaces}%
%    \end{macrocode}
%
% At the end of the \textsf{shortitemize} environment you must process the
% last item and close the \textsf{list} environment.
%    \begin{macrocode}
   {\endsh@rtitem\endlist}
%    \end{macrocode}
% \end{environment}
%
%
% \begin{environment}{shortenumerate}
% The definition of the \textsf{shortenumerate} environment is straight
% forward once you comprehend the \textsf{runenumerate} and
% \textsf{shortitemize} environments.
% \changes{1.1}{98/11/27}{Fixed the ragged right.}
%    \begin{macrocode}
\newenvironment{shortenumerate}[1][\hbox to \shortitemwidth{\hfil}]{%
   \ifnum \@enumdepth >\thr@@\@toodeep\let\endsh@rtitem\relax\else
   \ifx\item\sh@rtitem\sh@rtnesterr\let\endsh@rtitem\relax\else
   \advance\@enumdepth\@ne
   \edef\@enumctr{enum\romannumeral\the\@enumdepth}%
   \settowidth\shortitemwidth{#1}%
   \list{}{\addtolength\leftmargin\itemindent
           \addtolength\leftmargin{-\labelwidth}%
           \addtolength\leftmargin{-\labelsep}%
           \setlength\itemindent\z@}%
   \item\relax
   \@rightskip\@flushglue \rightskip\@rightskip
   \let\endsh@rtitem\noindent
   \let\item\sh@rtitem
   \usecounter{\@enumctr}%
   \def\@itemlabel{\csname label\@enumctr \endcsname}%
   \fi\fi\ignorespaces}%
   {\endsh@rtitem\endlist}
%    \end{macrocode}
% \end{environment}
%
% \begin{macro}{\TX@ftn}\begin{macro}{\TX@ftntext}\begin{macro}{\TX@xftntext}
% Since each item is typeset inside a box, \TeX\ gobbles up all footnotes.
% David Carlisle has solved that problem in his \textsf{tabularx} package
% \cite[code lines 122--127]{tabularx}.  To
% require all of that package every time seems a bit much, so just copy those
% lines of code if needed.
% These special versions of \verb:\@footnotetext: and \verb:\@xfootnotetext:
% store appropriate \verb:\footnotetext: commands in the token list
% \verb:\TX@ftn: for later processing.
%    \begin{macrocode}
\ifx\TX@ftn\undefined
   \newtoks\TX@ftn
   \long\def\TX@ftntext#1{%
     \edef\@tempa{\the\TX@ftn\noexpand\footnotetext
                       [\the\csname c@\@mpfn\endcsname]}%
     \global\TX@ftn\expandafter{\@tempa{#1}}}%
   \long\def\TX@xftntext[#1]#2{%
     \global\TX@ftn\expandafter{\the\TX@ftn\footnotetext[#1]{#2}}}
\fi
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}
%
% \begin{macro}{\sh@rtitem}
% You need to capture each item in a box.  Thus each \verb:\item: must close
% and process the previous box before it begins capturing the next item.  The
% custom version of \verb:\item: therefore first calls \verb:\endsh@rtitem: to
% finish off the last item, then checks for an optional argument, stores the
% answer in \verb:\@noitemarg:, and calls \verb:\sh@rt@item: or
% \verb:\sh@rt@item[\@itemlabel]: as appropriate.  Here \verb:\@itemlabel: is
% the default label.
%    \begin{macrocode}
\def\sh@rtitem{%
  \endsh@rtitem
  \@inmatherr\item
  \@ifnextchar [\sh@rt@item{\@noitemargtrue \sh@rt@item[\@itemlabel]}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\sh@rt@item}
% \begin{macro}{\endsh@rtitem}
% The \verb:\sh@rt@item: command first (re-)defines \verb:\endsh@rtitem:.  An
% \textsf{lrbox} environment captures the label and the text of the item in
% the box \verb:\@tempboxa:, so close that environment---only use
% \verb:\begingroup\lrbox: and \verb:\endlrbox\endgroup: instead of
% \verb:\begin{lrbox}: and \verb:\end{lrbox}: as for \verb:\list: above (the
% extra group is necessary due to the convoluted workings of \textsf{lrbox}
% \cite[code lines 69--80]{ltboxes}).
%    \begin{macrocode}
\def\sh@rt@item[#1]{%
   \def\endsh@rtitem{\endlrbox\endgroup%
%    \end{macrocode}
% Measure the width of the box---that is, the width of the label, the space
% between the label and the item, and the item itself.  Let $a$ be that width
% plus one \verb:\labelsep: (for the separation between this item and the next
% label).
%    \begin{macrocode}
      \setlength\@tempdima{\wd\@tempboxa}%
      \addtolength\@tempdima\labelsep
%    \end{macrocode}
% Then let $b$ be the ``fixed length;'' that is, $\verb:\labelwidth: +
% 2\verb:\labelsep: + \verb:\shortitemwidth:$.
%    \begin{macrocode}
      \setlength\@tempdimb\shortitemwidth
      \addtolength\@tempdimb{2\labelsep}%
      \addtolength\@tempdimb{\labelwidth}%
%    \end{macrocode}
% Then calculate how many multiples of $b$ you need to contain $a$; that is,
% calculate $\lceil \frac ab \rceil b$.  However, \LaTeX\ does not provide a
% ceiling function, so use \TeX's integer division command, which (for
% positive integers) calculates $\lfloor \frac ab \rfloor$, and add one.  The
% result is fine except when $b$ divides $a$ perfectly---which could happen if
% the item is a \verb:\parbox{\shortitemwidth}:, so cheat:  decrease $a$ by A
% Very Small Length first.
%    \begin{macrocode}
      \addtolength\@tempdima{-1sp}% subtract a Very Small Length
      \divide\@tempdima by \@tempdimb%
      \addtolength\@tempdima{1sp}%  add one
      \multiply\@tempdimb by \@tempdima%
%    \end{macrocode}
% Now $b$ is the desired width of the box. Instead of actually making a box of
% that width, typeset the box as is followed by a suitable amount of space
% (which will then nicely disappear if it happens to land on the right-hand
% margin).
%    \begin{macrocode}
      \addtolength\@tempdimb{-\wd\@tempboxa}%
      \usebox\@tempboxa
%    \end{macrocode}
% Now $b$ is the amount of space which you must remember to set once the
% footnotes have been processed..
%
% The following line of code (from \cite[code line 50]{tabularx}) inserts the
% footnotes (or, rather, \verb:\footnotetext:-s) that were collected inside
% the box.
% The \verb:\expandafter: trickery causes \TeX\ to first clear the token list
% \verb:\TX@ftn:, then execute the \verb:\footnotetext: commands that it
% contained.  This convoluted order ensures that the \verb:\footnotetext:-s go
% back into \verb:\TX@ftn: if the short-list is nested inside a
% \textsf{tabularx} environment (so that \textsf{tabularx} can typeset them in
% due time).
%   \begin{macrocode}
      \global\TX@ftn\expandafter{\expandafter}\the\TX@ftn
      \hspace\@tempdimb}%
%    \end{macrocode}
% \end{macro}
%
% That was the end---now back to the beginning.  First ref-step the counter if
% appropriate.
%    \begin{macrocode}
   \if@noitemarg
      \@noitemargfalse
      \if@nmbrlist\refstepcounter{\@listctr}\fi
   \fi
%    \end{macrocode}
% Issue a warning if the label is too wide---it may overlap the previous item.
%    \begin{macrocode}
   \settowidth\@tempdima{#1}%
   \ifdim\@tempdima>\labelwidth\PackageWarning{shortlst}%
      {label too wide
       (set \string\labelwidth\space to at least \the\@tempdima)}%
   \fi
%    \end{macrocode}
% Then begin collecting an lrbox.  Once inside the box, use the custom
% footnotes and set the label and some space before the item itself.
%    \begin{macrocode}
   \begingroup\lrbox{\@tempboxa}%
      \let\@footnotetext\TX@ftntext\let\@xfootnotenext\TX@xftntext
      \makebox[\labelwidth][r]{#1}%
      \hspace{\labelsep}\ignorespaces}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\sh@rtnesterr}
% That's it!  You just need a single custom error message.
%    \begin{macrocode}
\newcommand{\sh@rtnesterr}{\PackageError{shortlst}
   {nested short-lists}
   {don't nest short-list environments within each other}}
%</package>
%    \end{macrocode}
% \end{macro}
% \Finale