%%% ====================================================================
%%%  @LaTeX-style-file{
%%%     filename        = "showkeys.sty",
%%%     version         = "1.01",
%%%     date            = "25 August 1992",
%%%     time            = "11:32:08 BST",
%%%     author          = "David Carlisle",
%%%     address         = "Computer Science Department
%%%                        Manchester University
%%%                        Oxford Road
%%%                        Manchester
%%%                        England
%%%                        M13 9PL",
%%%     telephone       = "+44 61 275 6139",
%%%     FAX             = "+44 61 275 6236",
%%%     checksum        = "61501 431 1786 14304",
%%%     email           = "carlisle@cs.man.ac.uk (Internet)",
%%%     codetable       = "ISO/ASCII",
%%%     keywords        = "LaTeX, label, ref, citation, keys",
%%%     supported       = "yes",
%%%     docstring       = "
%%%
%%%     showkeys.sty
%%%
%%%     A LaTeX style option which causes
%%%     \label, \ref, \pageref, \cite and \bibitem
%%%     to print their argument for proof reading purposes. The main
%%%     feature of this style is that these labels are printed in such a
%%%     way as to minimise the changes caused to the formatting of the
%%%     rest of the document text.
%%%
%%%     Documentation requires Mittelbach's doc.sty.
%%%
%%%     The checksum field above was produced by
%%%     Robert Solovay's checksum utility.",
%%%  }
%%% ====================================================================
%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%<*x>
% This file may be used without modification as a style (.sty) file.
%
% If you have Mittelbach's doc.sty, this file may be formatted with a
% command like:
%                latex showkeys.sty
%
% If you have the Mittelbach/Duchier/Braams docstrip utility, you may
% produce a faster loading .sty file. Rename this file to: showkeys.doc
% Then run this file through *plain* TeX:
%                tex showkeys.doc
% This should produce the file showkeys.sty.
% If you do not have plain TeX on your system, you can trick LaTeX into
% doing the work as follows:
%                latex \def\fmtname{plain} \input showkeys.doc
% Note that you may need to quote the arguments here to stop your
% operating system treating the \ characters incorrectly.
%
%                latex showkeys.doc
% Will produce a typeset version of the documentation, as above.
%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\def\plain{plain}\ifx\fmtname\plain\csname fi\endcsname
     \def\batchfile{showkeys.doc}
     \input docstrip
     \preamble

     Do not distribute the stripped version of this file.
     The checksum in the header refers to the documented version.

     \endpreamble
     \generateFile{showkeys.sty}{t}{\from{showkeys.doc}{}}
     \endinput
\fi
%
\ifcat a\noexpand @\let\next\relax\else\def\next{%
    \documentstyle[showkeys,doc]{article}\MakePercentIgnore}\fi\next
%
%\def\eatmodule<#1>{}\eatmodule
%</x>
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \textwidth=355pt   ^^A Allow macrocode text with 72 columns.
% \CodelineIndex     ^^A Code lines numbered.
% \DisableCrossrefs  ^^A No Cross references.
% \MakeShortVerb{\"} ^^A "\foo" works like \verb+\foo+
%
% \title{showkeys.sty}
% \author{D. P. Carlisle}
% \date{21 August 1992}
% \begin{document}
% \showboxdepth=100
% \showboxbreadth=100
% \maketitle
%
% \section{Introduction}\label{sec:intro}
% "showkeys.sty" modifies the "\label", "\ref", "\pageref", "\cite", and
% "\bibitem" commands so that the `internal' key is printed. The style
% tries hard to position these labels so that the formatting of the rest
% of the document is unchanged. "\label" and "\bibitem" cause the
% key to appear in a box either in the margin, or in a \TeX\ box of zero
% width, which may possibly over-print other text. The "\ref",
% "\pageref" and "\cite" commands print their arguments in small type,
% raised just above the line, like this: \ref{sec:intro}.
% Works with "fleqn.sty". If used with "leqno.sty", or the AMS\LaTeX\
% options, "showkeys" must come later in the option list of the
% "\documentstyle" command.
%
% The only other similar style that I could find in the macro index,
% \cite{DMJ:mi}, was "showlabels.sty", \cite{GN:sl}. After the first
% draft of this style was written, I found \cite{anon:sk} on my local
% installation! I think the current style is more robust than
% \cite{anon:sk}, but I thought that "showkeys" was rather a good name,
% so I have stolen it for this style.
%
% \begin{enumerate}
% \item \label{e^1}This has "\label" immediately after "\item".
% \item This has the "\label" at the end.\label{e^2}
% \end{enumerate}
%
% \[
% \mbox{A "minipage" :- }\left\{
% \begin{minipage}{3in}
% Within environments like this "minipage", We can not use "\marginpar",
% so the appearance is slightly different. Here is that "enumerate"
% environment again:
%
% \begin{enumerate}
% \item \label{m&e^1}This has "\label" immediately after "\item".
% \item This has the "\label" at the end.\label{m&e^2}
% \end{enumerate}
% \end{minipage}
% \right.
% \]
%
% Displayed math (without "equation" counter).
% \[0=0\label{disp}\]
%
% Some text refering to the maths on page~\pageref{disp},  and the
% item~\ref{e^1}.
%
% If "showkeys" thinks that the current environment is going to produce
% an ``equation number'', then it does not show the label where the
% "\label" command occurs, but tries to put it in the margin, as shown
% with equation~\ref{eq:xx}.
% The style `knows' about the standard "equation" and "eqnarray"
% environments, and also all the numbered alignment environments offered
% by the AMS\LaTeX\ option, "amstex". ("amstex.sty" must be loaded
% before "showkeys.sty" for this to work.)
% \begin{equation}
% 1=1\label{eq:xx}
% \end{equation}
%
% \begin{eqnarray}
% 2&=&2\label{eqnar:a}\\
% 3&=&3\nonumber\\
% 4&=&4\label{eqnar:b}
% \end{eqnarray}
%
% \begin{figure}[h]
% Within a "figure" environment, the "\label" must not come  before the
% "\caption" command. If you place "\label" inside the argument of
% "\caption" the label will be shown like this:
%
% \caption{Within the caption argument.\label{cap:a}}
%
% If you place "\label" immediately after the "\caption" command it will
% be shown like this:
%
% \caption{Immediately after the caption argument.}\label{cap:b}
%
% If you place the "\label" command at some random point after the
% "\caption" command, it may be shown like:
%
% \caption{In vertical mode not immediately after a box.}
% \vspace{2pt}
%
% \label{cap:c}
% \end{figure}
%
%
% \begin{thebibliography}{9}
%
% \bibitem{GN:sl}
% Gil Neiger, {\em showlabels.sty},
% Undated style option, similar to this one, but shows labels
% inline, affecting the formating of the document.
%
% \bibitem{anon:sk}
% Annonymous, {\em showkeys.sty},
% Style option, dated 14 May 1988. Very similar to this one,
% also uses "\marginpar" in outer vertical mode.
%
% \bibitem{DMJ:mi}
% David M. Jones, {\em \TeX\ Macro Index},
% A catalogue of \TeX\ macros, including \LaTeX\ style files,
% available from all good \TeX\ archives.
%
% \end{thebibliography}
%
% \typeout{End of the Introduction and Examples.}
% \typein[\answer]
%   {Do you want an annotated listing of the macro definitions (y/n) ?}
% \def\next{y}\ifx\answer\next\else\expandafter\enddocument\fi
%
% \section{The Macros}
% As usual, prevent this file being read twice.
%    \begin{macrocode}
\@ifundefined{SK@label}{}{\endinput}
%    \end{macrocode}
%
% Again my usual hack to stop "\reset@font" generating an error when
% this style is used with old versions of \LaTeX.
%    \begin{macrocode}
\@ifundefined{reset@font}{}{}
%    \end{macrocode}
%
% \begin{macro}{\SK@label}
% \begin{macro}{\SK@bibitem}
% \begin{macro}{\SK@lbibitem}
% \begin{macro}{\SK@ref}
% \begin{macro}{\SK@pageref}
% \begin{macro}{\SK@citex}
% The saved original definitions
%    \begin{macrocode}
\let\SK@label\label
\let\SK@bibitem\@bibitem
\let\SK@lbibitem\@lbibitem
\let\SK@ref\ref
\let\SK@pageref\pageref
\let\SK@citex\@citex
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\SK@tag@form@}
% \begin{macro}{\SK@eqnnum}
% Saved original definitions of macros that print equation numbers.
%    \begin{macrocode}
\let\SK@tagform@\tagform@
\let\SK@eqnnum\@eqnnum
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\label}
% \begin{macro}{\@bibitem}
% \begin{macro}{\@lbibitem}
% The new definition, print the argument, and then do the old
% definition.
%    \begin{macrocode}
\def\label#1{\@bsphack\SK@\SK@@label{#1}\SK@label{#1}\@esphack}
\def\@bibitem#1{\SK@\SK@@label{#1}\SK@bibitem{#1}\ignorespaces}
\def\@lbibitem[#1]#2{%
  \SK@\SK@@label{#2}\SK@lbibitem[#1]{#2}\ignorespaces}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\SK@}
% Grab hold of "#2" via "\meaning" so characters like "&" and
% "^" do not cause problems later, and pass the result on to the command
% "#1".
%    \begin{macrocode}
\def\SK@#1#2{\def\@tempa{#2}\expandafter#1\meaning\@tempa\SK@}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\SK@@label}
% Strip off the initial segment of the "\meaning" output, and then put
% the rest either in a "\marginpar" or in a box of size 0pt,
% hopefully not disturbing the surrounding text.
%    \begin{macrocode}
\def\SK@@label#1>#2\SK@{%
%    \end{macrocode}
% Need to work globally as in some cases like alignments, and "fleqn",
% the counter will be printed in a different group to the "\label"
% command.
%    \begin{macrocode}
  \gdef\SK@lab{\smash{\fbox{\reset@font\small\tt#2}}}%
  \ifvmode
    \ifinner
%    \end{macrocode}
% Because of the contortions of the "list" environment, we might be in
% inner vertical mode if the "\label" immediately follows an "\item".
% The code for inner vertical mode is mainly optimised for the
% "\caption" command, and would fail miserably here, so use "\mbox" to
% get into horizontal mode, and to give a \meta{box} for "\lastbox" to
% get hold of. Did any one say `kludge'?
%    \begin{macrocode}
      \if@inlabel
        \mbox{}\let\@tempa\SK@lab
                \def\SK@lab{\llap{\@tempa\kern\leftmargin}}%
      \fi
%    \end{macrocode}
% In inner vertical mode, attach the label to the right of the
% immediately preceding box, if it is a box before the current point.
% Otherwise just put it in a box of zero dimensions, with no interline
% skip. (This may slightly move the surrounding text.)
%    \begin{macrocode}
      \setbox\z@=\lastbox
      \ifvoid\z@
        \nointerlineskip\SK@labx
      \else
        \hbox{\box\z@\SK@labx}%
      \fi
    \else
%    \end{macrocode}
% In outer vertical mode, use a "\marginpar".
%    \begin{macrocode}
      \marginpar{\SK@lab}\SK@lab@relax
    \fi
  \else
%    \end{macrocode}
% If we are in an numbered equation-style environment, do nothing as the
% code to print the number will also print the label, otherwise just
% stick the label at the current point, in a box of zero dimensions.
%    \begin{macrocode}
    \csname SK@\@currenvir\endcsname
    \ifSK@equation\else\SK@labx\fi
  \fi}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\iftagsleft@}
% Make sure that this AMS\LaTeX\ command really is an "\if.."
%    \begin{macrocode}
\def\@tempa{\let\iftagsleft@\iffalse}
\ifx\iftagsleft@\undefined\@tempa\fi
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\tag@form@}
% \begin{macro}{\eqnnum}
% Perhaps if "leqno" is operative, I should define "\@eqnnum" with the
% `left' version, but it does not really matter.
%    \begin{macrocode}
\iftagsleft@
  \def\tagform@#1{\llap{\SK@lab\kern\marginparsep}%
                   \SK@lab@relax\SK@tagform@{#1}}
  \def\@eqnnum{\llap{\SK@lab\kern\displaywidth\kern\marginparsep}%
                   \SK@lab@relax\SK@eqnnum}
\else
  \def\tagform@#1{\SK@tagform@{#1}%
                   \rlap{\kern\marginparsep\SK@lab}\SK@lab@relax}
  \def\@eqnnum{\SK@eqnnum\rlap{\kern\marginparsep\SK@lab}\SK@lab@relax}
\fi
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\SK@labx}
% Print the label, and then globally reset the print command to
% "\relax".
%    \begin{macrocode}
\def\SK@labx{\rlap\SK@lab\global\let\SK@lab\relax}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\SK@lab@relax}
% Clear the label.
%    \begin{macrocode}
\def\SK@lab@relax{\global\let\SK@lab\relax}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\SK@equation}
% \begin{macro}{\SK@eqnaray}
% \begin{macro}{\SK@align}
% \begin{macro}{\SK@alignat}
% \begin{macro}{\SK@xalignat}
% \begin{macro}{\SK@xxalignat}
% \begin{macro}{\SK@gather}
% \begin{macro}{\SK@multline}
% The following environments print an equation number, so "\label"
% should not print its argument at the point where it appears.
% Note this will fail to show the label if you are in an "eqnarray"
% environment, and use "\label" together with "\nonumber" This might
% just about make sense if you are going to use "\pageref", but that is
% too bad\ldots
%    \begin{macrocode}
\newif\ifSK@equation
\let\SK@equation\SK@equationtrue
\let\SK@eqnarray\SK@equationtrue
\let\SK@align\SK@equationtrue
\let\SK@alignat\SK@equationtrue
\let\SK@xalignat\SK@equationtrue
\let\SK@xxalignat\SK@equationtrue
\let\SK@gather\SK@equationtrue
\let\SK@multline\SK@equationtrue
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\ref}
% \begin{macro}{\pageref}
% \begin{macro}{\@citex}
% Print the argument with "\SK@@ref", and then call the original
% definition. then call the original macro.
%    \begin{macrocode}
\def\ref#1{\SK@\SK@@ref{#1}\SK@ref{#1}}
\def\pageref#1{\SK@\SK@@ref{#1}\SK@pageref{#1}}
\def\@citex[#1]#2{\SK@\SK@@ref{#2}\SK@citex[#1]{#2}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\SK@@ref}
% This is much simpler than the printing of the label, as we know that
% we can be in horizontal mode.
%    \begin{macrocode}
\def\SK@@ref#1>#2\SK@{%
  \leavevmode\vbox to \z@{\vss
    \rlap{\vrule\raise .75em
       \hbox{\underbar{\reset@font\footnotesize\tt#2}}}}}
%    \end{macrocode}
% \end{macro}
%
% \end{document}
\endinput