summaryrefslogtreecommitdiff
path: root/macros/latex-dev/required/latex-lab/latex-lab-math.dtx
diff options
context:
space:
mode:
Diffstat (limited to 'macros/latex-dev/required/latex-lab/latex-lab-math.dtx')
-rw-r--r--macros/latex-dev/required/latex-lab/latex-lab-math.dtx1314
1 files changed, 1314 insertions, 0 deletions
diff --git a/macros/latex-dev/required/latex-lab/latex-lab-math.dtx b/macros/latex-dev/required/latex-lab/latex-lab-math.dtx
new file mode 100644
index 0000000000..d593f93320
--- /dev/null
+++ b/macros/latex-dev/required/latex-lab/latex-lab-math.dtx
@@ -0,0 +1,1314 @@
+% \iffalse meta-comment
+%
+%% File: latex-lab-math.dtx
+%
+% Copyright (C) 2022-2023 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.
+%
+%
+\def\ltlabmathdate{2023-09-11}
+\def\ltlabmathversion{0.5c}
+%
+%<*driver>
+\documentclass{l3doc}
+\EnableCrossrefs
+\CodelineIndex
+
+\usepackage{todonotes}
+
+\begin{document}
+ \DocInput{latex-lab-math.dtx}
+\end{document}
+%</driver>
+%
+% \fi
+%
+%
+% \title{The \texttt{latex-lab-math} code\thanks{}}
+% \author{Frank Mittelbach, Joseph Wright, \LaTeX{} Project}
+% \date{v\ltlabmathversion\ \ltlabmathdate}
+%
+% \maketitle
+%
+% \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}}
+%
+% ^^A \car {...} for marginal comments
+% ^^A \car*{...} for longer inline comments
+%
+% \NewDocumentCommand\car{sO{}m}
+% {\IfBooleanTF{#1}{\todo[inline,color=blue!10,#2]{#3}}^^A
+% {\todo[color=blue!10,#2]{#3}}}
+%
+% \NewDocumentCommand\fmi{sO{}m}
+% {\IfBooleanTF{#1}{\todo[inline,#2]{#3}}^^A
+% {\todo[#2]{#3}}}
+%
+%
+%
+% \begin{abstract}
+% This is an experimental prototype. It captures math material
+% (basically okay, but the interfaces for packages aren't yet
+% there) and tags the material (which is not yet anywhere near the
+% final state). That part is provided for experimentation and to
+% gather feedback, etc.
+% \end{abstract}
+%
+% \tableofcontents
+%
+% \section{Introduction}
+% \car*{Todo: update all the documentation! Both here and
+% (what little there is!) in the implementation section.}
+%
+% This file implements capture of all math mode material at the outer
+% level, i.e., a formula is captured in its entirety with inner text
+% blocks (possibly containing further math) absorbed as part of the
+% formula. For example,
+%\begin{verbatim}
+% \[ a \in A \text{ for all $a<5$} \]
+%\end{verbatim}
+% would only result in a single capture of the tokens
+% ``\verb*/a \in A \text{ for all $a<5$}/''.
+%
+% \subsection{Code level interfaces}
+%
+% \begin{function}{\math_register_env:n, \math_register_env:nn}
+% \begin{syntax}
+% \cs{math_register_env:n} \Arg{env}
+% \cs{math_register_env:nn} \Arg{env} \Arg{options}
+% \end{syntax}
+% Registers the \meta{env} as a math environment which should be captured
+% and made available. This is necessary for all top-level math mode
+% environments: low-level errors may result if these are not correct
+% set up. One or more key--value \meta{options} may also be given:
+% \begin{itemize}
+% \item[\texttt{arg-spec}] The argument specification taken by the
+% beginning of the environment; this is used to remove non-mathematical
+% material.
+% \end{itemize}
+% \end{function}
+%
+% \begin{function}{\math_processor:n}
+% \begin{syntax}
+% \cs{math_processor:n} \Arg{tokens}
+% \end{syntax}
+% Declares that the captured math content should be passed to the
+% \meta{tokens}, which will receive the environment type as |#1| and
+% the content as |#2|.
+% \end{function}
+%
+% \subsection{Document level interfaces}
+%
+% \begin{function}{\RegisterMathEnvironment}
+% \begin{syntax}
+% \cs{RegisterMathEnvironment} \oarg{options} \Arg{env}
+% \end{syntax}
+% Registers the \meta{env} as a math environment which should be captured
+% and made available. This is necessary for all top-level math mode
+% environments: low-level errors may result if these are not correct
+% set up. One or more key--value \meta{options} may also be given:
+% \begin{itemize}
+% \item[\texttt{arg-spec}] The argument specification taken by the
+% beginning of the environment; this is used to remove non-mathematical
+% material.
+% \end{itemize}
+% \end{function}
+%
+% \section{Known current bugs, etc.}
+% \car*{New Section, now with subsections.\\
+% As indicated, these lists are probably incomplete.\\
+% Some of these have been addressed in a more recent branch.}
+%
+% \subsection{Capture/grabbing problems}
+%
+% \begin{enumerate}
+% \item Incorrect grabbing of |$|-math when there is also
+% explicit |$|-math within a \textit{text environment}
+% that is itself within the math that should all be grabbed.
+% \item Similar incorrect grabbing with |$$| also.
+% \item The grabbing, for all the display environments (and |\) \]|), needs
+% to deal with nesting: \pkg{amsmath} contains code for this.
+% \item
+% \end{enumerate}
+%
+% \subsection{Other problems}
+%
+% \begin{enumerate}
+% \item
+% The presence of \cs{m@th} in association with \cs{ensuremath}
+% does not necessarily indicate fakemath. This is because
+% wanting mathsurround to be zero is very reasonable and common,
+% \emph{even when the math is genuine} (and hence needs to be collected).
+% \item User-defined environments can create problems; but this area, of
+% new, copied and changed environments, has not yet been developed.
+%
+% \car*{Joseph wrote, inter alia:\\
+% My thinking [regarding] \cs{RegisterMathEnvironment}\\
+% - (New) Math environments should not be created-then-patched, but only
+% generated by a [(future)] dedicated command (\cs{DeclareMathEnviornment},
+% presumably)\\
+% - Math environments created with \pkg{ltcmd} [commands] should not be copied, . . .\\
+% - Package authors should be able to manually set up math environments with a public boolean.}
+%
+% \item
+% \end{enumerate}
+%
+%
+% \subsection{Other ToDos}
+%
+% \begin{enumerate}
+% \item Add (some of) the math display commands that were \enquote{lifted from
+% plain}, e.g., \cs{displaylines} \cs{eqalign}(??).
+% \item
+% \end{enumerate}
+%
+%
+% \car*{\cs{MaybeStop} (temporarily) not executed, as it is unknown on Chris' system.}
+% \iffalse
+% \MaybeStop{\setlength\IndexMin{200pt} \PrintIndex }
+% \else
+% \StopEventually{\setlength\IndexMin{200pt} \PrintIndex }
+% \fi
+%
+% \section{The Implementation}
+%
+% \begin{macrocode}
+%<@@=math>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*kernel>
+% \end{macrocode}
+%
+% \subsection{File declaration}
+%
+% \car{Change description here?}
+% \begin{macrocode}
+\ProvidesFile{latex-lab-math.ltx}
+ [\ltlabmathdate\space
+ v\ltlabmathversion\space
+ Grab all the math(s) and tag it (experiments)]
+% \end{macrocode}
+%
+% Temp loading \ldots
+% \begin{macrocode}
+\AddToHook{begindocument/before}{\RequirePackage{latex-lab-testphase-block}}
+% \end{macrocode}
+%
+% \begin{macrocode}
+\ExplSyntaxOn
+% \end{macrocode}
+%
+% \subsection{Setup}
+%
+% Loading \pkg{amsmath} is an absolute requirement: this avoids needing to
+% have conditional definitions and deals with how to define \cs{[}/\cs{]}
+% neatly.
+% \begin{macrocode}
+\tl_gput_right:Nn \@kernel@before@begindocument
+ { \RequirePackage { amsmath } }
+% \end{macrocode}
+%
+%
+% \subsection{Data structures}
+%
+%
+%
+% \begin{variable}{\l_@@_collected_bool}
+% Tracks whether math mode material has been collected, which happens inside
+% \pkg{amsmath} environments as well as those handled directly here.
+%
+%
+% \begin{macrocode}
+\bool_new:N \l_@@_collected_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \car{Change first tl name below: `env' $=>$ `info'?\\
+% Or do we need an extra storage tl?}
+%
+% \begin{variable}{\g_@@_grabbed_env_tl, \g_@@_grabbed_math_tl}
+% \begin{macrocode}
+\tl_new:N \g_@@_grabbed_env_tl
+\tl_new:N \g_@@_grabbed_math_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \subsection{Interface commands}
+%
+% \begin{macro}
+% {\@@_process:nn, \@@_process:Vn, \@@_process_auxi:nn, \@@_process_auxii:nn}
+% A no-op place-holder; the internal wrapper means that it does not need to
+% be concerned with internals.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_process:nn #1#2
+ {
+ \legacy_if:nF { measuring@ }
+ {
+ \tl_if_in:nnF {#2} { \m@th }
+ { \tl_trim_spaces_apply:nN {#2} \@@_process_auxi:nn {#1} }
+ }
+ }
+\cs_generate_variant:Nn \@@_process:nn { V }
+\cs_new_protected:Npn \@@_process_auxi:nn #1#2
+ {
+ \tl_gset:Nn \g_@@_grabbed_env_tl {#2}
+ \tl_gset:Nn \g_@@_grabbed_math_tl {#1}
+ \@@_process_auxii:nn {#2} {#1}
+ }
+\cs_new_protected:Npn \@@_process_auxii:nn #1#2 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\math_processor:n}
+% A simple installer
+% \begin{macrocode}
+\cs_new_protected:Npn \math_processor:n #1
+ { \cs_set_protected:Npn \@@_process_auxii:nn ##1##2 {#1} }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Content grabbing}
+%
+% \begin{macro}{\@@_grab_dollar:w}
+% Grab up to a single |$|, for inline math mode, suppressing
+% any processing if the first token is \tn{m@th}.
+%
+% \fmi{what's that test doing?}
+%
+% \car{It is some kind of fix, to avoid the remote
+% possibility that the math is empty, making the code
+% produce an unwanted \texttt{\$\$}.}
+%
+%\car{cf.~the code for this in \cs{@ensuredmath}}
+%
+%\car{It is harmless but unnecessary in the dollardollar grabbing below.}
+%
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_grab_dollar:w % $
+ #1 $
+ {
+% \end{macrocode}
+% \fmi{what's that test doing?}
+% \begin{macrocode}
+ \tl_if_blank:nF {#1}
+ {
+ \@@_process:nn { math } {#1} % $
+% fairly simple this one
+% \end{macrocode}
+% We do not want math tagging in fakemath or when measuring,
+% so we imitate the test inside
+% \cs{@@_process:nn} for now, see https://github.com/latex3/tagging-project/issues/5
+% \begin{macrocode}
+ \legacy_if:nTF { measuring@ }
+ { #1 $ }
+ {
+ \tl_if_in:nnTF {#1} { \m@th }
+ { #1 $ }
+ {
+ \tagmcend %end P-chunk, in code: \tag_mc_end_push:
+ \@kernel@math@begin
+ #1 $
+ \@kernel@math@end
+ \tagmcbegin{} % restart P-chunk (whatsits in pdftex)
+ }
+ }
+
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\@@_grab_dollardollar:w}
+% And for the classical \TeX{} display structure.
+% \begin{macrocode}
+
+\skip_new:N \l_@@_tmpa_skip
+
+\cs_new_protected:Npn \@@_grab_dollardollar:w % $$
+ #1 $$
+ {
+ \tl_if_blank:nF {#1}
+ {
+ \@@_tag_dollardollar_display:nn { equation* }{#1}
+ #1
+ $$
+ }
+ }
+% \end{macrocode}
+% To allow to use the code without tagging we guard. But probably tagpdf should
+% provide some tools for such manual para-ends.
+% \begin{macrocode}
+\cs_new_protected:Npn \@kernel@close@P {
+ \tag_if_active:T
+ {
+ \tagmcend %end P-chunk, should perhaps be \tag_mc_end_push: ...
+ \int_gincr:N \g__tag_para_end_int
+ \bool_if:NT \l__tag_para_show_bool
+ { \tag_mc_begin:n{artifact}
+ \rlap{\color_select:n{red}\tiny\ \int_use:N\g__tag_para_end_int}
+ \tag_mc_end:
+ }
+ \tag_struct_end:
+ }
+}
+
+
+
+\cs_new_protected:Npn \@@_tag_dollardollar_display:nn #1#2 {
+ \@@_process:nn {#1} {#2}
+ \@kernel@close@P
+ \@kernel@math@begin
+% \skip_set:Nn \belowdisplayskip {-\belowdisplayskip}
+% \skip_set:Nn \belowdisplayshortskip {-\belowdisplayshortskip}
+% \int_set:Nn \postdisplaypenalty {10000}
+%%
+% \group_insert_after:N \@@_tag_dollardollar_display_end:
+}
+
+\cs_new_protected:Npn \@@_tag_dollardollar_display_end: {
+% \typeout{== tag dollarldollar display end}
+% \ShowTagging{struct-stack}
+ \tagpdfparaOff
+ \para_raw_end:
+ \tagpdfparaOn
+ \l_@@_tmpa_skip \lastskip
+ \@kernel@math@end
+ \penalty \postdisplaypenalty
+% \end{macrocode}
+% This reinserts the below display skips. It must be doubled to
+% get the right amount:
+% \begin{macrocode}
+ \skip_vertical:n { -\l_@@_tmpa_skip * 2 }
+%
+ \@doendpe % this has no \end{...} to take care of it
+}
+
+% \end{macrocode}
+% \end{macro}
+%
+%
+% \begin{macro}{\@@_grab_inline:w}
+% Collect inline math content and deal with the need to move to math mode.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_grab_inline:w % \(
+ #1 \)
+ {
+ \tl_if_blank:nF {#1}
+ {
+ \@@_process:nn { math } {#1}
+ $ #1 $
+ }
+ \bool_set_false:N \l_@@_collected_bool
+ }
+% \end{macrocode}
+% \end{macro}
+% \begin{macro}{\@@_grab_eqn:w}
+% For the most common use of \cs{[}/\cs{]}: turn into an environment.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_grab_eqn:w % \[
+ #1 \]
+ {
+% \typeout{collected? = \bool_if:NTF \l_@@_collected_bool {true}{false}}
+ \begin { equation* } #1 \end { equation* }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Marking math environments}
+%
+% A general mechanism for math mode environments that do not grab their
+% content (\emph{cf.}~most \pkg{amsmath} environments).
+%
+% \begin{variable}{\l_@@_env_name_tl}
+% To allow us to carry out \enquote{special effects}
+% \begin{macrocode}
+\tl_new:N \l_@@_env_name_tl
+% \end{macrocode}
+% \end{variable}
+%
+% Here we set up specialised handling of environments. The idea for the
+% \texttt{arg-spec} key is that if an environment takes arguments, we
+% don't worry during the main grabbing. Rather, we remove the arguments
+% from the grabbed content and forward only the payload. That is done by
+% (ab)using \pkg{ltcmd}.
+% \begin{macrocode}
+\keys_define:nn { @@ }
+ {
+ arg-spec .code:n =
+ {
+ \ExpandArgs { c } \DeclareDocumentCommand
+ { @@_env \l_@@_env_name_tl _aux: }
+ {#1}
+ { \@@_env_forward:w }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\math_register_env:nn}
+% \begin{macro}{\math_register_env:n}
+% \begin{macro}{\RegisterMathEnvironment}
+% Set up to capture environment content and make available.
+%
+% \begin{macrocode}
+\cs_new_protected:Npn \math_register_env:nn #1#2
+ {
+ \tl_set:Nn \l_@@_env_name_tl {#1}
+ \keys_set:nn { @@ } {#2}
+ \cs_gset_eq:cc { @@_env_ #1 _begin: } {#1}
+ \cs_gset_eq:cc { @@_env_ #1 _end: } { end #1 }
+%
+ \ExpandArgs { nnx } \RenewDocumentEnvironment {#1} { b }
+ {
+% \bool_set_true:N \exp_not:N \l_@@_collected_bool
+% \cs_if_exist:cTF { @@_env #1 _aux: }
+% {
+% \exp_not:c { @@_env #1 _aux: }
+% ####1 \exp_not:N \@@_env_end: {#1}
+% }
+% { \exp_not:N \@@_process:nn {#1} {####1} }
+ \exp_not:N \bool_if:NTF \exp_not:N \l_@@_collected_bool
+ {
+% \typeout{===>B1}
+ }
+ {
+% \typeout{===>B2}
+ \cs_if_exist:cTF { @@_env #1 _aux: }
+ {
+ \exp_not:c { @@_env #1 _aux: }
+ ####1 \exp_not:N \@@_env_end: {#1}
+ }
+ { \exp_not:N \@@_process:nn {#1} {####1} }
+ \exp_not:n { \@kernel@math@registered@begin }
+ \bool_set_true:N \exp_not:N \l_@@_collected_bool
+ }
+% \exp_not:N \tracingall
+ \exp_not:c { @@_env_ #1 _begin: }
+ ####1
+ \exp_not:c { @@_env_ #1 _end: }
+% \exp_not:c { @@_env_ #1 _end: }
+% \exp_not:N \tracingnone
+% \exp_not:n { \@kernel@math@registered@end }
+ }
+ {
+ }
+ }
+
+\cs_set_protected:Npn \__cs_tmp:w #1
+ {
+ \group_begin:
+ \exp_args:No \__cs_generate_internal_variant:n
+ { \tl_to_str:n {#1} }
+ \group_end:
+ }
+\__cs_tmp:w { nnxx }
+
+
+\cs_new_protected:Npn \math_register_halign_env:nn #1#2
+ {
+ \tl_set:Nn \l_@@_env_name_tl {#1}
+ \keys_set:nn { @@ } {#2}
+ \cs_gset_eq:cc { @@_env_ #1 _begin: } {#1}
+ \cs_gset_eq:cc { @@_env_ #1 _end: } { end #1 }
+%
+ \ExpandArgs { nnxx } \RenewDocumentEnvironment {#1} { b }
+ {
+% \bool_set_true:N \exp_not:N \l_@@_collected_bool
+% \cs_if_exist:cTF { @@_env #1 _aux: }
+% {
+% \exp_not:c { @@_env #1 _aux: }
+% ####1 \exp_not:N \@@_env_end: {#1}
+% }
+% { \exp_not:N \@@_process:nn {#1} {####1} }
+ \exp_not:N \bool_if:NTF \exp_not:N \l_@@_collected_bool
+ {
+% \typeout{===>B1}
+ }
+ {
+% \typeout{===>B2}
+ \cs_if_exist:cTF { @@_env #1 _aux: }
+ {
+ \exp_not:c { @@_env #1 _aux: }
+ ####1 \exp_not:N \@@_env_end: {#1}
+ }
+ { \exp_not:N \@@_process:nn {#1} {####1} }
+ \exp_not:n { \@kernel@math@registered@begin }
+ \bool_set_true:N \exp_not:N \l_@@_collected_bool
+ }
+% \exp_not:N \tracingall
+ \exp_not:c { @@_env_ #1 _begin: }
+ ####1
+% \exp_not:c { @@_env_ #1 _end: }
+% \exp_not:N \tracingnone
+ }
+ {
+ \exp_not:c { @@_env_ #1 _end: }
+ }
+ }
+
+\cs_new_protected:Npn \math_register_odd_env:nn #1#2
+ {
+ \tl_set:Nn \l_@@_env_name_tl {#1}
+ \keys_set:nn { @@ } {#2}
+ \cs_gset_eq:cc { @@_env_ #1 _begin: } {#1}
+ \cs_gset_eq:cc { @@_env_ #1 _end: } { end #1 }
+%
+ \ExpandArgs { nnxx } \RenewDocumentEnvironment {#1} { b }
+ {
+ \exp_not:N \bool_if:NTF \exp_not:N \l_@@_collected_bool
+ {
+% \typeout{===>B1}
+ }
+ {
+% \typeout{===>B2}
+ \cs_if_exist:cTF { @@_env #1 _aux: }
+ {
+ \exp_not:c { @@_env #1 _aux: }
+ ####1 \exp_not:N \@@_env_end: {#1}
+ }
+ { \exp_not:N \@@_process:nn {#1} {####1} }
+ \exp_not:n { \@kernel@math@registered@begin }
+ \bool_set_true:N \exp_not:N \l_@@_collected_bool
+ }
+% \exp_not:N \tracingall
+ \exp_not:c { @@_env_ #1 _begin: }
+ ####1
+ }
+ {
+ \exp_not:c { @@_env_ #1 _end: }
+% needed if we don't have $$...$$
+% \exp_not:n { \typeout{---> @kernel@math@registered@end }}
+ \exp_not:n { \@kernel@math@registered@end }
+ }
+ }
+
+
+% FMi: compare with block change!
+%
+% \DeclareRobustCommand*\begin[1]{%
+% \UseHook{env/#1/before}%
+% \@ifundefined{#1}%
+% {\def\reserved@a{\@latex@error{Environment #1 undefined}\@eha}}%
+% {\def\reserved@a{\def\@currenvir{#1}%
+% \edef\@currenvline{\on@line}%
+% \@execute@begin@hook{#1}%
+% \csname #1\endcsname}}%
+% \@ignorefalse
+% \begingroup
+% \@endpefalse % tmp!!! is it ok to drop this here?
+% \reserved@a}
+
+
+\cs_new:Npn \@kernel@math@registered@begin {
+% \ShowTagging{struct-stack}
+%\typeout{==>A1}\ShowTagging{struct-stack,mc-current}
+ \mode_if_vertical:TF
+ {
+% \legacy_if:nTF { @endpe }
+% { \legacy_if_set_false:n { @endpe } }
+% { \__block_list_beginpar_vmode: }
+%
+% \typeout{==>~ at:~ \g__tag_struct_tag_tl}
+%
+ \exp_args:Noo\str_if_eq:nnF \g__tag_struct_tag_tl { \l__tag_para_main_tag_tl } % needs correction!
+ {
+% \typeout{==>A2}
+ \__block_beginpar_vmode:
+ } % needs correction!
+ }
+ {
+% \typeout{==>A3}
+ \@kernel@close@P
+% \tagmcend % needs correction!
+ }
+ \@kernel@math@begin
+ \tagpdfparaOff
+% \typeout{==>MC1}\ShowTagging{mc-current}
+}
+
+\cs_new:Npn \@kernel@math@registered@end {
+% \typeout{==>MC2}\ShowTagging{mc-current}
+ \para_raw_end:
+ \tagpdfparaOn
+ \@kernel@math@end
+% \typeout{==>MC3}\ShowTagging{mc-current}
+ \@endpetrue
+}
+
+\cs_new_protected:Npn \math_register_env:n #1
+ { \math_register_env:nn {#1} { } }
+\NewDocumentCommand \RegisterMathEnvironment { O{} m }
+ { \math_register_env:nn {#2} {#1} }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_env_forward:w}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_env_forward:w #1 \@@_env_end: #2
+ { \@@_process:nn {#2} {#1} }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Document commands}
+%
+% \car*{Add one more here: \texttt{displaymath}, which
+% is equivalent to \cs{[} , \cs{]}\\
+% and hence to the basic \texttt{equation*}.\\
+% Added in more recent branch.}
+%
+% \begin{macro}
+% {\equation, \@@_equation_begin:, \equation*, \@@_equation_star_begin:}
+% \begin{macro}
+% {\endequation, \@@_equation_end:, \endequation*, \@@_equation_star_end:}
+% These environments are not set up by \pkg{amsmath} to collect their body,
+% so we do that here. This has to be done \emph{after} we can be sure
+% \pkg{amsmath} is loaded.
+%
+% \car*{Note that with \pkg{amsmath} loaded, \texttt{equation*} and \texttt{equation}\\
+% are the two basics: they are used to define the other single-row\\
+% display environments, etc.}
+%
+% \begin{macrocode}
+\tl_gput_right:Nn \@kernel@before@begindocument
+ {
+ \math_register_env:n { equation }
+ \math_register_env:n { equation* }
+% at the moment register_env can only do display math
+% \math_register_env:n { math }
+ \RenewDocumentEnvironment{math} {b}{$#1$}{}
+% and this one doesn't work either
+% \math_register_env:n { displaymath }
+ \RenewDocumentEnvironment{displaymath} {b}{\[#1\]}{}
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\(, \)}
+% If math mode has not been collected, we need to do that; otherwise, worry
+% about whether we are in math mode or not. The closing command here can only
+% occur inside a collected math block: otherwise it will be simply used as
+% a delimiter.
+% \begin{macrocode}
+\cs_gset_protected:Npn \( % \)
+ {
+ \bool_if:NTF \l_@@_collected_bool
+ {
+ \mode_if_math:TF
+ { \@badmath }
+ { $ }
+ }
+ {
+ \bool_set_true:N \l_@@_collected_bool
+ \@@_grab_inline:w
+ }
+ } % \(
+\cs_gset_protected:Npn \)
+ {
+ \mode_if_math:TF
+ { $ }
+ { \@badmath }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\[, \]}
+% Again, we need to watch for when \pkg{amsmath} is loaded after this code.
+% The flag usage here is to cover the case where \cs{[}/\cs{]} is hidden
+% inside another environment. In this case the grabbing happens on
+% the outer level and should not be repeated.
+% \begin{macrocode}
+\tl_gput_right:Nn \@kernel@before@begindocument
+ {
+ \cs_gset_protected:Npn \[ % \]
+ {
+ \bool_if:NTF \l_@@_collected_bool
+ { \begin { equation* } }
+ { \@@_grab_eqn:w }
+ } % \[
+ \cs_gset_protected:Npn \]
+ {
+ \bool_if:NTF \l_@@_collected_bool
+ { \end{ equation* } }
+ { \@badmath }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+%
+% \begin{macro}{\ensuremath}
+% A bit of nesting fun to make sure we collect only if required.
+% \fmi{why does ensuremath need handling at all?}
+%
+% \car{Indeed! Currently, this is setup to process the math that
+% it has anyways already captured as its argument; thus it is more
+% efficient than leaving the capture to be repeated by the \cs{everymath}}
+%
+% \begin{macrocode}
+%\cs_gset_protected:Npn \ensuremath #1
+% {
+% \mode_if_math:TF
+% {#1}
+% {
+% \bool_if:NTF \l_@@_collected_bool
+% { \@ensuredmath {#1} }
+% {
+% \bool_set_true:N \l_@@_collected_bool
+% \@@_process:nn { math } {#1}
+% \@ensuredmath {#1}
+% \bool_set_false:N \l_@@_collected_bool
+% }
+% }
+% }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{\cs{everymath} and \cs{everydisplay}}
+%
+% The business end for grabbing inline math and \enquote{raw} \TeX{}
+% display. Most display math mode is actually handled elsewhere, as we
+% have macro control.
+% \begin{macrocode}
+
+\tl_new:N\tmpmathcontent
+
+
+\def\@kernel@math@begin {
+% \typeout{==>~math~begin}
+% needs different handling if we support nesting
+ \tl_gset:Nx\tmpmathcontent
+ {
+ LaTeX~ formula~ starts~
+ \exp_not:N\begin{\g__math_grabbed_env_tl}
+ \space
+ \exp_not:V\g__math_grabbed_math_tl
+ \space
+ \exp_not:N\end{\g__math_grabbed_env_tl}
+ \space LaTeX~ formula~ ends~
+ }
+ \tagstructbegin{tag=Formula,
+ AFinline-o=\tmpmathcontent,
+ title-o=\g__math_grabbed_env_tl,
+ actualtext=\tmpmathcontent
+% alt=\tmpmathcontent
+ }
+% inner formula if multiple parts (not really implemented yet)
+ \grabaformulapartandstart
+% the above does:
+% \tagstructbegin{tag=Formula}\tagmcbegin{}
+% or just
+% \tagmcbegin{}
+}
+\def\@kernel@math@end {
+% \typeout{==>~math~end}
+% \ShowTagging{struct-stack}
+ \tagmcend
+ \if@subformulas
+ \tagstructend
+ \else
+ \fi
+ \tagstructend
+% \ShowTagging{struct-stack}
+}
+
+\exp_args:No \tex_everymath:D
+ {
+ \tex_the:D \tex_everymath:D
+ \bool_if:NF \l_@@_collected_bool
+ {
+ \bool_set_true:N \l_@@_collected_bool
+ \@@_grab_dollar:w
+ }
+ }
+
+\exp_args:No \tex_everydisplay:D
+ {
+ \tex_the:D \tex_everydisplay:D
+ \iftrue % this may have to be a settable flag!
+% {
+% \typeout{==>~ in~ everydisplay}
+% \end{macrocode}
+% flipping the \cs{belowdisplay} values is done so that we get (assumption)
+% a negative skip and not make the page bigger then we take that out,
+% then we add the tagging code (in \cs{@@_tag_dollardollar_display_end} ) and
+% then we put a real \cs{postdisplaypenalty} in and
+% the right skip (of which we don't know if it is short or a
+% normal \cs{belowdisplayskip}). This might need some refinement if that skip
+% is actually negative from the start
+% (not sure it ever is and is worth bothering about)
+% \begin{macrocode}
+ \skip_set:Nn \belowdisplayskip {-\belowdisplayskip}
+ \skip_set:Nn \belowdisplayshortskip {-\belowdisplayshortskip}
+ \int_set:Nn \postdisplaypenalty {10000}
+%
+ \group_insert_after:N \@@_tag_dollardollar_display_end:
+% }
+ \fi
+ \bool_if:NF \l_@@_collected_bool
+ {
+ \bool_set_true:N \l_@@_collected_bool
+ \@@_grab_dollardollar:w
+ }
+ }
+% \end{macrocode}
+%
+% \subsection{Modifying kernel environments}
+%
+% We need to cover this even though it is, of course, not encouraged.
+% \begin{macrocode}
+\math_register_env:n { eqnarray }
+\math_register_env:n { eqnarray* }
+% \end{macrocode}
+%
+% Places where math mode is (ab)used.
+% \begin{macrocode}
+\clist_map_inline:nn
+ { tabular }
+ {
+ \AddToHook{ env / #1 / begin }
+ { \bool_set_true:N \l_@@_collected_bool }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_m@th:, \m@th}
+% Handle non-math use of math mode. At present nesting isn't supported as
+% \cs{m@th} pops up in a few places that \emph{are} math mode!
+% \begin{macrocode}
+\cs_new_eq:NN \@@_m@th: \m@th
+\cs_gset_protected:Npn \m@th
+ {
+ \bool_set_true:N \l_@@_collected_bool
+ \@@_m@th:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Modifying \pkg{amsmath}}
+%
+% \begin{macro}{\@@_amsmath_align@:nn}
+% \begin{macro}
+% {
+% \@@_amsmath_gather@:n ,
+% \@@_amsmath_multline@:n
+% }
+% \begin{macro}{\align@}
+% \begin{macro}{\gather@, \multline@}
+% Mark up all of the display environments as the content is captured anyway.
+% We then use an internal macro in each environment type to insert the
+% processing code. Each of these is slightly different, so we cannot use a
+% simple loop here. The test for \cs{split@tag} is required as the
+% \texttt{split} environment internally uses \texttt{gather} \emph{when not
+% within an \pkg{amsmath}} environment, for example inside \texttt{equation}.
+% Without the precaution, we'd get two copies of the grabbed math, the second
+% of which would start with \cs{split@tag}.
+% \begin{macrocode}
+
+
+
+\tl_gput_right:Nn \@kernel@before@begindocument {
+%
+\renewenvironment{gather*}{%
+ \start@gather\st@rredtrue
+}
+{%
+% this redirection doesn't work if we alter "gather"!
+ % \endgather
+% so replace it with its real meaning
+ \math@cr \black@\totwidth@ \egroup
+ $$\ignorespacesafterend
+}
+% \end{macrocode}
+%
+% \begin{macrocode}
+\def\common@align@ending {
+ \math@cr \black@\totwidth@
+ \egroup
+ \ifingather@
+ \restorealignstate@
+ \egroup
+ \nonumber
+ \ifnum0=`{\fi\iffalse}\fi
+ \else
+ $$%
+ \fi
+ \ignorespacesafterend
+}
+\renewenvironment{alignat}{%
+ \start@align\z@\st@rredfalse
+}{%
+ \common@align@ending
+}
+\renewenvironment{alignat*}{%
+ \start@align\z@\st@rredtrue
+}{%
+ \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
+}
+\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{flalign}{%
+ \start@align\tw@\st@rredfalse\m@ne
+}{%
+ \common@align@ending
+}
+\renewenvironment{flalign*}{%
+ \start@align\tw@\st@rredtrue\m@ne
+}{%
+ \common@align@ending
+}
+%
+\renewenvironment{multline*}{\start@multline\st@rredtrue}
+{%
+ \iftagsleft@ \@xp\lendmultline@ \else \@xp\rendmultline@ \fi
+ \ignorespacesafterend
+}
+% \end{macrocode}
+% Also for "false?"
+% \begin{macrocode}
+\def\measuring@true{\let\ifmeasuring@\iftrue\tag_stop:}
+% \end{macrocode}
+%
+% \begin{macrocode}
+%
+ \math_register_halign_env:nn {align}{}
+ \math_register_halign_env:nn {align*}{}
+ \math_register_halign_env:nn {flalign}{}
+ \math_register_halign_env:nn {flalign*}{}
+ \math_register_halign_env:nn {gather}{}
+ \math_register_halign_env:nn {gather*}{}
+ \math_register_halign_env:nn {multline}{}
+ \math_register_halign_env:nn {multline*}{}
+ \math_register_halign_env:nn {xalignat}{}
+ \math_register_halign_env:nn {xalignat*}{}
+ \math_register_halign_env:nn {xxalignat}{}
+ %
+ \@namedef{maketag @ @ @} #1{%
+% \typeout{--->maketag @ @ @}
+ \ifmeasuring@
+ \hbox{\m@th\normalfont#1}%
+ \else
+ \tagmcend \tagstructbegin{tag=Lbl}%
+ \tagmcbegin{tag=Lbl}%
+ \hbox{\m@th\normalfont#1}%
+ \tagmcend \tagstructend \tagmcbegin{}%
+ \fi
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+ \def\intertext@{%
+ \def\intertext##1{%
+ \ifvmode\else\\\@empty\fi
+ \noalign{%
+% we have to flip the sign on the skip because we flipped it on the outside
+ \penalty\postdisplaypenalty\vskip-\belowdisplayskip
+ \vbox{
+% \end{macrocode}
+% Stop tagging when measuring:
+% \begin{macrocode}
+ \ifmeasuring@\tag_stop:\fi
+ \normalbaselines
+ \ifdim\linewidth=\columnwidth
+ \else \parshape\@ne \@totalleftmargin \linewidth
+ \fi
+% \end{macrocode}
+% End the previous mc:\fmi{if we use 2 levels of formulas this would
+% need changing}
+% \begin{macrocode}
+ \tag_mc_end_push:
+% \end{macrocode}
+% We are already in a par so we change now to Span:\fmi{not true any longer}
+% \begin{macrocode}
+ \tagpdfsetup{paratag=P}%
+ \tagpdfparaOn
+ \noindent\ignorespaces##1\par
+% \end{macrocode}
+% Restart the MC
+% \begin{macrocode}
+ \tag_mc_begin_pop:n{}}%
+ \penalty\predisplaypenalty\vskip\abovedisplayskip%
+ }%
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@namedef{math@cr @ @ @ gather}{%
+ \ifst@rred\nonumber\fi
+ &\relax
+ \make@display@tag
+%
+ \maybestartnewformulatag
+%
+ \ifst@rred\else\global\@eqnswtrue\fi
+ \global\advance\row@\@ne
+ \cr
+}
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@namedef{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
+%
+ \maybestartnewformulatag
+%
+ \ifst@rred\else\global\@eqnswtrue\fi
+ \global\lineht@\z@
+ \cr
+}
+% \end{macrocode}
+%
+% \begin{macrocode}
+\def\restore@math@cr{\@namedef{math@cr @ @ @}{
+%
+ \maybestartnewformulatag
+%
+ \cr}}
+\restore@math@cr
+% \end{macrocode}
+%
+% \begin{macrocode}
+}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+%
+%
+
+% \begin{macro}{}
+%
+% \begin{macrocode}
+\cs_new:Npn \@@_split_at_nl_first:w #1 \\ #2 \\ #3 \s_stop
+ {
+ \quark_if_nil:nTF {#2}
+ { {#1} { } }
+ {
+ \@@_split_chk_if_begin:ww #1 \begin \q_nil \s_mark
+ #2 \\ #3 \s_stop
+ }
+ }
+\cs_new:Npn \@@_split_chk_if_begin:ww #1 \begin #2 #3 \s_mark
+ #4 \\ \q_nil \\ \s_stop
+ {
+ \quark_if_nil:nTF {#2}
+ { {#1} {#4} }
+ {
+ \exp_after:wN \@@_split_collect_one_end:w
+ \@@_split_cleanup_begin_q_nil:w #1 \begin{#2} #3 \\ #4 \s_stop
+ { } { 1 }
+ }
+ }
+\cs_new:Npn \@@_split_cleanup_begin_q_nil:w #1 \begin \q_nil {#1}
+\cs_new:Npn \@@_split_collect_one_end:w #1 \end #2 #3 \s_stop #4 #5
+ {
+ \exp_args:Nf \@@_split_check_count_begins:nnnn
+ { \@@_split_count_begins:n { #4 #1 } } {#5}
+ { #4 #1 \end{#2} } {#3}
+ }
+\cs_new:Npn \@@_split_count_begins:n #1
+ { \int_eval:n { 0 \@@_split_count_begins:w #1 \begin \q_nil } }
+\cs_new:Npn \@@_split_count_begins:w #1 \begin #2
+ { \quark_if_nil:nF {#2} { +1 \@@_split_count_begins:w } }
+\cs_new:Npn \@@_split_check_count_begins:nnnn #1 #2 #3 #4
+ {
+ \int_compare:nNnTF {#1} = {#2}
+ {
+ \exp_last_unbraced:Nf \@@_split_final_cleanup:nn
+ { \split:n { \@@_split_guard:n {#3} #4 } }
+ }
+ {
+ \exp_args:No \use_ii_i:nn
+ { \exp_after:wN { \int_value:w \int_eval:n { #2 + 1 } } }
+ { \@@_split_collect_one_end:w #4 \s_stop {#3} }
+ }
+ }
+\cs_new:Npn \@@_split_final_cleanup:nn #1 #2
+ {
+ \exp:w \@@_split_final_cleanup:w #1
+ \@@_split_guard:n \q_nil \s_mark { }
+ {#2}
+ }
+\cs_new:Npn \@@_split_final_cleanup:w #1 \@@_split_guard:n #2 #3 \s_mark #4
+ {
+ \quark_if_nil:nTF {#2}
+ { \exp_end: { #4 #1 } }
+ { \@@_split_final_cleanup:w #3 \s_mark { #4 #1 #2 } }
+ }
+\NewDocumentCommand \splitnl { mm +m }
+ {
+ \tl_set:Nf \l_tmpa_tl { \split:n {#3} }
+ \show \l_tmpa_tl
+ \exp_after:wN \__splitnl_aux:nnNN \l_tmpa_tl #1 #2
+ }
+
+
+\cs_new:Npn \split:n #1 {
+ \@@_split_at_nl_first:w #1 \\ \q_nil \\ \s_stop }
+
+\cs_new:Npn \@@_split_at_nl:NN #1#2 {
+ \tl_set:Nf \l_tmpa_tl {
+ \exp_after:wN \@@_split_at_nl_first:w #1 \\ \q_nil \\ \s_stop }
+ \exp_after:wN \@@_split_at_nl_aux:nnNN \l_tmpa_tl #1 #2
+}
+
+\cs_new_protected:Npn \@@_split_at_nl_aux:nnNN #1 #2 #3 #4
+ {
+ \tl_gset:Nn #4 {#1}
+ \tl_gset:Nn #3 {#2}
+}
+
+% \end{macrocode}
+% \end{macro}
+%
+%
+% \begin{macro}{\maybestartnewformulatag}
+%
+% \begin{macrocode}
+
+\newif\if@subformulas
+\tl_new:N \result
+
+\cs_new_protected:Npn\grabaformulapartandstart {
+ \@@_split_at_nl:NN \g__math_grabbed_math_tl \result
+ \typeout{====>first-result=\meaning\result}
+ \typeout{====>first-tmpmathcontent=\meaning\g__math_grabbed_math_tl}
+ \tl_if_empty:NTF \g__math_grabbed_math_tl
+ {
+ \typeout{====>formula~ has~ no~ subparts}
+ \global\@subformulasfalse
+ }
+ {
+ \typeout{====>formula~ has~ subparts}
+ \global\@subformulastrue
+ \edef\resulttitle{\g__math_grabbed_env_tl\space (part)}
+ \tagstructbegin{tag=Formula,
+% \end{macrocode}
+% For now we don't put anything in /alt or /ActualText on subformulas
+% \begin{macrocode}
+% alt=\result,
+ title-o=\resulttitle
+ }
+ }
+ \tagmcbegin{}
+}
+
+\cs_new_protected:Npn\grabaformulapartandmayberestart {
+ \@@_split_at_nl:NN \g__math_grabbed_math_tl \result
+ \typeout{====>result=\meaning\result}
+ \typeout{====>tmpmathcontent=\meaning\g__math_grabbed_math_tl}
+% \tl_if_empty:NTF \g__math_grabbed_math_tl
+% {
+% \typeout{====>tmpmathcontent=empty}
+% }
+% {
+% \typeout{====>tmpmathcontent=not-empty}
+ \edef\resulttitle{\g__math_grabbed_env_tl\space (part)}
+ \tagstructbegin{tag=Formula,
+ alt=\result,
+ title-o=\resulttitle
+ }
+% }
+ \tagmcbegin{}
+}
+% \end{macrocode}
+% \end{macro}
+%
+%
+%
+%
+% \begin{macrocode}
+\def\maybestartnewformulatag {
+\if@subformulas
+ \ifmeasuring@\else
+%
+ \tl_if_empty:NF \g__math_grabbed_math_tl
+ {
+ \tagmcend
+ \tagstructend
+ \grabaformulapartandmayberestart
+ }
+ \fi
+\fi
+}
+% \end{macrocode}
+%
+% The breqn packages changes catcodes and that isn't yet covered
+% by our mechanism.
+% \begin{macrocode}
+%\AddToHook{package/breqn/after}{
+% \typeout{===>~ in~ hook}
+% \math_register_halign_env:nn {dmath}{}
+% \math_register_halign_env:nn {dgroup*}{}
+%}
+% \end{macrocode}
+%
+% \begin{macrocode}
+\ExplSyntaxOff
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<@@=>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</kernel>
+% \end{macrocode}
+%
+% \Finale
+%
+%