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% Copyright (C) 2022 by Julien Labbé <Julien.Labbe@univ-grenoble-alpes.fr>
%
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% This file may be distributed and/or modified under the conditions of the LaTeX
% Project Public License, either version 1.3 of this license or (at your option)
% any later version. The latest version of this license is in:
%
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% http://www.latex-project.org/lppl.txt
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% Note : this file was created from the version 2.1 of the dtxtut tutorial,
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%<*driver>
\ProvidesFile{altsubsup.dtx}
%</driver>
%<package> \NeedsTeXFormat{LaTeX2e}
%<package> \ProvidesPackage{altsubsup}
%<*package>
[2022/03/15 v1.1 .dtx altsubsup file]
%</package>
%
%<*driver>
\documentclass{ltxdoc}
\usepackage{altsubsup}
\usepackage{spbmark}
\usepackage[hidelinks]{hyperref}
\usepackage{xcolor}
\EnableCrossrefs
\CodelineIndex
\RecordChanges
% \OnlyDescription
\begin{document}
\DocInput{altsubsup.dtx}
\PrintChanges
\PrintIndex
\end{document}
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% \fi
%
% \CheckSum{147}
%
% \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         \~}
%
%
% \changes{v1.0}{2022/01/23}{Initial version.}
%
% \GetFileInfo{altsubsup.dtx}
%
% \DoNotIndex{\newcommand,\newenvironment,\let}
% \DoNotIndex{\#,\$,\%,\&,\@,\\,\{,\},\^,\_,\~,\ }
% \DoNotIndex{\begingroup,\endgroup,\bgroup,\egroup}
% \DoNotIndex{\catcode,\mathcode,\lccode,\lowercase}
% \DoNotIndex{\relax,\expandafter,\endinput}
% \DoNotIndex{\def,\edef,\gdef,\global,\newif,\ifx,\else,\fi}
% \DoNotIndex{\@ifnextchar,\@let@token}
% \DoNotIndex{\sb,\sp,\text}
%
% \title{The \textsf{altsubsup} package\thanks{This document
% corresponds to \textsf{altsubsup}~\fileversion, dated \filedate.}}
% \author{Julien Labb\'e \\ \texttt{Julien.Labbe@univ-grenoble-alpes.fr}}
%
% \maketitle
%
% \begin{abstract}
%   A \LaTeX{} package to write alternative and customisable subscripts and
%   superscripts, with  square brackets.
%
%   Typical use:
%   \begin{center}
%     \begin{tabular}{ccc}
%         |x_[roman]^{italic}|& $\longrightarrow$ & $x_[roman]^{italic}$ \\[6pt]
%         |x_{italic}^[roman]|& $\longrightarrow$ & $x_{italic}^[roman]$
%     \end{tabular}
%   \end{center}
% \end{abstract}
%
% \tableofcontents{}
% \clearpage
%
% \section{Introduction}
%
% The \textsf{altsubsup} package allows to write alternate subscripts and
% superscripts, in math mode, with square brackets :
% \begin{center}
%   |x_[my subscript]| \quad or \quad |x^[my superscript]|.
% \end{center}
% These alternate superscripts and superscripts are formatted by the commands
% set, respectively,  with |\SetAltSubscriptCommand| and
% |\SetAltSuperscriptCommand|. By default,  the |\text| command, from
% \textsf{amstext} (part of \textsf{amsmath}) is used. This gives:
% \begin{center}
%   $x_[my subscript]$ \quad or \quad $x^[my superscript]$.
% \end{center}
%
% This package redefine |_| and |^| symbols. Options allow to redefine both
% (by default), only subscript |_| symbol, or only superscript |^| symbol.
%
% \section{Motivations}
%
% Common typographic conventions\footnotemark{} use italic (sloping) type for
% physical quantities or mathematical variables and roman (upright) type for
% words or fixed numbers. For example, heat capacity at constant pressure should
% be printed $C_P$, but kinetic energy $E_[k]$ (instead of $E_k$) and relative
% permeability $\mu_[r]$ (instead of $\mu_r$). This can be obtainted in \LaTeX{}
% with\footnotemark{} |E_{\mathrm{k}}| and |\mu_{\mathrm{r}}|. This package
% allows to write them simply |E_[k]| and |\mu_[r]|.
% \footnotetext{See, for example: International Organization for
% Standardization. (2009). \emph{Quantities and units -- Part 1: General} (ISO
% Standard No. 80000-1:2009).
% \href{https://www.iso.org/standard/30669.html}{https://www.iso.org/standard/30669.html}.}
% \footnotetext{Instead of \texttt{\textbackslash{}mathrm}, a best choice is
% the \texttt{\textbackslash{}text} macro provided by \textsf{amsmath}
% package, which, for example, handle spaces. It's the formatting macro used
% by default by the \textsf{altsubsup} package.}
%
% \section{User interface}
%
% \subsection{Usage}
%
% \DescribeMacro{\SetAltSubscriptCommand\marg{cmd}}
%
% Set the command \meta{cmd} used to format square brackets subscripts
% |_[...]|. By default, \meta{cmd} is the |\text| command, provided by the
% \textsf{amstext} package (part of \textsf{amsmath} package).
%
% \DescribeMacro{\SetAltSuperscriptCommand\marg{cmd}}
%
% Set the command \meta{cmd} used to format square brackets superscripts
% |^[...]|. By default, \meta{cmd} is the |\text| command, provided by the
% \textsf{amstext} package (part of \textsf{amsmath} package).
%
% \DescribeMacro{\SetAltSubSupCommands\marg{cmd}}
%
% Set both square brackets subscripts and square brackets superscripts, with the
% same command \meta{cmd}.
%
% \pagebreak
% \subsection{Options}
%
% To load the package, add in your preamble:
% \begin{center}
%   \begin{minipage}{0.7\linewidth}
%     |\usepackage|\oarg{option}|{altsubsup}|
%   \end{minipage}
% \end{center}
% Available values for \meta{option}:
% \begin{description}
%  \item[|subscript|] redefine only the |_| subscript symbol.
%  \item[|superscript|] redefine only the |^| superscript symbol.
%  \item[|both|] redefine both |_| and |^| symbols (default).
%  \item[|spbmark|] use the \textsf{spbmark} package to handle bracket form of
%  superscripts and superscripts (see below).
% \end{description}
%
% \subsubsection*{\texttt{spbmark} option}
%
% The \textsf{spbmark} package
% (\href{https://www.ctan.org/pkg/spbmark}{https://www.ctan.org/pkg/spbmark}),
% by Qu Yi, allows a complete customisation of subscripts and superscripts.
% With the |spbmark| option, the \textsf{altsubsup} package use the |\sub| and
% |\super| macros of the \textsf{spbmark} package to handle subscripts and
% superscripts in place of the standard |_| and |^| commands.
%
% Theses two macros are called with the respective |altsub| and |altsup| styles,
% allowing simple customization (these styles are initially created empty).
% For example, to display subscripts in blue and superscripts in red, use:
% \begin{center}\begin{minipage}{0.7\linewidth}
% \begin{verbatim}
%   \defspbstyle{altsub}{cmd=\color{blue}}
%   \defspbstyle{altsup}{cmd=\color{red}}
% \end{verbatim}
% \end{minipage}\end{center}
%
% A major limitation is that using simultaneously a subscript and a superscript gives
% bad formatting (the \textsf{spbmark} macro for this is |\supersub|).
% For example, |x_[sub]^[super]| gives $x\sub{\text{sub}}\super{\text{super}}$
% instead of $x_[sub]^[super]$.
%
% \pagebreak
% \section{Example}
%
% The following input:
% \begin{center}\begin{minipage}{0.7\linewidth}
% \begin{verbatim}
% Default:
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
%
% New formats:
% % \text from amstext package
% % \color from xcolor package
% \newcommand{\bluecolor}[1]{\text{\color{blue}#1}}
% \newcommand{\redcolor}[1] {\text{\color{red}#1}}
% \SetAltSubscriptCommand{\bluecolor}
% \SetAltSuperscriptCommand{\redcolor}
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
%
% Same command for subscripts and superscripts:
% \SetAltSubSupCommands{\mathbf}
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
% \end{verbatim}
% \end{minipage}\end{center}
%
% gives:
% \begin{center}\begin{minipage}{0.7\linewidth}
% Default:
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
%
% New formats:
% \newcommand{\bluecolor}[1]{\text{\color{blue}#1}}
% \newcommand{\redcolor}[1] {\text{\color{red}#1}}
% \SetAltSubscriptCommand{\bluecolor}
% \SetAltSuperscriptCommand{\redcolor}
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
%
% Same command for subscripts and superscripts:
% \SetAltSubSupCommands{\mathbf}
% \begin{displaymath}
%   x_a^b  \quad
%   x_{braces sub}^{braces sup}  \quad
%   x_[brackets sub]^{braces sup}  \quad
%   x_{braces sub}^[brackets sup]  \quad
%   x_[brackets sub]^[brackets sup]
% \end{displaymath}
% \end{minipage}\end{center}
%
% \section{Complements}
%
% \subsection{Known issue}
%
% The use of the prime symbol |'| can raise the \emph{Double superscript}
% error message. This is normally fixed (|x'^2| gives $x'^2$ correctly).
% If needed, enclose the expression with |{...}|. In particular, |x'^[sup]|
% doesn't work, and should be written: |{x'}^[sup]|.
%
% \subsection{Alternative}
%
% \begin{description}
%  \item[the \textsf{subtext} package]
%   (\href{https://www.ctan.org/pkg/subtext}{https://www.ctan.org/pkg/subtext}),
%   by Palle J\o{}rgensen, formats |_[...]| subscripts with |\text| (the
%   differences, is that the \textsf{altsubsup} package works both for
%   subscripts and superscripts, allows to customise the commands, and
%   redefine symbols only in math mode).
% \end{description}
%
% \subsection{Changelog}
%
% \begin{description}
%  \item[v1.1]
% \begin{itemize}
% \item Backup standard subscript |_| and superscript |^| commands to handle
% packages that redefine |\sb| or |\sp| macros, as \textsf{spbmark}.
% \item Add option |spbmark| to format subscripts and superscripts with the
% \textsf{spbmark} package.
% \end{itemize}
%  \item[v1.0] Initial version.
% \end{description}

% \StopEventually{}
% \section{Implementation}
%
% \subsection*{Package declaration}
%
%    \begin{macrocode}
\ProvidesPackage{altsubsup}[2022/03/15, v1.1, Alternative and customisable
subscripts and superscripts, with  square brackets.]
%    \end{macrocode}
%
% \subsection*{Flags declaration}
%
% \subsubsection*{Determine the commands that will be redefined}
%
%    \begin{macrocode}
\newif\ifaltsbsp@subscript    \altsbsp@subscripttrue
\newif\ifaltsbsp@superscript  \altsbsp@superscripttrue
%    \end{macrocode}
%
% \subsubsection*{Use the spbmark mechanism}
%
%    \begin{macrocode}
\newif\ifaltsbsp@spbmark      \altsbsp@spbmarkfalse
%    \end{macrocode}
%
% \subsection*{Options declarations and processing}
%
% \changes{v1.1}{2022/03/15}{Add sbpmark option}
%    \begin{macrocode}
\DeclareOption{subscript}   {\altsbsp@subscripttrue   \altsbsp@superscriptfalse}
\DeclareOption{superscript} {\altsbsp@subscriptfalse  \altsbsp@superscripttrue }
\DeclareOption{both}        {\altsbsp@subscripttrue   \altsbsp@superscripttrue }
\DeclareOption{spbmark}     {\altsbsp@spbmarktrue}
\DeclareOption*{\PackageWarning{altsubsup}{Unknown option \CurrentOption.}}
\ProcessOptions\relax
\ifaltsbsp@spbmark
  \RequirePackage{spbmark}
\fi
%    \end{macrocode}
%
% \subsection*{Backup standard superscript and subscript commands}
%
% \changes{v1.1}{2022/03/15}{Backup standard superscript and superscript commands}
%
%    \begin{macrocode}
\AtBeginDocument{%
  \begingroup\catcode`\_=8 \global\let\altsbsp@standardsub=_\endgroup
  \begingroup\catcode`\^=7 \global\let\altsbsp@standardsup=^\endgroup
%    \end{macrocode}
%
% \subsection*{Redefine catcodes and make symbols active in mathmode}
%
%    \begin{macrocode}
  \ifaltsbsp@subscript    \catcode`\_=12 \mathcode`\_="8000 \fi%
  \ifaltsbsp@superscript  \catcode`\^=12 \mathcode`\^="8000 \fi%
}
%    \end{macrocode}
%
% \subsection*{Redefinition of the subscript symbol}
%
%    \begin{macrocode}
\ifaltsbsp@subscript%
\begingroup\lccode`\~=`\_\lowercase{\endgroup%
  \def~}{\@ifnextchar[% dummy bracket ]
  {\altsbsp@subwrapper}% bracket wrapper
  {\altsbsp@standardsub}% standard form
}%
\fi
%    \end{macrocode}
%
% \subsection*{Redefinition of the superscript symbol}
%
%    \begin{macrocode}
\ifaltsbsp@superscript%
\begingroup\lccode`\~=`\^\lowercase{\endgroup%
  \def~}{\@ifnextchar[% dummy bracket ]
  {\altsbsp@supwrapper}% bracket wrapper
  {\altsbsp@standardsup}% standard form
}%
\fi
%    \end{macrocode}
%
% \subsection*{User macros}
%
% \begin{macro}{\SetAltSubscriptCommand}
%    \begin{macrocode}
\def\SetAltSubscriptCommand#1{\let\altsbsp@altsubcmd#1}%
%    \end{macrocode}
% \end{macro}
%
%    \begin{macrocode}
\ifaltsbsp@spbmark%
  \defspbstyle{altsub}{}
  \def\altsbsp@subwrapper[#1]{\sub[style=altsub]{\altsbsp@altsubcmd{#1}}}%
\else
  \def\altsbsp@subwrapper[#1]{\altsbsp@standardsub{\altsbsp@altsubcmd{#1}}}%
\fi
%    \end{macrocode}
%
% \begin{macro}{\SetAltSuperscriptCommand}
%    \begin{macrocode}
\def\SetAltSuperscriptCommand#1{\let\altsbsp@altsupcmd#1}%
%    \end{macrocode}
% \end{macro}
%
%    \begin{macrocode}
\ifaltsbsp@spbmark%
  \defspbstyle{altsup}{}
  \def\altsbsp@supwrapper[#1]{\super[style=altsup]{\altsbsp@altsupcmd{#1}}}%
\else
  \def\altsbsp@supwrapper[#1]{\altsbsp@standardsup{\altsbsp@altsupcmd{#1}}}%
\fi
%    \end{macrocode}
%
% \begin{macro}{\SetAltSubSupCommands}
%    \begin{macrocode}
\newcommand{\SetAltSubSupCommands}[1]{%
  \SetAltSubscriptCommand{#1}%
  \SetAltSuperscriptCommand{#1}%
}
%    \end{macrocode}
% \end{macro}
%
% \subsection*{Set default commands}
%
%    \begin{macrocode}
\RequirePackage{amstext}%
\SetAltSubSupCommands{\text}%
%    \end{macrocode}
%
% \subsection*{Fix prime symbol}
%
%    \begin{macrocode}
\ifaltsbsp@superscript%
\begingroup \catcode`\^=12%
\gdef\altsbsp@pr@m@s{% copy of \@pr@m@s code from latex.ltx
  \ifx'\@let@token
    \expandafter\pr@@@s
  \else
    \ifx^\@let@token
      \expandafter\expandafter\expandafter\pr@@@t
    \else
      \egroup
    \fi
  \fi}
\endgroup
\let\pr@m@s\altsbsp@pr@m@s
\fi
%    \end{macrocode}
%
% \subsection*{End of the package}
%
%    \begin{macrocode}
\endinput
%    \end{macrocode}
% \Finale
\endinput