% \iffalse meta-comment
%
%% File: latex-lab-amsmath.dtx
%
% Copyright (C) 2022-2025 The LaTeX Project
%
% It may be distributed and/or modified under the conditions of the
% LaTeX Project Public License (LPPL), either version 1.3c of this
% license or (at your option) any later version. The latest version
% of this license is in the file
%
% https://www.latex-project.org/lppl.txt
%
%
% The development version of the bundle can be found below
%
% https://github.com/latex3/latex2e/required/latex-lab
%
% for those people who are interested or want to report an issue.
%
%<*driver>
\documentclass{l3doc}
\EnableCrossrefs
\CodelineIndex
\begin{document}
\DocInput{latex-lab-amsmath.dtx}
\end{document}
%</driver>
%
% \fi
%
%
% \title{The \texttt{latex-lab-amsmath} code\thanks{}}
% \author{\LaTeX{} Project}
%
% \maketitle
%
% \newcommand\fmi[1]{\begin{quote} TODO: \itshape #1\end{quote}}
% \newcommand\NEW[1]{\marginpar{\mbox{}\hfill\fbox{New: #1}}}
% \providecommand\class[1]{\texttt{#1.cls}}
% \providecommand\pkg[1]{\texttt{#1}}
% \providecommand\hook[1]{\texttt{#1}}
%
% \begin{abstract}
% \end{abstract}
%
% \tableofcontents
%
% \section{Introduction}
%
% This file implements adaptations to the \pkg{amsmath} package needed for
% the tagging project.
%
% \MaybeStop{\setlength\IndexMin{200pt} \PrintIndex }
%
% \section{The Implementation}
%
% Better no @@ expansion here \ldots ...
% \begin{macrocode}
%<@@=>
% \end{macrocode}
%
% \begin{macrocode}
%<*kernel>
% \end{macrocode}
%
% \subsection{File declaration}
% \begin{macrocode}
\ProvidesFile{latex-lab-amsmath.ltx}
[2025-01-31 v0.1e amsmath adaptions]
% \end{macrocode}
% \subsection{Tagpdf support}
% To make the code independent from tagging being loaded and active
% we load the \pkg{tagpdf-base} package:
%
% \begin{macrocode}
\RequirePackage{tagpdf-base}
% \end{macrocode}
%
% \begin{macrocode}
\ExplSyntaxOn
% \end{macrocode}
%
% \subsection{Measuring}
% When measuring we neither want tagging nor the luamml processing.
% \begin{macro}{\measuring@true}
% \begin{macrocode}
\def\measuring@true{\let\ifmeasuring@\iftrue\tag_suspend:n{\measuring}\luamml_ignore:}
% \end{macrocode}
% \end{macro}
%
% \subsection{Display environments}
% \changes{0.1e}{2025-01-31}{moved redefinitions from latex-lab-math and luamml into this file}
%
% \subsubsection{Tag}
% The tag/label must be saved, so that it can be reinserted later.
%
% TODO: \cs{maketag@@@} is perhaps used in places where tagging/luamml handling
% is not wanted. This must be checked and handled.
% \begin{macro}{\maketag@@@}
% \begin{macrocode}
\def\maketag@@@#1
{%
\ifmeasuring@
\hbox{\m@th\normalfont#1}%
\else
\UseTaggingSocket{math/display/tag/begin}
\hbox{\m@th\normalfont#1
\UseTaggingSocket{math/luamml/mtable/tag/save}
}%
\UseTaggingSocket{math/display/tag/end}
\fi
}
% \end{macrocode}
% \end{macro}
% \cs{eqref} uses \cs{tagform@} and so \cs{maketag@@@} but we do not want this tagging
% there.
%
% \begin{macro}{\eqref}
% \begin{macro}{\maketag@@@notog}
% \begin{macrocode}
\def\maketag@@@notag#1{\hbox{\m@th\normalfont#1}}
\DeclareRobustCommand{\eqref}[1]
{\textup{\let\maketag@@@\maketag@@@notag\tagform@{\ref{#1}}}}
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \subsubsection{align \& friends}
%
% Most display environment uses a common command for the end which contains
% the luamml socket to finalize the mtable.
% \begin{macro}{\common@align@ending}
% \begin{macrocode}
\def\common@align@ending {
\math@cr \black@\totwidth@
\UseExpandableTaggingSocket {math/luamml/mtable/finalize} {align}
\egroup
\ifingather@
\restorealignstate@
\egroup
\nonumber
\ifnum0=`{\fi\iffalse}\fi
\else
$$%
\fi
\ignorespacesafterend
}
% \end{macrocode}
% \end{macro}
% Now we redefine the display alignments to use these ending.
% \begin{macrocode}
\renewenvironment{align}{%
\start@align\@ne\st@rredfalse\m@ne
}{%
\common@align@ending
}
\renewenvironment{align*}{%
\start@align\@ne\st@rredtrue\m@ne
}{%
\common@align@ending
}
\renewenvironment{alignat}{%
\start@align\z@\st@rredfalse
}{%
\common@align@ending
}
\renewenvironment{alignat*}{%
\start@align\z@\st@rredtrue
}{%
\common@align@ending
}
\renewenvironment{flalign}{%
\start@align\tw@\st@rredfalse\m@ne
}{%
\common@align@ending
}
\renewenvironment{flalign*}{%
\start@align\tw@\st@rredtrue\m@ne
}{%
\common@align@ending
}
\renewenvironment{xalignat}{%
\start@align\@ne\st@rredfalse
}{%
\common@align@ending
}
\renewenvironment{xalignat*}{%
\start@align\@ne\st@rredtrue
}{%
\common@align@ending
}
\renewenvironment{xxalignat}{%
\start@align\tw@\st@rredtrue
}{%
\common@align@ending
}
% \end{macrocode}
%
% And register these environments for the math grabbing.
% \begin{macrocode}
\math_register_halign_env:nn {align}{}
\math_register_halign_env:nn {align*}{}
\math_register_halign_env:nn {alignat}{}
\math_register_halign_env:nn {alignat*}{}
\math_register_halign_env:nn {flalign}{}
\math_register_halign_env:nn {flalign*}{}
\math_register_halign_env:nn {xalignat}{}
\math_register_halign_env:nn {xalignat*}{}
\math_register_halign_env:nn {xxalignat}{}
% \end{macrocode}
%
% The align preamble (used in \cs{align@}) needs code for luamml
% to save the cells.
% \begin{macro}{\align@preamble}
% \begin{macrocode}
\def\align@preamble{%
&\hfil
\strut@
\setboxz@h
{
\@lign
$
\m@th\displaystyle{##}
\ifmeasuring@
\luamml_ignore:
\else
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
\fi
$
}%
\ifmeasuring@
\savefieldlength@
\else
\UseTaggingSocket{math/luamml/mtable/finalizecol}{box}
\fi
\set@field
\tabskip\z@skip
&\setboxz@h
{
\@lign
$
\m@th\displaystyle{{}##}
\ifmeasuring@
\luamml_ignore:
\else
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
\fi
$
}%
\ifmeasuring@
\savefieldlength@
\else
\UseTaggingSocket{math/luamml/mtable/finalizecol}{box}
\fi
\set@field
\hfil
\tabskip\alignsep@
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\math@cr@@@align}
% \begin{macrocode}
\def\math@cr@@@align{%
\ifst@rred\nonumber\fi
\if@eqnsw \global\tag@true \fi
\global\advance\row@\@ne
\add@amps\maxfields@
\omit
\kern-\alignsep@
\iftag@
\setboxz@h{\@lign\strut@{\make@display@tag}}%
\place@tag
\fi
\UseTaggingSocket{math/luamml/mtable/tag/set}
\ifst@rred\else\global\@eqnswtrue\fi
\global\lineht@\z@
\cr
}
% \end{macrocode}
% \end{macro}
%
% \subsubsection{\texttt{gather} and \texttt{gather*}}
%
% \begin{macro}{\gather@}
% \begin{macrocode}
\def\gather@#1{%
\ingather@true \let\split\insplit@
\let\tag\tag@in@align \let\label\label@in@display
\chardef\dspbrk@context\z@
\intertext@ \displ@y@ \Let@
\let\math@cr@@@\math@cr@@@gather
\gmeasure@{#1}%
\global\shifttag@false
\tabskip\z@skip
\global\row@\@ne
\halign to\displaywidth\bgroup
\strut@
\setboxz@h
{
$\m@th\displaystyle{##}
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
}%
\UseTaggingSocket{math/luamml/mtable/finalizecol}{box}
\calc@shift@gather
\set@gather@field
\tabskip\@centering
&\setboxz@h{\strut@{##}}%
\place@tag@gather
\UseTaggingSocket{math/luamml/mtable/tag/set}
\tabskip \iftagsleft@ \gdisplaywidth@ \else \z@skip \span\fi
\crcr
#1%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\endgather}
% \begin{macrocode}
\def\endgather{
\math@cr
\black@ \totwidth@
\UseExpandableTaggingSocket{math/luamml/mtable/finalize} {gather}
\egroup
$$
\ignorespacesafterend
}
% \end{macrocode}
% \end{macro}
%
% The original definition of \texttt{gather*} uses \cs{endgather}
% but this redirection doesn't work if we alter \texttt{gather} so we use
% the real meaning and add the socket.
% \begin{environment}{gather*}
% \begin{macrocode}
\renewenvironment{gather*}
{
\start@gather\st@rredtrue
}
{
\math@cr
\black@\totwidth@
\UseExpandableTaggingSocket{math/luamml/mtable/finalize} {gather}
\egroup
$$\ignorespacesafterend
}
% \end{macrocode}
% \end{environment}
%
% Register both environments
% \begin{macrocode}
\math_register_halign_env:nn {gather}{}
\math_register_halign_env:nn {gather*}{}
% \end{macrocode}
%
% \subsubsection{gathered, aligned and alignedat}
% These environments are not grabbed as they are inside other display
% environments but they need various sockets for luamml support.
% \begin{macro}{\start@aligned}
% \begin{macrocode}
\renewcommand{\start@aligned}[2]{
\RIfM@
\else
\nonmatherr@ {\begin{\@currenvir}}
\fi
\savecolumn@ % Assumption: called inside a group
\UseTaggingSocket{math/luamml/annotate/false}{}{ \alignedspace@left }
\ams@start@box {#1} \bgroup
\maxfields@ #2 \relax
\ifnum \maxfields@ > \m@ne
\multiply \maxfields@ \tw@
\let \math@cr@@@ \math@cr@@@alignedat
\alignsep@ \z@skip
\else
\let \math@cr@@@ \math@cr@@@aligned
\alignsep@ \minalignsep
\fi
\Let@ \chardef \dspbrk@context \@ne
\default@tag
\spread@equation % no-op if already called
\global \column@ \z@
\ialign \bgroup
& \column@plus
\hfil
\strut@
$
\m@th
\displaystyle
{##}
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\tabskip \z@skip
& \column@plus
$
\m@th
\displaystyle
{
{}
##
}
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\hfil
\tabskip\alignsep@
\crcr
\ams@return@opt@arg
}
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{gathered}
% \begin{macrocode}
\renewenvironment{gathered}[1][c]{%
\RIfM@\else
\nonmatherr@{\begin{gathered}}%
\fi
% \end{macrocode}
% This annotates the space
% \begin{macrocode}
\UseTaggingSocket{ math/luamml/annotate/false } {}{ \alignedspace@left }
\ams@start@box{#1}\bgroup
\Let@ \chardef\dspbrk@context\@ne \restore@math@cr
\spread@equation
\ialign\bgroup
\hfil\strut@$\m@th\displaystyle##
% \end{macrocode}
% This save the cell and then finalize it.
% \begin{macrocode}
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\hfil
\crcr
\ams@return@opt@arg
}{%
\endaligned
}
% \end{macrocode}
% \end{environment}
%
% \begin{macro}{\endaligned}
% \begin{macrocode}
\def\endaligned
{
\crcr
\UseExpandableTaggingSocket{math/luamml/mtable/innertable/save}
\egroup
\restorecolumn@
\egroup
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}
}
% \end{macrocode}
% \end{macro}
%
% \subsubsection{multline and multline*}
%
% \texttt{multline*} needs a redefinition before it is registered as it uses
% \cs{endmultline}, this must be replaced by the true code.
%
% \begin{environment}{multline*}
% \begin{macrocode}
\renewenvironment{multline*}{\start@multline\st@rredtrue}
{%
\iftagsleft@ \@xp\lendmultline@ \else \@xp\rendmultline@ \fi
\ignorespacesafterend
}
% \end{macrocode}
% \end{environment}
%
% And now we register both
% \begin{macrocode}
\math_register_halign_env:nn {multline}{}
\math_register_halign_env:nn {multline*}{}
% \end{macrocode}
%
% In the internal commands we have to add sockets for alignment attributes
% \begin{macro}{\multline@}
% \begin{macrocode}
\def\multline@#1{%
\Let@
\@display@init{\global\advance\row@\@ne \global\dspbrk@lvl\m@ne}%
\chardef\dspbrk@context\z@
\restore@math@cr
\let\tag\tag@in@align
\global\tag@false \global\let\raise@tag\@empty
\mmeasure@{#1}%
\let\tag\gobble@tag \let\label\@gobble
\tabskip \if@fleqn \@mathmargin \else \z@skip \fi
\totwidth@\displaywidth
\if@fleqn
\advance\totwidth@-\@mathmargin
\fi
\halign\bgroup
\hbox to\totwidth@{%
\if@fleqn
\hskip \@centering \relax
\else
\hfil
\fi
\strut@
$\m@th\displaystyle{}##\endmultline@math
\hfil
}%
\crcr
\if@fleqn
\hskip-\@mathmargin
\def\multline@indent{\hskip\@mathmargin}% put it back
\else
\hfilneg
\def\multline@indent{\hskip\multlinegap}%
\fi
\iftagsleft@
\iftag@
\begingroup
\ifshifttag@
\rlap{\vbox{%
\normalbaselines
\hbox{%
\strut@
\make@display@tag
}%
\vbox to\lineht@{}%
\raise@tag
}}%
\multline@indent
\else
\setbox\z@\hbox{\make@display@tag}%
\dimen@\@mathmargin \advance\dimen@-\wd\z@
\ifdim\dimen@<\multlinetaggap
\dimen@\multlinetaggap
\fi
\box\z@ \hskip\dimen@\relax
\fi
\endgroup
\else
\multline@indent
\fi
\else
\multline@indent
\fi
\ifmeasuring@ \else
\UseTaggingSocket{math/luamml/mtable/aligncol} {left}
\fi
#1%
\ifmeasuring@ \else
\UseTaggingSocket{math/luamml/mtable/aligncol} {right}
\fi
}
% \end{macrocode}
% \end{macro}
%
% Luckily, \texttt{multline} uses \cs{endmultline@math} in exactly
% the spot where we have to set the flag.
% Less luckily, \cs{endmultline@math} sometimes get overwritten for the last line.
% But that isn't much of a problem since we want special behavior there anyway.
% \begin{macro}{\endmultline@math}
% \begin{macrocode}
\def\endmultline@math
{
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\rendmultline@}
% \begin{macrocode}
\def\rendmultline@{%
\iftag@
% \end{macrocode}
% we need to surround the math token with tagging sockets.
% \begin{macrocode}
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\let\endmultline@math\relax
\ifshifttag@
\hskip\multlinegap
\llap{\vtop{%
\raise@tag
\normalbaselines
\setbox\@ne\null
\dp\@ne\lineht@
\box\@ne
\hbox{\strut@\make@display@tag}%
}}%
\else
\hskip\multlinetaggap
\make@display@tag
\fi
% \end{macrocode}
% Here we set the tag TODO: is that sensible with multline? Where is the tag saved?
% \begin{macrocode}
\UseTaggingSocket{math/luamml/mtable/tag/set}
\else
\hskip\multlinegap
\fi
\hfilneg
\math@cr
% \end{macrocode}
% Now we finalize the mtable.
% \begin{macrocode}
\UseExpandableTaggingSocket {math/luamml/mtable/finalize} {multline}
\egroup$$%
}
% \end{macrocode}
% \end{macro}
% And something similar for the left version
% \begin{macro}{\lendmultline@}
% \begin{macrocode}
\def\lendmultline@{%
\hfilneg
\hskip\multlinegap
\math@cr
\UseExpandableTaggingSocket {math/luamml/mtable/finalize} {multline}
\egroup
$$%
}
% \end{macrocode}
% \end{macro}
%
% \subsection{Cases}
%
% \begin{macro}{env@cases}
% \begin{macrocode}
\def\env@cases{%
\let\@ifnextchar\new@ifnextchar
\left\lbrace
\def\arraystretch{1.2}%
\array{@{}l@{\quad}l@{\luamml_ignore:}}%
}
% \end{macrocode}
% \end{macro}
%
% \subsubsection{smallmatrix}
% \begin{environment}{smallmatrix}
% \begin{macrocode}
\renewenvironment {smallmatrix} {
\UseTaggingSocket{ math/luamml/annotate/false } {} { \null\, }
\vcenter \bgroup
\Let@
\restore@math@cr
\default@tag
\baselineskip 6 \ex@
\lineskip 1.5 \ex@
\lineskiplimit \lineskip
\ialign \bgroup
\hfil
$
\m@th
\scriptstyle
##
% No \scriptsize here since we want to add the mstyle nodes
\UseTaggingSocket{math/luamml/save/nn}{ {} {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\hfil
&&
\thickspace
\hfil
$
\m@th
\scriptstyle
##
% No \scriptsize here since we want to add the mstyle nodes
\UseTaggingSocket{math/luamml/save/nn}{ {} {mtd} }
$
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}
\hfil
\crcr
}{%
\crcr
\UseExpandableTaggingSocket{math/luamml/mtable/smallmatrix/save}
\egroup
\egroup
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}
\UseTaggingSocket{ math/luamml/annotate/false } {}{ \, }
}
% \end{macrocode}
% \end{environment}
%
% \subsection{The split environment}
%
% The split environment is not trivial to handle as it has a rather convoluted
% implementation in amsmath: depending on in which display environment it is embedded
% it takes different branches, which makes it difficult to finalize the mtable.
%
% The following patches work with leqno and reqno if the (default) \texttt{centertags}
% are used.
% The currently fail (the structure is wrong) if the option \texttt{tbtags} is used.
% The alignment of the cells is currently not handled.
% A simple debug command until everything is sorted.
% \begin{macro}{\__math_split_debug_typeout:n}
% \begin{macrocode}
\cs_new:Npn\__math_split_debug_typeout:n#1{\use_none:n{#1}}
% \end{macrocode}
% \end{macro}
% We need to detect if \cs{gather@split} has been used or not
% \begin{macro}{\l__math_gathersplit_bool}
% \begin{macrocode}
\bool_new:N\l__math_gathersplit_bool
% \end{macrocode}
% \end{macro}
% At first a redefinition of the main environment. Here we only have to add
% the saving command for the inner table:
% \begin{environment}{split}
% \begin{macrocode}
\renewenvironment{split}{%
\__math_split_debug_typeout:n {begin~split}
\if@display
\ifinner
\@xp\@xp\@xp\split@aligned
\else
\ifst@rred \else \global\@eqnswtrue \fi
\fi
\else
\let\endsplit\@empty \@xp\collect@body\@xp\split@err
\fi
\collect@body\gather@split
}{\__math_split_debug_typeout:n{end~split}%
\crcr
\UseExpandableTaggingSocket{math/luamml/mtable/innertable/save}%
\egroup
\egroup
\iftagsleft@ \@xp\lendsplit@ \else \@xp\rendsplit@ \fi
}
% \end{macrocode}
% \end{environment}
%
% In \cs{gather@split} we have to add the finalization socket.
% We also set the boolean to true so that we can detect if
% the finalization has already happened. Perhaps this
% could be done in the luamml code instead?
% \begin{macro}{\gather@split}
% \begin{macrocode}
\def\gather@split#1#2#3{
\__math_split_debug_typeout:n{gather@split}%
\@xp\endgroup \reset@equation % math@cr will handle equation numbering
\iftag@
\toks@\@xp{\df@tag}%
\edef\split@tag{%
\gdef\@nx\df@tag{\the\toks@}%
\global\@nx\tag@true \@nx\nonumber
}%
\else \let\split@tag\@empty
\fi
\bool_set_true:N\l__math_gathersplit_bool
\spread@equation
\vcenter\bgroup
\gather@{\split@tag
\begin{split}#1\end{split}}%
\def\endmathdisplay@a{%
\__math_split_debug_typeout:n{endmathdisplay@a}
\__math_split_debug_typeout:n{finalize~innertable~endmathdisplay@a}
\math@cr
\black@ \totwidth@
\egroup
\egroup
\UseExpandableTaggingSocket{math/luamml/mtable/innertable/finalize}%
}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\insplit@}
% In \cs{insplit@} we have to add the sockets which store the cell content.
% \begin{macrocode}
\def\insplit@{\__math_split_debug_typeout:n{insplit@}%
\global\setbox\z@\vbox\bgroup
\Let@ \chardef\dspbrk@context\@ne \restore@math@cr
\default@tag % disallow use of \tag here
\ialign\bgroup
\hfil
\strut@
$\m@th\displaystyle {##}%
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }%
$%
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}%
&$\m@th\displaystyle {{}##}%
\UseTaggingSocket{math/luamml/save/nNn}{ {} \displaystyle {mtd} }%
$%
\UseTaggingSocket{math/luamml/mtable/finalizecol}{last}%
\hfill % Why not \hfil?---dmj, 1994/12/28
\crcr
}
% \end{macrocode}
% \end{macro}
% And now the difficult part. Depending on the options leqno/reqno \cs{lendsplit@}
% or \cs{rendsplit@} are used for the typesetting and the inner table must
% be finalized here in case this hasn't happen yet. This must be tested with the
% boolean from \cs{gather@split}
% \begin{macrocode}
\def\lendsplit@{%
\global\setbox9\vtop{\unvcopy\z@}%
\ifinalign@
\setbox\@ne\vbox{%
\unvcopy\z@
\global\setbox8\lastbox
}%
\setbox\@ne\hbox{%
\unhcopy8%
\unskip
\setbox\tw@\lastbox
\unskip
\global\setbox\thr@@\lastbox
}%
\__math_split_debug_typeout:n{lendsplit@/aligncase}
\ifctagsplit@
\__math_split_debug_typeout:n{lendsplit@/aligncase/centertags}
\gdef\split@{%
\hbox to\wd\thr@@{}%
&\vcenter{\vbox{\moveleft\wd\thr@@\box9}}%
\__math_split_debug_typeout:n{finalize~innertable~aligncase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}%
}%
\else
%TODO, not correct yet.
\__math_split_debug_typeout:n{lendsplit@/aligncase/tbtags}
\gdef\split@{%
\hbox to\wd\thr@@{}%
&\vbox{\moveleft\wd\thr@@\box9}%
\__math_split_debug_typeout:n{finalize~innertable~aligncase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}%
}%
\fi
\else
% \end{macrocode}
% If not in align we need to test for \cs{gather@split}
% \begin{macrocode}
\ifctagsplit@
\bool_if:NTF \l__math_gathersplit_bool
{
\__math_split_debug_typeout:n{lendsplit/equationcase/centertags}
\gdef\split@%
{\UseTaggingSocket{math/luamml/annotate/false}{}{\vcenter{\box9}}}
}
{
\__math_split_debug_typeout:n {lendsplit/gathercase/centertags}
\gdef\split@{\vcenter{\box9}%
\__math_split_debug_typeout:n {finalize~innertable~gathercase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}}
}
\else
% TODO tbtags not correct yet.
\bool_if:NTF \l__math_gathersplit_bool
{
\__math_split_debug_typeout:n {lendsplit/equationcase/tbtags}
\gdef\split@%
{\UseTaggingSocket{math/luamml/annotate/false}{}{\box9}}
}
{
\__math_split_debug_typeout:n {lendsplit/gathercase/tbtags}
\gdef\split@{
\box9%
\__math_split_debug_typeout:n {finalize~innertable~gathercase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}}
}
\fi
\fi
\aftergroup\split@
}
% \end{macrocode}
%
% \begin{macro}{\rendsplit@}
% And more or less the same for the \cs{rendsplit@} environment.
% \begin{macrocode}
\def\rendsplit@{%
\ifinalign@
\global\setbox9 \vtop{%
\unvcopy\z@
\global\setbox8 \lastbox
\unskip
}%
\setbox\@ne\hbox{%
\unhcopy8
\unskip
\global\setbox\tw@\lastbox
\unskip
\global\setbox\thr@@\lastbox
}%
\ifctagsplit@
\gdef\split@{%
\hbox to\wd\thr@@{}
&\vcenter{\vbox{\moveleft\wd\thr@@\boxz@}}%
\__math_split_debug_typeout:n {rendsplit/aligncase/centertags}
\__math_split_debug_typeout:n {finalize~innertable~aligncase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}
}%
\else
\__math_split_debug_typeout:n{rendsplit@/aligncase/tbtags}
%TODO tbtags is not correct yet
\global\setbox7 \hbox{\unhbox\tw@\unskip}%
\gdef\split@{%
\global\@tempcnta\column@
&\setboxz@h{}%
\savetaglength@
\global\advance\row@\@ne
\vbox{\moveleft\wd\thr@@\box9}%
\crcr
\noalign{\global\lineht@\z@}%
\add@amps\@tempcnta
\UseTaggingSocket{math/luamml/annotate/false}{}{\box\thr@@}
&\box7
\__math_split_debug_typeout:n {finalize~innertable~aligncase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}%
}%
\fi
% \end{macrocode}
% and again the if we are not in align we need to test for \cs{gathersplit}
% \begin{macrocode}
\else
\ifctagsplit@
\bool_if:NTF \l__math_gathersplit_bool
{
\__math_split_debug_typeout:n {rendsplit/equationcase/centertags}
\gdef\split@%
{\UseTaggingSocket{math/luamml/annotate/false}{}{\vcenter{\boxz@}}}
}
{
\__math_split_debug_typeout:n {rendsplit/gathercase/centertags}
\gdef\split@{\vcenter{\boxz@}%
\__math_split_debug_typeout:n {finalize~innertable~gathercase}
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}}
}
\else
\bool_if:NTF \l__math_gathersplit_bool
{
\__math_split_debug_typeout:n {rendsplit/equationcase/tbtags}
\gdef\split@{%
\UseTaggingSocket{math/luamml/annotate/false}{}{\boxz@}}
}
{
\__math_split_debug_typeout:n {rendsplit/gathercase/tbtags}
\gdef\split@{%
\boxz@
\UseTaggingSocket{math/luamml/mtable/innertable/finalize}}
}
\fi
\fi
\aftergroup\split@
}
% \end{macrocode}
% \end{macro}
% \subsection{\cs{intertext}}
% The \cs{intertext} command errors with active tagging as it is processed twice
% which leads to duplicated structures.
%
% \begin{macro}{\intertext@}
% TODO: review and add sockets!
% \begin{macrocode}
\def\intertext@{%
\def\intertext##1{%
\ifvmode\else\\\@empty\fi
\noalign{%
% \end{macrocode}
% we have to flip the sign and use a negative \cs{belowdisplayskip}
% as we flipped the sign at the outside.
% \begin{macrocode}
\penalty\postdisplaypenalty\vskip-\belowdisplayskip
\vbox{
% \end{macrocode}
% Stop tagging when measuring:
% \begin{macrocode}
\ifmeasuring@\tag_suspend:n{\measuring}\fi
\normalbaselines
\ifdim\linewidth=\columnwidth
\else \parshape\@ne \@totalleftmargin \linewidth
\fi
% \end{macrocode}
% End the previous mc:
% \begin{macrocode}
\tag_mc_end_push:
% \end{macrocode}
% We are already in a par so we change now to text:
% \begin{macrocode}
\tagpdfsetup{para/tag=P}%
% \end{macrocode}
% TODO why \cs{tagpdfparaOn} needed?
% \begin{macrocode}
\tagpdfparaOn
\noindent\ignorespaces##1\par
% \end{macrocode}
% Restart the MC
% \begin{macrocode}
\tag_mc_begin_pop:n{}}%
\penalty\predisplaypenalty\vskip\abovedisplayskip%
}%
}}
% \end{macrocode}
% \end{macro}
%
% \subsection{\cs{text}}
%
% The \cs{text} command uses \cs{mathchoice} which \enquote{typesets} the argument
% four times. This makes it quite problematic for tagging. Without precautions
% structure objects would be created four times and would get MC-chunks as kids
% that don't really exist. amsmath contains a switch that allows to execute code
% only in the first (displaymath) branch, but that isn't usable here. At first because
% we don't know if the first branch creates the same structure as the one that is
% actually used. At second because the engines executes some commands like \cs{label}
% and \cs{pdfannot} only at shipout from the branch that really was used. So we would
% get structure data from one \cs{mathchoice}-branch and MC-labels and links from another
% one and that gets very messy.
%
% We therefore have to avoid that tagging is active in unused branches. In pdflatex it
% is not possible to detect the mathstyle before, so we use a label. With lualatex is
% is possible to redefine \cs{text} not to use \cs{mathchoice}
%
% \begin{macro}{\text@}
% \begin{macrocode}
\AddToHook{package/amstext/after}
{
% \end{macrocode}
% currently amsmath is loaded in a begindocument hook, so this
% test is fine. If amstext is loaded earlier (in the kernel), this needs perhaps a change.
% \changes{v0.1d}{2024/12/03}{Add tagging socket for luamml support}
% \begin{macrocode}
\tag_if_active:T
{
\sys_if_engine_luatex:TF
{
\def\text@#1{
\tag_socket_use:nnn {math/luamml/hbox}{}
{{%
\ifcase\mathstyle
\hbox{{#1}}\or
\hbox{{#1}}\or
\hbox{{#1}}\or
\hbox{{#1}}\or
\hbox{{\let\f@size\sf@size\selectfont#1}}\or
\hbox{{\let\f@size\sf@size\selectfont#1}}\or
\hbox{{\let\f@size\ssf@size\selectfont#1}}\or
\hbox{{\let\f@size\ssf@size\selectfont#1}}\or
\ERROR
\fi
\check@mathfonts
}}}
}
{
\def\text@#1
{{
\int_gincr:N\g__math_mathchoice_int
\tag_suspend:n{\text@}
\mathchoice
{
\__math_tag_if_mathstyle:en{mathchoice-\int_use:N\g__math_mathchoice_int}{0}
\textdef@\displaystyle\f@size{#1}
}
{
\__math_tag_if_mathstyle:en{mathchoice-\int_use:N\g__math_mathchoice_int}{2}
\textdef@\textstyle\f@size{\firstchoice@false #1}
}
{
\__math_tag_if_mathstyle:en{mathchoice-\int_use:N\g__math_mathchoice_int}{4}
\textdef@\textstyle\sf@size{\firstchoice@false #1}
}
{
\__math_tag_if_mathstyle:en{mathchoice-\int_use:N\g__math_mathchoice_int}{6}
\textdef@\textstyle \ssf@size{\firstchoice@false #1}
}
\check@mathfonts
}}
}
}
}
% \end{macrocode}
% \end{macro}
%
% \subsection{\cs{pmb}}
% \cs{pmb} prints its argument three times. For tagging we must mark
% two of occurrences as artifact.
% For luatex the attributes in the box must be reset, for this
% we switch to expl3-boxes.
% \begin{macro}{\pbm@@,\pmb@}
% \begin{macrocode}
\AddToHook{package/amsbsy/after}
{
\def\pmb@@#1#2#3{\leavevmode\hbox_set:Nn\l_@@_tmpa_box{xxx#3}
\dimen@-\box_wd:N\l_@@_tmpa_box
\kern-.5\ex@\box_use:N\l_@@_tmpa_box
\tag_mc_end:\tag_mc_begin:n{artifact}
\tag_mc_reset_box:N\l_@@_tmpa_box
\kern\dimen@\kern.25\ex@\raise.4\ex@\box_use:N\l_@@_tmpa_box
\kern\dimen@\kern.25\ex@\box_use_drop:N\l_@@_tmpa_box
\tag_mc_end:\tag_mc_begin:n{}
}
\def\pmb@#1#2{\hbox_set:Nn\l_@@_tmpa_box{$\m@th#1{#2}$}
\setboxz@h{$\m@th#1\mkern.5mu$}\pmbraise@\wdz@
\binrel@{#2}
\dimen@-\box_wd:N\l_@@_tmpa_box
\binrel@@{
\mkern-.8mu\box_use:N\l_@@_tmpa_box
\tag_mc_end:\tag_mc_begin:n{artifact}
\tag_mc_reset_box:N\l_@@_tmpa_box
\kern\dimen@\mkern.4mu\raise\pmbraise@\box_use:N\l_@@_tmpa_box
\kern\dimen@\mkern.4mu\box_use_drop:N\l_@@_tmpa_box
\tag_mc_end:\tag_mc_begin:n{}
}
}
}
% \end{macrocode}
% \end{macro}
% \begin{macrocode}
\ExplSyntaxOff
% \end{macrocode}
%
% \begin{macrocode}
%</kernel>
% \end{macrocode}
%
% \Finale
%