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authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /macros/latex/contrib/unravel
Initial commit
Diffstat (limited to 'macros/latex/contrib/unravel')
-rw-r--r--macros/latex/contrib/unravel/README.md36
-rw-r--r--macros/latex/contrib/unravel/unravel.dtx8879
-rw-r--r--macros/latex/contrib/unravel/unravel.ins23
-rw-r--r--macros/latex/contrib/unravel/unravel.pdfbin0 -> 689310 bytes
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diff --git a/macros/latex/contrib/unravel/README.md b/macros/latex/contrib/unravel/README.md
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+unravel: Watching TeX digest tokens
+====================================================
+* E-mail: blflatex+unravel@gmail.com
+* Released under the LaTeX Project Public License v1.3c or later
+ See http://www.latex-project.org/lppl.txt
+
+The `unravel` LaTeX package provides tools to explore TeX code,
+performing expansion and assignments step by step.
+
+TeX is a strange beast. Its eyes read files, making characters
+into tokens. Its mouth then chews tokens, expanding them if
+possible, namely, expanding user-defined macros, or conditionals,
+etc. When meeting a so called 'unexpandable' token, TeX's
+stomach comes into play, performing assignments, or moving boxes
+around, eventually typesetting the result thanks to its great
+line- and page-breaking algorithms.
+
+All of this is interleaved, and difficult to follow. Of course,
+one can always use `\tracingall`, but the result is... messy.
+This package is an attempt to replicate how TeX digests tokens,
+and to make the process easier to follow. Namely,
+`\unravel{\some\tokens}` will let you go through expansions and
+assignments performed by TeX upon seeing of `\some\tokens`,
+step by step.
+
+Some parts of TeX are not covered. In particular, category codes
+are fixed for the whole argument of `\unravel` when it is read.
+
+This package requires up-to-date versions of the `l3kernel`,
+`l3packages` and `l3experimental` bundles.
+
+The package is extracted by running `pdflatex unravel.ins`.
+For the documentation, run `pdflatex unravel.dtx` twice.
+
+This is work in progress, all suggestions/comments/bug reports
+are welcome! See https://github.com/blefloch/latex-unravel/
diff --git a/macros/latex/contrib/unravel/unravel.dtx b/macros/latex/contrib/unravel/unravel.dtx
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+% \iffalse
+%% File: unravel.dtx Copyright (C) 2013, 2015, 2018-2019 Bruno Le Floch
+%%
+%% 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
+%%
+%% http://www.latex-project.org/lppl.txt
+%%
+%% -----------------------------------------------------------------------
+%
+%<*driver>
+%\fi
+%\iffalse
+\documentclass[full]{l3doc}
+\usepackage{unravel}
+\begin{document}
+ \DocInput{unravel.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+% \title{The \textsf{unravel} package: \\
+% watching TeX digest tokens\thanks{This
+% file has version number 0.2g, last revised 2019/03/23.}}
+% \author{Bruno Le Floch}
+% \date{2019/03/23}
+%
+% \maketitle
+% \tableofcontents
+%
+% \begin{documentation}
+%
+% \section{\pkg{unravel} documentation}
+%
+% The aim of this \LaTeX{} package is to help debug complicated macros.
+% This is done by letting the user step through the execution of some
+% \TeX{} code, going through the details of nested expansions,
+% performing assignments, as well as some simple typesetting commands.
+% To use this package, one should normally run \TeX{} in a terminal.
+%
+% \subsection{Commands}
+%
+% \begin{function}{\unravel}
+% \begin{syntax}
+% \cs{unravel} \oarg{key-value list} \marg{code}
+% \end{syntax}
+% This command shows in the terminal the steps performed by \TeX{}
+% when running the \meta{code}. By default, it pauses to let the
+% user read the description of every step: simply press |<return>| to
+% proceed. Typing |s|\meta{integer} instead will go forward
+% \meta{integer} steps somewhat silently. In the future it will be
+% possible to use a negative \meta{integer} to go back a few steps.
+% Typing |h| gives a list of various other possibilities.
+% The available \meta{key-value} options are described in
+% Section~\ref{sec:options}.
+% \end{function}
+%
+% \begin{function}{\unravelsetup}
+% \begin{syntax}
+% \cs{unravelsetup} \marg{options}
+% \end{syntax}
+% Sets \meta{options} that apply to all subsequent \cs{unravel}. See
+% options in Section~\ref{sec:options}.
+% \end{function}
+%
+% \begin{function}{\unravel:nn}
+% \begin{syntax}
+% \cs{unravel:nn} \Arg{options} \Arg{code}
+% \end{syntax}
+% See \cs{unravel}.
+% \end{function}
+%
+% \begin{function}{\unravel_get:nnN}
+% \begin{syntax}
+% \cs{unravel_get:nnN} \Arg{options} \Arg{code} \meta{tl var}
+% \end{syntax}
+% Performs \cs{unravel:nn} with the \meta{options} and \meta{code}
+% then saves the output into the \meta{tl var}. The option
+% |mute| is useful in this case.
+% \end{function}
+%
+% \begin{function}{\unravel_setup:n}
+% \begin{syntax}
+% \cs{unravel_setup:n} \Arg{options}
+% \end{syntax}
+% See \cs{unravelsetup}.
+% \end{function}
+%
+% \subsection{Examples}
+%
+% The \pkg{unravel} package is currently based on the behaviour of
+% \pdfTeX{}, but it should work in all engines supported by \pkg{expl3}
+% (\pdfTeX{}, \XeTeX{}, \LuaTeX{}, ep\TeX{}, eup\TeX{}) as long as none
+% of the primitives specific to those engines is used. Any
+% difference between how \pkg{unravel} and (pdf)\TeX{} process a given
+% piece of code, unless described in the section~\ref{sec:differences},
+% should be reported on the issue tracker
+% (\url{https://github.com/blefloch/latex-unravel/issues}).
+%
+% As a simple example, one can run \LaTeX{} on the following file.
+% \begin{verbatim}
+% \documentclass{article}
+% \usepackage{unravel}
+% \unravel
+% {
+% \title{My title}
+% \author{Me}
+% \date{\today}
+% }
+% \begin{document}
+% \maketitle
+% \end{document}
+% \end{verbatim}
+%
+% A more elaborate example is to understand how \tn{newcommand} works.
+% \begin{verbatim}
+% \documentclass{article}
+% \usepackage{unravel}
+% \begin{document}
+% \unravel
+% {
+% \newcommand*{\foo}[1]{bar(#1)}
+% \foo{3}
+% }
+% \end{document}
+% \end{verbatim}
+%
+% The \pkg{unravel} package understands deeply nested expansions as can
+% be seen for instance by unravelling functions from \pkg{l3fp}, such as
+% with the following code (given the current default settings, this code
+% runs for roughly 2000 steps: you can type |s1980| as a response to the
+% prompt, then press ``enter'' a few times to see the last few steps of
+% expansion).
+% \begin{verbatim}
+% \documentclass{article}
+% \usepackage{unravel}
+% \begin{document}
+% \ExplSyntaxOn
+% \unravel { \fp_eval:n { 3.45 * 2 pi } }
+% \ExplSyntaxOff
+% \end{document}
+% \end{verbatim}
+%
+% Given all the work that \pkg{unravel} has to do to emulate \TeX{}, it
+% is not fast on very large pieces of code. For instance, running it on
+% |\documentclass{article}| takes about thirty seconds on my machine, and
+% finishes after somewhat less than $21000$ steps.
+% \begin{verbatim}
+% \RequirePackage{unravel}
+% \unravel{\documentclass{article}\relax}
+% \usepackage{lipsum}
+% \begin{document}
+% \lipsum
+% \end{document}
+% \end{verbatim}
+% The \tn{relax} command is needed after |\documentclass{article}|
+% because this command tries to look for an optional argument:
+% \cs{unravel} would not find any token, and would give up, as \TeX{}
+% would if your file ended just after |\documentclass{article}|. After
+% running the above through \pdfTeX{}, one can check that the result is
+% identical to that without \pkg{unravel}. Note that
+% \cs{unravel}|{\usepackage{lipsum}\relax}|, despite taking roughly as many steps
+% to complete, is ten times slower, because \tn{newcommand} uses
+% delimited arguments, which prevent some optimizations that
+% \pkg{unravel} can otherwise obtain. For comparison,
+% |\unravel{\lipsum[1-30]}| also takes $20000$ step and is ten times
+% faster than loading the package.
+%
+% \subsection{Options}
+% \label{sec:options}
+%
+% \begin{function}{explicit-prompt}
+% Boolean option (default \texttt{false}) determining whether to give
+% an explicit prompt. If \texttt{true}, the text ``|Your input=|''
+% will appear at the beginning of lines where user input is expected.
+% \end{function}
+%
+% \begin{function}{internal-debug}
+% Boolean option (default \texttt{false}) used to debug \pkg{unravel}
+% itself.
+% \end{function}
+%
+% \begin{function}{machine}
+% Option which takes no value and makes \pkg{unravel} produce an
+% output that is somewhat more suitable for automatic processing. In
+% particular, it sets |max-action|, |max-output|, |max-input| to very
+% large values, and |number-steps| to \texttt{false}.
+% \end{function}
+%
+% \begin{function}{max-action, max-output, max-input}
+% Integer options (defaults $50$, $300$, $300$) determining the
+% maximum number of characters displayed for the action, the output
+% part, and the input part.
+% \end{function}
+%
+% \begin{function}{mute}
+% Make none of the steps produce any output, by setting
+% |trace-assigns|, |trace-expansion|, |trace-other|, |welcome-message|
+% to \texttt{false}. This is only useful with \cs{unravel_get:nnN} or
+% when other options change some of these settings.
+% \end{function}
+%
+% \begin{function}{number-steps}
+% Boolean option (default \texttt{true}) determining whether to
+% number steps.
+% \end{function}
+%
+% \begin{function}{online}
+% Integer option determining where to write the output: terminal and
+% log if the option is positive, log only if the option is zero,
+% neither if the option is negative.
+% \end{function}
+%
+% \begin{function}{trace-assigns, trace-expansion, trace-other}
+% Boolean options (default \texttt{true}) controlling what steps
+% produce any output at all. The keys |trace-assigns|,
+% |trace-expansion|, |trace-other| control tracing of different types
+% of steps.
+% \end{function}
+%
+% \begin{function}{welcome-message}
+% Boolean option (default \texttt{true}) determining whether to
+% display the welcome message.
+% \end{function}
+%
+% \subsection{Differences between \pkg{unravel} and \TeX{}'s processing}
+% \label{sec:differences}
+%
+% Bugs are listed at \url{https://github.com/blefloch/latex-unravel/issues}.
+%
+% Differences.
+% \begin{itemize}
+% \item Kerning between letters of a word is omitted, which can lead to
+% incorrect widths.
+% \item Some primitives are not implemented yet: alignments
+% (\tn{halign}, \tn{valign}, \tn{noalign}, \tn{omit}, \tn{span},
+% \tn{cr}, \tn{crcr},~|&|), many math mode primitives, and
+% \tn{pdfprimitive}, \tn{discretionary}, as well as
+% all primitives specific to engines other than \pdfTeX{}.
+% This list may sadly be incomplete!
+% \item \tn{aftergroup} is only partially implemented.
+% \item \tn{everyhbox}, \tn{everyvbox}, \tn{everymath},
+% \tn{everydisplay}, \tn{lastkern}, \tn{lastnodetype},
+% \tn{lastpenalty}, \tn{lastskip}, \tn{currentiflevel} and
+% \tn{currentiftype} may have wrong values. Perhaps
+% \tn{currentgrouplevel} and \tn{currentgrouptype} too.
+% \item Tokens passed to \tn{afterassignment} are not yet kept after
+% \pkg{unravel} is done even if there has been no assignment.
+% \item Tokens passed to \tn{aftergroup} are lost when \pkg{unravel} is
+% done.
+% \item In \XeTeX{}, characters beyond the basic multilingual plane may
+% break \pkg{unravel} (not tested).
+% \item For \pkg{unravel}, category codes are fixed when a file is read
+% using \tn{input},
+% while \TeX{} only fixes category codes when the corresponding
+% characters are converted to tokens. Similarly, the argument of
+% \tn{scantokens} is converted to the new category code r\'egime in
+% one go, and the result must be balanced.
+% \item Explicit begin-group and end-group characters other than the
+% usual left and right braces may make \pkg{unravel} choke, or may be
+% silently replaced by the usual left and right braces.
+% \item \tn{endinput} is ignored with a warning, as it is very difficult
+% to implement it in a way similar to \TeX{}'s, and as it is most
+% often used at the very end of files, in a redundant way.
+% \item \tn{outer} is not supported.
+% \item \cs{unravel} cannot be nested.
+% \item Control sequences of the form \cs{notexpanded:\ldots{}} are
+% reserved for use by \pkg{unravel}.
+% \end{itemize}
+%
+% \subsection{Future perhaps}
+%
+% \begin{itemize}
+% \item Allow users to change some settings globally/for one |\unravel|.
+% \item Allow to replay steps that have already been run.
+% \item Fix the display for \tn{if} and \tn{ifcat} (remove extraneous
+% \cs{exp_not:N}).
+% \item Use the |file-error| fatal error message: first implement
+% \cs{@@_file_if_exist:nTF} and use it to determine whether
+% \tn{input} will throw a fatal error in \tn{batchmode} and
+% \tn{nonstopmode}.
+% \item Use the |interwoven-preambles| fatal error message once
+% alignments are implemented.
+% \item Look at all places where \TeX{}'s procedure |prepare_mag| is
+% called.
+% \item Find out why so many input levels are used (see the log of the
+% |unravel003| testfile for instance)
+% \end{itemize}
+%
+% \end{documentation}
+%
+% \begin{implementation}
+%
+% \section{\pkg{unravel} implementation}
+%
+% Some support packages are loaded first, then we declare the package's
+% name, date, version, and purpose.
+%
+% \begin{macrocode}
+%<*package>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<@@=unravel>
+% \end{macrocode}
+%
+% Catcode settings. In a group, set |\c| to be a synonym of |\catcode|
+% for short, set the catcode of space to be 10 (using |\fam| to avoid
+% needing a space or an equal sign to separate the two integer
+% arguments of |\catcode|) and that of |%| to be 14 (using |\fam| again
+% to avoid needing the digit 7 to have catcode other: we need the digit
+% 5 anyway in two steps). Then make |-|, |6|, |7|, |8|, |9| other (we
+% must assume that |0| through |5| are already other), and make |:|,
+% |_|, |h|, |j|, |k|, |q|, |s|, |w|, |x|, |y|, |z| letters (other
+% lowercase letters already need to be letters in the rest of the
+% code). Make sure there is no |\endlinechar|. We are finally ready
+% to safely test whether the package has already been loaded and bail
+% out in case it has. Expanding |\fi| before ending the group ensures
+% that the whole line has been read by \TeX{} before restoring earlier
+% catcodes.
+% \begin{macrocode}
+\begingroup\let\c\catcode\fam32\c\fam10\advance\fam5\c\fam14\c45 12 %
+\c54 12\c55 12\c56 12\c57 12\c58 11\c95 11\c104 11\c106 11\c107 11 %
+\c113 11\c115 11\c119 11\c120 11\c121 11\c122 11\endlinechar-1 %
+\expandafter\ifx\csname unravel\endcsname\relax
+\else\endinput\expandafter\endgroup\fi
+% \end{macrocode}
+%
+% Set |T| and |X| to be letters for an error message. Set up braces
+% and |#| for definitions, |=| for nicer character code assignments,
+% |>| for integer comparison, |+| for integer expressions.
+% \begin{macrocode}
+\c84 11\c88 11\c35 6\c123 1\c125 2\c62 12\c61 12\c43 12 %
+% \end{macrocode}
+%
+% If \eTeX{}'s \tn{numexpr} or \tn{protected} are not available, bail
+% out with an error.
+% \begin{macrocode}
+\expandafter\ifx\csname numexpr\endcsname\relax
+\errmessage{unravel requires \numexpr from eTeX}
+\endinput\expandafter\endgroup\fi
+\expandafter\ifx\csname protected\endcsname\relax
+\errmessage{unravel requires \protected from eTeX}
+\endinput\expandafter\endgroup\fi
+% \end{macrocode}
+%
+% If \pkg{unravel} is loaded within a group, bail out because
+% \pkg{expl3} would not be loaded properly.
+% \begin{macrocode}
+\expandafter\ifx\csname currentgrouplevel\endcsname\relax\else
+\ifnum\currentgrouplevel>1 \errmessage{unravel loaded in a group}
+\endinput\expandafter\expandafter\expandafter\endgroup\fi\fi
+% \end{macrocode}
+%
+% Make spaces ignored and make |~| a space, to prettify code.
+% \begin{macrocode}
+\catcode 32 = 9 \relax
+\catcode 126 = 10 \relax
+% \end{macrocode}
+%
+% \begin{variable}{\l_@@_setup_restore_tl}
+% This token list variable will contain code to restore category
+% codes to their value when the package was loaded.
+% \begin{macrocode}
+\gdef \l_@@_setup_restore_tl { }
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_setup_restore:}
+% Use the token list to restore catcodes to their former values, then
+% empty the list since there is no catcode to restore anymore. This
+% mechanism cannot be nested.
+% \begin{macrocode}
+\protected \gdef \@@_setup_restore:
+ {
+ \l_@@_setup_restore_tl
+ \def \l_@@_setup_restore_tl { }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_save:}
+% \begin{macro}[EXP]{\@@_setup_save_aux:n}
+% This saves into \cs{l_@@_setup_restore_tl} the current catcodes
+% (from $0$ to $255$ only), \tn{endlinechar}, \tn{escapechar},
+% \tn{newlinechar}.
+% \begin{macrocode}
+\protected \gdef \@@_setup_save:
+ {
+ \edef \l_@@_setup_restore_tl
+ {
+ \@@_setup_save_aux:w 0 =
+ \endlinechar = \the \endlinechar
+ \escapechar = \the \escapechar
+ \newlinechar = \the \newlinechar
+ \relax
+ }
+ }
+\long \gdef \@@_setup_save_aux:w #1 =
+ {
+ \catcode #1 = \the \catcode #1 ~
+ \ifnum 255 > #1 ~
+ \expandafter \@@_setup_save_aux:w
+ \the \numexpr #1 + 1 \expandafter =
+ \fi
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_catcodes:nnn}
+% This sets all characters from |#1| to |#2| (inclusive) to have
+% catcode |#3|.
+% \begin{macrocode}
+\protected \long \gdef \@@_setup_catcodes:nnn #1 #2 #3
+ {
+ \ifnum #1 > #2 ~ \else
+ \catcode #1 = #3 ~
+ \expandafter \@@_setup_catcodes:nnn \expandafter
+ { \the \numexpr #1 + 1 } {#2} {#3}
+ \fi
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_latexe:}
+% This saves the catcodes and related parameters, then sets them to
+% the value they normally have in a \LaTeXe{} package (in particular,
+% |@| is a letter).
+% \begin{macrocode}
+\protected \gdef \@@_setup_latexe:
+ {
+ \@@_setup_save:
+ \@@_setup_catcodes:nnn {0} {8} {15}
+ \catcode 9 = 10 ~
+ \catcode 10 = 12 ~
+ \catcode 11 = 15 ~
+ \catcode 12 = 13 ~
+ \catcode 13 = 5 ~
+ \@@_setup_catcodes:nnn {14} {31} {15}
+ \catcode 32 = 10 ~
+ \catcode 33 = 12 ~
+ \catcode 34 = 12 ~
+ \catcode 35 = 6 ~
+ \catcode 36 = 3 ~
+ \catcode 37 = 14 ~
+ \catcode 38 = 4 ~
+ \@@_setup_catcodes:nnn {39} {63} {12}
+ \@@_setup_catcodes:nnn {64} {90} {11}
+ \catcode 91 = 12 ~
+ \catcode 92 = 0 ~
+ \catcode 93 = 12 ~
+ \catcode 94 = 7 ~
+ \catcode 95 = 8 ~
+ \catcode 96 = 12 ~
+ \@@_setup_catcodes:nnn {97} {122} {11}
+ \catcode 123 = 1 ~
+ \catcode 124 = 12 ~
+ \catcode 125 = 2 ~
+ \catcode 126 = 13 ~
+ \catcode 127 = 15 ~
+ \@@_setup_catcodes:nnn {128} {255} {12}
+ \endlinechar = 13 ~
+ \escapechar = 92 ~
+ \newlinechar = 10 ~
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_setup_unravel:}
+% Catcodes for \pkg{unravel} (in particular, |@| is other, |:| and
+% |_| are letters, spaces are ignored, |~| is a space).
+% \begin{macrocode}
+\protected \gdef \@@_setup_unravel:
+ {
+ \@@_setup_save:
+ \@@_setup_catcodes:nnn {0} {8} {15}
+ \catcode 9 = 9 ~
+ \catcode 10 = 12 ~
+ \catcode 11 = 15 ~
+ \catcode 12 = 13 ~
+ \catcode 13 = 5 ~
+ \@@_setup_catcodes:nnn {14} {31} {15}
+ \catcode 32 = 9 ~
+ \catcode 33 = 12 ~
+ \catcode 34 = 12 ~
+ \catcode 35 = 6 ~
+ \catcode 36 = 3 ~
+ \catcode 37 = 14 ~
+ \catcode 38 = 4 ~
+ \@@_setup_catcodes:nnn {39} {57} {12}
+ \catcode 58 = 11 ~
+ \@@_setup_catcodes:nnn {59} {64} {12}
+ \@@_setup_catcodes:nnn {65} {90} {11}
+ \catcode 91 = 12 ~
+ \catcode 92 = 0 ~
+ \catcode 93 = 12 ~
+ \catcode 94 = 7 ~
+ \catcode 95 = 11 ~
+ \catcode 96 = 12 ~
+ \@@_setup_catcodes:nnn {97} {122} {11}
+ \catcode 123 = 1 ~
+ \catcode 124 = 12 ~
+ \catcode 125 = 2 ~
+ \catcode 126 = 10 ~
+ \catcode 127 = 15 ~
+ \@@_setup_catcodes:nnn {128} {255} {12}
+ \escapechar = 92 ~
+ \endlinechar = 32 ~
+ \newlinechar = 10 ~
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% End the group where all catcodes where changed, but expand
+% \cs{@@_setup_latexe:} to sanitize catcodes again outside the
+% group. The catcodes are saved.
+% \begin{macrocode}
+\expandafter \endgroup \@@_setup_latexe:
+% \end{macrocode}
+%
+% Load a few dependencies: \pkg{expl3}, \pkg{xparse}, \pkg{gtl}.
+% Load \pkg{l3str} if \pkg{expl3} is too old and does not define
+% \cs{str_range:nnn}. Otherwise loading \pkg{l3str} would give
+% an error.
+% \begin{macrocode}
+\RequirePackage{expl3,xparse}[2018/02/21]
+\RequirePackage{gtl}[2018/12/28]
+\csname cs_if_exist:cF\endcsname{str_range:nnn}{\RequirePackage{l3str}}
+% \end{macrocode}
+%
+% Before loading \pkg{unravel}, restore catcodes, so that the implicit
+% \cs{ExplSyntaxOn} in \cs{ProvidesExplPackage} picks up the correct
+% catcodes to restore when \cs{ExplSyntaxOff} is run at the end of the
+% package. The place where catcodes are restored are beyond
+% \pkg{unravel}'s reach, which is why we cannot bypass \pkg{expl3} and
+% simply restore the catcodes once everything is done. To avoid issues
+% with crazy catcodes, make \TeX{} read the arguments of
+% \cs{ProvidesExplPackage} before restoring catcodes. Then immediately
+% go to the catcodes we want.
+% \begin{macrocode}
+\csname use:n\endcsname
+ {%
+ \csname @@_setup_restore:\endcsname
+ \ProvidesExplPackage
+ {unravel} {2019/03/23} {0.2g} {Watching TeX digest tokens}%
+ \csname @@_setup_unravel:\endcsname
+ }%
+% \end{macrocode}
+%
+% \subsection{Primitives, variants, and helpers}
+%
+% \subsubsection{Renamed primitives}
+%
+% \begin{macro}
+% {
+% \@@_currentgrouptype:, \@@_everyeof:w, \@@_everypar:w,
+% \@@_set_escapechar:n, \@@_nullfont:,
+% \@@_hbox:w, \@@_the:w,
+% }
+% Copy primitives which are used multiple times, to avoid littering
+% the code with |:D| commands. Primitives are left as |:D| in the
+% code when that is clearer (typically when testing the meaning of
+% a token against that of a primitive).
+% \begin{macrocode}
+\cs_new_eq:NN \@@_currentgrouptype: \tex_currentgrouptype:D
+\cs_new_protected:Npn \@@_set_escapechar:n
+ { \int_set:Nn \tex_escapechar:D }
+\cs_new_eq:NN \@@_everyeof:w \tex_everyeof:D
+\cs_new_eq:NN \@@_everypar:w \tex_everypar:D
+\cs_new_eq:NN \@@_hbox:w \tex_hbox:D
+\cs_new_eq:NN \@@_mag: \tex_mag:D
+\cs_new_eq:NN \@@_nullfont: \tex_nullfont:D
+\cs_new_eq:NN \@@_the:w \tex_the:D
+\cs_new_eq:NN \@@_number:w \tex_number:D
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_special_relax:}
+% A special marker slightly different from \tn{relax} (its
+% \tn{meaning} is \tn{relax} but it differs from \tn{relax} according
+% to \tn{ifx}). In the right-hand side of our assignment,
+% \cs{@@_special_relax:} could be replaced by any other expandable
+% command.
+% \begin{macrocode}
+\exp_after:wN \cs_new_eq:NN
+ \exp_after:wN \@@_special_relax:
+ \exp_not:N \@@_special_relax:
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\c_@@_prompt_ior, \c_@@_noprompt_ior}
+% These are not quite primitives, but are very low-level
+% |ior| streams to prompt the user explicitly or not.
+% \begin{macrocode}
+\int_const:Nn \c_@@_prompt_ior { 16 }
+\int_const:Nn \c_@@_noprompt_ior { -1 }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Variants}
+%
+% Variants that we need.
+% \begin{macrocode}
+\cs_generate_variant:Nn \seq_push:Nn { Nf }
+\cs_generate_variant:Nn \str_head:n { f }
+\cs_generate_variant:Nn \tl_to_str:n { o }
+\cs_generate_variant:Nn \tl_if_eq:nnTF { o }
+\cs_generate_variant:Nn \tl_if_head_eq_meaning:nNT { V }
+\cs_generate_variant:Nn \tl_if_single_token:nT { V }
+\cs_generate_variant:Nn \gtl_gput_right:Nn { NV }
+\cs_generate_variant:Nn \gtl_if_empty:NTF { c }
+\cs_generate_variant:Nn \gtl_if_tl:NT { c }
+\cs_generate_variant:Nn \gtl_to_str:N { c }
+\cs_generate_variant:Nn \gtl_gpop_left:NN { c }
+\cs_generate_variant:Nn \gtl_get_left:NN { c }
+\cs_generate_variant:Nn \gtl_gset:Nn { c }
+\cs_generate_variant:Nn \gtl_gconcat:NNN { ccc , cNc }
+\cs_generate_variant:Nn \gtl_gclear:N { c }
+\cs_generate_variant:Nn \gtl_gclear_new:N { c }
+\cs_generate_variant:Nn \gtl_left_tl:N { c }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_tl_if_in:ooTF}
+% Analogue of \cs{tl_if_in:ooTF} but with an extra group because that
+% function redefines an auxiliary that may appear in the code being
+% debugged (see Github issue |#27|).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tl_if_in:ooTF #1#2#3#4
+ {
+ \group_begin:
+ \exp_args:Noo \tl_if_in:nnTF {#1} {#2}
+ { \group_end: #3 } { \group_end: #4 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{variable}{\l_@@_exp_tl}
+% \begin{macro}{\@@_exp_args:Nx, \@@_exp_args:NNx}
+% Low-level because \cs{exp_args:Nx} redefines an internal
+% \pkg{l3expan} variable which may be appearing in code that we debug.
+% \begin{macrocode}
+\tl_new:N \l_@@_exp_tl
+\cs_new_protected:Npn \@@_exp_args:Nx #1#2
+ {
+ \cs_set_nopar:Npx \l_@@_exp_tl { \exp_not:N #1 {#2} }
+ \l_@@_exp_tl
+ }
+\cs_new_protected:Npn \@@_exp_args:NNx #1#2#3
+ {
+ \cs_set_nopar:Npx \l_@@_exp_tl { \exp_not:N #1 \exp_not:N #2 {#3} }
+ \l_@@_exp_tl
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{variable}
+%
+% \subsubsection{Miscellanous helpers}
+%
+% \begin{macro}{\@@_tmp:w}
+% Temporary function used to define other functions.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tmp:w { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_file_get:nN}
+% \begin{macro}{\@@_file_get_aux:wN}
+% \begin{macrocode}
+\cs_set_protected:Npn \@@_tmp:w #1
+ {
+ \cs_new_protected:Npn \@@_file_get:nN ##1##2
+ {
+ \group_begin:
+ \@@_everyeof:w { #1 ##2 }
+ \exp_after:wN \@@_file_get_aux:wN
+ \exp_after:wN \prg_do_nothing:
+ \tex_input:D ##1 \scan_stop:
+ }
+ \cs_new_protected:Npn \@@_file_get_aux:wN ##1 #1 ##2
+ {
+ \group_end:
+ \tl_set:Nx ##2
+ { \exp_not:o {##1} \exp_not:V \@@_everyeof:w }
+ }
+ }
+\exp_args:No \@@_tmp:w { \token_to_str:N : : }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_tl_first_int:N}
+% \begin{macro}[EXP]{\@@_tl_first_int_aux:Nn}
+% Function that finds an explicit number in a token list. This is
+% used for instance when implementing \tn{read}, to find the stream
+% \meta{number} within the whole \tn{read} \meta{number} |to|
+% \meta{cs} construction. The auxiliary initially has itself as a
+% first argument, and once a first digit is found it has
+% \cs{use_none_delimit_by_q_stop:w}. That first argument is used
+% whenever what follows is not a digit, hence initially we loop,
+% while after the first digit is found any non-digit stops the
+% recursion. If no integer is found, $0$ is left in the token list.
+% The surrounding \cs{int_eval:n} lets us dump digits in the input
+% stream while keeping the function fully expandable.
+% \begin{macrocode}
+\cs_new:Npn \@@_tl_first_int:N #1
+ {
+ \int_eval:n
+ {
+ \exp_after:wN \@@_tl_first_int_aux:Nn
+ \exp_after:wN \@@_tl_first_int_aux:Nn
+ #1 ? 0 ? \q_stop
+ }
+ }
+\cs_new:Npn \@@_tl_first_int_aux:Nn #1#2
+ {
+ \tl_if_single:nT {#2}
+ {
+ \token_if_eq_catcode:NNT + #2
+ {
+ \if_int_compare:w 1 < 1 #2 \exp_stop_f:
+ #2
+ \exp_after:wN \use_i_ii:nnn
+ \exp_after:wN \@@_tl_first_int_aux:Nn
+ \exp_after:wN \use_none_delimit_by_q_stop:w
+ \fi:
+ }
+ }
+ #1
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_prepare_mag:}
+% Used whenever \TeX{} needs the value of \tn{mag}. ^^A todo: move
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prepare_mag:
+ {
+ \int_compare:nNnT { \g_@@_mag_set_int } > { 0 }
+ {
+ \int_compare:nNnF { \@@_mag: } = { \g_@@_mag_set_int }
+ {
+ \@@_tex_error:nn { incompatible-mag } { }
+ \int_gset_eq:NN \@@_mag: \g_@@_mag_set_int
+ }
+ }
+ \int_compare:nF { 1 <= \@@_mag: <= 32768 }
+ {
+ \@@_tex_error:nV { illegal-mag } \l_@@_head_tl
+ \int_gset:Nn \@@_mag: { 1000 }
+ }
+ \int_gset_eq:NN \g_@@_mag_set_int \@@_mag:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{String helpers}
+%
+% \begin{macro}{\@@_strip_escape:w}
+% \begin{macro}{\@@_strip_escape_aux:N, \@@_strip_escape_aux:w}
+% This is based on the 2013-07-19 (and earlier) version of
+% \cs{cs_to_str:N}. There are three cases. If the escape character
+% is printable, the charcode test is false, and
+% \cs{@@_strip_escape_aux:N} removes one character. If the escape
+% character is a space, the charcode test is true, and if there is no
+% escape charcter, the test is unfinished after |\token_to_str:N \ |.
+% In both of those cases, \cs{@@_strip_escape_aux:w} inserts
+% |-\@@_number:w \fi: \c_zero_int|. If the escape character was a
+% space, the test was true, and \cs{int_value:w} converts
+% \cs{c_zero_int} to~|0|, hence the leading roman numeral expansion
+% removes a space from what follows (it is important that what follows
+% cannot start with a digit). Otherwise, the test takes~|-| as its
+% second operand, is false, and the roman numeral expansion only sees
+% \cs{c_zero_int}, thus does not remove anything from what follows.
+% \begin{macrocode}
+\cs_new:Npn \@@_strip_escape:w
+ {
+ \tex_romannumeral:D
+ \if_charcode:w \token_to_str:N \ \@@_strip_escape_aux:w \fi:
+ \@@_strip_escape_aux:N
+ }
+\cs_new:Npn \@@_strip_escape_aux:N #1 { \c_zero_int }
+\cs_new:Npn \@@_strip_escape_aux:w #1#2
+ { - \@@_number:w #1 \c_zero_int }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% ^^A todo: change approach: this abuses future l3obj.
+% \begin{macro}[EXP]{\@@_to_str:n}
+% \begin{macro}[EXP]
+% {\@@_to_str_auxi:w, \@@_to_str_auxii:w, \@@_gtl_to_str:n}
+% Use the type-appropriate conversion to string.
+% \begin{macrocode}
+\cs_new:Npn \@@_to_str:n #1
+ {
+ \tl_if_head_eq_meaning:nNTF {#1} \scan_stop:
+ { \@@_to_str_auxi:w #1 ? \q_stop }
+ { \tl_to_str:n }
+ {#1}
+ }
+\cs_set:Npn \@@_tmp:w #1
+ {
+ \cs_new:Npn \@@_to_str_auxi:w ##1##2 \q_stop
+ {
+ \exp_after:wN \@@_to_str_auxii:w \token_to_str:N ##1 \q_mark
+ #1 tl \q_mark \q_stop
+ }
+ \cs_new:Npn \@@_to_str_auxii:w ##1 #1 ##2 \q_mark ##3 \q_stop
+ { \cs_if_exist_use:cF { @@_ ##2 _to_str:n } { \tl_to_str:n } }
+ }
+\exp_args:No \@@_tmp:w { \tl_to_str:n { s _ _ } }
+\cs_new:Npn \@@_gtl_to_str:n { \gtl_to_str:n }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_str_truncate_left:nn}
+% \begin{macro}{\@@_str_truncate_left_aux:nnn}
+% Truncate the string |#1| to a maximum of |#2| characters. If it is
+% longer, replace some characters on the left of the string by
+% |(123~more~chars)~| with the appropriate number instead of~|123|.
+% In any reasonable case, $25$ is big enough to fit this extra text.
+% \begin{macrocode}
+\cs_new:Npn \@@_str_truncate_left:nn #1#2
+ {
+ \exp_args:Nf \@@_str_truncate_left_aux:nnn
+ { \str_count:n {#1} } {#1} {#2}
+ }
+\cs_new:Npn \@@_str_truncate_left_aux:nnn #1#2#3
+ {
+ \int_compare:nNnTF {#1} > {#3}
+ {
+ ( \int_eval:n { #1 - #3 + 25 } ~ more~chars ) ~
+ \str_range:nnn {#2} { #1 - #3 + 26 } {#1}
+ }
+ { \tl_to_str:n {#2} }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_str_truncate_right:nn}
+% \begin{macro}{\@@_str_truncate_right_aux:nnn}
+% Truncate the string |#1| to a maximum of |#2| characters. If it is
+% longer, replace some characters on the right of the string by
+% |~(123~more~chars)| with the appropriate number instead of~|123|.
+% In any reasonable case, $25$ is big enough to fit this extra text.
+% \begin{macrocode}
+\cs_new:Npn \@@_str_truncate_right:nn #1#2
+ {
+ \exp_args:Nf \@@_str_truncate_right_aux:nnn
+ { \str_count:n {#1} } {#1} {#2}
+ }
+\cs_new:Npn \@@_str_truncate_right_aux:nnn #1#2#3
+ {
+ \int_compare:nNnTF {#1} > {#3}
+ {
+ \str_range:nnn {#2} { 1 } { #3 - 25 } ~
+ ( \int_eval:n { #1 - #3 + 25 } ~ more~chars )
+ }
+ { \tl_to_str:n {#2} }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Helpers for control flow}
+%
+% \begin{macro}[EXP]{\@@_exit:w, \@@_exit_error:w, \@@_exit_hard:w, \@@_exit_point:}
+% Jump to the very end of this instance of \cs{unravel}.
+% \begin{macrocode}
+\cs_new_eq:NN \@@_exit_point: \prg_do_nothing:
+\cs_new:Npn \@@_exit:w #1 \@@_exit_point: { }
+\cs_new:Npn \@@_exit_error:w #1 \@@_exit_point: #2 \@@_final_bad:
+ {
+ \@@_error:nnnnn { runaway-unravel } { } { } { } { }
+ #2
+ }
+\cs_new:Npn \@@_exit_hard:w #1 \@@_exit_point: #2 \@@_exit_point: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_break:w, \@@_break_point:}
+% Useful to jump out of complicated conditionals.
+% \begin{macrocode}
+\cs_new_eq:NN \@@_break_point: \prg_do_nothing:
+\cs_new:Npn \@@_break:w #1 \@@_break_point: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_cmd_if_internal:TF}
+% Test whether the \cs{l_@@_head_cmd_int} denotes an ``internal''
+% command, between |min_internal| and |max_internal| (see
+% Section~\ref{sec:numeric-codes}).
+% \begin{macrocode}
+\prg_new_conditional:Npnn \@@_cmd_if_internal: { TF }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int < { \@@_tex_use:n { min_internal } }
+ { \prg_return_false: }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int
+ > { \@@_tex_use:n { max_internal } }
+ { \prg_return_false: }
+ { \prg_return_true: }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Helpers concerning tokens}
+%
+% \begin{macro}{\@@_token_to_char:N}
+% \begin{macro}{\@@_meaning_to_char:n, \@@_meaning_to_char:o}
+% \begin{macro}
+% {\@@_meaning_to_char_auxi:w, \@@_meaning_to_char_auxii:w}
+% From the meaning of a character token (with arbitrary character
+% code, except active), extract the character itself (with string
+% category codes). This is somewhat robust against wrong input.
+% \begin{macrocode}
+\cs_new:Npn \@@_meaning_to_char:n #1
+ { \@@_meaning_to_char_auxi:w #1 \q_mark ~ {} ~ \q_mark \q_stop }
+\cs_new:Npn \@@_meaning_to_char_auxi:w #1 ~ #2 ~ #3 \q_mark #4 \q_stop
+ { \@@_meaning_to_char_auxii:w #3 ~ #3 ~ \q_stop }
+\cs_new:Npn \@@_meaning_to_char_auxii:w #1 ~ #2 ~ #3 \q_stop
+ { \tl_if_empty:nTF {#2} { ~ } {#2} }
+\cs_generate_variant:Nn \@@_meaning_to_char:n { o }
+\cs_new:Npn \@@_token_to_char:N #1
+ { \@@_meaning_to_char:o { \token_to_meaning:N #1 } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[EXP,pTF]{\@@_token_if_expandable:N}
+% We need to cook up our own version of \cs{token_if_expandable:NTF}
+% because the \pkg{expl3} one does not think that |undefined| is
+% expandable.
+% \begin{macrocode}
+\prg_new_conditional:Npnn \@@_token_if_expandable:N #1
+ { p , T , F , TF }
+ {
+ \exp_after:wN \if_meaning:w \exp_not:N #1 #1
+ \prg_return_false:
+ \else:
+ \prg_return_true:
+ \fi:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP,pTF]{\@@_token_if_protected:N}
+% Returns \texttt{true} if the token is either not expandable or is a
+% protected macro.
+% \begin{macrocode}
+\prg_new_conditional:Npnn \@@_token_if_protected:N #1
+ { p , T , F , TF }
+ {
+ \@@_token_if_expandable:NTF #1
+ {
+ \token_if_protected_macro:NTF #1
+ { \prg_return_true: }
+ {
+ \token_if_protected_long_macro:NTF #1
+ { \prg_return_true: }
+ { \prg_return_false: }
+ }
+ }
+ { \prg_return_true: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[TF]{\@@_token_if_active_char:N}
+% Lowercase the token after setting its \tn{lccode} (more precisely
+% the \tn{lccode} of the first character in its string representation)
+% to a known value, then compare the result with that active
+% character.
+% \begin{macrocode}
+\group_begin:
+ \char_set_catcode_active:n { `Z }
+ \prg_new_protected_conditional:Npnn \@@_token_if_active_char:N #1
+ { TF }
+ {
+ \group_begin:
+ \@@_exp_args:Nx \char_set_lccode:nn
+ { ` \exp_args:No \str_head:n { \token_to_str:N #1 } }
+ { ` Z }
+ \tex_lowercase:D { \tl_if_eq:nnTF {#1} } { Z }
+ { \group_end: \prg_return_true: }
+ { \group_end: \prg_return_false: }
+ }
+\group_end:
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[TF]{\@@_token_if_definable:N}
+% Within a group, set the escape character to a non-space value
+% (backslash). Convert the token to a string with
+% \cs{token_to_str:N}. The result is multiple characters if the token
+% is a control sequence, and a single character otherwise (even for
+% explicit catcode~$6$ character tokens which would be doubled if we
+% used \cs{tl_to_str:n} instead of \cs{token_to_str:N}). Thus
+% \cs{str_tail:n} gives a non-empty result exactly for control
+% sequences. Those are definable (technically, not always:
+% |\expandafter\font\csname\endcsname=cmr10|
+% |\expandafter\def\the\csname\endcsname{}|). For characters just
+% check for active characters. In both cases remember to end the
+% group.
+% \begin{macrocode}
+\group_begin:
+ \char_set_catcode_active:n { `Z }
+ \prg_new_protected_conditional:Npnn \@@_token_if_definable:N #1
+ { TF }
+ {
+ \group_begin:
+ \@@_set_escapechar:n { 92 }
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \exp_args:No \str_tail:n { \token_to_str:N #1 } }
+ \tl_if_empty:NTF \l_@@_tmpa_tl
+ {
+ \@@_token_if_active_char:NTF #1
+ { \group_end: \prg_return_true: }
+ { \group_end: \prg_return_false: }
+ }
+ { \group_end: \prg_return_true: }
+ }
+\group_end:
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[TF]{\@@_gtl_if_head_is_definable:N}
+% Tests if a generalized token list is a single control sequence or a
+% single active character. First test that it is single, then filter
+% out the case of (explicit) begin-group, end-group, and blank space
+% characters: those are neither control sequences nor active. Then
+% feed the single normal token to a first auxiliary.
+% \begin{macrocode}
+\prg_new_protected_conditional:Npnn \@@_gtl_if_head_is_definable:N #1
+ { TF , F }
+ {
+ \gtl_if_single_token:NTF #1
+ {
+ \gtl_if_head_is_N_type:NTF #1
+ {
+ \gtl_head_do:NN #1 \@@_token_if_definable:NTF
+ { \prg_return_true: }
+ { \prg_return_false: }
+ }
+ { \prg_return_false: }
+ }
+ { \prg_return_false: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Helpers for previous input}
+%
+% \begin{macro}[EXP]{\@@_prev_input_count:, \@@_prev_input_count_aux:n}
+% \begin{macrocode}
+\cs_new:Npn \@@_prev_input_count:
+ {
+ \int_eval:n
+ {
+ 0
+ \seq_map_function:NN \g_@@_prev_input_seq
+ \@@_prev_input_count_aux:n
+ }
+ }
+\cs_new:Npn \@@_prev_input_count_aux:n #1
+ { \tl_if_empty:nF {#1} { + 1 } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_prev_input_get:N,
+% \@@_prev_input_gpush:,
+% \@@_prev_input_gpush:N,
+% \@@_prev_input_gpop:N,
+% \@@_prev_input_gpush_gtl:,
+% \@@_prev_input_gpush_gtl:N,
+% \@@_prev_input_gpop_gtl:N,
+% }
+% ^^A todo: doc and add optional sanity checking
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prev_input_get:N
+ { \seq_get_right:NN \g_@@_prev_input_seq }
+\cs_new_protected:Npn \@@_prev_input_gpush:
+ { \seq_gput_right:Nn \g_@@_prev_input_seq { } }
+\cs_new_protected:Npn \@@_prev_input_gpush:N
+ { \seq_gput_right:NV \g_@@_prev_input_seq }
+\cs_new_protected:Npn \@@_prev_input_gpop:N
+ { \seq_gpop_right:NN \g_@@_prev_input_seq }
+\cs_new_protected:Npn \@@_prev_input_gpush_gtl:
+ { \seq_gput_right:NV \g_@@_prev_input_seq \c_empty_gtl }
+\cs_new_protected:Npn \@@_prev_input_gpush_gtl:N
+ { \seq_gput_right:NV \g_@@_prev_input_seq }
+\cs_new_protected:Npn \@@_prev_input_gpop_gtl:N
+ { \seq_gpop_right:NN \g_@@_prev_input_seq }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_prev_input_silent:n,
+% \@@_prev_input_silent:V,
+% \@@_prev_input_silent:x
+% }
+% \begin{macro}
+% {
+% \@@_prev_input:n,
+% \@@_prev_input:V,
+% \@@_prev_input:x
+% }
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prev_input_silent:n #1
+ {
+ \@@_prev_input_gpop:N \l_@@_prev_input_tl
+ \tl_put_right:Nn \l_@@_prev_input_tl {#1}
+ \@@_prev_input_gpush:N \l_@@_prev_input_tl
+ }
+\cs_generate_variant:Nn \@@_prev_input_silent:n { V }
+\cs_new_protected:Npn \@@_prev_input_silent:x
+ { \@@_exp_args:Nx \@@_prev_input_silent:n }
+\cs_new_protected:Npn \@@_prev_input:n #1
+ {
+ \@@_prev_input_silent:n {#1}
+ \@@_print_action:x { \tl_to_str:n {#1} }
+ }
+\cs_generate_variant:Nn \@@_prev_input:n { V }
+\cs_new_protected:Npn \@@_prev_input:x
+ { \@@_exp_args:Nx \@@_prev_input:n }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_prev_input_gtl:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prev_input_gtl:N #1
+ {
+ \@@_prev_input_gpop_gtl:N \l_@@_prev_input_gtl
+ \gtl_concat:NNN \l_@@_prev_input_gtl \l_@@_prev_input_gtl #1
+ \@@_prev_input_gpush_gtl:N \l_@@_prev_input_gtl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_prev_input_join_get:nN}
+% \begin{macro}{\@@_join_get_aux:NNN}
+% Pops the previous-input sequence twice to get some value in
+% \cs{l_@@_head_tl} and some sign or decimal number in
+% \cs{l_@@_tmpa_tl}. Combines them into a value, using
+% the appropriate evaluation function, determined based
+% on~|#1|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prev_input_join_get:nN #1
+ {
+ \int_case:nnF {#1}
+ {
+ { 2 } { \@@_join_get_aux:NNN \skip_eval:n \tex_glueexpr:D }
+ { 3 } { \@@_join_get_aux:NNN \muskip_eval:n \tex_muexpr:D }
+ }
+ {
+ \@@_error:nnnnn { internal } { join-factor } { } { } { }
+ \@@_join_get_aux:NNN \use:n \prg_do_nothing:
+ }
+ }
+\cs_new_protected:Npn \@@_join_get_aux:NNN #1#2#3
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_set:Nx #3 { #1 { \l_@@_tmpa_tl #2 \l_@@_head_tl } }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Variables}
+%
+% \subsubsection{User interaction}
+%
+% \begin{variable}{\g_@@_before_print_state_tl, \g_@@_before_prompt_tl}
+% Code to run before printing the state or before the prompt.
+% \begin{macrocode}
+\tl_new:N \g_@@_before_print_state_tl
+\tl_new:N \g_@@_before_prompt_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_prompt_tmpa_int}
+% \begin{macrocode}
+\int_new:N \l_@@_prompt_tmpa_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_nonstop_int}
+% The number of prompts to skip.
+% \begin{macrocode}
+\int_new:N \g_@@_nonstop_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}
+% {
+% \g_@@_default_explicit_prompt_bool , \g_@@_explicit_prompt_bool ,
+% \g_@@_default_internal_debug_bool , \g_@@_internal_debug_bool ,
+% \g_@@_default_number_steps_bool , \g_@@_number_steps_bool ,
+% \g_@@_default_online_int , \g_@@_online_int ,
+% \g_@@_default_trace_assigns_bool , \g_@@_trace_assigns_bool ,
+% \g_@@_default_trace_expansion_bool , \g_@@_trace_expansion_bool ,
+% \g_@@_default_trace_other_bool , \g_@@_trace_other_bool ,
+% \g_@@_default_welcome_message_bool , \g_@@_welcome_message_bool ,
+% }
+% Variables for the options |explicit-prompt|,
+% |internal-debug|, |number-steps|, and so on. The
+% \texttt{default_} booleans/integers store the default value of these
+% options, and are affected by \cs{unravelsetup} or
+% \cs{unravel_setup:n}.
+% \begin{macrocode}
+\bool_new:N \g_@@_default_explicit_prompt_bool
+\bool_new:N \g_@@_default_internal_debug_bool
+\bool_new:N \g_@@_default_number_steps_bool
+\int_new:N \g_@@_default_online_int
+\bool_new:N \g_@@_default_trace_assigns_bool
+\bool_new:N \g_@@_default_trace_expansion_bool
+\bool_new:N \g_@@_default_trace_other_bool
+\bool_new:N \g_@@_default_welcome_message_bool
+\bool_gset_true:N \g_@@_default_number_steps_bool
+\int_gset:Nn \g_@@_default_online_int { 1 }
+\bool_gset_true:N \g_@@_default_trace_assigns_bool
+\bool_gset_true:N \g_@@_default_trace_expansion_bool
+\bool_gset_true:N \g_@@_default_trace_other_bool
+\bool_gset_true:N \g_@@_default_welcome_message_bool
+\bool_new:N \g_@@_explicit_prompt_bool
+\bool_new:N \g_@@_internal_debug_bool
+\bool_new:N \g_@@_number_steps_bool
+\int_new:N \g_@@_online_int
+\bool_new:N \g_@@_trace_assigns_bool
+\bool_new:N \g_@@_trace_expansion_bool
+\bool_new:N \g_@@_trace_other_bool
+\bool_new:N \g_@@_welcome_message_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_step_int}
+% Current expansion step.
+% \begin{macrocode}
+\int_new:N \g_@@_step_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_action_text_str}
+% Text describing the action, displayed at each step. This should
+% only be altered through \cs{@@_set_action_text:x}, which sets the
+% escape character as appropriate before converting the argument to a
+% string.
+% \begin{macrocode}
+\str_new:N \g_@@_action_text_str
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}
+% {
+% \g_@@_default_max_action_int,
+% \g_@@_default_max_output_int,
+% \g_@@_default_max_input_int,
+% \g_@@_max_action_int,
+% \g_@@_max_output_int,
+% \g_@@_max_input_int
+% }
+% Maximum length of various pieces of what is shown on the terminal.
+% \begin{macrocode}
+\int_new:N \g_@@_default_max_action_int
+\int_new:N \g_@@_default_max_output_int
+\int_new:N \g_@@_default_max_input_int
+\int_gset:Nn \g_@@_default_max_action_int { 50 }
+\int_gset:Nn \g_@@_default_max_output_int { 300 }
+\int_gset:Nn \g_@@_default_max_input_int { 300 }
+\int_new:N \g_@@_max_action_int
+\int_new:N \g_@@_max_output_int
+\int_new:N \g_@@_max_input_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_speedup_macros_bool}
+% If this boolean is true, speed up macros which have a simple
+% parameter text. This may not be safe if very weird macros appear.
+% \begin{macrocode}
+\bool_new:N \g_@@_speedup_macros_bool
+\bool_gset_true:N \g_@@_speedup_macros_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_print_int}
+% The length of one piece of the terminal output.
+% \begin{macrocode}
+\int_new:N \l_@@_print_int
+% \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{Working with tokens}
+%
+% \begin{variable}{\g_@@_input_int}
+% The user input, at each stage of expansion, is stored in multiple
+% \texttt{gtl} variables, from |\g_@@_input_|\meta{n}|_gtl| to
+% \cs{g_@@_input_1_gtl}. The split between variables is akin to
+% \TeX{}'s input stack, and allows us to manipulate smaller token
+% lists, speeding up processing. The total number \meta{n} of lists
+% is \cs{g_@@_input_int}. The highest numbered \texttt{gtl}
+% represents input that comes to the left of lower numbered ones.
+% \begin{macrocode}
+\int_new:N \g_@@_input_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_input_tmpa_int}
+% \begin{variable}{\l_@@_input_tmpa_tl}
+% \begin{macrocode}
+\int_new:N \g_@@_input_tmpa_int
+\tl_new:N \l_@@_input_tmpa_tl
+% \end{macrocode}
+% \end{variable}
+% \end{variable}
+%
+% \begin{variable}
+% {\g_@@_prev_input_seq, \l_@@_prev_input_tl, \l_@@_prev_input_gtl}
+% The different levels of expansion are stored in
+% \cs{g_@@_prev_input_seq}, with the innermost at the end of the
+% sequence (otherwise the sequence would have to be reversed for
+% display). When adding material to the last level of expansion,
+% \cs{l_@@_prev_input_tl} or \cs{l_@@_prev_input_gtl} are used to
+% temporarily store the last level of expansion.
+% \begin{macrocode}
+\seq_new:N \g_@@_prev_input_seq
+\tl_new:N \l_@@_prev_input_tl
+\gtl_new:N \l_@@_prev_input_gtl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_output_gtl}
+% Material that is ``typeset'' or otherwise sent further down \TeX{}'s
+% digestion.
+% \begin{macrocode}
+\gtl_new:N \g_@@_output_gtl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}
+% {
+% \l_@@_head_gtl,
+% \l_@@_head_tl,
+% \l_@@_head_token,
+% \l_@@_head_cmd_int,
+% \l_@@_head_char_int
+% }
+% First token in the input, as a generalized token list (general case)
+% or as a token list whenever this is possible. Also, a token set
+% equal to it, and its command code and character code, following
+% \TeX{}.
+% \begin{macrocode}
+\gtl_new:N \l_@@_head_gtl
+\tl_new:N \l_@@_head_tl
+\cs_new_eq:NN \l_@@_head_token ?
+\int_new:N \l_@@_head_cmd_int
+\int_new:N \l_@@_head_char_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_head_meaning_tl}
+% \begin{macrocode}
+\tl_new:N \l_@@_head_meaning_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_argi_tl, \l_@@_argii_tl}
+% Token list variables used to store first/second arguments.
+% \begin{macrocode}
+\tl_new:N \l_@@_argi_tl
+\tl_new:N \l_@@_argii_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_tmpa_tl, \l_@@_tmpb_gtl, \g_@@_tmpc_tl, \l_@@_tmpa_seq, \l_@@_unused_gtl, \l_@@_tmpb_token}
+% Temporary storage. The \cs{l_@@_unused_gtl} is only used once,
+% to ignore some unwanted tokens.
+% \begin{macrocode}
+\tl_new:N \l_@@_tmpa_tl
+\gtl_new:N \l_@@_unused_gtl
+\gtl_new:N \l_@@_tmpb_gtl
+\tl_new:N \g_@@_tmpc_tl
+\seq_new:N \l_@@_tmpa_seq
+\cs_new_eq:NN \l_@@_tmpb_token ?
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_defined_tl, \l_@@_defining_tl}
+% The token that is defined by the prefixed command (such as
+% \tn{chardef} or \tn{futurelet}), and the code to define it. We do
+% not use the the previous-input sequence to store that code: rather,
+% this sequence contains a string representation of the code, which is
+% not suitable for the definition. This is safe, as definitions
+% cannot be nested. This is needed for expanding assignments, as
+% expansion should be shown to the user, but then later should not be
+% performed again when defining.
+% \begin{macrocode}
+\tl_new:N \l_@@_defined_tl
+\tl_new:N \l_@@_defining_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_inaccessible:w}
+% \begin{macrocode}
+\cs_new_eq:NN \@@_inaccessible:w ?
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{variable}
+% {
+% \g_@@_after_assignment_gtl,
+% \g_@@_set_box_allowed_bool,
+% \g_@@_name_in_progress_bool
+% }
+% Global variables keeping track of the state of \TeX{}. Token to
+% insert after the next assignment. Is \tn{setbox} currently allowed?
+% Should \tn{input} expand?
+% \begin{macrocode}
+\gtl_new:N \g_@@_after_assignment_gtl
+\bool_new:N \g_@@_set_box_allowed_bool
+\bool_new:N \g_@@_name_in_progress_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_after_group_gtl}
+% Tokens to insert after the current group ends. This variable must
+% be emptied at the beginning of every group.
+% \begin{macrocode}
+\gtl_new:N \l_@@_after_group_gtl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\c_@@_parameters_tl}
+% Used to determine if a macro has simple parameters or not.
+% \begin{macrocode}
+\group_begin:
+ \cs_set:Npx \@@_tmp:w #1 { \c_hash_str #1 }
+ \tl_const:Nx \c_@@_parameters_tl
+ { ^ \tl_map_function:nN { 123456789 } \@@_tmp:w }
+\group_end:
+% \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{Numbers and conditionals}
+%
+% \begin{variable}{\g_@@_val_level_int}
+% See \TeX{}'s |cur_val_level| variable. This is set by
+% \cs{@@_scan_something_internal:n} to
+% \begin{itemize}
+% \item $0$ for integer values,
+% \item $1$ for dimension values,
+% \item $2$ for glue values,
+% \item $3$ for mu glue values,
+% \item $4$ for font identifiers,
+% \item $5$ for token lists.
+% \end{itemize}
+% \begin{macrocode}
+\int_new:N \g_@@_val_level_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_if_limit_tl}
+% \begin{variable}{\g_@@_if_limit_int}
+% \begin{variable}{\g_@@_if_depth_int}
+% Stack for what \TeX{} calls |if_limit|, and its depth.
+% \begin{macrocode}
+\tl_new:N \g_@@_if_limit_tl
+\int_new:N \g_@@_if_limit_int
+\int_new:N \g_@@_if_depth_int
+% \end{macrocode}
+% \end{variable}
+% \end{variable}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_if_nesting_int}
+% \begin{macrocode}
+\int_new:N \l_@@_if_nesting_int
+% \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{Boxes and groups}
+%
+% \begin{variable}{\l_@@_leaders_box_seq}
+% A stack of letters: the first token in the token list is |h|~if the
+% innermost explicit box (created with \tn{vtop}, \tn{vbox}, or
+% \tn{hbox}) appears in a horizontal (or math) mode leaders
+% construction; it is |v|~if the innermost explicit box appears in a
+% vertical mode leaders construction; it is |Z|~otherwise.
+% \begin{macrocode}
+\seq_new:N \l_@@_leaders_box_seq
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_ends_int}
+% Number of times \tn{end} will be put back into the input in case
+% there remains to ship some pages.
+% \begin{macrocode}
+\int_new:N \g_@@_ends_int
+\int_gset:Nn \g_@@_ends_int { 3 }
+% \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{Constants}
+%
+% \begin{variable}
+% {
+% \c_@@_plus_tl, \c_@@_minus_tl, \c_@@_times_tl, \c_@@_over_tl,
+% \c_@@_lq_tl, \c_@@_rq_tl, \c_@@_dq_tl, \c_@@_lp_tl, \c_@@_rp_tl,
+% \c_@@_eq_tl, \c_@@_comma_tl, \c_@@_point_tl,
+% }
+% \begin{macrocode}
+\tl_const:Nn \c_@@_plus_tl { + }
+\tl_const:Nn \c_@@_minus_tl { - }
+\tl_const:Nn \c_@@_times_tl { * }
+\tl_const:Nn \c_@@_over_tl { / }
+\tl_const:Nn \c_@@_lq_tl { ` }
+\tl_const:Nn \c_@@_rq_tl { ' }
+\tl_const:Nn \c_@@_dq_tl { " }
+\tl_const:Nn \c_@@_lp_tl { ( }
+\tl_const:Nn \c_@@_rp_tl { ) }
+\tl_const:Nn \c_@@_eq_tl { = }
+\tl_const:Nn \c_@@_comma_tl { , }
+\tl_const:Nn \c_@@_point_tl { . }
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\c_@@_frozen_relax_gtl}
+% \TeX{}'s |frozen_relax|, inserted by \cs{@@_insert_relax:}.
+% \begin{macrocode}
+\gtl_const:Nx \c_@@_frozen_relax_gtl { \if_int_compare:w 0 = 0 \fi: }
+% \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{\TeX{} parameters}
+%
+% \begin{variable}{\g_@@_mag_set_int}
+% The first time \TeX{} uses the value of \tn{mag}, it stores it in a
+% global parameter |mag_set| (initially $0$ to denote not being set).
+% Any time \TeX{} needs the value of \tn{mag}, it checks that the
+% value matches |mag_set|. This is done in \pkg{unravel} by
+% \cs{@@_prepare_mag:}, storing |mag_set| in \cs{g_@@_mag_set_int}.
+% \begin{macrocode}
+\int_new:N \g_@@_mag_set_int
+% \end{macrocode}
+% \end{variable}
+%
+% \subsection{Numeric codes}
+% \label{sec:numeric-codes}
+%
+% First we define some numeric codes, following Section~15 of the \TeX{}
+% web code, then we associate a command code to each \TeX{} primitive,
+% and a character code, to decide what action to perform upon seeing
+% them.
+%
+% \begin{macro}{\@@_tex_const:nn}
+% \begin{macro}[EXP]{\@@_tex_use:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tex_const:nn #1#2
+ { \int_const:cn { c_@@_tex_#1_int } {#2} }
+\cs_new:Npn \@@_tex_use:n #1 { \int_use:c { c_@@_tex_#1_int } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_tex_primitive:nnn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tex_primitive:nnn #1#2#3
+ {
+ \tl_const:cx { c_@@_tex_#1_tl }
+ { { \@@_tex_use:n {#2} } {#3} }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_new_tex_cmd:nn, \@@_new_eq_tex_cmd:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_new_tex_cmd:nn #1#2
+ {
+ \cs_new_protected:cpn
+ { @@_cmd_ \@@_tex_use:n {#1} : } {#2}
+ }
+\cs_new_protected:Npn \@@_new_eq_tex_cmd:nn #1#2
+ {
+ \cs_new_eq:cc
+ { @@_cmd_ \@@_tex_use:n {#1} : }
+ { @@_cmd_ \@@_tex_use:n {#2} : }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_new_tex_expandable:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_new_tex_expandable:nn #1#2
+ {
+ \cs_new_protected:cpn
+ { @@_expandable_ \@@_tex_use:n {#1} : } {#2}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% Contrarily to \TeX{}, all macros are |call|, no |long_call| and the
+% like.
+% \begin{macrocode}
+\@@_tex_const:nn { relax } { 0 }
+\@@_tex_const:nn { begin-group_char } { 1 }
+\@@_tex_const:nn { end-group_char } { 2 }
+\@@_tex_const:nn { math_char } { 3 }
+\@@_tex_const:nn { tab_mark } { 4 }
+\@@_tex_const:nn { alignment_char } { 4 }
+\@@_tex_const:nn { car_ret } { 5 }
+\@@_tex_const:nn { macro_char } { 6 }
+\@@_tex_const:nn { superscript_char } { 7 }
+\@@_tex_const:nn { subscript_char } { 8 }
+\@@_tex_const:nn { endv } { 9 }
+\@@_tex_const:nn { blank_char } { 10 }
+\@@_tex_const:nn { the_char } { 11 }
+\@@_tex_const:nn { other_char } { 12 }
+\@@_tex_const:nn { par_end } { 13 }
+\@@_tex_const:nn { stop } { 14 }
+\@@_tex_const:nn { delim_num } { 15 }
+\@@_tex_const:nn { max_char_code } { 15 }
+\@@_tex_const:nn { char_num } { 16 }
+\@@_tex_const:nn { math_char_num } { 17 }
+\@@_tex_const:nn { mark } { 18 }
+\@@_tex_const:nn { xray } { 19 }
+\@@_tex_const:nn { make_box } { 20 }
+\@@_tex_const:nn { hmove } { 21 }
+\@@_tex_const:nn { vmove } { 22 }
+\@@_tex_const:nn { un_hbox } { 23 }
+\@@_tex_const:nn { un_vbox } { 24 }
+\@@_tex_const:nn { remove_item } { 25 }
+\@@_tex_const:nn { hskip } { 26 }
+\@@_tex_const:nn { vskip } { 27 }
+\@@_tex_const:nn { mskip } { 28 }
+\@@_tex_const:nn { kern } { 29 }
+\@@_tex_const:nn { mkern } { 30 }
+\@@_tex_const:nn { leader_ship } { 31 }
+\@@_tex_const:nn { halign } { 32 }
+\@@_tex_const:nn { valign } { 33 }
+\@@_tex_const:nn { no_align } { 34 }
+\@@_tex_const:nn { vrule } { 35 }
+\@@_tex_const:nn { hrule } { 36 }
+\@@_tex_const:nn { insert } { 37 }
+\@@_tex_const:nn { vadjust } { 38 }
+\@@_tex_const:nn { ignore_spaces } { 39 }
+\@@_tex_const:nn { after_assignment } { 40 }
+\@@_tex_const:nn { after_group } { 41 }
+\@@_tex_const:nn { break_penalty } { 42 }
+\@@_tex_const:nn { start_par } { 43 }
+\@@_tex_const:nn { ital_corr } { 44 }
+\@@_tex_const:nn { accent } { 45 }
+\@@_tex_const:nn { math_accent } { 46 }
+\@@_tex_const:nn { discretionary } { 47 }
+\@@_tex_const:nn { eq_no } { 48 }
+\@@_tex_const:nn { left_right } { 49 }
+\@@_tex_const:nn { math_comp } { 50 }
+\@@_tex_const:nn { limit_switch } { 51 }
+\@@_tex_const:nn { above } { 52 }
+\@@_tex_const:nn { math_style } { 53 }
+\@@_tex_const:nn { math_choice } { 54 }
+\@@_tex_const:nn { non_script } { 55 }
+\@@_tex_const:nn { vcenter } { 56 }
+\@@_tex_const:nn { case_shift } { 57 }
+\@@_tex_const:nn { message } { 58 }
+\@@_tex_const:nn { extension } { 59 }
+\@@_tex_const:nn { in_stream } { 60 }
+\@@_tex_const:nn { begin_group } { 61 }
+\@@_tex_const:nn { end_group } { 62 }
+\@@_tex_const:nn { omit } { 63 }
+\@@_tex_const:nn { ex_space } { 64 }
+\@@_tex_const:nn { no_boundary } { 65 }
+\@@_tex_const:nn { radical } { 66 }
+\@@_tex_const:nn { end_cs_name } { 67 }
+\@@_tex_const:nn { min_internal } { 68 }
+\@@_tex_const:nn { char_given } { 68 }
+\@@_tex_const:nn { math_given } { 69 }
+\@@_tex_const:nn { last_item } { 70 }
+\@@_tex_const:nn { max_non_prefixed_command } { 70 }
+\@@_tex_const:nn { toks_register } { 71 }
+\@@_tex_const:nn { assign_toks } { 72 }
+\@@_tex_const:nn { assign_int } { 73 }
+\@@_tex_const:nn { assign_dimen } { 74 }
+\@@_tex_const:nn { assign_glue } { 75 }
+\@@_tex_const:nn { assign_mu_glue } { 76 }
+\@@_tex_const:nn { assign_font_dimen } { 77 }
+\@@_tex_const:nn { assign_font_int } { 78 }
+\@@_tex_const:nn { set_aux } { 79 }
+\@@_tex_const:nn { set_prev_graf } { 80 }
+\@@_tex_const:nn { set_page_dimen } { 81 }
+\@@_tex_const:nn { set_page_int } { 82 }
+\@@_tex_const:nn { set_box_dimen } { 83 }
+\@@_tex_const:nn { set_shape } { 84 }
+\@@_tex_const:nn { def_code } { 85 }
+\@@_tex_const:nn { def_family } { 86 }
+\@@_tex_const:nn { set_font } { 87 }
+\@@_tex_const:nn { def_font } { 88 }
+\@@_tex_const:nn { register } { 89 }
+\@@_tex_const:nn { max_internal } { 89 }
+\@@_tex_const:nn { advance } { 90 }
+\@@_tex_const:nn { multiply } { 91 }
+\@@_tex_const:nn { divide } { 92 }
+\@@_tex_const:nn { prefix } { 93 }
+\@@_tex_const:nn { let } { 94 }
+\@@_tex_const:nn { shorthand_def } { 95 }
+\@@_tex_const:nn { read_to_cs } { 96 }
+\@@_tex_const:nn { def } { 97 }
+\@@_tex_const:nn { set_box } { 98 }
+\@@_tex_const:nn { hyph_data } { 99 }
+\@@_tex_const:nn { set_interaction } { 100 }
+\@@_tex_const:nn { letterspace_font } { 101 }
+\@@_tex_const:nn { pdf_copy_font } { 102 }
+\@@_tex_const:nn { max_command } { 102 }
+\@@_tex_const:nn { undefined_cs } { 103 }
+\@@_tex_const:nn { expand_after } { 104 }
+\@@_tex_const:nn { no_expand } { 105 }
+\@@_tex_const:nn { input } { 106 }
+\@@_tex_const:nn { if_test } { 107 }
+\@@_tex_const:nn { fi_or_else } { 108 }
+\@@_tex_const:nn { cs_name } { 109 }
+\@@_tex_const:nn { convert } { 110 }
+\@@_tex_const:nn { the } { 111 }
+\@@_tex_const:nn { top_bot_mark } { 112 }
+\@@_tex_const:nn { call } { 113 }
+\@@_tex_const:nn { end_template } { 117 }
+% \end{macrocode}
+% So far we've implemented properly [71,104]; [107,113].
+%
+% A few minor differences with pdf\TeX{}'s internal numbers are as
+% follows.
+% \begin{itemize}
+% \item |case_shift| is shifted by |3983|.
+% \item |assign_toks| is shifted by |local_base=3412|.
+% \item |assign_int| is shifted by |int_base=5263|.
+% \item |assign_dimen| is shifted by |dimen_base=5830|.
+% \item |assign_glue| and |assign_mu_glue| are shifted by
+% |glue_base=2882|.
+% \item |set_shape| is shifted (in \eTeX{}) by |local_base|.
+% \item |def_code| and |def_family| is shifted by |cat_code_base=3983|.
+% \item In \TeX{}, |inputlineno.char=3| and |badness.char=4|.
+% \end{itemize}
+% A special case for \LuaTeX{} deals with the fact that the
+% \cs{@@_special_relax:} has a strange meaning \enquote{[unknown command
+% code! (0, 1)]}. For instance \tn{expandafter} \tn{show} \tn{noexpand}
+% \tn{undefined} shows this.
+% \begin{macrocode}
+\sys_if_engine_luatex:T
+ {
+ \@@_tex_primitive:nnn
+ { \exp_after:wN \use_none:n \token_to_meaning:N \@@_special_relax: }
+ { relax } { 1 }
+ }
+\@@_tex_primitive:nnn { relax } { relax } { 256 }
+\@@_tex_primitive:nnn { span } { tab_mark } { 256 }
+\@@_tex_primitive:nnn { cr } { car_ret } { 257 }
+\@@_tex_primitive:nnn { crcr } { car_ret } { 258 }
+\@@_tex_primitive:nnn { par } { par_end } { 256 }
+\@@_tex_primitive:nnn { end } { stop } { 0 }
+\@@_tex_primitive:nnn { dump } { stop } { 1 }
+\@@_tex_primitive:nnn { delimiter } { delim_num } { 0 }
+\@@_tex_primitive:nnn { char } { char_num } { 0 }
+\@@_tex_primitive:nnn { mathchar } { math_char_num } { 0 }
+\@@_tex_primitive:nnn { mark } { mark } { 0 }
+\@@_tex_primitive:nnn { marks } { mark } { 5 }
+\@@_tex_primitive:nnn { show } { xray } { 0 }
+\@@_tex_primitive:nnn { showbox } { xray } { 1 }
+\@@_tex_primitive:nnn { showthe } { xray } { 2 }
+\@@_tex_primitive:nnn { showlists } { xray } { 3 }
+\@@_tex_primitive:nnn { showgroups } { xray } { 4 }
+\@@_tex_primitive:nnn { showtokens } { xray } { 5 }
+\@@_tex_primitive:nnn { showifs } { xray } { 6 }
+\@@_tex_primitive:nnn { box } { make_box } { 0 }
+\@@_tex_primitive:nnn { copy } { make_box } { 1 }
+\@@_tex_primitive:nnn { lastbox } { make_box } { 2 }
+\@@_tex_primitive:nnn { vsplit } { make_box } { 3 }
+\@@_tex_primitive:nnn { vtop } { make_box } { 4 }
+\@@_tex_primitive:nnn { vbox } { make_box } { 5 }
+\@@_tex_primitive:nnn { hbox } { make_box } { 106 }
+\@@_tex_primitive:nnn { moveright } { hmove } { 0 }
+\@@_tex_primitive:nnn { moveleft } { hmove } { 1 }
+\@@_tex_primitive:nnn { lower } { vmove } { 0 }
+\@@_tex_primitive:nnn { raise } { vmove } { 1 }
+\@@_tex_primitive:nnn { unhbox } { un_hbox } { 0 }
+\@@_tex_primitive:nnn { unhcopy } { un_hbox } { 1 }
+\@@_tex_primitive:nnn { unvbox } { un_vbox } { 0 }
+\@@_tex_primitive:nnn { unvcopy } { un_vbox } { 1 }
+\@@_tex_primitive:nnn { pagediscards } { un_vbox } { 2 }
+\@@_tex_primitive:nnn { splitdiscards } { un_vbox } { 3 }
+\@@_tex_primitive:nnn { unpenalty } { remove_item } { 12 }
+\@@_tex_primitive:nnn { unkern } { remove_item } { 11 }
+\@@_tex_primitive:nnn { unskip } { remove_item } { 10 }
+\@@_tex_primitive:nnn { hfil } { hskip } { 0 }
+\@@_tex_primitive:nnn { hfill } { hskip } { 1 }
+\@@_tex_primitive:nnn { hss } { hskip } { 2 }
+\@@_tex_primitive:nnn { hfilneg } { hskip } { 3 }
+\@@_tex_primitive:nnn { hskip } { hskip } { 4 }
+\@@_tex_primitive:nnn { vfil } { vskip } { 0 }
+\@@_tex_primitive:nnn { vfill } { vskip } { 1 }
+\@@_tex_primitive:nnn { vss } { vskip } { 2 }
+\@@_tex_primitive:nnn { vfilneg } { vskip } { 3 }
+\@@_tex_primitive:nnn { vskip } { vskip } { 4 }
+\@@_tex_primitive:nnn { mskip } { mskip } { 5 }
+\@@_tex_primitive:nnn { kern } { kern } { 1 }
+\@@_tex_primitive:nnn { mkern } { mkern } { 99 }
+\@@_tex_primitive:nnn { shipout } { leader_ship } { 99 }
+\@@_tex_primitive:nnn { leaders } { leader_ship } { 100 }
+\@@_tex_primitive:nnn { cleaders } { leader_ship } { 101 }
+\@@_tex_primitive:nnn { xleaders } { leader_ship } { 102 }
+\@@_tex_primitive:nnn { halign } { halign } { 0 }
+\@@_tex_primitive:nnn { valign } { valign } { 0 }
+\@@_tex_primitive:nnn { beginL } { valign } { 4 }
+\@@_tex_primitive:nnn { endL } { valign } { 5 }
+\@@_tex_primitive:nnn { beginR } { valign } { 8 }
+\@@_tex_primitive:nnn { endR } { valign } { 9 }
+\@@_tex_primitive:nnn { noalign } { no_align } { 0 }
+\@@_tex_primitive:nnn { vrule } { vrule } { 0 }
+\@@_tex_primitive:nnn { hrule } { hrule } { 0 }
+\@@_tex_primitive:nnn { insert } { insert } { 0 }
+\@@_tex_primitive:nnn { vadjust } { vadjust } { 0 }
+\@@_tex_primitive:nnn { ignorespaces } { ignore_spaces } { 0 }
+\@@_tex_primitive:nnn { afterassignment } { after_assignment } { 0 }
+\@@_tex_primitive:nnn { aftergroup } { after_group } { 0 }
+\@@_tex_primitive:nnn { penalty } { break_penalty } { 0 }
+\@@_tex_primitive:nnn { indent } { start_par } { 1 }
+\@@_tex_primitive:nnn { noindent } { start_par } { 0 }
+\@@_tex_primitive:nnn { quitvmode } { start_par } { 2 }
+\@@_tex_primitive:nnn { / } { ital_corr } { 0 }
+\@@_tex_primitive:nnn { accent } { accent } { 0 }
+\@@_tex_primitive:nnn { mathaccent } { math_accent } { 0 }
+\@@_tex_primitive:nnn { - } { discretionary } { 1 }
+\@@_tex_primitive:nnn { discretionary } { discretionary } { 0 }
+\@@_tex_primitive:nnn { eqno } { eq_no } { 0 }
+\@@_tex_primitive:nnn { leqno } { eq_no } { 1 }
+\@@_tex_primitive:nnn { left } { left_right } { 30 }
+\@@_tex_primitive:nnn { right } { left_right } { 31 }
+\@@_tex_primitive:nnn { middle } { left_right } { 17 }
+\@@_tex_primitive:nnn { mathord } { math_comp } { 16 }
+\@@_tex_primitive:nnn { mathop } { math_comp } { 17 }
+\@@_tex_primitive:nnn { mathbin } { math_comp } { 18 }
+\@@_tex_primitive:nnn { mathrel } { math_comp } { 19 }
+\@@_tex_primitive:nnn { mathopen } { math_comp } { 20 }
+\@@_tex_primitive:nnn { mathclose } { math_comp } { 21 }
+\@@_tex_primitive:nnn { mathpunct } { math_comp } { 22 }
+\@@_tex_primitive:nnn { mathinner } { math_comp } { 23 }
+\@@_tex_primitive:nnn { underline } { math_comp } { 26 }
+\@@_tex_primitive:nnn { overline } { math_comp } { 27 }
+\@@_tex_primitive:nnn { displaylimits } { limit_switch } { 0 }
+\@@_tex_primitive:nnn { limits } { limit_switch } { 1 }
+\@@_tex_primitive:nnn { nolimits } { limit_switch } { 2 }
+\@@_tex_primitive:nnn { above } { above } { 0 }
+\@@_tex_primitive:nnn { over } { above } { 1 }
+\@@_tex_primitive:nnn { atop } { above } { 2 }
+\@@_tex_primitive:nnn { abovewithdelims } { above } { 3 }
+\@@_tex_primitive:nnn { overwithdelims } { above } { 4 }
+\@@_tex_primitive:nnn { atopwithdelims } { above } { 5 }
+\@@_tex_primitive:nnn { displaystyle } { math_style } { 0 }
+\@@_tex_primitive:nnn { textstyle } { math_style } { 2 }
+\@@_tex_primitive:nnn { scriptstyle } { math_style } { 4 }
+\@@_tex_primitive:nnn { scriptscriptstyle } { math_style } { 6 }
+\@@_tex_primitive:nnn { mathchoice } { math_choice } { 0 }
+\@@_tex_primitive:nnn { nonscript } { non_script } { 0 }
+\@@_tex_primitive:nnn { vcenter } { vcenter } { 0 }
+\@@_tex_primitive:nnn { lowercase } { case_shift } { 256 }
+\@@_tex_primitive:nnn { uppercase } { case_shift } { 512 }
+\@@_tex_primitive:nnn { message } { message } { 0 }
+\@@_tex_primitive:nnn { errmessage } { message } { 1 }
+\@@_tex_primitive:nnn { openout } { extension } { 0 }
+\@@_tex_primitive:nnn { write } { extension } { 1 }
+\@@_tex_primitive:nnn { closeout } { extension } { 2 }
+\@@_tex_primitive:nnn { special } { extension } { 3 }
+\@@_tex_primitive:nnn { immediate } { extension } { 4 }
+\@@_tex_primitive:nnn { setlanguage } { extension } { 5 }
+\@@_tex_primitive:nnn { pdfliteral } { extension } { 6 }
+\@@_tex_primitive:nnn { pdfobj } { extension } { 7 }
+\@@_tex_primitive:nnn { pdfrefobj } { extension } { 8 }
+\@@_tex_primitive:nnn { pdfxform } { extension } { 9 }
+\@@_tex_primitive:nnn { pdfrefxform } { extension } { 10 }
+\@@_tex_primitive:nnn { pdfximage } { extension } { 11 }
+\@@_tex_primitive:nnn { pdfrefximage } { extension } { 12 }
+\@@_tex_primitive:nnn { pdfannot } { extension } { 13 }
+\@@_tex_primitive:nnn { pdfstartlink } { extension } { 14 }
+\@@_tex_primitive:nnn { pdfendlink } { extension } { 15 }
+\@@_tex_primitive:nnn { pdfoutline } { extension } { 16 }
+\@@_tex_primitive:nnn { pdfdest } { extension } { 17 }
+\@@_tex_primitive:nnn { pdfthread } { extension } { 18 }
+\@@_tex_primitive:nnn { pdfstartthread } { extension } { 19 }
+\@@_tex_primitive:nnn { pdfendthread } { extension } { 20 }
+\@@_tex_primitive:nnn { pdfsavepos } { extension } { 21 }
+\@@_tex_primitive:nnn { pdfinfo } { extension } { 22 }
+\@@_tex_primitive:nnn { pdfcatalog } { extension } { 23 }
+\@@_tex_primitive:nnn { pdfnames } { extension } { 24 }
+\@@_tex_primitive:nnn { pdffontattr } { extension } { 25 }
+\@@_tex_primitive:nnn { pdfincludechars } { extension } { 26 }
+\@@_tex_primitive:nnn { pdfmapfile } { extension } { 27 }
+\@@_tex_primitive:nnn { pdfmapline } { extension } { 28 }
+\@@_tex_primitive:nnn { pdftrailer } { extension } { 29 }
+\@@_tex_primitive:nnn { pdfresettimer } { extension } { 30 }
+\@@_tex_primitive:nnn { pdffontexpand } { extension } { 31 }
+\@@_tex_primitive:nnn { pdfsetrandomseed } { extension } { 32 }
+\@@_tex_primitive:nnn { pdfsnaprefpoint } { extension } { 33 }
+\@@_tex_primitive:nnn { pdfsnapy } { extension } { 34 }
+\@@_tex_primitive:nnn { pdfsnapycomp } { extension } { 35 }
+\@@_tex_primitive:nnn { pdfglyphtounicode } { extension } { 36 }
+\@@_tex_primitive:nnn { pdfcolorstack } { extension } { 37 }
+\@@_tex_primitive:nnn { pdfsetmatrix } { extension } { 38 }
+\@@_tex_primitive:nnn { pdfsave } { extension } { 39 }
+\@@_tex_primitive:nnn { pdfrestore } { extension } { 40 }
+\@@_tex_primitive:nnn { pdfnobuiltintounicode } { extension } { 41 }
+\@@_tex_primitive:nnn { openin } { in_stream } { 1 }
+\@@_tex_primitive:nnn { closein } { in_stream } { 0 }
+\@@_tex_primitive:nnn { begingroup } { begin_group } { 0 }
+\@@_tex_primitive:nnn { endgroup } { end_group } { 0 }
+\@@_tex_primitive:nnn { omit } { omit } { 0 }
+\@@_tex_primitive:nnn { ~ } { ex_space } { 0 }
+\@@_tex_primitive:nnn { noboundary } { no_boundary } { 0 }
+\@@_tex_primitive:nnn { radical } { radical } { 0 }
+\@@_tex_primitive:nnn { endcsname } { end_cs_name } { 0 }
+\@@_tex_primitive:nnn { lastpenalty } { last_item } { 0 }
+\@@_tex_primitive:nnn { lastkern } { last_item } { 1 }
+\@@_tex_primitive:nnn { lastskip } { last_item } { 2 }
+\@@_tex_primitive:nnn { lastnodetype } { last_item } { 3 }
+\@@_tex_primitive:nnn { inputlineno } { last_item } { 4 }
+\@@_tex_primitive:nnn { badness } { last_item } { 5 }
+\@@_tex_primitive:nnn { pdftexversion } { last_item } { 6 }
+\@@_tex_primitive:nnn { pdflastobj } { last_item } { 7 }
+\@@_tex_primitive:nnn { pdflastxform } { last_item } { 8 }
+\@@_tex_primitive:nnn { pdflastximage } { last_item } { 9 }
+\@@_tex_primitive:nnn { pdflastximagepages } { last_item } { 10 }
+\@@_tex_primitive:nnn { pdflastannot } { last_item } { 11 }
+\@@_tex_primitive:nnn { pdflastxpos } { last_item } { 12 }
+\@@_tex_primitive:nnn { pdflastypos } { last_item } { 13 }
+\@@_tex_primitive:nnn { pdfretval } { last_item } { 14 }
+\@@_tex_primitive:nnn { pdflastximagecolordepth } { last_item } { 15 }
+\@@_tex_primitive:nnn { pdfelapsedtime } { last_item } { 16 }
+\@@_tex_primitive:nnn { pdfshellescape } { last_item } { 17 }
+\@@_tex_primitive:nnn { pdfrandomseed } { last_item } { 18 }
+\@@_tex_primitive:nnn { pdflastlink } { last_item } { 19 }
+\@@_tex_primitive:nnn { eTeXversion } { last_item } { 20 }
+\@@_tex_primitive:nnn { currentgrouplevel } { last_item } { 21 }
+\@@_tex_primitive:nnn { currentgrouptype } { last_item } { 22 }
+\@@_tex_primitive:nnn { currentiflevel } { last_item } { 23 }
+\@@_tex_primitive:nnn { currentiftype } { last_item } { 24 }
+\@@_tex_primitive:nnn { currentifbranch } { last_item } { 25 }
+\@@_tex_primitive:nnn { gluestretchorder } { last_item } { 26 }
+\@@_tex_primitive:nnn { glueshrinkorder } { last_item } { 27 }
+\@@_tex_primitive:nnn { fontcharwd } { last_item } { 28 }
+\@@_tex_primitive:nnn { fontcharht } { last_item } { 29 }
+\@@_tex_primitive:nnn { fontchardp } { last_item } { 30 }
+\@@_tex_primitive:nnn { fontcharic } { last_item } { 31 }
+\@@_tex_primitive:nnn { parshapelength } { last_item } { 32 }
+\@@_tex_primitive:nnn { parshapeindent } { last_item } { 33 }
+\@@_tex_primitive:nnn { parshapedimen } { last_item } { 34 }
+\@@_tex_primitive:nnn { gluestretch } { last_item } { 35 }
+\@@_tex_primitive:nnn { glueshrink } { last_item } { 36 }
+\@@_tex_primitive:nnn { mutoglue } { last_item } { 37 }
+\@@_tex_primitive:nnn { gluetomu } { last_item } { 38 }
+\@@_tex_primitive:nnn { numexpr } { last_item } { 39 }
+\@@_tex_primitive:nnn { dimexpr } { last_item } { 40 }
+\@@_tex_primitive:nnn { glueexpr } { last_item } { 41 }
+\@@_tex_primitive:nnn { muexpr } { last_item } { 42 }
+\@@_tex_primitive:nnn { toks } { toks_register } { 0 }
+\@@_tex_primitive:nnn { output } { assign_toks } { 1 }
+\@@_tex_primitive:nnn { everypar } { assign_toks } { 2 }
+\@@_tex_primitive:nnn { everymath } { assign_toks } { 3 }
+\@@_tex_primitive:nnn { everydisplay } { assign_toks } { 4 }
+\@@_tex_primitive:nnn { everyhbox } { assign_toks } { 5 }
+\@@_tex_primitive:nnn { everyvbox } { assign_toks } { 6 }
+\@@_tex_primitive:nnn { everyjob } { assign_toks } { 7 }
+\@@_tex_primitive:nnn { everycr } { assign_toks } { 8 }
+\@@_tex_primitive:nnn { errhelp } { assign_toks } { 9 }
+\@@_tex_primitive:nnn { pdfpagesattr } { assign_toks } { 10 }
+\@@_tex_primitive:nnn { pdfpageattr } { assign_toks } { 11 }
+\@@_tex_primitive:nnn { pdfpageresources } { assign_toks } { 12 }
+\@@_tex_primitive:nnn { pdfpkmode } { assign_toks } { 13 }
+\@@_tex_primitive:nnn { everyeof } { assign_toks } { 14 }
+\@@_tex_primitive:nnn { pretolerance } { assign_int } { 0 }
+\@@_tex_primitive:nnn { tolerance } { assign_int } { 1 }
+\@@_tex_primitive:nnn { linepenalty } { assign_int } { 2 }
+\@@_tex_primitive:nnn { hyphenpenalty } { assign_int } { 3 }
+\@@_tex_primitive:nnn { exhyphenpenalty } { assign_int } { 4 }
+\@@_tex_primitive:nnn { clubpenalty } { assign_int } { 5 }
+\@@_tex_primitive:nnn { widowpenalty } { assign_int } { 6 }
+\@@_tex_primitive:nnn { displaywidowpenalty } { assign_int } { 7 }
+\@@_tex_primitive:nnn { brokenpenalty } { assign_int } { 8 }
+\@@_tex_primitive:nnn { binoppenalty } { assign_int } { 9 }
+\@@_tex_primitive:nnn { relpenalty } { assign_int } { 10 }
+\@@_tex_primitive:nnn { predisplaypenalty } { assign_int } { 11 }
+\@@_tex_primitive:nnn { postdisplaypenalty } { assign_int } { 12 }
+\@@_tex_primitive:nnn { interlinepenalty } { assign_int } { 13 }
+\@@_tex_primitive:nnn { doublehyphendemerits } { assign_int } { 14 }
+\@@_tex_primitive:nnn { finalhyphendemerits } { assign_int } { 15 }
+\@@_tex_primitive:nnn { adjdemerits } { assign_int } { 16 }
+\@@_tex_primitive:nnn { mag } { assign_int } { 17 }
+\@@_tex_primitive:nnn { delimiterfactor } { assign_int } { 18 }
+\@@_tex_primitive:nnn { looseness } { assign_int } { 19 }
+\@@_tex_primitive:nnn { time } { assign_int } { 20 }
+\@@_tex_primitive:nnn { day } { assign_int } { 21 }
+\@@_tex_primitive:nnn { month } { assign_int } { 22 }
+\@@_tex_primitive:nnn { year } { assign_int } { 23 }
+\@@_tex_primitive:nnn { showboxbreadth } { assign_int } { 24 }
+\@@_tex_primitive:nnn { showboxdepth } { assign_int } { 25 }
+\@@_tex_primitive:nnn { hbadness } { assign_int } { 26 }
+\@@_tex_primitive:nnn { vbadness } { assign_int } { 27 }
+\@@_tex_primitive:nnn { pausing } { assign_int } { 28 }
+\@@_tex_primitive:nnn { tracingonline } { assign_int } { 29 }
+\@@_tex_primitive:nnn { tracingmacros } { assign_int } { 30 }
+\@@_tex_primitive:nnn { tracingstats } { assign_int } { 31 }
+\@@_tex_primitive:nnn { tracingparagraphs } { assign_int } { 32 }
+\@@_tex_primitive:nnn { tracingpages } { assign_int } { 33 }
+\@@_tex_primitive:nnn { tracingoutput } { assign_int } { 34 }
+\@@_tex_primitive:nnn { tracinglostchars } { assign_int } { 35 }
+\@@_tex_primitive:nnn { tracingcommands } { assign_int } { 36 }
+\@@_tex_primitive:nnn { tracingrestores } { assign_int } { 37 }
+\@@_tex_primitive:nnn { uchyph } { assign_int } { 38 }
+\@@_tex_primitive:nnn { outputpenalty } { assign_int } { 39 }
+\@@_tex_primitive:nnn { maxdeadcycles } { assign_int } { 40 }
+\@@_tex_primitive:nnn { hangafter } { assign_int } { 41 }
+\@@_tex_primitive:nnn { floatingpenalty } { assign_int } { 42 }
+\@@_tex_primitive:nnn { globaldefs } { assign_int } { 43 }
+\@@_tex_primitive:nnn { fam } { assign_int } { 44 }
+\@@_tex_primitive:nnn { escapechar } { assign_int } { 45 }
+\@@_tex_primitive:nnn { defaulthyphenchar } { assign_int } { 46 }
+\@@_tex_primitive:nnn { defaultskewchar } { assign_int } { 47 }
+\@@_tex_primitive:nnn { endlinechar } { assign_int } { 48 }
+\@@_tex_primitive:nnn { newlinechar } { assign_int } { 49 }
+\@@_tex_primitive:nnn { language } { assign_int } { 50 }
+\@@_tex_primitive:nnn { lefthyphenmin } { assign_int } { 51 }
+\@@_tex_primitive:nnn { righthyphenmin } { assign_int } { 52 }
+\@@_tex_primitive:nnn { holdinginserts } { assign_int } { 53 }
+\@@_tex_primitive:nnn { errorcontextlines } { assign_int } { 54 }
+\@@_tex_primitive:nnn { pdfoutput } { assign_int } { 55 }
+\@@_tex_primitive:nnn { pdfcompresslevel } { assign_int } { 56 }
+\@@_tex_primitive:nnn { pdfdecimaldigits } { assign_int } { 57 }
+\@@_tex_primitive:nnn { pdfmovechars } { assign_int } { 58 }
+\@@_tex_primitive:nnn { pdfimageresolution } { assign_int } { 59 }
+\@@_tex_primitive:nnn { pdfpkresolution } { assign_int } { 60 }
+\@@_tex_primitive:nnn { pdfuniqueresname } { assign_int } { 61 }
+\@@_tex_primitive:nnn
+ { pdfoptionalwaysusepdfpagebox } { assign_int } { 62 }
+\@@_tex_primitive:nnn
+ { pdfoptionpdfinclusionerrorlevel } { assign_int } { 63 }
+\@@_tex_primitive:nnn
+ { pdfoptionpdfminorversion } { assign_int } { 64 }
+\@@_tex_primitive:nnn { pdfminorversion } { assign_int } { 64 }
+\@@_tex_primitive:nnn { pdfforcepagebox } { assign_int } { 65 }
+\@@_tex_primitive:nnn { pdfpagebox } { assign_int } { 66 }
+\@@_tex_primitive:nnn
+ { pdfinclusionerrorlevel } { assign_int } { 67 }
+\@@_tex_primitive:nnn { pdfgamma } { assign_int } { 68 }
+\@@_tex_primitive:nnn { pdfimagegamma } { assign_int } { 69 }
+\@@_tex_primitive:nnn { pdfimagehicolor } { assign_int } { 70 }
+\@@_tex_primitive:nnn { pdfimageapplygamma } { assign_int } { 71 }
+\@@_tex_primitive:nnn { pdfadjustspacing } { assign_int } { 72 }
+\@@_tex_primitive:nnn { pdfprotrudechars } { assign_int } { 73 }
+\@@_tex_primitive:nnn { pdftracingfonts } { assign_int } { 74 }
+\@@_tex_primitive:nnn { pdfobjcompresslevel } { assign_int } { 75 }
+\@@_tex_primitive:nnn
+ { pdfadjustinterwordglue } { assign_int } { 76 }
+\@@_tex_primitive:nnn { pdfprependkern } { assign_int } { 77 }
+\@@_tex_primitive:nnn { pdfappendkern } { assign_int } { 78 }
+\@@_tex_primitive:nnn { pdfgentounicode } { assign_int } { 79 }
+\@@_tex_primitive:nnn { pdfdraftmode } { assign_int } { 80 }
+\@@_tex_primitive:nnn { pdfinclusioncopyfonts } { assign_int } { 81 }
+\@@_tex_primitive:nnn { tracingassigns } { assign_int } { 82 }
+\@@_tex_primitive:nnn { tracinggroups } { assign_int } { 83 }
+\@@_tex_primitive:nnn { tracingifs } { assign_int } { 84 }
+\@@_tex_primitive:nnn { tracingscantokens } { assign_int } { 85 }
+\@@_tex_primitive:nnn { tracingnesting } { assign_int } { 86 }
+\@@_tex_primitive:nnn { predisplaydirection } { assign_int } { 87 }
+\@@_tex_primitive:nnn { lastlinefit } { assign_int } { 88 }
+\@@_tex_primitive:nnn { savingvdiscards } { assign_int } { 89 }
+\@@_tex_primitive:nnn { savinghyphcodes } { assign_int } { 90 }
+\@@_tex_primitive:nnn { TeXXeTstate } { assign_int } { 91 }
+\@@_tex_primitive:nnn { parindent } { assign_dimen } { 0 }
+\@@_tex_primitive:nnn { mathsurround } { assign_dimen } { 1 }
+\@@_tex_primitive:nnn { lineskiplimit } { assign_dimen } { 2 }
+\@@_tex_primitive:nnn { hsize } { assign_dimen } { 3 }
+\@@_tex_primitive:nnn { vsize } { assign_dimen } { 4 }
+\@@_tex_primitive:nnn { maxdepth } { assign_dimen } { 5 }
+\@@_tex_primitive:nnn { splitmaxdepth } { assign_dimen } { 6 }
+\@@_tex_primitive:nnn { boxmaxdepth } { assign_dimen } { 7 }
+\@@_tex_primitive:nnn { hfuzz } { assign_dimen } { 8 }
+\@@_tex_primitive:nnn { vfuzz } { assign_dimen } { 9 }
+\@@_tex_primitive:nnn { delimitershortfall } { assign_dimen } { 10 }
+\@@_tex_primitive:nnn { nulldelimiterspace } { assign_dimen } { 11 }
+\@@_tex_primitive:nnn { scriptspace } { assign_dimen } { 12 }
+\@@_tex_primitive:nnn { predisplaysize } { assign_dimen } { 13 }
+\@@_tex_primitive:nnn { displaywidth } { assign_dimen } { 14 }
+\@@_tex_primitive:nnn { displayindent } { assign_dimen } { 15 }
+\@@_tex_primitive:nnn { overfullrule } { assign_dimen } { 16 }
+\@@_tex_primitive:nnn { hangindent } { assign_dimen } { 17 }
+\@@_tex_primitive:nnn { hoffset } { assign_dimen } { 18 }
+\@@_tex_primitive:nnn { voffset } { assign_dimen } { 19 }
+\@@_tex_primitive:nnn { emergencystretch } { assign_dimen } { 20 }
+\@@_tex_primitive:nnn { pdfhorigin } { assign_dimen } { 21 }
+\@@_tex_primitive:nnn { pdfvorigin } { assign_dimen } { 22 }
+\@@_tex_primitive:nnn { pdfpagewidth } { assign_dimen } { 23 }
+\@@_tex_primitive:nnn { pdfpageheight } { assign_dimen } { 24 }
+\@@_tex_primitive:nnn { pdflinkmargin } { assign_dimen } { 25 }
+\@@_tex_primitive:nnn { pdfdestmargin } { assign_dimen } { 26 }
+\@@_tex_primitive:nnn { pdfthreadmargin } { assign_dimen } { 27 }
+\@@_tex_primitive:nnn { pdffirstlineheight } { assign_dimen } { 28 }
+\@@_tex_primitive:nnn { pdflastlinedepth } { assign_dimen } { 29 }
+\@@_tex_primitive:nnn { pdfeachlineheight } { assign_dimen } { 30 }
+\@@_tex_primitive:nnn { pdfeachlinedepth } { assign_dimen } { 31 }
+\@@_tex_primitive:nnn { pdfignoreddimen } { assign_dimen } { 32 }
+\@@_tex_primitive:nnn { pdfpxdimen } { assign_dimen } { 33 }
+\@@_tex_primitive:nnn { lineskip } { assign_glue } { 0 }
+\@@_tex_primitive:nnn { baselineskip } { assign_glue } { 1 }
+\@@_tex_primitive:nnn { parskip } { assign_glue } { 2 }
+\@@_tex_primitive:nnn { abovedisplayskip } { assign_glue } { 3 }
+\@@_tex_primitive:nnn { belowdisplayskip } { assign_glue } { 4 }
+\@@_tex_primitive:nnn { abovedisplayshortskip } { assign_glue } { 5 }
+\@@_tex_primitive:nnn { belowdisplayshortskip } { assign_glue } { 6 }
+\@@_tex_primitive:nnn { leftskip } { assign_glue } { 7 }
+\@@_tex_primitive:nnn { rightskip } { assign_glue } { 8 }
+\@@_tex_primitive:nnn { topskip } { assign_glue } { 9 }
+\@@_tex_primitive:nnn { splittopskip } { assign_glue } { 10 }
+\@@_tex_primitive:nnn { tabskip } { assign_glue } { 11 }
+\@@_tex_primitive:nnn { spaceskip } { assign_glue } { 12 }
+\@@_tex_primitive:nnn { xspaceskip } { assign_glue } { 13 }
+\@@_tex_primitive:nnn { parfillskip } { assign_glue } { 14 }
+\@@_tex_primitive:nnn { thinmuskip } { assign_mu_glue } { 15 }
+\@@_tex_primitive:nnn { medmuskip } { assign_mu_glue } { 16 }
+\@@_tex_primitive:nnn { thickmuskip } { assign_mu_glue } { 17 }
+\@@_tex_primitive:nnn { fontdimen } { assign_font_dimen } { 0 }
+\@@_tex_primitive:nnn { hyphenchar } { assign_font_int } { 0 }
+\@@_tex_primitive:nnn { skewchar } { assign_font_int } { 1 }
+\@@_tex_primitive:nnn { lpcode } { assign_font_int } { 2 }
+\@@_tex_primitive:nnn { rpcode } { assign_font_int } { 3 }
+\@@_tex_primitive:nnn { efcode } { assign_font_int } { 4 }
+\@@_tex_primitive:nnn { tagcode } { assign_font_int } { 5 }
+\@@_tex_primitive:nnn { pdfnoligatures } { assign_font_int } { 6 }
+\@@_tex_primitive:nnn { knbscode } { assign_font_int } { 7 }
+\@@_tex_primitive:nnn { stbscode } { assign_font_int } { 8 }
+\@@_tex_primitive:nnn { shbscode } { assign_font_int } { 9 }
+\@@_tex_primitive:nnn { knbccode } { assign_font_int } { 10 }
+\@@_tex_primitive:nnn { knaccode } { assign_font_int } { 11 }
+\@@_tex_primitive:nnn { spacefactor } { set_aux } { 102 }
+\@@_tex_primitive:nnn { prevdepth } { set_aux } { 1 }
+\@@_tex_primitive:nnn { prevgraf } { set_prev_graf } { 0 }
+\@@_tex_primitive:nnn { pagegoal } { set_page_dimen } { 0 }
+\@@_tex_primitive:nnn { pagetotal } { set_page_dimen } { 1 }
+\@@_tex_primitive:nnn { pagestretch } { set_page_dimen } { 2 }
+\@@_tex_primitive:nnn { pagefilstretch } { set_page_dimen } { 3 }
+\@@_tex_primitive:nnn { pagefillstretch } { set_page_dimen } { 4 }
+\@@_tex_primitive:nnn { pagefilllstretch } { set_page_dimen } { 5 }
+\@@_tex_primitive:nnn { pageshrink } { set_page_dimen } { 6 }
+\@@_tex_primitive:nnn { pagedepth } { set_page_dimen } { 7 }
+\@@_tex_primitive:nnn { deadcycles } { set_page_int } { 0 }
+\@@_tex_primitive:nnn { insertpenalties } { set_page_int } { 1 }
+\@@_tex_primitive:nnn { interactionmode } { set_page_int } { 2 }
+\@@_tex_primitive:nnn { wd } { set_box_dimen } { 1 }
+\@@_tex_primitive:nnn { dp } { set_box_dimen } { 2 }
+\@@_tex_primitive:nnn { ht } { set_box_dimen } { 3 }
+\@@_tex_primitive:nnn { parshape } { set_shape } { 0 }
+\@@_tex_primitive:nnn { interlinepenalties } { set_shape } { 1 }
+\@@_tex_primitive:nnn { clubpenalties } { set_shape } { 2 }
+\@@_tex_primitive:nnn { widowpenalties } { set_shape } { 3 }
+\@@_tex_primitive:nnn { displaywidowpenalties } { set_shape } { 4 }
+\@@_tex_primitive:nnn { catcode } { def_code } { 0 }
+\@@_tex_primitive:nnn { lccode } { def_code } { 256 }
+\@@_tex_primitive:nnn { uccode } { def_code } { 512 }
+\@@_tex_primitive:nnn { sfcode } { def_code } { 768 }
+\@@_tex_primitive:nnn { mathcode } { def_code } { 1024 }
+\@@_tex_primitive:nnn { delcode } { def_code } { 1591 }
+\@@_tex_primitive:nnn { textfont } { def_family } { -48 }
+\@@_tex_primitive:nnn { scriptfont } { def_family } { -32 }
+\@@_tex_primitive:nnn { scriptscriptfont } { def_family } { -16 }
+\@@_tex_primitive:nnn { nullfont } { set_font } { 0 }
+\@@_tex_primitive:nnn { font } { def_font } { 0 }
+\@@_tex_primitive:nnn { count } { register } { 1 000 000 }
+\@@_tex_primitive:nnn { dimen } { register } { 2 000 000 }
+\@@_tex_primitive:nnn { skip } { register } { 3 000 000 }
+\@@_tex_primitive:nnn { muskip } { register } { 4 000 000 }
+\@@_tex_primitive:nnn { advance } { advance } { 0 }
+\@@_tex_primitive:nnn { multiply } { multiply } { 0 }
+\@@_tex_primitive:nnn { divide } { divide } { 0 }
+\@@_tex_primitive:nnn { long } { prefix } { 1 }
+\@@_tex_primitive:nnn { outer } { prefix } { 2 }
+\@@_tex_primitive:nnn { global } { prefix } { 4 }
+\@@_tex_primitive:nnn { protected } { prefix } { 8 }
+\@@_tex_primitive:nnn { let } { let } { 0 }
+\@@_tex_primitive:nnn { futurelet } { let } { 1 }
+\@@_tex_primitive:nnn { chardef } { shorthand_def } { 0 }
+\@@_tex_primitive:nnn { mathchardef } { shorthand_def } { 1 }
+\@@_tex_primitive:nnn { countdef } { shorthand_def } { 2 }
+\@@_tex_primitive:nnn { dimendef } { shorthand_def } { 3 }
+\@@_tex_primitive:nnn { skipdef } { shorthand_def } { 4 }
+\@@_tex_primitive:nnn { muskipdef } { shorthand_def } { 5 }
+\@@_tex_primitive:nnn { toksdef } { shorthand_def } { 6 }
+\@@_tex_primitive:nnn { read } { read_to_cs } { 0 }
+\@@_tex_primitive:nnn { readline } { read_to_cs } { 1 }
+\@@_tex_primitive:nnn { def } { def } { 0 }
+\@@_tex_primitive:nnn { gdef } { def } { 1 }
+\@@_tex_primitive:nnn { edef } { def } { 2 }
+\@@_tex_primitive:nnn { xdef } { def } { 3 }
+\@@_tex_primitive:nnn { setbox } { set_box } { 0 }
+\@@_tex_primitive:nnn { hyphenation } { hyph_data } { 0 }
+\@@_tex_primitive:nnn { patterns } { hyph_data } { 1 }
+\@@_tex_primitive:nnn { batchmode } { set_interaction } { 0 }
+\@@_tex_primitive:nnn { nonstopmode } { set_interaction } { 1 }
+\@@_tex_primitive:nnn { scrollmode } { set_interaction } { 2 }
+\@@_tex_primitive:nnn { errorstopmode } { set_interaction } { 3 }
+\@@_tex_primitive:nnn { letterspacefont } { letterspace_font } { 0 }
+\@@_tex_primitive:nnn { pdfcopyfont } { pdf_copy_font } { 0 }
+\@@_tex_primitive:nnn { undefined } { undefined_cs } { 0 }
+\@@_tex_primitive:nnn { ndefined } { undefined_cs } { 0 }
+\@@_tex_primitive:nnn { expandafter } { expand_after } { 0 }
+\@@_tex_primitive:nnn { unless } { expand_after } { 1 }
+\@@_tex_primitive:nnn { pdfprimitive } { no_expand } { 1 }
+\@@_tex_primitive:nnn { noexpand } { no_expand } { 0 }
+\@@_tex_primitive:nnn { input } { input } { 0 }
+\@@_tex_primitive:nnn { endinput } { input } { 1 }
+\@@_tex_primitive:nnn { scantokens } { input } { 2 }
+\@@_tex_primitive:nnn { if } { if_test } { 0 }
+\@@_tex_primitive:nnn { ifcat } { if_test } { 1 }
+\@@_tex_primitive:nnn { ifnum } { if_test } { 2 }
+\@@_tex_primitive:nnn { ifdim } { if_test } { 3 }
+\@@_tex_primitive:nnn { ifodd } { if_test } { 4 }
+\@@_tex_primitive:nnn { ifvmode } { if_test } { 5 }
+\@@_tex_primitive:nnn { ifhmode } { if_test } { 6 }
+\@@_tex_primitive:nnn { ifmmode } { if_test } { 7 }
+\@@_tex_primitive:nnn { ifinner } { if_test } { 8 }
+\@@_tex_primitive:nnn { ifvoid } { if_test } { 9 }
+\@@_tex_primitive:nnn { ifhbox } { if_test } { 10 }
+\@@_tex_primitive:nnn { ifvbox } { if_test } { 11 }
+\@@_tex_primitive:nnn { ifx } { if_test } { 12 }
+\@@_tex_primitive:nnn { ifeof } { if_test } { 13 }
+\@@_tex_primitive:nnn { iftrue } { if_test } { 14 }
+\@@_tex_primitive:nnn { iffalse } { if_test } { 15 }
+\@@_tex_primitive:nnn { ifcase } { if_test } { 16 }
+\@@_tex_primitive:nnn { ifdefined } { if_test } { 17 }
+\@@_tex_primitive:nnn { ifcsname } { if_test } { 18 }
+\@@_tex_primitive:nnn { iffontchar } { if_test } { 19 }
+\@@_tex_primitive:nnn { ifincsname } { if_test } { 20 }
+\@@_tex_primitive:nnn { ifpdfprimitive } { if_test } { 21 }
+\@@_tex_primitive:nnn { ifpdfabsnum } { if_test } { 22 }
+\@@_tex_primitive:nnn { ifpdfabsdim } { if_test } { 23 }
+\@@_tex_primitive:nnn { fi } { fi_or_else } { 2 }
+\@@_tex_primitive:nnn { else } { fi_or_else } { 3 }
+\@@_tex_primitive:nnn { or } { fi_or_else } { 4 }
+\@@_tex_primitive:nnn { csname } { cs_name } { 0 }
+\@@_tex_primitive:nnn { number } { convert } { 0 }
+\@@_tex_primitive:nnn { romannumeral } { convert } { 1 }
+\@@_tex_primitive:nnn { string } { convert } { 2 }
+\@@_tex_primitive:nnn { meaning } { convert } { 3 }
+\@@_tex_primitive:nnn { fontname } { convert } { 4 }
+\@@_tex_primitive:nnn { eTeXrevision } { convert } { 5 }
+\@@_tex_primitive:nnn { pdftexrevision } { convert } { 6 }
+\@@_tex_primitive:nnn { pdftexbanner } { convert } { 7 }
+\@@_tex_primitive:nnn { pdffontname } { convert } { 8 }
+\@@_tex_primitive:nnn { pdffontobjnum } { convert } { 9 }
+\@@_tex_primitive:nnn { pdffontsize } { convert } { 10 }
+\@@_tex_primitive:nnn { pdfpageref } { convert } { 11 }
+\@@_tex_primitive:nnn { pdfxformname } { convert } { 12 }
+\@@_tex_primitive:nnn { pdfescapestring } { convert } { 13 }
+\@@_tex_primitive:nnn { pdfescapename } { convert } { 14 }
+\@@_tex_primitive:nnn { leftmarginkern } { convert } { 15 }
+\@@_tex_primitive:nnn { rightmarginkern } { convert } { 16 }
+\@@_tex_primitive:nnn
+ { \sys_if_engine_xetex:F { pdf } strcmp } { convert } { 17 }
+\@@_tex_primitive:nnn { pdfcolorstackinit } { convert } { 18 }
+\@@_tex_primitive:nnn { pdfescapehex } { convert } { 19 }
+\@@_tex_primitive:nnn { pdfunescapehex } { convert } { 20 }
+\@@_tex_primitive:nnn { pdfcreationdate } { convert } { 21 }
+\@@_tex_primitive:nnn { pdffilemoddate } { convert } { 22 }
+\@@_tex_primitive:nnn { pdffilesize } { convert } { 23 }
+\@@_tex_primitive:nnn { pdfmdfivesum } { convert } { 24 }
+\@@_tex_primitive:nnn { pdffiledump } { convert } { 25 }
+\@@_tex_primitive:nnn { pdfmatch } { convert } { 26 }
+\@@_tex_primitive:nnn { pdflastmatch } { convert } { 27 }
+\@@_tex_primitive:nnn { pdfuniformdeviate } { convert } { 28 }
+\@@_tex_primitive:nnn { pdfnormaldeviate } { convert } { 29 }
+\@@_tex_primitive:nnn { pdfinsertht } { convert } { 30 }
+\@@_tex_primitive:nnn { pdfximagebbox } { convert } { 31 }
+\@@_tex_primitive:nnn { jobname } { convert } { 32 }
+\sys_if_engine_luatex:T
+ {
+ \@@_tex_primitive:nnn { directlua } { convert } { 33 }
+ \@@_tex_primitive:nnn { expanded } { convert } { 34 }
+ \@@_tex_primitive:nnn { luaescapestring } { convert } { 35 }
+ }
+\sys_if_engine_xetex:T
+ {
+ \@@_tex_primitive:nnn { Ucharcat } { convert } { 40 }
+ }
+\@@_tex_primitive:nnn { the } { the } { 0 }
+\@@_tex_primitive:nnn { unexpanded } { the } { 1 }
+\@@_tex_primitive:nnn { detokenize } { the } { 5 }
+\@@_tex_primitive:nnn { topmark } { top_bot_mark } { 0 }
+\@@_tex_primitive:nnn { firstmark } { top_bot_mark } { 1 }
+\@@_tex_primitive:nnn { botmark } { top_bot_mark } { 2 }
+\@@_tex_primitive:nnn { splitfirstmark } { top_bot_mark } { 3 }
+\@@_tex_primitive:nnn { splitbotmark } { top_bot_mark } { 4 }
+\@@_tex_primitive:nnn { topmarks } { top_bot_mark } { 5 }
+\@@_tex_primitive:nnn { firstmarks } { top_bot_mark } { 6 }
+\@@_tex_primitive:nnn { botmarks } { top_bot_mark } { 7 }
+\@@_tex_primitive:nnn { splitfirstmarks } { top_bot_mark } { 8 }
+\@@_tex_primitive:nnn { splitbotmarks } { top_bot_mark } { 9 }
+% \end{macrocode}
+%
+% \subsection{Get next token}
+%
+% We define here two functions which fetch the next token in the token
+% list.
+% \begin{itemize}
+% \item \cs{@@_get_next:} sets \cs{l_@@_head_gtl}, \cs{l_@@_head_token},
+% and if possible \cs{l_@@_head_tl} (otherwise it is cleared).
+% \item \cs{@@_get_token:} additionally sets \cs{l_@@_head_cmd_int} and
+% \cs{l_@@_head_char_int}.
+% \end{itemize}
+% The latter is based on \cs{@@_set_cmd:} which derives the
+% \cs{l_@@_head_cmd_int} and \cs{l_@@_head_char_int} from
+% \cs{l_@@_head_token}.
+%
+% \begin{macro}{\@@_get_next:}
+% \begin{macro}{\@@_get_next_aux:w}
+% If the input is empty, forcefully exit. Otherwise,
+% remove the first token in the input, and store it in
+% \cs{l_@@_head_gtl}. Set \cs{l_@@_head_token} equal in meaning to
+% that first token. Then set \cs{l_@@_head_tl} to contain the token,
+% unless it is a begin-group or end-group character, in which case
+% this token list is emptied.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_next:
+ {
+ \@@_input_if_empty:TF
+ { \@@_exit_error:w }
+ {
+ \@@_input_gpop:N \l_@@_head_gtl
+ \gtl_head_do:NN \l_@@_head_gtl \@@_get_next_aux:w
+ \gtl_if_tl:NTF \l_@@_head_gtl
+ {
+ \tl_set:Nx \l_@@_head_tl
+ { \gtl_head:N \l_@@_head_gtl }
+ \token_if_eq_meaning:NNT
+ \l_@@_head_token \@@_special_relax:
+ \@@_get_next_notexpanded:
+ }
+ { \tl_clear:N \l_@@_head_tl }
+ }
+ }
+\cs_new_protected:Npn \@@_get_next_aux:w
+ { \cs_set_eq:NN \l_@@_head_token }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_next_notexpanded:}
+% \begin{macro}{\@@_notexpanded_test:w, \@@_notexpanded_expand:nN, \@@_notexpanded_expand:NN}
+% At this point we have likely encountered a special \tn{relax} marker
+% that we use to mark cases where \tn{noexpand} acts on a control
+% sequence or an active character. To make sure of that check the
+% control sequence has the form \cs{notexpanded:\ldots{}}. Since we
+% don't know the escape character we must use \cs{cs_to_str:N}, but
+% that function is not meant for active characters and has a runaway
+% argument if its argument is a space (active since we know its
+% meaning is the special \tn{relax}). To avoid the runaway we include
+% an arbitrary delimiter~|Z|. If the token in \cs{l_@@_head_tl} is
+% not \cs{notexpanded:\ldots{}} we do nothing. Otherwise
+% \cs{@@_notexpanded_expand:n} reconstructs the token that was hit
+% with \tn{noexpand} (an active character if the argument is a single
+% character) and do the job of \cs{@@_get_next:}, setting
+% \cs{l_@@_head_token} to the special \tn{relax} marker for expandable
+% commands, as \tn{noexpand} would.
+% \begin{macrocode}
+\cs_set_protected:Npn \@@_tmp:w #1
+ {
+ \cs_new_protected:Npn \@@_get_next_notexpanded:
+ {
+ \tl_if_eq:onTF { \l_@@_head_tl } { \@@_unravel_marker: }
+ { \@@_get_next_marker: }
+ {
+ \@@_exp_args:NNx \use:nn \@@_notexpanded_test:w
+ { \scan_stop: \exp_after:wN \cs_to_str:N \l_@@_head_tl Z }
+ \q_mark \@@_notexpanded_expand:n
+ #1 Z \q_mark \use_none:n
+ \q_stop
+ }
+ }
+ \cs_new_protected:Npn \@@_notexpanded_test:w
+ ##1 #1 ##2 Z \q_mark ##3##4 \q_stop
+ { ##3 {##2} }
+ }
+\exp_args:Nx \@@_tmp:w { \scan_stop: \tl_to_str:n { notexpanded: } }
+\group_begin:
+ \char_set_catcode_active:n { 0 }
+ \cs_new_protected:Npn \@@_notexpanded_expand:n #1
+ {
+ \@@_exp_args:Nx \tl_if_empty:nTF { \str_tail:n {#1} }
+ {
+ \group_begin:
+ \char_set_lccode:nn { 0 } { `#1 }
+ \tex_lowercase:D
+ {
+ \group_end:
+ \@@_notexpanded_expand:N ^^@
+ }
+ }
+ {
+ \group_begin: \exp_args:NNc \group_end:
+ \@@_notexpanded_expand:N { \use_none:n #1 }
+ }
+ }
+\group_end:
+\cs_new_protected:Npn \@@_notexpanded_expand:N #1
+ {
+ \gtl_set:Nn \l_@@_head_gtl {#1}
+ \tl_set:Nn \l_@@_head_tl {#1}
+ \cs_set_eq:NN \l_@@_head_token \@@_special_relax:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_next_marker:}
+% This is used to deal with nested unravel.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_next_marker:
+ {
+ \@@_get_next:
+ \tl_if_eq:onTF \l_@@_head_tl { \@@:nn }
+ { \@@_error:nxxxx { nested-unravel } { } { } { } { } }
+ { \@@_error:nxxxx { internal } { marker~unknown } { } { } { } }
+ \@@_input_gpop_item:NF \l_@@_argi_tl
+ { \@@_error:nxxxx { internal } { marker~1 } { } { } { } }
+ \@@_input_gpop_item:NF \l_@@_argii_tl
+ { \@@_error:nxxxx { internal } { marker~2 } { } { } { } }
+ \exp_args:Nno \keys_set:nn { unravel } \l_@@_argi_tl
+ \@@_exp_args:Nx \@@_back_input:n
+ { \exp_not:N \exp_not:n { \exp_not:o \l_@@_argii_tl } }
+ \@@_get_next:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_token:}
+% Call \cs{@@_get_next:} to set \cs{l_@@_head_gtl}, \cs{l_@@_head_tl}
+% and \cs{l_@@_head_token}, then call \cs{@@_set_cmd:} to set
+% \cs{l_@@_head_cmd_int} and \cs{l_@@_head_char_int}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_token:
+ {
+ \@@_get_next:
+ \@@_set_cmd:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd:}
+% After the call to \cs{@@_get_next:}, we find the command code
+% \cs{l_@@_head_cmd_int} and the character code
+% \cs{l_@@_head_char_int}, based only on \cs{l_@@_head_token}. First
+% set \cs{l_@@_head_meaning_tl} from the \tn{meaning} of the first
+% token. If the corresponding primitive exists, use the information
+% to set the two integers. If the token is expandable, it can either
+% be a macro or be a primitive that we somehow do not know
+% (\emph{e.g.}, an expandable \XeTeX{} or \LuaTeX{} primitive
+% perhaps). Otherwise, it can be a control sequence or a character.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd:
+ {
+ \@@_set_cmd_aux_meaning:
+ \@@_set_cmd_aux_primitive:oTF { \l_@@_head_meaning_tl }
+ { }
+ {
+ \@@_token_if_expandable:NTF \l_@@_head_token
+ {
+ \token_if_macro:NTF \l_@@_head_token
+ { \@@_set_cmd_aux_macro: }
+ { \@@_set_cmd_aux_unknown: }
+ }
+ {
+ \token_if_cs:NTF \l_@@_head_token
+ { \@@_set_cmd_aux_cs: }
+ { \@@_set_cmd_aux_char: }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd_aux_meaning:}
+% \begin{macro}[EXP]{\@@_set_cmd_aux_meaning:w}
+% Remove the leading escape character (\cs{@@_strip_escape:w} takes
+% care of special cases there) from the \tn{meaning} of the first
+% token, then remove anything after the first~|:|, which is present
+% for macros, for marks, and for that character too. For any
+% primitive except \tn{nullfont}, this leaves the primitive's name.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_meaning:
+ {
+ \tl_set:Nx \l_@@_head_meaning_tl
+ {
+ \exp_after:wN \@@_strip_escape:w
+ \token_to_meaning:N \l_@@_head_token
+ \tl_to_str:n { : }
+ }
+ \tl_set:Nx \l_@@_head_meaning_tl
+ {
+ \exp_after:wN \@@_set_cmd_aux_meaning:w
+ \l_@@_head_meaning_tl \q_stop
+ }
+ }
+\use:x
+ {
+ \cs_new:Npn \exp_not:N \@@_set_cmd_aux_meaning:w
+ ##1 \token_to_str:N : ##2 \exp_not:N \q_stop {##1}
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_set_cmd_aux_primitive:nTF, \@@_set_cmd_aux_primitive:oTF}
+% \begin{macro}{\@@_set_cmd_aux_primitive:nn}
+% Test if there is any information about the given (cleaned-up)
+% \tn{meaning}. If there is, use that as the command and character
+% integers.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_primitive:nTF #1#2
+ {
+ \cs_if_exist:cTF { c_@@_tex_#1_tl }
+ {
+ \exp_last_unbraced:Nv \@@_set_cmd_aux_primitive:nn
+ { c_@@_tex_#1_tl }
+ #2
+ }
+ }
+\cs_generate_variant:Nn \@@_set_cmd_aux_primitive:nTF { o }
+\cs_new_protected:Npn \@@_set_cmd_aux_primitive:nn #1#2
+ {
+ \int_set:Nn \l_@@_head_cmd_int {#1}
+ \int_set:Nn \l_@@_head_char_int {#2}
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd_aux_macro:}
+% The token is a macro. There is no need to determine whether the
+% macro is long/outer.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_macro:
+ {
+ \int_set:Nn \l_@@_head_cmd_int { \@@_tex_use:n { call } }
+ \int_zero:N \l_@@_head_char_int
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd_aux_unknown:}
+% Complain about an unknown primitive, and consider it as if it were
+% \tn{relax}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_unknown:
+ {
+ \exp_last_unbraced:NV \@@_set_cmd_aux_primitive:nn
+ \c_@@_tex_relax_tl
+ \@@_error:nxxxx { unknown-primitive }
+ { \l_@@_head_meaning_tl } { } { } { }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd_aux_cs:}
+% If the \tn{meaning} contains \verb*|elect font|, the control
+% sequence is \tn{nullfont} or similar (note that we do not search for
+% \verb*|select font|, as the code to trim the escape character from
+% the meaning may have removed the leading~|s|). Otherwise, we expect
+% the \tn{meaning} to be \tn{char} or \tn{mathchar} followed by
+% |"|~and an uppercase hexadecimal number, or one of \tn{count},
+% \tn{dimen}, \tn{skip}, \tn{muskip} or \tn{toks} followed by a
+% decimal number.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_cs:
+ {
+ \@@_tl_if_in:ooTF \l_@@_head_meaning_tl
+ { \tl_to_str:n { elect~font } }
+ {
+ \exp_last_unbraced:NV \@@_set_cmd_aux_primitive:nn
+ \c_@@_tex_nullfont_tl
+ }
+ { \@@_set_cmd_aux_numeric: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_set_cmd_aux_numeric:,
+% \@@_set_cmd_aux_numeric:w,
+% \@@_set_cmd_aux_given:n
+% }
+% \begin{macro}[rEXP]{\@@_set_cmd_aux_numeric:N}
+% Insert \cs{q_mark} before the first non-letter (in fact, anything
+% less than~|A|) in the \tn{meaning} by looping one character at a
+% time (skipping spaces, but there should be none). We expect the
+% first part to be |char| or~|mathchar| (or |kchar| in up\TeX{}),
+% or one of |count|, |dimen|,
+% |skip|, |muskip|, or |toks|. In the first two (three) cases, the command is
+% |char_given| or |math_given|. It is otherwise identical to the
+% corresponding primitive (\tn{count} \emph{etc.}). We then keep
+% track of the associated number (part after \cs{q_mark}) in
+% \cs{l_@@_head_char_int}. For unknown non-expandable primitives,
+% assuming that their meaning consists solely of letters, the
+% \cs{q_mark} is inserted at their end, and is followed by~|+0|, so
+% nothing breaks.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_numeric:
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ {
+ \exp_after:wN \@@_set_cmd_aux_numeric:N
+ \l_@@_head_meaning_tl + 0
+ }
+ \exp_after:wN \@@_set_cmd_aux_numeric:w
+ \l_@@_tmpa_tl \q_stop
+ }
+\cs_new:Npn \@@_set_cmd_aux_numeric:N #1
+ {
+ \if_int_compare:w `#1 < `A \exp_stop_f:
+ \exp_not:N \q_mark
+ \exp_after:wN \use_i:nn
+ \fi:
+ #1 \@@_set_cmd_aux_numeric:N
+ }
+\cs_new_protected:Npn \@@_set_cmd_aux_numeric:w #1 \q_mark #2 \q_stop
+ {
+ \str_case:nnF {#1}
+ {
+ { char } { \@@_set_cmd_aux_given:n { char_given } }
+ { kchar } { \@@_set_cmd_aux_given:n { char_given } }
+ { mathchar } { \@@_set_cmd_aux_given:n { math_given } }
+ }
+ {
+ \@@_set_cmd_aux_primitive:nTF {#1}
+ { }
+ { \@@_set_cmd_aux_unknown: }
+ \int_add:Nn \l_@@_head_char_int { 100 000 }
+ }
+ \int_add:Nn \l_@@_head_char_int {#2}
+ }
+\cs_new_protected:Npn \@@_set_cmd_aux_given:n #1
+ {
+ \int_set:Nn \l_@@_head_cmd_int { \@@_tex_use:n {#1} }
+ \int_zero:N \l_@@_head_char_int
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_cmd_aux_char:}
+% \begin{macro}{\@@_set_cmd_aux_char:w}
+% At this point, the \tn{meaning} token list has been shortened by the
+% code meant to remove the escape character. We thus set it again to
+% the \tn{meaning} of the leading token. The command is then the
+% first word (delimited by a space) of the \tn{meaning}, followed by
+% |_char|, except for category other, where we use |other_char|. For
+% the character code, there is a need to expand
+% \cs{@@_token_to_char:N} before placing~|`|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_cmd_aux_char:
+ {
+ \tl_set:Nx \l_@@_head_meaning_tl
+ { \token_to_meaning:N \l_@@_head_token }
+ \token_if_eq_catcode:NNT \l_@@_head_token \c_catcode_other_token
+ { \tl_set:Nn \l_@@_head_meaning_tl { other~ } }
+ \exp_after:wN \@@_set_cmd_aux_char:w
+ \l_@@_head_meaning_tl \q_stop
+ \@@_exp_args:NNx \int_set:Nn \l_@@_head_char_int
+ { ` \@@_token_to_char:N \l_@@_head_token }
+ }
+\cs_new_protected:Npn \@@_set_cmd_aux_char:w #1 ~ #2 \q_stop
+ {
+ \int_set:Nn \l_@@_head_cmd_int
+ { \@@_tex_use:n { #1_char } }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Manipulating the input}
+%
+% \subsubsection{Elementary operations}
+%
+% \begin{macro}[rEXP]{\@@_input_to_str:}
+% Map \cs{gtl_to_str:c} through the input stack.
+% \begin{macrocode}
+\cs_new:Npn \@@_input_to_str:
+ {
+ \int_step_function:nnnN \g_@@_input_int { -1 } { 1 }
+ \@@_input_to_str_aux:n
+ }
+\cs_new:Npn \@@_input_to_str_aux:n #1
+ { \gtl_to_str:c { g_@@_input_#1_gtl } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_if_empty:TF}
+% If the input stack is empty, the input contains no token.
+% Otherwise, check the top of the stack for tokens: if there are, then
+% the input is non-empty, and if there are none, then we get rid of
+% the top of stack and loop.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_if_empty:TF
+ {
+ \int_compare:nNnTF \g_@@_input_int = 0
+ { \use_i:nn }
+ {
+ \gtl_if_empty:cTF
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ {
+ \int_gdecr:N \g_@@_input_int
+ \@@_input_if_empty:TF
+ }
+ {
+ \@@_input_split:
+ \use_ii:nn
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: profiling to know if \@@_input_split: is beneficial.
+%
+% \begin{macro}{\@@_input_split:}
+% If the input is completely flat, and is a token list starting with
+% an |N|-type token, try to unflatten it by splitting at each
+% occurence of that first character
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_split:
+ {
+ \int_compare:nNnT \g_@@_input_int = 1
+ {
+ \exp_args:Nc \@@_input_split_aux:N
+ { g_@@_input_1_gtl }
+ }
+ }
+\cs_new_protected:Npn \@@_input_split_aux:N #1
+ {
+ \gtl_if_tl:NT #1
+ {
+ \gtl_if_head_is_N_type:NT #1
+ {
+ \tl_set:Nx \l_@@_input_tmpa_tl { \gtl_left_tl:N #1 }
+ \@@_exp_args:NNx \use:nn
+ \@@_input_split_auxii:N
+ { \tl_head:N \l_@@_input_tmpa_tl }
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_input_split_auxii:N #1
+ {
+ \token_if_parameter:NF #1
+ {
+ \tl_replace_all:Nnn \l_@@_input_tmpa_tl {#1}
+ { \@@_input_split_end: \@@_input_split_auxiii:w #1 }
+ \group_begin:
+ \cs_set:Npn \@@_input_split_auxiii:w
+ ##1 \@@_input_split_end: { + 1 }
+ \int_gset:Nn \g_@@_input_int
+ { 0 \l_@@_input_tmpa_tl \@@_input_split_end: }
+ \group_end:
+ \int_gset_eq:NN \g_@@_input_tmpa_int \g_@@_input_int
+ \l_@@_input_tmpa_tl \@@_input_split_end:
+ }
+ }
+\cs_new:Npn \@@_input_split_end: { }
+\cs_new_protected:Npn \@@_input_split_auxiii:w
+ #1 \@@_input_split_end:
+ {
+ \gtl_gclear_new:c
+ { g_@@_input_ \int_use:N \g_@@_input_tmpa_int _gtl }
+ \gtl_gset:cn
+ { g_@@_input_ \int_use:N \g_@@_input_tmpa_int _gtl } {#1}
+ \int_gdecr:N \g_@@_input_tmpa_int
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_gset:n}
+% At first, all of the input is in the same~\texttt{gtl}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_gset:n
+ {
+ \int_gzero:N \g_@@_input_int
+ \@@_back_input:n
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_get:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_get:N #1
+ {
+ \@@_input_if_empty:TF
+ { \gtl_set:Nn #1 { \q_no_value } }
+ {
+ \gtl_get_left:cN
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl } #1
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_get_left:N, \@@_input_get_left_aux:nN}
+% \begin{variable}{\l_@@_input_get_left_tl}
+% \begin{macrocode}
+\tl_new:N \l_@@_input_get_left_tl
+\cs_new_protected:Npn \@@_input_get_left:N #1
+ {
+ \tl_clear:N #1
+ \exp_args:NV \@@_input_get_left_aux:nN \g_@@_input_int #1
+ }
+\cs_new_protected:Npn \@@_input_get_left_aux:nN #1#2
+ {
+ \int_compare:nNnF {#1} = 0
+ {
+ \tl_set:Nx \l_@@_input_get_left_tl
+ { \gtl_left_tl:c { g_@@_input_#1_gtl } }
+ \tl_concat:NNN #2 #2 \l_@@_input_get_left_tl
+ \gtl_if_tl:cT { g_@@_input_#1_gtl }
+ {
+ \exp_args:Nf \@@_input_get_left_aux:nN
+ { \int_eval:n { #1 - 1 } } #2
+ }
+ }
+ }
+% \end{macrocode}
+% \end{variable}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_gpop:N}
+% Call \cs{@@_input_if_empty:TF} to remove empty levels from the input
+% stack, then extract the first token from the left-most non-empty
+% level.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_gpop:N #1
+ {
+ \@@_input_if_empty:TF
+ { \gtl_set:Nn #1 { \q_no_value } }
+ {
+ \gtl_gpop_left:cN
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl } #1
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_merge:}
+% Merge the top two levels of input. This requires, but does not
+% check, that \cs{g_@@_input_int} is at least~$2$.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_merge:
+ {
+ \int_gdecr:N \g_@@_input_int
+ \gtl_gconcat:ccc
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ { g_@@_input_ \int_eval:n { \g_@@_input_int + 1 } _gtl }
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ \gtl_gclear:c
+ { g_@@_input_ \int_eval:n { \g_@@_input_int + 1 } _gtl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[TF]{\@@_input_gpop_item:N}
+% \begin{macro}{\@@_input_gpop_item_aux:NN}
+% If there is no input, we cannot pop an item. Othewise, try to pop
+% from the top of the input stack. If this succeeds, or if this
+% failed and the top of stack has extra end-group characters, or if
+% the input stack contains only the top-most item, then the answer
+% given by \cs{gtl_gpop_left_item:NNTF} is the correct one, which we
+% return. Otherwise, merge the top two levels and repeat.
+% \begin{macrocode}
+\prg_new_protected_conditional:Npnn \@@_input_gpop_item:N #1 { F }
+ {
+ \int_compare:nNnTF \g_@@_input_int = 0
+ { \prg_return_false: }
+ {
+ \exp_args:Nc \@@_input_gpop_item_aux:NN
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl } #1
+ }
+ }
+\cs_new_protected:Npn \@@_input_gpop_item_aux:NN #1#2
+ {
+ \gtl_gpop_left_item:NNTF #1#2
+ { \prg_return_true: }
+ {
+ \int_compare:nNnTF { \gtl_extra_end:N #1 } > 0
+ { \prg_return_false: }
+ {
+ \int_compare:nNnTF \g_@@_input_int = 1
+ { \prg_return_false: }
+ {
+ \@@_input_merge:
+ \exp_args:Nc \@@_input_gpop_item_aux:NN
+ {
+ g_@@_input_
+ \int_use:N \g_@@_input_int _gtl
+ }
+ #2
+ }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_input_gpop_tl:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_input_gpop_tl:N #1
+ { \tl_clear:N #1 \@@_input_gpop_tl_aux:N #1 }
+\cs_new_protected:Npn \@@_input_gpop_tl_aux:N #1
+ {
+ \int_compare:nNnF \g_@@_input_int = 0
+ {
+ \exp_args:Nc \@@_input_gpop_tl_aux:NN
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl } #1
+ }
+ }
+\cs_new_protected:Npn \@@_input_gpop_tl_aux:NN #1#2
+ {
+ \gtl_if_tl:NTF #1
+ {
+ \tl_put_right:Nx #2 { \gtl_left_tl:N #1 }
+ \gtl_gclear:N #1
+ \int_gdecr:N \g_@@_input_int
+ \@@_input_gpop_tl_aux:N #2
+ }
+ {
+ \int_compare:nNnTF \g_@@_input_int > 1
+ { \int_compare:nNnTF { \gtl_extra_end:N #1 } > 0 }
+ { \use_i:nn }
+ {
+ \tl_put_right:Nx #2 { \gtl_left_tl:N #1 }
+ \gtl_gpop_left_tl:N #1
+ }
+ {
+ \@@_input_merge:
+ \@@_input_gpop_tl_aux:N #2
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_back_input:n, \@@_back_input:x}
+% Insert a token list back into the input. Use \cs{gtl_gclear_new:c}
+% to define the gtl variable if necessary: this happens whenever a
+% new largest value of \cs{g_@@_input_int} is reached.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_back_input:n
+ {
+ \int_gincr:N \g_@@_input_int
+ \gtl_gclear_new:c { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ \gtl_gset:cn { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ }
+\cs_generate_variant:Nn \@@_back_input:n { V , o }
+\cs_new_protected:Npn \@@_back_input:x
+ { \@@_exp_args:Nx \@@_back_input:n }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_back_input_gtl:N}
+% Insert a generalized token list back into the input.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_back_input_gtl:N #1
+ {
+ \gtl_if_tl:NTF #1
+ { \@@_back_input:x { \gtl_left_tl:N #1 } }
+ {
+ \gtl_gconcat:cNc
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ #1
+ { g_@@_input_ \int_use:N \g_@@_input_int _gtl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_back_input:}
+% Insert the last token read back into the input stream.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_back_input:
+ { \@@_back_input_gtl:N \l_@@_head_gtl }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_back_input_tl_o:}
+% Insert the \cs{l_@@_head_tl} (may or may not be the last token read)
+% back into the input stream, after expanding it once. Then print
+% some diagnostic information.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_back_input_tl_o:
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \exp_args:NV \exp_not:o \l_@@_head_tl }
+ \@@_back_input:V \l_@@_tmpa_tl
+ \@@_print_expansion:x
+ { \tl_to_str:N \l_@@_head_tl = \tl_to_str:N \l_@@_tmpa_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Insert token for error recovery}
+%
+% \begin{macro}{\@@_insert_relax:}
+% This function inserts \TeX{}'s |frozen_relax|. It is called when a
+% conditional is not done finding its condition, but hits the
+% corresponding \tn{fi} or \tn{or} or \tn{else}, or when \tn{input}
+% appears while \cs{g_@@_name_in_progress_bool} is \texttt{true}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_insert_relax:
+ {
+ \@@_back_input:
+ \gtl_set_eq:NN \l_@@_head_gtl \c_@@_frozen_relax_gtl
+ \@@_back_input:
+ \@@_print_action:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_insert_group_begin_error:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_insert_group_begin_error:
+ {
+ \tl_set_eq:NN \l_@@_tmpa_tl \l_@@_head_tl
+ \@@_back_input:
+ \gtl_set_eq:NN \l_@@_head_gtl \c_group_begin_gtl
+ \@@_back_input:
+ \@@_tex_error:nV { missing-lbrace } \l_@@_tmpa_tl
+ \@@_print_action:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_insert_dollar_error:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_insert_dollar_error:
+ {
+ \@@_back_input:
+ \@@_back_input:n { $ } % $
+ \@@_error:nnnnn { missing-dollar } { } { } { } { }
+ \@@_print_action:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Macro calls}
+%
+% \begin{macro}[EXP]
+% {
+% \@@_macro_prefix:N,
+% \@@_macro_parameter:N,
+% \@@_macro_replacement:N
+% }
+% \begin{macrocode}
+\use:x
+ {
+ \exp_not:n { \cs_new:Npn \@@_macro_split_do:NN #1 }
+ {
+ \exp_not:n { \exp_after:wN \@@_macro_split_do:wN }
+ \exp_not:n { \token_to_meaning:N #1 \q_mark { } }
+ \tl_to_str:n { : } \exp_not:n { -> \q_mark \use_none:nnnn }
+ \exp_not:N \q_stop
+ }
+ \exp_not:n { \cs_new:Npn \@@_macro_split_do:wN }
+ \exp_not:n {#1} \tl_to_str:n { : } \exp_not:n { #2 -> }
+ \exp_not:n { #3 \q_mark #4 #5 \q_stop #6 }
+ { \exp_not:n { #4 #6 {#1} {#2} {#3} } }
+ }
+\cs_new:Npn \@@_macro_prefix:N #1
+ { \@@_macro_split_do:NN #1 \use_i:nnn }
+\cs_new:Npn \@@_macro_parameter:N #1
+ { \@@_macro_split_do:NN #1 \use_ii:nnn }
+\cs_new:Npn \@@_macro_replacement:N #1
+ { \@@_macro_split_do:NN #1 \use_iii:nnn }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: redoc
+% \begin{macro}{\@@_macro_call:}
+% \begin{macro}
+% {
+% \@@_macro_call_safe:,
+% \@@_macro_call_quick:,
+% \@@_macro_call_quick_loop:NNN,
+% \@@_macro_call_quick_runaway:Nw,
+% }
+% Macros are simply expanded once. We cannot determine precisely
+% which tokens a macro will need for its parameters, but we know that
+% it must form a balanced token list. Thus we can be safe by
+% extracting the longest balanced prefix in the input and working with
+% that.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_macro_call:
+ {
+ \bool_if:NTF \g_@@_speedup_macros_bool
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ {^ \exp_after:wN \@@_macro_parameter:N \l_@@_head_tl }
+ \@@_tl_if_in:ooTF \c_@@_parameters_tl \l_@@_tmpa_tl
+ { \@@_macro_call_quick: } { \@@_macro_call_safe: }
+ }
+ { \@@_macro_call_safe: }
+ \exp_args:NV \@@_back_input:o \l_@@_head_tl
+ \@@_print_expansion:
+ }
+\cs_new_protected:Npn \@@_macro_call_safe:
+ {
+ \@@_input_gpop_tl:N \l_@@_tmpa_tl
+ \tl_put_right:NV \l_@@_head_tl \l_@@_tmpa_tl
+ }
+\cs_new_protected:Npn \@@_macro_call_quick:
+ {
+ \exp_after:wN \@@_macro_call_quick_loop:NNN \l_@@_tmpa_tl
+ { ? \use_none_delimit_by_q_stop:w } \q_stop
+ }
+\cs_new_protected:Npn \@@_macro_call_quick_loop:NNN #1#2#3
+ {
+ \use_none:n #2
+ \@@_input_gpop_item:NF \l_@@_tmpa_tl
+ { \@@_macro_call_quick_runaway:Nw #3 }
+ \tl_put_right:Nx \l_@@_head_tl
+ { { \exp_not:V \l_@@_tmpa_tl } }
+ \@@_macro_call_quick_loop:NNN
+ #3
+ }
+\cs_new_protected:Npn \@@_macro_call_quick_runaway:Nw #1#2 \q_stop
+ {
+ \@@_error:nxxxx { runaway-macro-parameter }
+ { \tl_to_str:N \l_@@_head_tl } { \tl_to_str:n {#1} } { } { }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Expand next token}
+%
+% \begin{macro}{\@@_expand_do:N}
+% The argument is a command that will almost always be run to continue
+% a loop whose aim is to find the next non-expandable token, for
+% various purposes. The only case where we will end up grabbing the
+% argument is to suppress the loop by \cs{@@_noexpand:N}.
+% \begin{itemize}
+% \item \cs{@@_get_x_next:} when \TeX{} is looking for the first
+% non-expandable token in the main loop or when looking for numbers,
+% optional spaces etc.
+% \item \cs{@@_get_x_or_protected:} at the start of an alignment cell.
+% \item \cs{@@_get_token_xdef:} in the replacement text of \tn{edef}
+% and \tn{xdef}.
+% \item \cs{@@_get_token_x:} in the argument of \tn{message} and the
+% like.
+% \item \cs{prg_do_nothing:} in \cs{@@_expandafter:} namely after
+% \tn{expandafter}.
+% \end{itemize}
+% We mimick \TeX{}'s structure, distinguishing macros from other
+% commands because we find macro arguments very differently from
+% primitives.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_expand_do:N
+ {
+ \@@_set_action_text:
+ \bool_if:NT \g_@@_internal_debug_bool
+ {
+ \@@_set_cmd:
+ \@@_exp_args:Nx \iow_term:n { Exp:~\int_to_arabic:n { \l_@@_head_cmd_int } }
+ }
+ \token_if_macro:NTF \l_@@_head_token
+ { \@@_macro_call: }
+ { \@@_expand_nonmacro: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_expand_nonmacro:}
+% The token is a primitive. We find its (cleaned-up) \tn{meaning},
+% and call the function implementing that expansion. If we do not
+% recognize the meaning then it is probably an unknown primitive.
+% Then do something similar to what we do for macros: get all tokens
+% that are not too unlikely to appear in the arguments of the
+% primitive and expand the resulting token list once before putting it
+% back into the input stream.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_expand_nonmacro:
+ {
+ \@@_set_cmd_aux_meaning:
+ \@@_set_cmd_aux_primitive:oTF { \l_@@_head_meaning_tl }
+ {
+ \cs_if_exist_use:cF
+ { @@_expandable_ \int_use:N \l_@@_head_cmd_int : }
+ { \@@_error:nxxxx { internal } { expandable } { } { } { } }
+ }
+ {
+ \@@_error:nxxxx { unknown-primitive }
+ { \l_@@_head_meaning_tl } { } { } { }
+ \@@_input_gpop_tl:N \l_@@_tmpa_tl
+ \tl_put_right:NV \l_@@_head_tl \l_@@_tmpa_tl
+ \exp_args:NV \@@_back_input:o \l_@@_head_tl
+ \@@_print_expansion:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_x_next:}
+% Get a token. If it is expandable, then expand it, and repeat. This
+% function does not set the |cmd| and |char| integers. It is the
+% basis of all routines that look for keywords, numbers, equal signs,
+% filenames, optional spaces etc (in the language of \LaTeX3 these are
+% situations where \TeX{} \enquote{\texttt{f}-expands}). It is also
+% the basis of the \cs{@@_main_loop:}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_x_next:
+ {
+ \@@_get_next:
+ \@@_token_if_expandable:NT \l_@@_head_token
+ { \@@_expand_do:N \@@_get_x_next: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_x_or_protected:}
+% Get a token. If it is expandable, but not protected, then expand
+% it, and repeat. This function does not set the |cmd| and |char|
+% integers. This function is not used at present: it will be used at
+% the start of alignment cells.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_x_or_protected:
+ {
+ \@@_get_next:
+ \@@_token_if_protected:NF \l_@@_head_token
+ { \@@_expand_do:N \@@_get_x_or_protected: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_token_xdef:, \@@_get_token_x:}
+% These are similar to \cs{@@_get_x_next:}, for use when reading the
+% replacement text of \tn{edef}/\tn{xdef} or the argument of a
+% primitive like \tn{message} that should be expanded as we read
+% tokens. Loop until finding a non-expandable token (or protected
+% macro).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_token_xdef:
+ {
+ \@@_get_next:
+ \@@_token_if_protected:NF \l_@@_head_token
+ { \@@_expand_do:N \@@_get_token_xdef: }
+ }
+\cs_new_protected:Npn \@@_get_token_x:
+ {
+ \@@_get_next:
+ \@@_token_if_protected:NF \l_@@_head_token
+ { \@@_expand_do:N \@@_get_token_x: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Basic scanning subroutines}
+%
+% ^^A todo: implement |test_no_ligatures|?
+% ^^A todo: implement |get_tag_code|?
+%
+% \begin{macro}{\@@_get_x_non_blank:}
+% This function does not set the |cmd| and |char| integers.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_x_non_blank:
+ {
+ \@@_get_x_next:
+ \token_if_eq_catcode:NNT \l_@@_head_token \c_space_token
+ { \@@_get_x_non_blank: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_get_x_non_relax:}
+% This function does not set the |cmd| and |char| integers.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_x_non_relax:
+ {
+ \@@_get_x_next:
+ \token_if_eq_meaning:NNTF \l_@@_head_token \scan_stop:
+ { \@@_get_x_non_relax: }
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \@@_special_relax:
+ { \@@_get_x_non_relax: }
+ {
+ \token_if_eq_catcode:NNT \l_@@_head_token \c_space_token
+ { \@@_get_x_non_relax: }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_skip_optional_space:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_skip_optional_space:
+ {
+ \@@_get_x_next:
+ \token_if_eq_catcode:NNF \l_@@_head_token \c_space_token
+ { \@@_back_input: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_optional_equals:}
+% See \TeX{}'s |scan_optional_equals|. In all cases we forcefully
+% insert an equal sign in the output, because this sign is required,
+% as \cs{@@_scan_something_internal:n} leaves raw numbers in
+% the previous-input sequence.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_optional_equals:
+ {
+ \@@_get_x_non_blank:
+ \tl_if_eq:NNTF \l_@@_head_tl \c_@@_eq_tl
+ { \@@_prev_input:n { = } }
+ {
+ \@@_prev_input_silent:n { = }
+ \@@_back_input:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_left_brace:}
+% The presence of \tn{relax} is allowed before a begin-group token.
+% If there is no begin-group token, insert one, produce an error, and
+% scan that begin-group using \cs{@@_get_next:}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_left_brace:
+ {
+ \@@_get_x_non_relax:
+ \token_if_eq_catcode:NNF \l_@@_head_token \c_group_begin_token
+ {
+ \@@_insert_group_begin_error:
+ \@@_get_next:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_keyword:n}
+% \begin{macro}[TF]{\@@_scan_keyword:n}
+% \begin{macro}
+% {
+% \@@_scan_keyword_loop:NNN,
+% \@@_scan_keyword_test:NNTF,
+% \@@_scan_keyword_true:,
+% \@@_scan_keyword_false:w
+% }
+%
+% The details of how \TeX{} looks for keywords are quite tricky to get
+% right, in particular with respect to expansion, case-insensitivity,
+% and spaces. We get rid of the case issue by requiring the keyword
+% to be given in both cases, intertwined: for instance,
+% \cs{@@_scan_keyword:n} |{| |pPtT| |}|. Then loop through pairs of
+% letters (which should be matching lowercase and uppercase letters).
+% The looping auxiliary takes three arguments, the first of which is a
+% boolean, \texttt{true} if spaces are allowed (no letter of the
+% keyword has been found yet). At each iteration, get a token, with
+% expansion, and test whether it is a non-active character equal (in
+% character code) to either letter of the pair: this happens if the
+% token is not ``definable'' (neither a control sequence nor an active
+% character) and it has the right string representation\ldots{} well,
+% it could also be doubled (macro parameter character), hence we look
+% at the first character only; spaces become an empty string, but this
+% works out because no keyword contains a space. So, at each
+% iteration, if the token is the correct non-active character, add it
+% to the previous-input sequence (as a generalized token list since
+% keywords may match begin-group or end-group characters), and
+% otherwise break with \cs{@@_scan_keyword_false:w}, unless we are
+% still at the beginning of the keyword and the token is a space.
+% When the loop reaches the end of the keyword letter pairs, complain
+% if there were an odd number of letters, and otherwise conclude the
+% loop with \cs{@@_scan_keyword_true:}, which stores the keyword,
+% converted to a string. Note that \TeX{}'s skipping of leading
+% spaces here must be intertwined with the search for keyword, as is
+% shown by the (plain \TeX{}) example
+% \begin{verbatim}
+% \lccode32=`f \lowercase{\def\fspace{ }}
+% \skip0=1pt plus 1 \fspace il\relax
+% \message{\the\skip0} % => 1pt plus 1fil
+% \end{verbatim}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_keyword:n #1
+ { \@@_scan_keyword:nTF {#1} { } { } }
+\prg_new_protected_conditional:Npnn \@@_scan_keyword:n #1
+ { T , F , TF }
+ {
+ \@@_prev_input_gpush_gtl:
+ \@@_scan_keyword_loop:NNN \c_true_bool
+ #1 \q_recursion_tail \q_recursion_tail \q_recursion_stop
+ }
+\cs_new_protected:Npn \@@_scan_keyword_loop:NNN #1#2#3
+ {
+ \quark_if_recursion_tail_stop_do:nn {#2}
+ { \@@_scan_keyword_true: }
+ \quark_if_recursion_tail_stop_do:nn {#3}
+ { \@@_error:nxxxx { internal } { odd-keyword-length } { } { } { } }
+ \@@_get_x_next:
+ \@@_scan_keyword_test:NNTF #2#3
+ {
+ \@@_prev_input_gtl:N \l_@@_head_gtl
+ \@@_scan_keyword_loop:NNN \c_false_bool
+ }
+ {
+ \token_if_eq_catcode:NNF \l_@@_head_token \c_space_token
+ { \@@_scan_keyword_false:w }
+ \bool_if:NF #1
+ { \@@_scan_keyword_false:w }
+ \@@_scan_keyword_loop:NNN #1#2#3
+ }
+ }
+\prg_new_protected_conditional:Npnn \@@_scan_keyword_test:NN #1#2
+ { TF }
+ {
+ \@@_gtl_if_head_is_definable:NTF \l_@@_head_gtl
+ { \prg_return_false: }
+ {
+ \str_if_eq:eeTF
+ { \str_head:f { \gtl_to_str:N \l_@@_head_gtl } } {#1}
+ { \prg_return_true: }
+ {
+ \str_if_eq:eeTF
+ { \str_head:f { \gtl_to_str:N \l_@@_head_gtl } } {#2}
+ { \prg_return_true: }
+ { \prg_return_false: }
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_scan_keyword_true:
+ {
+ \@@_prev_input_gpop_gtl:N \l_@@_tmpb_gtl
+ \@@_prev_input:x { \gtl_to_str:N \l_@@_tmpb_gtl }
+ \prg_return_true:
+ }
+\cs_new_protected:Npn \@@_scan_keyword_false:w
+ #1 \q_recursion_stop
+ {
+ \@@_back_input:
+ \@@_prev_input_gpop_gtl:N \l_@@_tmpb_gtl
+ \@@_back_input_gtl:N \l_@@_tmpb_gtl
+ \prg_return_false:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_to:}
+% Used when |to| is mandatory: after \tn{read} or \tn{readline} and
+% after \tn{vsplit}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_to:
+ {
+ \@@_scan_keyword:nF { tToO }
+ {
+ \@@_error:nnnnn { missing-to } { } { } { } { }
+ \@@_prev_input:n { to }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_font_ident:}
+% Find a font identifier.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_font_ident:
+ {
+ \@@_get_x_non_blank:
+ \@@_set_cmd:
+ \int_case:nnF \l_@@_head_cmd_int
+ {
+ { \@@_tex_use:n { def_font } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { letterspace_font } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { pdf_copy_font } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { set_font } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { def_family } }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_int:
+ }
+ }
+ {
+ \@@_error:nnnnn { missing-font-id } { } { } { } { }
+ \@@_back_input:
+ \@@_prev_input:n { \@@_nullfont: }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_font_int:}
+% Find operands for one of \tn{hyphenchar}'s friends (command code
+% |assign_font_int=78|).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_font_int:
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 0 } { \@@_scan_font_ident: }
+ { 1 } { \@@_scan_font_ident: }
+ { 6 } { \@@_scan_font_ident: }
+ }
+ { \@@_scan_font_ident: \@@_scan_int: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_font_dimen:}
+% Find operands for \tn{fontdimen}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_font_dimen:
+ {
+ \@@_scan_int:
+ \@@_scan_font_ident:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: rename this function because all other scan functions do get_x_next themselves.
+% \begin{macro}{\@@_scan_something_internal:n}
+% \begin{macro}{\@@_scan_something_aux:nwn}
+% Receives an (explicit) \enquote{level} argument:
+% \begin{itemize}
+% \item |int_val=0| for integer values;
+% \item |dimen_val=1| for dimension values;
+% \item |glue_val=2| for glue specifications;
+% \item |mu_val=3| for math glue specifications;
+% \item |ident_val=4| for font identifiers (this never happens);
+% \item |tok_val=5| for token lists (after |\the| or |\showthe|).
+% \end{itemize}
+% Scans something internal, and places its value, converted to the
+% given level, to the right of the last item of
+% the previous-input sequence, then sets \cs{g_@@_val_level_int} to the
+% found level (level before conversion, so this may be higher than
+% requested).
+%
+% From \cs{@@_thing_case:}, get the information about what level is
+% produced by the given token once it has received all its operands
+% (head of \cs{l_@@_tmpa_tl}), and about what to do to find those
+% operands (tail of \cs{l_@@_tmpa_tl}). If the first token may not
+% appear after \tn{the} at all, \cs{@@_thing_case:} gives level~$8$.
+%
+% If the argument (|#3|~in the auxiliary) is $<4$ but the level that
+% will be produced (|#1|~in the auxiliary) is $\geq 4$ (that is,
+% $4$, $5$, or $8$) complain about a missing number and insert a
+% zero dimension, to get exactly \TeX{}'s error recovery. If the
+% level produced is~$8$, complain that |\the| cannot do this.
+%
+% Otherwise, scan the arguments (in a new input level). If both the
+% argument and the level produced are $<4$, then get the value with
+% \cs{@@_thing_use_get:nnNN} which downgrades from glue to dimension
+% to integer and produces the |incompatible-units| error if needed.
+% The only remaining case is that the argument is $5$ (since $4$ is
+% never used) and the level produced is that or less: then the value
+% found is used with \cs{@@_the:w}.
+%
+% Finally, tell the user the tokens that have been found (if there
+% was a single token, its meaning as well) and their value. Use |=>|
+% rather than |=| because the value displayed is the value used, not
+% the actual value (this matters in constructions such as
+% |\parindent=\parskip| where a skip or a dimen is downgraded to a
+% dimen or an int, or when there was an error).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_something_internal:n #1
+ {
+ \@@_set_cmd:
+ \@@_set_action_text:
+ \tl_set:Nf \l_@@_tmpa_tl { \@@_thing_case: }
+ \exp_after:wN \@@_scan_something_aux:nwn
+ \l_@@_tmpa_tl \q_stop {#1}
+ }
+\cs_new_protected:Npn \@@_scan_something_aux:nwn #1#2 \q_stop #3
+ {
+ \int_compare:nT { #3 < 4 <= #1 }
+ {
+ \@@_back_input:
+ \@@_tex_error:nV { missing-number } \l_@@_head_tl
+ \@@_thing_use_get:nnNN { 1 } {#3} \c_zero_dim \l_@@_tmpa_tl
+ \@@_scan_something_internal_auxii:Vn \l_@@_tmpa_tl { 1 }
+ \@@_break:w
+ }
+ \int_compare:nNnT {#1} = { 8 }
+ {
+ \@@_tex_error:nV { the-cannot } \l_@@_head_tl
+ \@@_scan_something_internal_auxii:nn 0 { 0 }
+ \@@_break:w
+ }
+ \tl_if_empty:nF {#2}
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ #2
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ }
+ \int_compare:nNnTF {#3} < { 4 }
+ { \@@_thing_use_get:nnNN {#1} {#3} \l_@@_head_tl \l_@@_tmpa_tl }
+ { \tl_set:Nx \l_@@_tmpa_tl { \@@_the:w \l_@@_head_tl } }
+ \@@_scan_something_internal_auxii:Vn \l_@@_tmpa_tl {#1}
+ \@@_break_point:
+ \int_compare:nNnT {#3} < { 4 } { \@@_print_action: }
+ }
+\cs_new_protected:Npn \@@_scan_something_internal_auxii:nn #1#2
+ {
+ \@@_prev_input_silent:n {#1}
+ \@@_set_action_text:
+ \@@_set_action_text:x
+ { \g_@@_action_text_str \use:n { ~ => ~ } \tl_to_str:n {#1} }
+ \int_gset:Nn \g_@@_val_level_int {#2}
+ }
+\cs_generate_variant:Nn \@@_scan_something_internal_auxii:nn { V }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% ^^A todo: \the can be followed by ignore_spaces
+% \begin{macro}[EXP]
+% {\@@_thing_case:, \@@_thing_last_item:, \@@_thing_register:}
+% This expands to a digit (the level generated by whatever token is
+% the current |head|), followed by some code to fetch necessary
+% operands. In most cases, this can be done by simply looking at the
+% |cmd| integer, but for |last_item|, |set_aux| and |register|, the level of the
+% token depends on the |char| integer. When the token is not allowed
+% after \tn{the} (or at any other position where
+% \cs{@@_scan_something_internal:n} is called), the resulting level
+% is~$8$, large enough so that the main function knows it is
+% forbidden.
+% \begin{macrocode}
+\cs_new:Npn \@@_thing_case:
+ {
+ \int_case:nnF \l_@@_head_cmd_int
+ {
+ { 68 } { 0 } % char_given
+ { 69 } { 0 } % math_given
+ { 70 } { \@@_thing_last_item: } % last_item
+ { 71 } { 5 \@@_scan_toks_register: } % toks_register
+ { 72 } { 5 } % assign_toks
+ { 73 } { 0 } % assign_int
+ { 74 } { 1 } % assign_dimen
+ { 75 } { 2 } % assign_glue
+ { 76 } { 3 } % assign_mu_glue
+ { 77 } { 1 \@@_scan_font_dimen: } % assign_font_dimen
+ { 78 } { 0 \@@_scan_font_int: } % assign_font_int
+ { 79 } { \@@_thing_set_aux: } % set_aux
+ { 80 } { 0 } % set_prev_graf
+ { 81 } { 1 } % set_page_dimen
+ { 82 } { 0 } % set_page_int
+ { 83 } { 1 \@@_scan_int: } % set_box_dimen
+ { 84 } { 0 \@@_scan_int: } % set_shape
+ { 85 } { 0 \@@_scan_int: } % def_code
+ { 86 } { 4 \@@_scan_int: } % def_family
+ { 87 } { 4 } % set_font
+ { 88 } { 4 } % def_font
+ { 89 } { \@@_thing_register: } % register
+ {101 } { 4 } % letterspace_font
+ {102 } { 4 } % pdf_copy_font
+ }
+ { 8 }
+ }
+\cs_new:Npn \@@_thing_set_aux:
+ { \int_compare:nNnTF \l_@@_head_char_int = { 1 } { 1 } { 0 } }
+\cs_new:Npn \@@_thing_last_item:
+ {
+ \int_compare:nNnTF \l_@@_head_char_int < { 26 }
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 1 } { 1 } % lastkern
+ { 2 } { 2 } % lastskip
+ }
+ { 0 } % other integer parameters
+ }
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 26 } { 0 \@@_scan_normal_glue: } % gluestretchorder
+ { 27 } { 0 \@@_scan_normal_glue: } % glueshrinkorder
+ { 28 } % fontcharwd
+ { 1 \@@_scan_font_ident: \@@_scan_int: }
+ { 29 } % fontcharht
+ { 1 \@@_scan_font_ident: \@@_scan_int: }
+ { 30 } % fontchardp
+ { 1 \@@_scan_font_ident: \@@_scan_int: }
+ { 31 } % fontcharic
+ { 1 \@@_scan_font_ident: \@@_scan_int: }
+ { 32 } { 1 \@@_scan_int: } % parshapelength
+ { 33 } { 1 \@@_scan_int: } % parshapeindent
+ { 34 } { 1 \@@_scan_int: } % parshapedimen
+ { 35 } { 1 \@@_scan_normal_glue: } % gluestretch
+ { 36 } { 1 \@@_scan_normal_glue: } % glueshrink
+ { 37 } { 2 \@@_scan_mu_glue: } % mutoglue
+ { 38 } { 3 \@@_scan_normal_glue: } % gluetomu
+ { 39 } % numepr
+ { 0 \@@_scan_expr:N \@@_scan_int: }
+ { 40 } % dimexpr
+ { 1 \@@_scan_expr:N \@@_scan_normal_dimen: }
+ { 41 } % glueexpr
+ { 2 \@@_scan_expr:N \@@_scan_normal_glue: }
+ { 42 } % muexpr
+ { 3 \@@_scan_expr:N \@@_scan_mu_glue: }
+ }
+ { }
+ }
+ }
+\cs_new:Npn \@@_thing_register:
+ {
+ \int_eval:n { \l_@@_head_char_int / 1 000 000 - 1 }
+ \int_compare:nNnT { \tl_tail:V \l_@@_head_char_int } = 0
+ { \@@_scan_int: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_toks_register:}
+% A case where getting operands is not completely trivial.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_toks_register:
+ {
+ \int_compare:nNnT \l_@@_head_char_int = 0
+ { \@@_scan_int: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_thing_use_get:nnNN}
+% Given a level found~|#1| and a target level~|#2| (both in $[0,3]$),
+% turn the token list |#3| into the desired level or less, and store
+% the result in |#4|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_thing_use_get:nnNN #1#2#3#4
+ {
+ \int_compare:nNnTF {#2} < { 3 }
+ {
+ \int_compare:nNnT {#1} = { 3 }
+ { \@@_tex_error:nV { incompatible-units } #3 }
+ \tl_set:Nx #4
+ {
+ \int_case:nn { \int_min:nn {#1} {#2} }
+ {
+ { 0 } \int_eval:n
+ { 1 } \dim_eval:n
+ { 2 } \skip_eval:n
+ }
+ { \int_compare:nNnT {#1} = { 3 } \tex_mutoglue:D #3 }
+ }
+ }
+ {
+ \int_case:nnF {#1}
+ {
+ { 0 } { \tl_set:Nx #4 { \int_eval:n {#3} } }
+ { 3 } { \tl_set:Nx #4 { \muskip_eval:n {#3} } }
+ }
+ {
+ \@@_tex_error:nV { incompatible-units } #3
+ \tl_set:Nx #4 { \muskip_eval:n { \tex_gluetomu:D #3 } }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: comment
+% \begin{macro}{\@@_scan_expr:N}
+% \begin{macro}{\@@_scan_expr_aux:NN, \@@_scan_factor:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_expr:N #1
+ { \@@_scan_expr_aux:NN #1 \c_false_bool }
+\cs_new_protected:Npn \@@_scan_expr_aux:NN #1#2
+ {
+ \@@_get_x_non_blank:
+ \@@_scan_factor:N #1
+ \@@_scan_expr_op:NN #1#2
+ }
+\cs_new_protected:Npn \@@_scan_expr_op:NN #1#2
+ {
+ \@@_get_x_non_blank:
+ \tl_case:NnF \l_@@_head_tl
+ {
+ \c_@@_plus_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_expr_aux:NN #1#2
+ }
+ \c_@@_minus_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_expr_aux:NN #1#2
+ }
+ \c_@@_times_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_non_blank:
+ \@@_scan_factor:N \@@_scan_int:
+ \@@_scan_expr_op:NN #1#2
+ }
+ \c_@@_over_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_non_blank:
+ \@@_scan_factor:N \@@_scan_int:
+ \@@_scan_expr_op:NN #1#2
+ }
+ \c_@@_rp_tl
+ {
+ \bool_if:NTF #2
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_back_input: }
+ }
+ }
+ {
+ \bool_if:NTF #2
+ {
+ \@@_error:nnnnn { missing-rparen } { } { } { } { }
+ \@@_back_input:
+ \@@_prev_input:V \c_@@_rp_tl
+ }
+ {
+ \token_if_eq_meaning:NNF \l_@@_head_token \scan_stop:
+ { \@@_back_input: }
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_scan_factor:N #1
+ {
+ \tl_if_eq:NNTF \l_@@_head_tl \c_@@_lp_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_expr_aux:NN #1 \c_true_bool
+ }
+ {
+ \@@_back_input:
+ #1
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_signs:}
+% Skips blanks, scans signs, and places them to the right of the last
+% item of \cs{@@_prev_input:n}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_signs:
+ {
+ \@@_get_x_non_blank:
+ \tl_if_eq:NNTF \l_@@_head_tl \c_@@_plus_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_signs:
+ }
+ {
+ \tl_if_eq:NNT \l_@@_head_tl \c_@@_minus_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_signs:
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_int:}
+% \begin{macro}
+% {\@@_scan_int_char:, \@@_scan_int_lq:, \@@_scan_int_explicit:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_int:
+ {
+ \@@_scan_signs:
+ \@@_set_cmd:
+ \@@_cmd_if_internal:TF
+ { \@@_scan_something_internal:n { 0 } }
+ { \@@_scan_int_char: }
+ }
+\cs_new_protected:Npn \@@_scan_int_char:
+ {
+ \tl_case:NnF \l_@@_head_tl
+ {
+ \c_@@_lq_tl { \@@_scan_int_lq: }
+ \c_@@_rq_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_next:
+ \@@_scan_int_explicit:Nn \c_false_bool { ' }
+ }
+ \c_@@_dq_tl
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_next:
+ \@@_scan_int_explicit:Nn \c_false_bool { " }
+ }
+ }
+ { \@@_scan_int_explicit:Nn \c_false_bool { } }
+ }
+\cs_new_protected:Npn \@@_scan_int_lq:
+ {
+ \@@_get_next:
+ \@@_gtl_if_head_is_definable:NF \l_@@_head_gtl
+ {
+ \tl_set:Nx \l_@@_head_tl
+ { \@@_token_to_char:N \l_@@_head_token }
+ }
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \int_eval:n { \exp_after:wN ` \l_@@_head_tl } }
+ \@@_prev_input_silent:V \l_@@_tmpa_tl
+ \@@_print_action:x
+ { ` \gtl_to_str:N \l_@@_head_gtl = \l_@@_tmpa_tl }
+ \@@_skip_optional_space:
+ }
+\cs_new_protected:Npn \@@_scan_int_explicit:Nn #1#2
+ {
+ \if_int_compare:w 1
+ < #2 1 \exp_after:wN \exp_not:N \l_@@_head_tl \exp_stop_f:
+ \exp_after:wN \use_i:nn
+ \else:
+ \exp_after:wN \use_ii:nn
+ \fi:
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_next:
+ \@@_scan_int_explicit:Nn \c_true_bool {#2}
+ }
+ {
+ \token_if_eq_catcode:NNF \l_@@_head_token \c_space_token
+ { \@@_back_input: }
+ \bool_if:NF #1
+ {
+ \@@_tex_error:nV { missing-number } \l_@@_head_tl
+ \@@_prev_input:n { 0 }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_normal_dimen:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_normal_dimen:
+ { \@@_scan_dimen:nN { 2 } \c_false_bool }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_dimen:nN}
+% The first argument is $2$ if the unit may not be |mu| and $3$ if
+% the unit must be |mu| (or |fil|). The second argument is
+% \cs{c_true_bool} if |fil|, |fill|, |filll| are permitted, and is
+% otherwise |false|. These arguments are similar to those of
+% \TeX{}'s own |scan_dimen| procedure, in which |mu| is |bool(#1=3)|
+% and |inf| is |#2|. The third argument of this procedure is omitted
+% here, as the corresponding shortcut is provided as a separate
+% function, \cs{@@_scan_dim_unit:nN}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_dimen:nN #1#2
+ {
+ \@@_scan_signs:
+ \@@_prev_input_gpush:
+ \@@_set_cmd:
+ \@@_cmd_if_internal:TF
+ {
+ \int_compare:nNnTF {#1} = { 3 }
+ { \@@_scan_something_internal:n { 3 } }
+ { \@@_scan_something_internal:n { 1 } }
+ \int_compare:nNnT \g_@@_val_level_int = { 0 }
+ { \@@_scan_dim_unit:nN {#1} #2 }
+ }
+ { \@@_scan_dimen_char:nN {#1} #2 }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_prev_input_silent:V \l_@@_head_tl
+ }
+\cs_new_protected:Npn \@@_scan_dimen_char:nN #1#2
+ {
+ \tl_if_eq:NNT \l_@@_head_tl \c_@@_comma_tl
+ { \tl_set_eq:NN \l_@@_head_tl \c_@@_point_tl }
+ \tl_if_eq:NNTF \l_@@_head_tl \c_@@_point_tl
+ {
+ \@@_prev_input:n { . }
+ \@@_scan_decimal_loop:
+ }
+ {
+ \@@_tl_if_in:ooTF { 0123456789 } \l_@@_head_tl
+ {
+ \@@_back_input:
+ \@@_scan_int:
+ \tl_if_eq:NNT \l_@@_head_tl \c_@@_comma_tl
+ { \tl_set_eq:NN \l_@@_head_tl \c_@@_point_tl }
+ \tl_if_eq:NNT \l_@@_head_tl \c_@@_point_tl
+ {
+ \@@_input_gpop:N \l_@@_tmpb_gtl
+ \@@_prev_input:n { . }
+ \@@_scan_decimal_loop:
+ }
+ }
+ {
+ \@@_back_input:
+ \@@_scan_int:
+ }
+ }
+ \@@_scan_dim_unit:nN {#1} #2
+ }
+\cs_new_protected:Npn \@@_scan_dim_unit:nN #1#2
+ {
+ \bool_if:NT #2
+ {
+ \@@_scan_keyword:nT { fFiIlL }
+ {
+ \@@_scan_inf_unit_loop:
+ \@@_break:w
+ }
+ }
+ \@@_get_x_non_blank:
+ \@@_set_cmd:
+ \@@_cmd_if_internal:TF
+ {
+ \@@_prev_input_gpush:
+ \@@_scan_something_internal:n {#1}
+ \@@_prev_input_join_get:nN {#1} \l_@@_tmpa_tl
+ \@@_prev_input_gpush:N \l_@@_tmpa_tl
+ \@@_break:w
+ }
+ { \@@_back_input: }
+ \int_compare:nNnT {#1} = { 3 }
+ {
+ \@@_scan_keyword:nT { mMuU } { \@@_break:w }
+ \@@_tex_error:nV { missing-mu } \l_@@_head_tl
+ \@@_prev_input:n { mu }
+ \@@_break:w
+ }
+ \@@_scan_keyword:nT { eEmM } { \@@_break:w }
+ \@@_scan_keyword:nT { eExX } { \@@_break:w }
+ \@@_scan_keyword:nT { pPxX } { \@@_break:w }
+ \@@_scan_keyword:nT { tTrRuUeE }
+ { \@@_prepare_mag: }
+ \@@_scan_keyword:nT { pPtT } { \@@_break:w }
+ \@@_scan_keyword:nT { iInN } { \@@_break:w }
+ \@@_scan_keyword:nT { pPcC } { \@@_break:w }
+ \@@_scan_keyword:nT { cCmM } { \@@_break:w }
+ \@@_scan_keyword:nT { mMmM } { \@@_break:w }
+ \@@_scan_keyword:nT { bBpP } { \@@_break:w }
+ \@@_scan_keyword:nT { dDdD } { \@@_break:w }
+ \@@_scan_keyword:nT { cCcC } { \@@_break:w }
+ \@@_scan_keyword:nT { nNdD } { \@@_break:w }
+ \@@_scan_keyword:nT { nNcC } { \@@_break:w }
+ \@@_scan_keyword:nT { sSpP } { \@@_break:w }
+ \@@_tex_error:nV { missing-pt } \l_@@_head_tl
+ \@@_prev_input:n { pt }
+ \@@_break_point:
+ }
+\cs_new_protected:Npn \@@_scan_inf_unit_loop:
+ { \@@_scan_keyword:nT { lL } { \@@_scan_inf_unit_loop: } }
+\cs_new_protected:Npn \@@_scan_decimal_loop:
+ {
+ \@@_get_x_next:
+ \tl_if_empty:NTF \l_@@_head_tl
+ { \use_ii:nn }
+ { \@@_tl_if_in:ooTF { 0123456789 } \l_@@_head_tl }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_decimal_loop:
+ }
+ {
+ \token_if_eq_catcode:NNF \l_@@_head_token \c_space_token
+ { \@@_back_input: }
+ \@@_prev_input_silent:n { ~ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_normal_glue:, \@@_scan_mu_glue:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_normal_glue:
+ { \@@_scan_glue:n { 2 } }
+\cs_new_protected:Npn \@@_scan_mu_glue:
+ { \@@_scan_glue:n { 3 } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_glue:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_glue:n #1
+ {
+ \@@_prev_input_gpush:
+ \@@_scan_signs:
+ \@@_prev_input_gpush:
+ \@@_set_cmd:
+ \@@_cmd_if_internal:TF
+ {
+ \@@_scan_something_internal:n {#1}
+ \int_case:nnF \g_@@_val_level_int
+ {
+ { 0 } { \@@_scan_dim_unit:nN {#1} \c_false_bool }
+ { 1 } { }
+ }
+ { \@@_break:w }
+ }
+ { \@@_back_input: \@@_scan_dimen:nN {#1} \c_false_bool }
+ \@@_prev_input_join_get:nN {#1} \l_@@_tmpa_tl
+ \@@_prev_input_gpush:
+ \@@_prev_input_gpush:N \l_@@_tmpa_tl
+ \@@_scan_keyword:nT { pPlLuUsS }
+ { \@@_scan_dimen:nN {#1} \c_true_bool }
+ \@@_scan_keyword:nT { mMiInNuUsS }
+ { \@@_scan_dimen:nN {#1} \c_true_bool }
+ \@@_break_point:
+ \@@_prev_input_join_get:nN {#1} \l_@@_tmpa_tl
+ \@@_prev_input_silent:V \l_@@_tmpa_tl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: allow \input".. .."
+% \begin{macro}{\@@_scan_file_name:}
+% ^^A todo: area_delimiter and ext_delimiter ??
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_file_name:
+ {
+ \bool_gset_true:N \g_@@_name_in_progress_bool
+ \@@_get_x_non_blank:
+ \@@_scan_file_name_loop:
+ \bool_gset_false:N \g_@@_name_in_progress_bool
+ \@@_prev_input_silent:n { ~ }
+ }
+\cs_new_protected:Npn \@@_scan_file_name_loop:
+ {
+ \@@_gtl_if_head_is_definable:NTF \l_@@_head_gtl
+ { \@@_back_input: }
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \@@_token_to_char:N \l_@@_head_token }
+ \tl_if_eq:NNF \l_@@_tmpa_tl \c_space_tl
+ {
+ \@@_prev_input_silent:V \l_@@_tmpa_tl
+ \@@_get_x_next:
+ \@@_scan_file_name_loop:
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_r_token:}
+% This is analogous to \TeX{}'s |get_r_token|. We store in
+% \cs{l_@@_defined_tl} the token which we found, as this is what will
+% be defined by the next assignment.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_r_token:
+ {
+ \bool_do_while:nn
+ { \tl_if_eq_p:NN \l_@@_head_tl \c_space_tl }
+ { \@@_get_next: }
+ \@@_gtl_if_head_is_definable:NF \l_@@_head_gtl
+ {
+ \@@_error:nnnnn { missing-cs } { } { } { } { }
+ \@@_back_input:
+ \tl_set:Nn \l_@@_head_tl { \@@_inaccessible:w }
+ }
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \tl_set_eq:NN \l_@@_defined_tl \l_@@_head_tl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: hash doubling is wrong
+% \begin{macro}{\@@_scan_toks_to_str:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_toks_to_str:
+ {
+ \@@_prev_input_gpush:
+ \@@_scan_toks:NN \c_false_bool \c_true_bool
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_prev_input_silent:x
+ { { \exp_after:wN \tl_to_str:n \l_@@_tmpa_tl } }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_pdf_ext_toks:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_pdf_ext_toks:
+ {
+ \@@_prev_input_gpush:
+ \@@_scan_toks:NN \c_false_bool \c_true_bool
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_prev_input_silent:x
+ { { \exp_not:N \exp_not:n \exp_not:V \l_@@_tmpa_tl } }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: provide separate functions for defs (avoid hash doubling).
+% \begin{macro}{\@@_scan_toks:NN}
+% The boolean |#1| is true if we are making a definition (then we
+% start by scanning the parameter text), false if we are simply
+% scanning a general text. The boolean |#2| is true if we need to
+% expand, false otherwise (for instance for \tn{lowercase}).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_toks:NN #1#2
+ {
+ \bool_if:NT #1 { \@@_scan_param: }
+ \@@_scan_left_brace:
+ \bool_if:NTF #2
+ { \@@_scan_group_x:N #1 }
+ { \@@_scan_group_n:N #1 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_param:}
+% \begin{macro}{\@@_scan_param_aux:}
+% Collect the parameter text into \cs{l_@@_tmpa_tl}, and when seeing
+% either a begin-group or an end-group character, put it back into the
+% input, stop looping, and put what we collected into
+% \cs{l_@@_defining_tl} and into the |prev_input|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_param:
+ {
+ \tl_clear:N \l_@@_tmpa_tl
+ \@@_scan_param_aux:
+ \tl_put_right:NV \l_@@_defining_tl \l_@@_tmpa_tl
+ \@@_prev_input_silent:V \l_@@_tmpa_tl
+ }
+\cs_new_protected:Npn \@@_scan_param_aux:
+ {
+ \@@_get_next:
+ \tl_concat:NNN \l_@@_tmpa_tl
+ \l_@@_tmpa_tl \l_@@_head_tl
+ \tl_if_empty:NTF \l_@@_head_tl
+ { \@@_back_input: } { \@@_scan_param_aux: }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_group_n:N}
+% The boolean |#1| is true if we are making a definition, false
+% otherwise. In both cases put the open brace back and grab the first
+% item. The only difference is that when making a definition we store
+% the data into \cs{l_@@_defining_tl} as well.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_group_n:N #1
+ {
+ \gtl_set_eq:NN \l_@@_head_gtl \c_group_begin_gtl
+ \@@_back_input:
+ \@@_input_gpop_item:NF \l_@@_head_tl
+ {
+ \@@_error:nnnnn { runaway-text } { } { } { } { }
+ \@@_exit_hard:w
+ }
+ \tl_set:Nx \l_@@_head_tl { { \exp_not:V \l_@@_head_tl } }
+ \bool_if:NT #1
+ { \tl_put_right:NV \l_@@_defining_tl \l_@@_head_tl }
+ \@@_prev_input_silent:V \l_@@_head_tl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_group_x:N}
+% The boolean |#1| is true if we are making a definition, false
+% otherwise.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_group_x:N #1
+ {
+ \@@_input_gpop_tl:N \l_@@_head_tl
+ \@@_back_input:V \l_@@_head_tl
+ \bool_if:NTF #1
+ {
+ \@@_prev_input_silent:V \c_left_brace_str
+ \tl_put_right:Nn \l_@@_defining_tl { { \if_false: } \fi: }
+ \@@_scan_group_xdef:n { 1 }
+ }
+ {
+ \@@_prev_input_gpush_gtl:
+ \@@_prev_input_gtl:N \l_@@_head_gtl
+ \@@_scan_group_x:n { 1 }
+ \@@_prev_input_gpop_gtl:N \l_@@_tmpb_gtl
+ \@@_prev_input_silent:x
+ { \gtl_left_tl:N \l_@@_tmpb_gtl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_group_xdef:n}
+% This is to scan the replacement text of an \tn{edef} or \tn{xdef}.
+% The integer |#1| counts the brace balance.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_group_xdef:n #1
+ {
+ \@@_get_token_xdef:
+ \tl_if_empty:NTF \l_@@_head_tl
+ {
+ \gtl_if_head_is_group_begin:NTF \l_@@_head_gtl
+ {
+ \@@_prev_input_silent:V \c_left_brace_str
+ \tl_put_right:Nn \l_@@_defining_tl { { \if_false: } \fi: }
+ \@@_scan_group_xdef:f { \int_eval:n { #1 + 1 } }
+ }
+ {
+ \@@_prev_input_silent:V \c_right_brace_str
+ \tl_put_right:Nn \l_@@_defining_tl { \if_false: { \fi: } }
+ \int_compare:nNnF {#1} = 1
+ { \@@_scan_group_xdef:f { \int_eval:n { #1 - 1 } } }
+ }
+ }
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \tl_put_right:Nx \l_@@_defining_tl
+ { \exp_not:N \exp_not:N \exp_not:V \l_@@_head_tl }
+ \@@_scan_group_xdef:n {#1}
+ }
+ }
+\cs_generate_variant:Nn \@@_scan_group_xdef:n { f }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_group_x:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_group_x:n #1
+ {
+ \@@_get_token_x:
+ \@@_prev_input_gtl:N \l_@@_head_gtl
+ \tl_if_empty:NTF \l_@@_head_tl
+ {
+ \gtl_if_head_is_group_begin:NTF \l_@@_head_gtl
+ { \@@_scan_group_x:f { \int_eval:n { #1 + 1 } } }
+ {
+ \int_compare:nNnF {#1} = 1
+ { \@@_scan_group_x:f { \int_eval:n { #1 - 1 } } }
+ }
+ }
+ { \@@_scan_group_x:n {#1} }
+ }
+\cs_generate_variant:Nn \@@_scan_group_x:n { f }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: catch runaway expand/get_x_next. (get_next too, probably)
+%
+% \begin{macro}{\@@_scan_alt_rule:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_alt_rule:
+ {
+ \@@_scan_keyword:nTF { wWiIdDtThH }
+ {
+ \@@_scan_normal_dimen:
+ \@@_scan_alt_rule:
+ }
+ {
+ \@@_scan_keyword:nTF { hHeEiIgGhHtT }
+ {
+ \@@_scan_normal_dimen:
+ \@@_scan_alt_rule:
+ }
+ {
+ \@@_scan_keyword:nT { dDeEpPtThH }
+ {
+ \@@_scan_normal_dimen:
+ \@@_scan_alt_rule:
+ }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_spec:}
+% Some \TeX{} primitives accept the keywords |to| and |spread|,
+% followed by a dimension.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_spec:
+ {
+ \@@_scan_keyword:nTF { tToO } { \@@_scan_normal_dimen: }
+ {
+ \@@_scan_keyword:nT { sSpPrReEaAdD }
+ { \@@_scan_normal_dimen: }
+ }
+ \@@_scan_left_brace:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Working with boxes}
+%
+% \begin{macro}{\@@_do_box:N}
+% When this procedure is called, the last item in
+% the previous-input sequence is
+% \begin{itemize}
+% \item empty if the box is meant to be put in the input stream,
+% \item \tn{setbox}\meta{int} if it is meant to be stored somewhere,
+% \item \tn{moveright}\meta{dim}, \tn{moveleft}\meta{dim},
+% \tn{lower}\meta{dim}, \tn{raise}\meta{dim} if it is meant to be
+% shifted,
+% \item \tn{leaders} or \tn{cleaders} or \tn{xleaders}, in which case
+% the argument is \cs{c_true_bool} (otherwise \cs{c_false_bool}).
+% \end{itemize}
+% If a |make_box| command follows, we fetch the operands. If leaders
+% are followed by a rule, then this is also ok. In all other cases,
+% call \cs{@@_do_box_error:} to clean up.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_box:N #1
+ {
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { make_box } }
+ { \@@_do_begin_box:N #1 }
+ {
+ \bool_if:NTF #1
+ {
+ \int_case:nnTF \l_@@_head_cmd_int
+ {
+ { \@@_tex_use:n { hrule } } { }
+ { \@@_tex_use:n { vrule } } { }
+ }
+ { \@@_do_leaders_rule: }
+ { \@@_do_box_error: }
+ }
+ { \@@_do_box_error: }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_box_error:}
+% Put the (non-|make_box|) command back into the input and complain.
+% Then recover by throwing away the action (last item of
+% the previous-input sequence). For some reason (this appears to be what
+% \TeX{} does), there is no need to remove the after assignment token
+% here.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_box_error:
+ {
+ \@@_back_input:
+ \@@_error:nnnnn { missing-box } { } { } { } { }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_begin_box:N}
+% We have just found a |make_box| command and placed it into the last
+% item of the previous-input sequence. If it is ``simple''
+% (\tn{box}\meta{int}, \tn{copy}\meta{int}, \tn{lastbox},
+% \tn{vsplit}\meta{int} \texttt{to} \meta{dim}) then we grab its
+% operands, then call \cs{@@_do_simple_box:N} to finish up. If it is
+% \tn{vtop} or \tn{vbox} or \tn{hbox}, we need to work harder.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_begin_box:N #1
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \int_case:nnTF \l_@@_head_char_int
+ {
+ { 0 } { \@@_scan_int: } % box
+ { 1 } { \@@_scan_int: } % copy
+ { 2 } { } % lastbox
+ { 3 } % vsplit
+ {
+ \@@_scan_int:
+ \@@_scan_to:
+ \@@_scan_normal_dimen:
+ }
+ }
+ { \@@_do_simple_box:N #1 }
+ { \@@_do_box_explicit:N #1 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_simple_box:N}
+% For leaders, we need to fetch a glue. In all cases, retrieve the
+% box construction (such as |\raise3pt\vsplit7to5em|). Finally, let
+% \TeX{} run the code and print what we have done.
+% In the case of \tn{shipout}, check that \tn{mag} has a value
+% between $1$ and $32768$.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_simple_box:N #1
+ {
+ \bool_if:NTF #1 { \@@_do_leaders_fetch_skip: }
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_if_head_eq_meaning:VNT \l_@@_head_tl \tex_shipout:D
+ { \@@_prepare_mag: }
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_leaders_fetch_skip:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_leaders_fetch_skip:
+ {
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnTF \l_@@_head_cmd_int
+ = { \@@_tex_use:n { \mode_if_vertical:TF { vskip } { hskip } } }
+ {
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_put_left:NV \l_@@_head_tl \l_@@_tmpa_tl
+ \@@_do_append_glue:
+ }
+ {
+ \@@_back_input:
+ \@@_error:nnnnn { improper-leaders } { } { } { } { }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: less intrusive hooking into \everyhbox/\everyvbox?
+% \begin{macro}{\@@_do_box_explicit:N}
+% At this point, the last item in the previous-input sequence is
+% typically |\setbox0\hbox| or |\raise 3pt\hbox|. Scan for keywords
+% |to| and |spread| and a left brace. Install a hook in
+% \tn{everyhbox} or \tn{everyvbox} (whichever \TeX{} is going to
+% insert in the box). We then retrieve all the material that led to
+% the current box into \cs{l_@@_head_tl} in order to print it, then
+% let \TeX{} perform the box operation (here we need to provide the
+% begin-group token, as it was scanned but not placed in
+% the previous-input sequence). \TeX{} inserts \tn{everyhbox} or
+% \tn{everyvbox} just after the begin-group token, and the hook we did
+% is such that all that material is collected and put into the input
+% that we will study.
+% We must remember to find a glue for leaders, and for this
+% we use a stack of letters |v|, |h| for vertical/horizontal
+% leaders, and |Z| for normal boxes.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_box_explicit:N #1
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \@@_hbox:w
+ { \@@_box_hook:N \tex_everyhbox:D }
+ { \@@_box_hook:N \tex_everyvbox:D }
+ % ^^A todo: TeX calls |normal_paragraph| here.
+ \@@_scan_spec:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_set_action_text:x
+ { \tl_to_str:N \l_@@_head_tl \iow_char:N \{ }
+ \seq_push:Nf \l_@@_leaders_box_seq
+ { \bool_if:NTF #1 { \mode_if_vertical:TF { v } { h } } { Z } }
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \gtl_gconcat:NNN \g_@@_output_gtl
+ \g_@@_output_gtl \c_group_begin_gtl
+ \tl_use:N \l_@@_head_tl
+ \c_group_begin_token \@@_box_hook_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_box_hook:N}
+% \begin{macro}{\@@_box_hook:w, \@@_box_hook_end:}
+% Used to capture the contents of an \tn{everyhbox} or similar,
+% without altering \tn{everyhbox} too much (just add one token at the
+% start). The various \texttt{o}-expansions remove
+% \cs{prg_do_nothing:}, used to avoid losing braces.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_box_hook:N #1
+ {
+ \tl_set:NV \l_@@_tmpa_tl #1
+ \str_if_eq:eeF
+ { \tl_head:N \l_@@_tmpa_tl } { \exp_not:N \@@_box_hook:w }
+ {
+ \@@_exp_args:Nx #1
+ {
+ \exp_not:n { \@@_box_hook:w \prg_do_nothing: }
+ \exp_not:V #1
+ }
+ }
+ \cs_gset_protected:Npn \@@_box_hook:w ##1 \@@_box_hook_end:
+ {
+ \exp_args:No #1 {##1}
+ \cs_gset_eq:NN \@@_box_hook:w \prg_do_nothing:
+ \gtl_clear:N \l_@@_after_group_gtl
+ \@@_print_action:
+ \@@_back_input:o {##1}
+ \@@_set_action_text:x
+ { \token_to_meaning:N #1 = \tl_to_str:o {##1} }
+ \tl_if_empty:oF {##1} { \@@_print_action: }
+ }
+ }
+\cs_new_eq:NN \@@_box_hook:w \prg_do_nothing:
+\cs_new_eq:NN \@@_box_hook_end: \prg_do_nothing:
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_leaders_rule:}
+% After finding a |vrule| or |hrule| command and looking for |depth|,
+% |heigh| and |width| keywords, we are in the same situation as after
+% finding a box. Fetch the required skip accordingly.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_leaders_rule:
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_alt_rule:
+ \@@_do_leaders_fetch_skip:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Paragraphs}
+%
+% \begin{macro}[TF]{\@@_charcode_if_safe:n}
+% \begin{macrocode}
+\prg_new_protected_conditional:Npnn \@@_charcode_if_safe:n #1 { TF }
+ {
+ \bool_if:nTF
+ {
+ \int_compare_p:n { #1 = `! }
+ || \int_compare_p:n { `' <= #1 <= `[ }
+ || \int_compare_p:n { #1 = `] }
+ || \int_compare_p:n { ` ` <= #1 <= `z }
+ }
+ { \prg_return_true: }
+ { \prg_return_false: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_char:n, \@@_char:V, \@@_char:x}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_char:n #1
+ {
+ \tex_char:D #1 \scan_stop:
+ \@@_charcode_if_safe:nTF {#1}
+ { \tl_set:Nx \l_@@_tmpa_tl { \char_generate:nn {#1} { 12 } } }
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \exp_not:N \char \int_eval:n {#1} ~ }
+ }
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_tmpa_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_tmpa_tl }
+ }
+\cs_generate_variant:Nn \@@_char:n { V }
+\cs_new_protected:Npn \@@_char:x
+ { \@@_exp_args:Nx \@@_char:n }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_char_in_mmode:n, \@@_char_in_mmode:V, \@@_char_in_mmode:x}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_char_in_mmode:n #1
+ {
+ \int_compare:nNnTF { \tex_mathcode:D #1 } = { "8000 }
+ { % math active
+ \@@_exp_args:NNx \gtl_set:Nn \l_@@_head_gtl
+ { \char_generate:nn {#1} { 12 } }
+ \@@_back_input:
+ }
+ { \@@_char:n {#1} }
+ }
+\cs_generate_variant:Nn \@@_char_in_mmode:n { V }
+\cs_new_protected:Npn \@@_char_in_mmode:x
+ { \@@_exp_args:Nx \@@_char_in_mmode:n }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_mathchar:n, \@@_mathchar:x}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_mathchar:n #1
+ {
+ \tex_mathchar:D #1 \scan_stop:
+ \tl_set:Nx \l_@@_tmpa_tl
+ { \exp_not:N \mathchar \int_eval:n {#1} ~ }
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_tmpa_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_tmpa_tl }
+ }
+\cs_new_protected:Npn \@@_mathchar:x
+ { \@@_exp_args:Nx \@@_mathchar:n }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_new_graf:N}
+% The argument is a boolean, indicating whether the paragraph should
+% be indented. We have much less work to do here than \TeX{} itself.
+% Our only task is to correctly position the \tn{everypar} tokens in
+% the input that we will read, rather than letting \TeX{} run the code
+% right away.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_new_graf:N #1
+ {
+ \tl_set:NV \l_@@_tmpa_tl \@@_everypar:w
+ \@@_everypar:w { }
+ \bool_if:NTF #1 { \tex_indent:D } { \tex_noindent:D }
+ \exp_args:NV \@@_everypar:w \l_@@_tmpa_tl
+ \@@_back_input:V \l_@@_tmpa_tl
+ \@@_print_action:x
+ {
+ \g_@@_action_text_str \c_space_tl : ~
+ \token_to_str:N \everypar = { \tl_to_str:N \l_@@_tmpa_tl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_end_graf:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_end_graf:
+ { \mode_if_horizontal:T { \@@_normal_paragraph: } }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: Do we need to do more?
+% \begin{macro}{\@@_normal_paragraph:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_normal_paragraph:
+ {
+ \tex_par:D
+ \gtl_gput_right:Nn \g_@@_output_gtl { \par }
+ \@@_print_action:x { Paragraph~end. }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: do something to the \output routine?
+% \begin{macro}{\@@_build_page:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_build_page:
+ {
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Groups}
+%
+% ^^A todo: implement \@@_end_align_group:
+% ^^A todo: implement \@@_end_no_align_group: (start = \@@_end_graf:)
+% ^^A todo: implement \@@_end_output_group:
+% ^^A todo: implement \@@_end_disc_group:
+% ^^A todo: implement \@@_end_math_choice_group:
+%
+% \begin{macro}{\@@_handle_right_brace:}
+% When an end-group character is sensed, the result depends on the
+% current group type.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_handle_right_brace:
+ {
+ \int_compare:nTF { 1 <= \@@_currentgrouptype: <= 13 }
+ {
+ \gtl_gconcat:NNN \g_@@_output_gtl
+ \g_@@_output_gtl \c_group_end_gtl
+ \@@_back_input_gtl:N \l_@@_after_group_gtl
+ \int_case:nn \@@_currentgrouptype:
+ {
+ { 1 } { \@@_end_simple_group: } % simple
+ { 2 } { \@@_end_box_group: } % hbox
+ { 3 } { \@@_end_box_group: } % adjusted_hbox
+ { 4 } { \@@_end_graf: \@@_end_box_group: } % vbox
+ { 5 } { \@@_end_graf: \@@_end_box_group: } % vtop
+ { 6 } { \@@_end_align_group: } % align
+ { 7 } { \@@_end_no_align_group: } % no_align
+ { 8 } { \@@_end_output_group: } % output
+ { 9 } { \@@_end_simple_group: } % math
+ { 10 } { \@@_end_disc_group: } % disc
+ { 11 } { \@@_end_graf: \@@_end_simple_group: } % insert
+ { 12 } { \@@_end_graf: \@@_end_simple_group: } % vcenter
+ { 13 } { \@@_end_math_choice_group: } % math_choice
+ }
+ }
+ { % bottom_level, semi_simple, math_shift, math_left
+ \l_@@_head_token
+ \@@_print_action:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_end_simple_group:}
+% This command is used to simply end a group, when there are no
+% specific operations to perform.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_end_simple_group:
+ {
+ \l_@@_head_token
+ \@@_print_action:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_end_box_group:}
+% The end of an explicit box (generated by \tn{vtop}, \tn{vbox}, or
+% \tn{hbox}) can either be simple, or can mean that we need to find a
+% skip for a \tn{leaders}/\tn{cleaders}/\tn{xleaders} construction.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_end_box_group:
+ {
+ \seq_pop:NN \l_@@_leaders_box_seq \l_@@_tmpa_tl
+ \exp_args:No \@@_end_box_group_aux:n { \l_@@_tmpa_tl }
+ }
+\cs_new_protected:Npn \@@_end_box_group_aux:n #1
+ {
+ \str_if_eq:eeTF {#1} { Z }
+ { \@@_end_simple_group: }
+ {
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnTF \l_@@_head_cmd_int
+ = { \@@_tex_use:n { #1 skip } }
+ {
+ \tl_put_left:Nn \l_@@_head_tl { \c_group_end_token }
+ \@@_do_append_glue:
+ }
+ {
+ \@@_back_input:
+ \c_group_end_token \group_begin: \group_end:
+ \@@_print_action:
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_off_save:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_off_save:
+ {
+ \int_compare:nNnTF \@@_currentgrouptype: = { 0 }
+ { % bottom-level
+ \@@_error:nxxxx { extra-close }
+ { \token_to_meaning:N \l_@@_head_token } { } { } { }
+ }
+ {
+ \@@_back_input:
+ \int_case:nnF \@@_currentgrouptype:
+ {
+ { 14 } % semi_simple_group
+ { \gtl_set:Nn \l_@@_head_gtl { \group_end: } }
+ { 15 } % math_shift_group
+ { \gtl_set:Nn \l_@@_head_gtl { $ } } % $
+ { 16 } % math_left_group
+ { \gtl_set:Nn \l_@@_head_gtl { \tex_right:D . } }
+ }
+ { \gtl_set_eq:NN \l_@@_head_gtl \c_group_end_gtl }
+ \@@_back_input:
+ \@@_error:nxxxx { off-save }
+ { \gtl_to_str:N \l_@@_head_gtl } { } { } { }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Modes}
+% ^^A todo: implement \aftergroup and things happening at end-group
+% ^^A todo: implement \@@_scan_math:
+%
+% \begin{macro}
+% {\@@_mode_math:n, \@@_mode_non_math:n, \@@_mode_vertical:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_mode_math:n #1
+ { \mode_if_math:TF {#1} { \@@_insert_dollar_error: } }
+\cs_new_protected:Npn \@@_mode_non_math:n #1
+ { \mode_if_math:TF { \@@_insert_dollar_error: } {#1} }
+\cs_new_protected:Npn \@@_mode_vertical:n #1
+ {
+ \mode_if_math:TF
+ { \@@_insert_dollar_error: }
+ { \mode_if_horizontal:TF { \@@_head_for_vmode: } {#1} }
+ }
+\cs_new_protected:Npn \@@_mode_non_vertical:n #1
+ {
+ \mode_if_vertical:TF
+ { \@@_back_input: \@@_new_graf:N \c_true_bool }
+ {#1}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_head_for_vmode:}
+% See \TeX{}'s |head_for_vmode|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_head_for_vmode:
+ {
+ \mode_if_inner:TF
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_hrule:D
+ {
+ \@@_error:nnnnn { hrule-bad-mode } { } { } { } { }
+ \@@_print_action:
+ }
+ { \@@_off_save: }
+ }
+ {
+ \@@_back_input:
+ \gtl_set:Nn \l_@@_head_gtl { \par }
+ \@@_back_input:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: should push_math be provided?
+% \begin{macro}{\@@_goto_inner_math:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_goto_inner_math:
+ {
+ \@@_box_hook:N \tex_everymath:D
+ $ % $
+ \@@_box_hook_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_goto_display_math:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_goto_display_math:
+ {
+ \@@_box_hook:N \tex_everydisplay:D
+ $ $
+ \@@_box_hook_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_after_math:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_after_math:
+ {
+ \mode_if_inner:TF
+ {
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_back_input_gtl:N \l_@@_after_group_gtl
+ $ % $
+ }
+ {
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_get_x_next:
+ \token_if_eq_catcode:NNF
+ \l_@@_head_token \c_math_toggle_token
+ {
+ \@@_back_input:
+ \tl_set:Nn \l_@@_head_tl { $ } % $
+ \@@_error:nnnnn { missing-dollar } { } { } { } { }
+ }
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_back_input_gtl:N \l_@@_after_group_gtl
+ $ $
+ }
+ \@@_print_action:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{One step}
+%
+% \begin{macro}{\@@_do_step:}
+% Perform the action if the corresponding command exists. If that
+% command does not exist, complain, and leave the token in the output.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_step:
+ {
+ \@@_set_action_text:
+ \bool_if:NT \g_@@_internal_debug_bool
+ { \@@_exp_args:Nx \iow_term:n { Cmd:~\int_to_arabic:n { \l_@@_head_cmd_int } } }
+ \cs_if_exist_use:cF
+ { @@_cmd_ \int_use:N \l_@@_head_cmd_int : }
+ { \@@_error:nxxxx { internal } { unknown-command } { } { } { } }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Commands}
+%
+% We will implement commands in order of their command codes (some of
+% the more elaborate commands call auxiliaries defined in other
+% sections).
+%
+% \subsubsection{Characters: from 0 to 15}
+%
+% This section is about command codes in the range $[0, 15]$.
+% \begin{itemize}
+% \item |relax=0| for \tn{relax}.
+% \item |begin-group_char=1| for begin-group characters (catcode~$1$).
+% \item |end-group_char=2| for end-group characters (catcode~$2$).
+% \item |math_char=3| for math shift (math toggle in \pkg{expl3})
+% characters (catcode~$3$).
+% \item |tab_mark=4| for \tn{span}
+% \item |alignment_char=4| for alignment tab characters (catcode~$4$).
+% \item |car_ret=5| for \tn{cr} and \tn{crcr}.
+% \item |macro_char=6| for macro parameter characters (catcode~$6$).
+% \item |superscript_char=7| for superscript characters (catcode~$7$).
+% \item |subscript_char=8| for subscript characters (catcode~$8$).
+% \item |endv=9| for |?|.
+% \item |blank_char=10| for blank spaces (catcode~$10$).
+% \item |the_char=11| for letters (catcode~$11$).
+% \item |other_char=12| for other characters (catcode~$12$).
+% \item |par_end=13| for \tn{par}.
+% \item |stop=14| for \tn{end} and \tn{dump}.
+% \item |delim_num=15| for \tn{delimiter}.
+% \end{itemize}
+% Not implemented at all: |endv|.
+%
+% \tn{relax} does nothing.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { relax } % 0
+ {
+ \token_if_eq_meaning:NNT \l_@@_head_token \@@_special_relax:
+ {
+ \exp_after:wN \@@_token_if_expandable:NTF \l_@@_head_tl
+ {
+ \@@_set_action_text:x
+ { \iow_char:N \\notexpanded: \g_@@_action_text_str }
+ }
+ { }
+ }
+ \@@_print_action:
+ }
+% \end{macrocode}
+%
+% Begin-group characters are sent to the output, as their grouping
+% behaviour may affect the scope of font changes, for instance. They are
+% also performed.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { begin-group_char } % 1
+ {
+ \gtl_gconcat:NNN \g_@@_output_gtl
+ \g_@@_output_gtl \c_group_begin_gtl
+ \@@_print_action:
+ \l_@@_head_token
+ \gtl_clear:N \l_@@_after_group_gtl
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { end-group_char } % 2
+ { \@@_handle_right_brace: }
+% \end{macrocode}
+%
+% Math shift characters quit vertical mode, and start math mode.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_char } % 3
+ {
+ \@@_mode_non_vertical:n
+ {
+ \mode_if_math:TF
+ {
+ \int_compare:nNnTF
+ \@@_currentgrouptype: = { 15 } % math_shift_group
+ { \@@_after_math: }
+ { \@@_off_save: }
+ }
+ {
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_get_next:
+ \token_if_eq_catcode:NNTF
+ \l_@@_head_token \c_math_toggle_token
+ {
+ \mode_if_inner:TF
+ { \@@_back_input: \@@_goto_inner_math: }
+ {
+ \gtl_gput_right:NV
+ \g_@@_output_gtl \l_@@_head_tl
+ \@@_goto_display_math:
+ }
+ }
+ { \@@_back_input: \@@_goto_inner_math: }
+ }
+ }
+ }
+% \end{macrocode}
+%
+% Some commands are errors when they reach \TeX{}'s stomach. Among
+% others, |tab_mark=alignment_char|, |car_ret| and |macro_char|. We let
+% \TeX{} insert the proper error.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { alignment_char } % 4
+ { \l_@@_head_token \@@_print_action: }
+\@@_new_tex_cmd:nn { car_ret } % 5
+ { \l_@@_head_token \@@_print_action: }
+\@@_new_tex_cmd:nn { macro_char } % 6
+ { \l_@@_head_token \@@_print_action: }
+% \end{macrocode}
+%
+% ^^A todo: wrong: needs to collect subsup before output (otherwise b{}^2{}_3)
+% ^^A todo: wrong: mathcode "8000 is not recognized.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { superscript_char } % 7
+ { \@@_mode_math:n { \@@_sub_sup: } }
+\@@_new_tex_cmd:nn { subscript_char } % 8
+ { \@@_mode_math:n { \@@_sub_sup: } }
+\cs_new_protected:Npn \@@_sub_sup:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_case:nnTF \l_@@_head_cmd_int
+ {
+ { \@@_tex_use:n { the_char } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { other_char } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { char_given } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { char_num } }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_int:
+ }
+ { \@@_tex_use:n { math_char_num } }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_int:
+ }
+ { \@@_tex_use:n { math_given } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ { \@@_tex_use:n { delim_num } }
+ { \@@_prev_input:V \l_@@_head_tl \@@_scan_int: }
+ }
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ }
+ {
+ \@@_back_input:
+ \@@_scan_left_brace:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \gtl_gconcat:NNN \g_@@_output_gtl
+ \g_@@_output_gtl \c_group_begin_gtl
+ \tl_use:N \l_@@_head_tl \c_group_begin_token
+ }
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { endv } % 9
+ { \@@_not_implemented:n { alignments } }
+% \end{macrocode}
+%
+% Blank spaces are ignored in vertical and math modes in the same way as
+% \tn{relax} is in all modes. In horizontal mode, add them to the
+% output.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { blank_char } % 10
+ {
+ \mode_if_horizontal:T
+ {
+ \gtl_gput_right:Nn \g_@@_output_gtl { ~ }
+ \l_@@_head_token
+ }
+ \@@_print_action:
+ }
+% \end{macrocode}
+%
+% Letters and other characters leave vertical mode.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { the_char } % 11
+ {
+ \@@_mode_non_vertical:n
+ {
+ \tl_set:Nx \l_@@_tmpa_tl
+ { ` \@@_token_to_char:N \l_@@_head_token }
+ \mode_if_math:TF
+ { \@@_char_in_mmode:V \l_@@_tmpa_tl }
+ { \@@_char:V \l_@@_tmpa_tl }
+ }
+ }
+\@@_new_eq_tex_cmd:nn { other_char } { the_char } % 12
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { par_end } % 13
+ {
+ \@@_mode_non_math:n
+ {
+ \mode_if_vertical:TF
+ { \@@_normal_paragraph: }
+ {
+ % if align_state<0 then off_save;
+ \@@_end_graf:
+ \mode_if_vertical:T
+ { \mode_if_inner:F { \@@_build_page: } }
+ }
+ }
+ }
+% \end{macrocode}
+%
+% ^^A todo: \dump only at bottom-level (\currentgrouptype=0)
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { stop } % 14
+ {
+ \@@_mode_vertical:n
+ {
+ \mode_if_inner:TF
+ { \@@_forbidden_case: }
+ {
+ % ^^A todo: unless its_all_over
+ \int_gdecr:N \g_@@_ends_int
+ \int_compare:nNnTF \g_@@_ends_int > 0
+ {
+ \@@_back_input:
+ \@@_back_input:n
+ {
+ \@@_hbox:w to \tex_hsize:D { }
+ \tex_vfill:D
+ \tex_penalty:D - '10000000000 ~
+ }
+ \@@_build_page:
+ \@@_print_action:x { End~everything! }
+ }
+ {
+ \@@_print_outcome:
+ \l_@@_head_token
+ }
+ }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { delim_num } % 15
+ {
+ \@@_mode_math:n
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+%
+% \subsubsection{Boxes: from 16 to 31}
+%
+% \begin{itemize}
+% \item |char_num=16| for \tn{char}
+% \item |math_char_num=17| for \tn{mathchar}
+% \item |mark=18| for \tn{mark} and \tn{marks}
+% \item |xray=19| for \tn{show}, \tn{showbox}, \tn{showthe},
+% \tn{showlists}, \tn{showgroups}, \tn{showtokens}, \tn{showifs}.
+% \item |make_box=20| for \tn{box}, \tn{copy}, \tn{lastbox},
+% \tn{vsplit}, \tn{vtop}, \tn{vbox}, and \tn{hbox}~(106).
+% \item |hmove=21| for \tn{moveright} and \tn{moveleft}.
+% \item |vmove=22| for \tn{lower} and \tn{raise}.
+% \item |un_hbox=23| for \tn{unhbox} and \tn{unhcopy}.
+% \item |unvbox=24| for \tn{unvbox}, \tn{unvcopy}, \tn{pagediscards},
+% and \tn{splitdiscards}.
+% \item |remove_item=25| for \tn{unpenalty}~(12), \tn{unkern}~(11),
+% \tn{unskip}~(10).
+% \item |hskip=26| for \tn{hfil}, \tn{hfill}, \tn{hss}, \tn{hfilneg},
+% \tn{hskip}.
+% \item |vskip=27| for \tn{vfil}, \tn{vfill}, \tn{vss}, \tn{vfilneg},
+% \tn{vskip}.
+% \item |mskip=28| for \tn{mskip}~(5).
+% \item |kern=29| for \tn{kern}~(1).
+% \item |mkern=30| for \tn{mkern}~(99).
+% \item |leader_ship=31| for \tn{shipout}~(99), \tn{leaders}~(100),
+% \tn{cleaders}~(101), \tn{xleaders}~(102).
+% \end{itemize}
+%
+% \tn{char} leaves vertical mode, then scans an integer operand, then
+% calls \cs{@@_char_in_mmode:n} or \cs{@@_char:n} depending on the mode.
+% See implementation of |the_char| and |other_char|.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { char_num } % 16
+ {
+ \@@_mode_non_vertical:n
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \mode_if_math:TF
+ { \@@_char_in_mmode:x { \tl_tail:N \l_@@_head_tl } }
+ { \@@_char:x { \tl_tail:N \l_@@_head_tl } }
+ }
+ }
+% \end{macrocode}
+%
+% Only allowed in math mode, \tn{mathchar} reads an integer operand, and
+% calls \cs{@@_mathchar:n}, which places the corresponding math
+% character in the \cs{g_@@_output_gtl}, and in the actual output.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_char_num } % 17
+ {
+ \@@_mode_math:n
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_mathchar:x { \tl_tail:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { mark } % 18
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \int_compare:nNnF \l_@@_head_char_int = 0
+ { \@@_scan_int: }
+ \@@_prev_input_gpush:
+ \@@_scan_toks:NN \c_false_bool \c_true_bool
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_print_action:x
+ { \tl_to_str:N \l_@@_head_tl \tl_to_str:N \l_@@_tmpa_tl }
+ \tl_put_right:Nx \l_@@_head_tl
+ { { \exp_not:N \exp_not:n \exp_not:V \l_@@_tmpa_tl } }
+ \tl_use:N \l_@@_head_tl
+ }
+% \end{macrocode}
+%
+% We now implement the primitives \tn{show}, \tn{showbox}, \tn{showthe},
+% \tn{showlists}, \tn{showgroups}, \tn{showtokens} and \tn{showifs}.
+% Those with no operand are sent to \TeX{} after printing the action.
+% Those with operands print first, then scan their operands, then are
+% sent to \TeX{}. The case of \tn{show} is a bit special, as its
+% operand is a single token, which cannot easily be put into the
+% the previous-input sequence in general. Since no expansion can occur,
+% simply grab the token and show it.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { xray } % 19
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 0 }
+ { % show
+ \@@_get_next:
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \token_if_eq_meaning:NNTF
+ \l_@@_head_token \@@_special_relax:
+ {
+ \exp_after:wN \exp_after:wN \exp_after:wN \l_@@_tmpa_tl
+ \exp_after:wN \exp_not:N \l_@@_head_tl
+ }
+ { \gtl_head_do:NN \l_@@_head_gtl \l_@@_tmpa_tl }
+ }
+ { 2 }
+ { % showthe
+ \@@_get_x_next:
+ \@@_scan_something_internal:n { 5 }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_exp_args:Nx \use:n
+ { \tex_showtokens:D { \tl_tail:N \l_@@_head_tl } }
+ }
+ }
+ { % no operand for showlists, showgroups, showifs
+ \int_compare:nNnT \l_@@_head_char_int = 1 % showbox
+ { \@@_scan_int: }
+ \int_compare:nNnT \l_@@_head_char_int = 5 % showtokens
+ { \@@_scan_toks:NN \c_false_bool \c_false_bool }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ }
+ }
+% \end{macrocode}
+%
+% |make_box=20| for \tn{box}, \tn{copy}, \tn{lastbox},
+% \tn{vsplit}, \tn{vtop}, \tn{vbox}, and \tn{hbox}~(106).
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { make_box } % 20
+ {
+ \@@_prev_input_gpush:
+ \@@_back_input:
+ \@@_do_box:N \c_false_bool
+ }
+% \end{macrocode}
+%
+% ^^A todo: implement \@@_forbidden_case:
+%
+% \begin{macro}{\@@_do_move:}
+% Scan a dimension and a box, and perform the shift, printing the
+% appropriate action.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_move:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_normal_dimen:
+ \@@_do_box:N \c_false_bool
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% |hmove=21| for \tn{moveright} and \tn{moveleft}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { hmove } % 21
+ {
+ \mode_if_vertical:TF
+ { \@@_do_move: } { \@@_forbidden_case: }
+ }
+% \end{macrocode}
+%
+% |vmove=22| for \tn{lower} and \tn{raise}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { vmove } % 22
+ {
+ \mode_if_vertical:TF
+ { \@@_forbidden_case: } { \@@_do_move: }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_do_unpackage:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_unpackage:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% |un_hbox=23| for \tn{unhbox} and \tn{unhcopy}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { un_hbox } % 23
+ { \@@_mode_non_vertical:n { \@@_do_unpackage: } }
+% \end{macrocode}
+%
+% |unvbox=24| for \tn{unvbox}, \tn{unvcopy}, \tn{pagediscards}, and
+% \tn{splitdiscards}. The latter two take no operands, so we just let
+% \TeX{} do its thing, then we show the action.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { un_vbox } % 24
+ {
+ \@@_mode_vertical:n
+ {
+ \int_compare:nNnTF \l_@@_head_char_int > { 1 }
+ { \l_@@_head_token \@@_print_action: }
+ { \@@_do_unpackage: }
+ }
+ }
+% \end{macrocode}
+%
+% |remove_item=25| for \tn{unpenalty}~(12), \tn{unkern}~(11),
+% \tn{unskip}~(10). Those commands only act on \TeX{}'s box/glue data
+% structures, which \pkg{unravel} does not (and cannot) care about.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { remove_item } % 25
+ { \l_@@_head_token \@@_print_action: }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_do_append_glue:}
+% For \tn{hfil}, \tn{hfill}, \tn{hss}, \tn{hfilneg} and their vertical
+% analogs, simply call the primitive then print the action. For
+% \tn{hskip}, \tn{vskip} and \tn{mskip}, read a normal glue or a mu
+% glue (\cs{l_@@_head_char_int} is $4$ or~$5$), then call the
+% primitive with that operand, and print the whole thing as an action.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_append_glue:
+ {
+ \int_compare:nNnTF \l_@@_head_char_int < { 4 }
+ { \tl_use:N \l_@@_head_tl \@@_print_action: }
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \exp_args:Nf \@@_scan_glue:n
+ { \int_eval:n { \l_@@_head_char_int - 2 } }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% |hskip=26| for \tn{hfil}, \tn{hfill}, \tn{hss}, \tn{hfilneg},
+% \tn{hskip}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { hskip } % 26
+ { \@@_mode_non_vertical:n { \@@_do_append_glue: } }
+% \end{macrocode}
+%
+% |vskip=27| for \tn{vfil}, \tn{vfill}, \tn{vss}, \tn{vfilneg},
+% \tn{vskip}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { vskip } % 27
+ { \@@_mode_vertical:n { \@@_do_append_glue: } }
+% \end{macrocode}
+%
+% |mskip=28| for \tn{mskip}~(5).
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { mskip } % 28
+ { \@@_mode_math:n { \@@_do_append_glue: } }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_do_append_kern:}
+% See \cs{@@_do_append_glue:}. This function is used for the
+% primitives \tn{kern} and \tn{mkern} only.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_append_kern:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_kern:D
+ { \@@_scan_dimen:nN { 2 } \c_false_bool }
+ { \@@_scan_dimen:nN { 3 } \c_false_bool }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% |kern=29| for \tn{kern}~(1).
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { kern } % 29
+ { \@@_do_append_kern: }
+% \end{macrocode}
+%
+% |mkern=30| for \tn{mkern}~(99).
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { mkern } % 30
+ { \@@_mode_math:n { \@@_do_append_kern: } }
+% \end{macrocode}
+%
+% |leader_ship=31| for \tn{shipout}~(99), \tn{leaders}~(100),
+% \tn{cleaders}~(101), \tn{xleaders}~(102).
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { leader_ship } % 31
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_do_box:N \c_true_bool
+ }
+% \end{macrocode}
+%
+% \subsubsection{From 32 to 47}
+%
+% ^^A todo: implement \@@_begin_insert_or_adjust:
+%
+% \begin{itemize}
+% \item |halign=32|
+% \item |valign=33|
+% \item |no_align=34|
+% \item |vrule=35|
+% \item |hrule=36|
+% \item |insert=37|
+% \item |vadjust=38|
+% \item |ignore_spaces=39|
+% \item |after_assignment=40|
+% \item |after_group=41|
+% \item |break_penalty=42|
+% \item |start_par=43|
+% \item |ital_corr=44|
+% \item |accent=45|
+% \item |math_accent=46|
+% \item |discretionary=47|
+% \end{itemize}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { halign } % 32
+ { \@@_not_implemented:n { halign } }
+\@@_new_tex_cmd:nn { valign } % 33
+ { \@@_not_implemented:n { valign } }
+\@@_new_tex_cmd:nn { no_align } % 34
+ { \@@_not_implemented:n { noalign } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { vrule } % 35
+ { \@@_mode_non_vertical:n { \@@_do_rule: } }
+\@@_new_tex_cmd:nn { hrule } % 36
+ { \@@_mode_vertical:n { \@@_do_rule: } }
+\cs_new_protected:Npn \@@_do_rule:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_alt_rule:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { insert } % 37
+ { \@@_begin_insert_or_adjust: }
+\@@_new_tex_cmd:nn { vadjust } % 38
+ {
+ \mode_if_vertical:TF
+ { \@@_forbidden_case: } { \@@_begin_insert_or_adjust: }
+ }
+% \end{macrocode}
+%
+% ^^A todo: implement the internal \pdfprimitive business.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { ignore_spaces } % 39
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_ignorespaces:D
+ {
+ \@@_print_action:
+ \@@_get_x_non_blank:
+ \@@_set_cmd:
+ \@@_do_step:
+ }
+ { \@@_not_implemented:n { pdfprimitive } }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { after_assignment } % 40
+ {
+ \tl_set_eq:NN \l_@@_tmpa_tl \l_@@_head_tl
+ \@@_get_next:
+ \gtl_gset_eq:NN \g_@@_after_assignment_gtl \l_@@_head_gtl
+ \@@_print_action:x
+ {
+ Afterassignment:~\tl_to_str:N \l_@@_tmpa_tl
+ \gtl_to_str:N \l_@@_head_gtl
+ }
+ }
+% \end{macrocode}
+%
+% Save the next token at the end of \cs{l_@@_after_group_gtl}, unless
+% we are at the bottom group level, in which case, the token is ignored
+% completely.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { after_group } % 41
+ {
+ \tl_set_eq:NN \l_@@_tmpa_tl \l_@@_head_tl
+ \@@_get_next:
+ \int_compare:nNnTF \@@_currentgrouptype: = 0
+ {
+ \@@_print_action:x
+ {
+ Aftergroup~(level~0~=>~dropped):~
+ \tl_to_str:N \l_@@_tmpa_tl
+ \gtl_to_str:N \l_@@_head_gtl
+ }
+ }
+ {
+ \gtl_concat:NNN \l_@@_after_group_gtl
+ \l_@@_after_group_gtl \l_@@_head_gtl
+ \@@_print_action:x
+ {
+ Aftergroup:~\tl_to_str:N \l_@@_tmpa_tl
+ \gtl_to_str:N \l_@@_head_gtl
+ }
+ }
+ }
+% \end{macrocode}
+%
+% See \cs{@@_do_append_glue:}.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { break_penalty } % 42
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { start_par } % 43
+ {
+ \mode_if_vertical:TF
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_noindent:D
+ { \@@_new_graf:N \c_false_bool }
+ { \@@_new_graf:N \c_true_bool }
+ }
+ {
+ \int_compare:nNnT \l_@@_head_char_int = { 1 } % indent
+ {
+ \@@_hbox:w width \tex_parindent:D { }
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ }
+ \@@_print_action:
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { ital_corr } % 44
+ {
+ \mode_if_vertical:TF { \@@_forbidden_case: }
+ { \l_@@_head_token \@@_print_action: }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_do_accent:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_accent:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_do_assignments:
+ \bool_if:nTF
+ {
+ \token_if_eq_catcode_p:NN
+ \l_@@_head_token \c_catcode_letter_token
+ ||
+ \token_if_eq_catcode_p:NN
+ \l_@@_head_token \c_catcode_other_token
+ ||
+ \int_compare_p:nNn
+ \l_@@_head_cmd_int = { \@@_tex_use:n { char_given } }
+ }
+ { \@@_prev_input:V \l_@@_head_tl }
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_char:D
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_int:
+ }
+ { \@@_break:w }
+ }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ \@@_break_point:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_math_accent:}
+% \TeX{} will complain if \cs{l_@@_head_tl} happens to start with
+% \tn{accent} (the user used \tn{accent} in math mode).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_math_accent:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_scan_math:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { accent } % 45
+ {
+ \@@_mode_non_vertical:n
+ {
+ \mode_if_math:TF
+ { \@@_do_math_accent: } { \@@_do_accent: }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_accent } % 46
+ { \@@_mode_math:n { \@@_do_math_accent: } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { discretionary } % 47
+ { \@@_not_implemented:n { discretionary } }
+% \end{macrocode}
+%
+% \subsubsection{Maths: from 48 to 56}
+%
+% \begin{itemize}
+% \item |eq_no=48|
+% \item |left_right=49|
+% \item |math_comp=50|
+% \item |limit_switch=51|
+% \item |above=52|
+% \item |math_style=53|
+% \item |math_choice=54|
+% \item |non_script=55|
+% \item |vcenter=56|
+% \end{itemize}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { eq_no } % 48
+ { \@@_not_implemented:n { eqno } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { left_right } % 49
+ { \@@_not_implemented:n { left/right } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_comp } % 50
+ { \@@_not_implemented:n { math~comp } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { limit_switch } % 51
+ { \@@_not_implemented:n { limits } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { above } % 52
+ { \@@_not_implemented:n { above } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_style } % 53
+ { \@@_not_implemented:n { math~style } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_choice } % 54
+ { \@@_not_implemented:n { math~choice } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { non_script } % 55
+ { \@@_not_implemented:n { non~script } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { vcenter } % 56
+ { \@@_not_implemented:n { vcenter } }
+% \end{macrocode}
+%
+% \subsubsection{From 57 to 70}
+%
+% \begin{itemize}
+% \item |case_shift=57|
+% \item |message=58|
+% \item |extension=59|
+% \item |in_stream=60|
+% \item |begin_group=61|
+% \item |end_group=62|
+% \item |omit=63|
+% \item |ex_space=64|
+% \item |no_boundary=65|
+% \item |radical=66|
+% \item |end_cs_name=67|
+% \item |char_given=68|
+% \item |math_given=69|
+% \item |last_item=70|
+% \end{itemize}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { case_shift } % 57
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \exp_after:wN \@@_case_shift:Nn \l_@@_tmpa_tl
+ }
+\cs_new_protected:Npn \@@_case_shift:Nn #1#2
+ {
+ #1 { \@@_back_input:n {#2} }
+ \@@_print_action:x
+ { \token_to_meaning:N #1 ~ \tl_to_str:n { {#2} } }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { message } % 58
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_toks_to_str:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% Extensions are implemented in a later section.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { extension } % 59
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_extension_operands:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { in_stream } % 60
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_openin:D
+ {
+ \@@_scan_int:
+ \@@_scan_optional_equals:
+ \@@_scan_file_name:
+ }
+ { \@@_scan_int: }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { begin_group } % 61
+ {
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \l_@@_head_token
+ \gtl_clear:N \l_@@_after_group_gtl
+ \@@_print_action:
+ }
+\@@_new_tex_cmd:nn { end_group } % 62
+ {
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_back_input_gtl:N \l_@@_after_group_gtl
+ \l_@@_head_token
+ \@@_print_action:
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { omit } % 63
+ { \@@_not_implemented:n { omit } }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { ex_space } % 64
+ {
+ \@@_mode_non_vertical:n
+ { \l_@@_head_token \@@_print_action: }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { no_boundary } % 65
+ {
+ \@@_mode_non_vertical:n
+ { \l_@@_head_token \@@_print_action: }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { radical } % 66
+ {
+ \@@_mode_math:n
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_scan_math:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { end_cs_name } % 67
+ {
+ \@@_tex_error:nV { extra-endcsname } \l_@@_head_tl
+ \@@_print_action:
+ }
+% \end{macrocode}
+%
+% See |the_char| and |other_char|.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { char_given } % 68
+ {
+ \@@_mode_non_vertical:n
+ {
+ \mode_if_math:TF
+ { \@@_char_in_mmode:V \l_@@_head_char_int }
+ { \@@_char:V \l_@@_head_char_int }
+ }
+ }
+% \end{macrocode}
+%
+% See |math_char_num|.
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { math_given } % 69
+ {
+ \@@_mode_math:n
+ { \@@_mathchar:x { \int_use:N \l_@@_head_char_int } }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_cmd:nn { last_item } % 70
+ { \@@_forbidden_case: }
+% \end{macrocode}
+%
+% \subsubsection{Extensions}
+% ^^A todo: move this section.
+%
+% \begin{macro}{\@@_scan_extension_operands:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_extension_operands:
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 0 } % openout
+ {
+ \@@_scan_int:
+ \@@_scan_optional_equals:
+ \@@_scan_file_name:
+ }
+ { 1 } % write
+ {
+ \@@_scan_int:
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ }
+ { 2 } % closeout
+ { \@@_scan_int: }
+ { 3 } % special
+ { \@@_scan_toks_to_str: }
+ { 4 } % immediate
+ { \@@_scan_immediate_operands: }
+ { 5 } % setlanguage
+ {
+ \mode_if_horizontal:TF
+ { \@@_scan_int: }
+ { \@@_error:nnnnn { invalid-mode } { } { } { } { } }
+ }
+ { 6 } % pdfliteral
+ {
+ \@@_scan_keyword:nF { dDiIrReEcCtT }
+ { \@@_scan_keyword:n { pPaAgGeE } }
+ \@@_scan_pdf_ext_toks:
+ }
+ { 7 } % pdfobj
+ {
+ \@@_scan_keyword:nTF
+ { rReEsSeErRvVeEoObBjJnNuUmM }
+ { \@@_skip_optional_space: }
+ {
+ \@@_scan_keyword:nF { uUsSeEoObBjJnNuUmM }
+ { \@@_scan_int: }
+ \@@_scan_keyword:nT { sStTrReEaAmM }
+ {
+ \@@_scan_keyword:nT { aAtTtTrR }
+ { \@@_scan_pdf_ext_toks: }
+ }
+ \@@_scan_keyword:n { fFiIlLeE }
+ \@@_scan_pdf_ext_toks:
+ }
+ }
+ { 8 } % pdfrefobj
+ { \@@_scan_int: }
+ { 9 } % pdfxform
+ {
+ \@@_scan_keyword:nT { aAtTtTrR }
+ { \@@_scan_pdf_ext_toks: }
+ \@@_scan_keyword:nTF { rReEsSoOuUrRcCeEsS }
+ { \@@_scan_pdf_ext_toks: }
+ \@@_scan_int:
+ }
+ { 10 } % pdfrefxform
+ { \@@_scan_int: }
+ { 11 } % pdfximage
+ { \@@_scan_image: }
+ { 12 } % pdfrefximage
+ { \@@_scan_int: }
+ { 13 } % pdfannot
+ {
+ \@@_scan_keyword:nTF
+ { rReEsSeErRvVeEoObBjJnNuUmM }
+ { \@@_scan_optional_space: }
+ {
+ \@@_scan_keyword:nT { uUsSeEoObBjJnNuUmM }
+ { \@@_scan_int: }
+ \@@_scan_alt_rule:
+ \@@_scan_pdf_ext_toks:
+ }
+ }
+ { 14 } % pdfstartlink
+ {
+ \mode_if_vertical:TF
+ { \@@_error:nnnnn { invalid-mode } { } { } { } { } }
+ {
+ \@@_scan_rule_attr:
+ \@@_scan_action:
+ }
+ }
+ { 15 } % pdfendlink
+ {
+ \mode_if_vertical:T
+ { \@@_error:nnnnn { invalid-mode } { } { } { } { } }
+ }
+ { 16 } % pdfoutline
+ {
+ \@@_scan_keyword:nT { aAtTtTrR }
+ { \@@_scan_pdf_ext_toks: }
+ \@@_scan_action:
+ \@@_scan_keyword:nT { cCoOuUnNtT }
+ { \@@_scan_int: }
+ \@@_scan_pdf_ext_toks:
+ }
+ { 17 } % pdfdest
+ { \@@_scan_pdfdest_operands: }
+ { 18 } % pdfthread
+ { \@@_scan_rule_attr: \@@_scan_thread_id: }
+ { 19 } % pdfstartthread
+ { \@@_scan_rule_attr: \@@_scan_thread_id: }
+ { 20 } % pdfendthread
+ { }
+ { 21 } % pdfsavepos
+ { }
+ { 22 } % pdfinfo
+ { \@@_scan_pdf_ext_toks: }
+ { 23 } % pdfcatalog
+ {
+ \@@_scan_pdf_ext_toks:
+ \@@_scan_keyword:n { oOpPeEnNaAcCtTiIoOnN }
+ { \@@_scan_action: }
+ }
+ { 24 } % pdfnames
+ { \@@_scan_pdf_ext_toks: }
+ { 25 } % pdffontattr
+ {
+ \@@_scan_font_ident:
+ \@@_scan_pdf_ext_toks:
+ }
+ { 26 } % pdfincludechars
+ {
+ \@@_scan_font_ident:
+ \@@_scan_pdf_ext_toks:
+ }
+ { 27 } % pdfmapfile
+ { \@@_scan_pdf_ext_toks: }
+ { 28 } % pdfmapline
+ { \@@_scan_pdf_ext_toks: }
+ { 29 } % pdftrailer
+ { \@@_scan_pdf_ext_toks: }
+ { 30 } % pdfresettimer
+ { }
+ { 31 } % pdffontexpand
+ {
+ \@@_scan_font_ident:
+ \@@_scan_optional_equals:
+ \@@_scan_int:
+ \@@_scan_int:
+ \@@_scan_int:
+ \@@_scan_keyword:nT { aAuUtToOeExXpPaAnNdD }
+ { \@@_skip_optional_space: }
+ }
+ { 32 } % pdfsetrandomseed
+ { \@@_scan_int: }
+ { 33 } % pdfsnaprefpoint
+ { }
+ { 34 } % pdfsnapy
+ { \@@_scan_normal_glue: }
+ { 35 } % pdfsnapycomp
+ { \@@_scan_int: }
+ { 36 } % pdfglyphtounicode
+ {
+ \@@_scan_pdf_ext_toks:
+ \@@_scan_pdf_ext_toks:
+ }
+ { 37 } % pdfcolorstack
+ { \@@_scan_pdfcolorstack_operands: }
+ { 38 } % pdfsetmatrix
+ { \@@_scan_pdf_ext_toks: }
+ { 39 } % pdfsave
+ { }
+ { 40 } % pdfrestore
+ { }
+ { 41 } % pdfnobuiltintounicode
+ { \@@_scan_font_ident: }
+ }
+ { } % no other cases.
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_pdfcolorstack_operands:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_pdfcolorstack_operands:
+ {
+ \@@_scan_int:
+ \@@_scan_keyword:nF { sSeEtT }
+ {
+ \@@_scan_keyword:nF { pPuUsShH }
+ {
+ \@@_scan_keyword:nF { pPoOpP }
+ {
+ \@@_scan_keyword:nF { cCuUrRrReEnNtT }
+ {
+ \@@_error:nnnnn { color-stack-action-missing }
+ { } { } { } { }
+ }
+ }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_rule_attr:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_rule_attr:
+ {
+ \@@_scan_alt_rule:
+ \@@_scan_keyword:nT { aAtTtTrR }
+ { \@@_scan_pdf_ext_toks: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_action:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_action:
+ {
+ \@@_scan_keyword:nTF { uUsSeErR }
+ { \@@_scan_pdf_ext_toks: }
+ {
+ \@@_scan_keyword:nF { gGoOtToO }
+ {
+ \@@_scan_keyword:nF { tThHrReEaAdD }
+ { \@@_error:nnnnn { action-type-missing } { } { } { } { } }
+ }
+ }
+ \@@_scan_keyword:nT { fFiIlLeE }
+ { \@@_scan_pdf_ext_toks: }
+ \@@_scan_keyword:nTF { pPaAgGeE }
+ {
+ \@@_scan_int:
+ \@@_scan_pdf_ext_toks:
+ }
+ {
+ \@@_scan_keyword:nTF { nNaAmMeE }
+ { \@@_scan_pdf_ext_toks: }
+ {
+ \@@_scan_keyword:nTF { nNuUmM }
+ { \@@_scan_int: }
+ { \@@_error:nnnnn { identifier-type-missing } { } { } { } { } }
+ }
+ }
+ \@@_scan_keyword:nTF { nNeEwWwWiInNdDoOwW }
+ { \@@_skip_optional_space: }
+ {
+ \@@_scan_keyword:nT { nNoOnNeEwWwWiInNdDoOwW }
+ { \@@_skip_optional_space: }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_image:}
+% Used by \tn{pdfximage}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_image:
+ {
+ \@@_scan_rule_attr:
+ \@@_scan_keyword:nTF { nNaAmMeEdD }
+ { \@@_scan_pdf_ext_toks: }
+ {
+ \@@_scan_keyword:nT { pPaAgGeE }
+ { \@@_scan_int: }
+ }
+ \@@_scan_keyword:nT { cCoOlLoOrRsSpPaAcCeE }
+ { \@@_scan_int: }
+ \@@_scan_pdf_ext_toks:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_immediate_operands:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_immediate_operands:
+ {
+ \@@_get_x_next:
+ \@@_set_cmd:
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { extension } }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_char_int < { 3 } % openout, write, closeout
+ { \@@_scan_immediate_operands_aux: }
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 7 } { \@@_scan_extension_operands_aux: } % pdfobj
+ { 9 } { \@@_scan_extension_operands_aux: } % pdfxform
+ { 11 } { \@@_scan_extension_operands_aux: } %pdfximage
+ }
+ { \@@_scan_immediate_operands_bad: }
+ }
+ }
+ { \@@_scan_immediate_operands_bad: }
+ }
+\cs_new_protected:Npn \@@_scan_immediate_operands_aux:
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_extension_operands:
+ }
+\cs_new_protected:Npn \@@_scan_immediate_operands_bad:
+ {
+ \@@_back_input:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl ignored }
+ \@@_prev_input_gpush:
+ }
+
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_scan_pdfdest_operands:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_scan_pdfdest_operands:
+ {
+ \@@_scan_keyword:nTF { nNuUmM }
+ { \@@_scan_int: }
+ {
+ \@@_scan_keyword:nTF { nNaAmMeE }
+ { \@@_scan_pdf_ext_toks: }
+ { \@@_error:nnnnn { identifier-type-missing } { } { } { } { } }
+ }
+ \@@_scan_keyword:nTF { xXyYzZ }
+ {
+ \@@_scan_keyword:nT { zZoOoOmM }
+ { \@@_scan_int: }
+ }
+ {
+ \@@_scan_keyword:nF { fFiItTbBhH }
+ {
+ \@@_scan_keyword:nF { fFiItTbBvV }
+ {
+ \@@_scan_keyword:nF { fFiItTbB }
+ {
+ \@@_scan_keyword:nF { fFiItThHhH }
+ {
+ \@@_scan_keyword:nF { fFiItTvV }
+ {
+ \@@_scan_keyword:nTF
+ { fFiItTrR }
+ {
+ \@@_skip_optional_space:
+ \@@_scan_alt_rule:
+ \use_none:n
+ }
+ {
+ \@@_scan_keyword:nF
+ { fFiItT }
+ {
+ \@@_error:nnnnn { destination-type-missing }
+ { } { } { } { }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+ \@@_skip_optional_space:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Assignments}
+%
+% Quoting \texttt{tex.web}: ``Every prefix, and every command code that
+% might or might not be prefixed, calls the action procedure
+% |prefixed_command|. This routine accumulates a sequence of prefixes
+% until coming to a non-prefix, then it carries out the command.''
+% We define all those commands in one go, from
+% |max_non_prefixed_command+1=71| to |max_command=102|.
+% \begin{macrocode}
+\cs_set_protected:Npn \@@_tmp:w
+ {
+ \@@_prev_input_gpush:
+ \@@_prefixed_command:
+ }
+\int_step_inline:nnnn
+ { \@@_tex_use:n { max_non_prefixed_command } + 1 }
+ { 1 }
+ { \@@_tex_use:n { max_command } }
+ { \cs_new_eq:cN { @@_cmd_#1: } \@@_tmp:w }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_prefixed_command:}
+% Accumulated prefix codes so far are stored as the last item of
+% the previous-input sequence.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prefixed_command:
+ {
+ \int_while_do:nNnn
+ \l_@@_head_cmd_int = { \@@_tex_use:n { prefix } }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnF \l_@@_head_cmd_int
+ > { \@@_tex_use:n { max_non_prefixed_command } }
+ {
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_error:nxxxx { erroneous-prefixes }
+ { \tl_to_str:N \l_@@_tmpa_tl }
+ { \tl_to_str:N l_@@_head_tl }
+ { } { }
+ \@@_back_input:
+ \@@_omit_after_assignment:w
+ }
+ }
+ % ^^A todo: Discard non-\global prefixes if they are irrelevant
+ % ^^A todo: Adjust for the setting of \globaldefs
+ \cs_if_exist_use:cF
+ { @@_prefixed_ \int_use:N \l_@@_head_cmd_int : }
+ {
+ \@@_error:nnnnn { internal } { prefixed } { } { } { }
+ \@@_omit_after_assignment:w
+ }
+ \@@_after_assignment:
+ }
+% \end{macrocode}
+% \end{macro}
+% We now need to implement prefixed commands, for command codes in the
+% range $[71,102]$, with the exception of |prefix=93|, which would have
+% been collected by the \cs{@@_prefixed_command:} loop.
+%
+% \begin{macro}{\@@_after_assignment:}
+% \begin{macro}{\@@_omit_after_assignment:w}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_after_assignment:
+ {
+ \@@_back_input_gtl:N \g_@@_after_assignment_gtl
+ \gtl_gclear:N \g_@@_after_assignment_gtl
+ }
+\cs_new_protected:Npn \@@_omit_after_assignment:w
+ #1 \@@_after_assignment: { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_prefixed_new:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prefixed_new:nn #1#2
+ {
+ \cs_new_protected:cpn
+ { @@_prefixed_ \@@_tex_use:n {#1} : } {#2}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_assign_token:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_assign_token:n #1
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ #1
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_assigned_token:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_assign_register:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_assign_register:
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_assigned_register:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_assign_value:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_assign_value:nn #1#2
+ {
+ \tl_if_empty:nF {#1}
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ #1
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ }
+ \@@_prev_input:V \l_@@_head_tl
+ \tl_set_eq:NN \l_@@_defined_tl \l_@@_head_tl
+ \@@_scan_optional_equals:
+ #2
+ \@@_assign_register:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_assign_toks:}
+% \begin{macrocode}
+\@@_prefixed_new:nn { toks_register } % 71
+ {
+ \int_compare:nNnT \l_@@_head_char_int = 0
+ { % \toks
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_action:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ }
+ \@@_assign_toks:
+ }
+\@@_prefixed_new:nn { assign_toks } % 72
+ { \@@_assign_toks: }
+\cs_new_protected:Npn \@@_assign_toks:
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_print_action:
+ \tl_set_eq:NN \l_@@_defined_tl \l_@@_head_tl
+ \@@_scan_optional_equals:
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { toks_register } }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \int_compare:nNnT \l_@@_head_char_int = 0
+ { \@@_scan_int: }
+ }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { assign_toks } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ {
+ \@@_back_input:
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ }
+ }
+ \@@_assign_register:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_prefixed_new:nn { assign_int } % 73
+ { \@@_assign_value:nn { } { \@@_scan_int: } }
+\@@_prefixed_new:nn { assign_dimen } % 74
+ { \@@_assign_value:nn { } { \@@_scan_normal_dimen: } }
+\@@_prefixed_new:nn { assign_glue } % 75
+ { \@@_assign_value:nn { } { \@@_scan_normal_glue: } }
+\@@_prefixed_new:nn { assign_mu_glue } % 76
+ { \@@_assign_value:nn { } { \@@_scan_mu_glue: } }
+\@@_prefixed_new:nn { assign_font_dimen } % 77
+ {
+ \@@_assign_value:nn
+ { \@@_scan_int: \@@_scan_font_ident: }
+ { \@@_scan_normal_dimen: }
+ }
+\@@_prefixed_new:nn { assign_font_int } % 78
+ {
+ \@@_assign_value:nn
+ { \@@_scan_font_int: } { \@@_scan_int: }
+ }
+\@@_prefixed_new:nn { set_aux } % 79
+ { % prevdepth = 1, spacefactor = 102
+ \int_compare:nNnTF \l_@@_head_char_int = 1
+ { \@@_assign_value:nn { } { \@@_scan_normal_dimen: } }
+ { \@@_assign_value:nn { } { \@@_scan_int: } }
+ }
+\@@_prefixed_new:nn { set_prev_graf } % 80
+ { \@@_assign_value:nn { } { \@@_scan_int: } }
+\@@_prefixed_new:nn { set_page_dimen } % 81
+ { \@@_assign_value:nn { } { \@@_scan_normal_dimen: } }
+\@@_prefixed_new:nn { set_page_int } % 82
+ { \@@_assign_value:nn { } { \@@_scan_int: } }
+\@@_prefixed_new:nn { set_box_dimen } % 83
+ {
+ \@@_assign_value:nn
+ { \@@_scan_int: } { \@@_scan_normal_dimen: }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_prefixed_new:nn { set_shape } % 84
+ {
+ \@@_assign_value:nn { \@@_scan_int: }
+ {
+ \prg_replicate:nn
+ {
+ \tl_if_head_eq_meaning:VNT
+ \l_@@_defined_tl \tex_parshape:D { 2 * }
+ \tl_tail:N \l_@@_defined_tl
+ }
+ { \@@_scan_int: }
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_prefixed_new:nn { def_code } % 85
+ {
+ \@@_assign_value:nn
+ { \@@_scan_int: } { \@@_scan_int: }
+ }
+\@@_prefixed_new:nn { def_family } % 86
+ {
+ \@@_assign_value:nn
+ { \@@_scan_int: } { \@@_scan_font_ident: }
+ }
+\@@_prefixed_new:nn { set_font } % 87
+ {
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_put_left:NV \l_@@_head_tl \l_@@_tmpa_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \gtl_gput_right:NV \g_@@_output_gtl \l_@@_head_tl
+ \@@_print_action:
+ }
+\@@_prefixed_new:nn { def_font } % 88
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_set_action_text:x { \tl_to_str:N \l_@@_head_tl }
+ \@@_scan_r_token:
+ \@@_print_action:x
+ { \g_@@_action_text_str \tl_to_str:N \l_@@_defined_tl }
+ \@@_scan_optional_equals:
+ \@@_scan_file_name:
+ \bool_gset_true:N \g_@@_name_in_progress_bool
+ \@@_scan_keyword:nTF { aAtT }
+ { \@@_scan_normal_dimen: }
+ {
+ \@@_scan_keyword:nT { sScCaAlLeEdD }
+ { \@@_scan_int: }
+ }
+ \bool_gset_false:N \g_@@_name_in_progress_bool
+ \@@_assign_token:n { }
+ }
+% \end{macrocode}
+%
+% |register=89|, |advance=90|, |multiply=91|, |divide=92| are
+% implemented elsewhere. |prefix=93| is never needed (see explanation
+% above).
+%
+% |let|, |futurelet|
+% \begin{macrocode}
+\@@_prefixed_new:nn { let } % 94
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_let:D
+ { % |let|
+ \@@_scan_r_token:
+ \@@_prev_input_get:N \l_@@_tmpa_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_tmpa_tl }
+ \@@_get_next:
+ \bool_while_do:nn
+ { \token_if_eq_catcode_p:NN \l_@@_head_token \c_space_token }
+ { \@@_get_next: }
+ \tl_if_eq:NNT \l_@@_head_tl \c_@@_eq_tl
+ { \@@_get_next: }
+ \token_if_eq_catcode:NNT \l_@@_head_token \c_space_token
+ { \@@_get_next: }
+ }
+ { % |futurelet|
+ \@@_scan_r_token:
+ \@@_prev_input_get:N \l_@@_tmpa_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_tmpa_tl }
+ \@@_get_next:
+ \gtl_set_eq:NN \l_@@_tmpb_gtl \l_@@_head_gtl
+ \@@_get_next:
+ \@@_back_input:
+ \gtl_set_eq:NN \l_@@_head_gtl \l_@@_tmpb_gtl
+ \@@_back_input:
+ }
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_put_right:Nn \l_@@_tmpa_tl { = ~ \l_@@_head_token }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_exp_args:Nx \use:n
+ {
+ \exp_not:V \l_@@_head_tl
+ \tex_let:D \tl_tail:N \l_@@_tmpa_tl
+ }
+ \@@_print_assigned_token:
+ }
+% \end{macrocode}
+%
+% ^^A todo: print the temporary relax assignment?
+% \begin{macrocode}
+\@@_prefixed_new:nn { shorthand_def } % 95
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \tl_set:Nx \l_@@_prev_action_tl
+ { \tl_to_str:N \l_@@_head_tl }
+ \@@_scan_r_token:
+ \@@_print_action:x
+ { \l_@@_prev_action_tl \tl_to_str:N \l_@@_defined_tl }
+ \exp_after:wN \cs_set_eq:NN \l_@@_defined_tl \scan_stop:
+ \@@_scan_optional_equals:
+ \@@_scan_int:
+ \@@_assign_token:n { }
+ }
+% \end{macrocode}
+%
+% \begin{macro}[EXP]{\@@_read_to_cs_safe:nTF, \@@_read_to_cs_safe:fTF}
+% After \tn{read} or \tn{readline}, find an int, the mandatory
+% keyword |to|, and an assignable token. The \tn{read} and
+% \tn{readline} primitives throw a fatal error in \tn{nonstopmode}
+% and in \tn{batchmode} when trying to read from a stream that is
+% outside $[0,15]$ or that is not open (according to \tn{ifeof}). We
+% detect this situation using \cs{@@_read_to_cs_safe:nTF} after
+% grabbing all arguments of the primitives. If reading is unsafe,
+% let the user know that \TeX{} would have thrown a fatal error.
+% \begin{macrocode}
+\@@_prefixed_new:nn { read_to_cs } % 96
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_print_action:x { \tl_to_str:N \l_@@_head_tl }
+ \@@_scan_int:
+ \@@_scan_to:
+ \@@_scan_r_token:
+ \@@_prev_input_get:N \l_@@_tmpa_tl
+ \@@_read_to_cs_safe:fTF
+ { \@@_tl_first_int:N \l_@@_tmpa_tl }
+ { \@@_assign_token:n { } }
+ {
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_tex_fatal_error:nV { cannot-read } \l_@@_head_tl
+ }
+ }
+\prg_new_conditional:Npnn \@@_read_to_cs_safe:n #1 { TF }
+ {
+ \int_compare:nNnTF { \tex_interactionmode:D } > { 1 }
+ { \prg_return_true: }
+ {
+ \int_compare:nNnTF {#1} < { 0 }
+ { \prg_return_false: }
+ {
+ \int_compare:nNnTF {#1} > { 15 }
+ { \prg_return_false: }
+ {
+ \tex_ifeof:D #1 \exp_stop_f:
+ \prg_return_false:
+ \else:
+ \prg_return_true:
+ \fi:
+ }
+ }
+ }
+ }
+\cs_generate_variant:Nn \@@_read_to_cs_safe:nTF { f }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_prefixed_new:nn { def } % 97
+ {
+ \@@_prev_input_get:N \l_@@_tmpa_tl
+ \tl_set:NV \l_@@_defining_tl \l_@@_tmpa_tl
+ \tl_put_right:NV \l_@@_defining_tl \l_@@_head_tl
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \int_compare:nNnTF \l_@@_head_char_int < 2
+ { % def/gdef
+ \@@_scan_r_token:
+ \tl_put_right:NV \l_@@_defining_tl \l_@@_defined_tl
+ \@@_scan_toks:NN \c_true_bool \c_false_bool
+ }
+ { % edef/xdef
+ \@@_scan_r_token:
+ \tl_put_right:NV \l_@@_defining_tl \l_@@_defined_tl
+ \@@_scan_toks:NN \c_true_bool \c_true_bool
+ }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_assign_token:n
+ { \tl_set_eq:NN \l_@@_head_tl \l_@@_defining_tl }
+ }
+% \end{macrocode}
+%
+% \tn{setbox} is a bit special: directly put it in
+% the previous-input sequence with the prefixes; the box code will take
+% care of things, and expects a single item containing what it needs to
+% do.
+% \begin{macrocode}
+\@@_prefixed_new:nn { set_box } % 98
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_int:
+ \@@_scan_optional_equals:
+ \bool_if:NTF \g_@@_set_box_allowed_bool
+ { \@@_do_box:N \c_false_bool }
+ {
+ \@@_error:nnnnn { improper-setbox } { } { } { } { }
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_omit_after_assignment:w
+ }
+ }
+% \end{macrocode}
+%
+% ^^A todo: \hyphenation{...{...}...} recovers weirdly (no nesting).
+% \tn{hyphenation} and \tn{patterns}
+% \begin{macrocode}
+\@@_prefixed_new:nn { hyph_data } % 99
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ \@@_assign_token:n { }
+ }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_prefixed_new:nn { set_interaction } % 100
+ {
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_put_left:NV \l_@@_head_tl \l_@@_tmpa_tl
+ \tl_use:N \l_@@_head_tl \scan_stop:
+ \@@_print_assignment:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+%
+% ^^A todo: print the temporary nullfont assignment?
+% \begin{macrocode}
+\@@_prefixed_new:nn { letterspace_font } % 101
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_set_action_text:x { \tl_to_str:N \l_@@_head_tl }
+ \@@_scan_r_token:
+ \@@_print_action:x
+ { \g_@@_action_text_str \tl_to_str:N \l_@@_defined_tl }
+ \exp_after:wN \cs_set_eq:NN \l_@@_defined_tl \@@_nullfont:
+ \@@_scan_optional_equals:
+ \@@_scan_font_ident:
+ \@@_scan_int:
+ \@@_assign_token:n { }
+ }
+% \end{macrocode}
+%
+% ^^A todo: print the temporary nullfont assignment?
+% \begin{macrocode}
+\@@_prefixed_new:nn { pdf_copy_font } % 102
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_set_action_text:x { \tl_to_str:N \l_@@_head_tl }
+ \@@_scan_r_token:
+ \@@_print_action:x
+ { \g_@@_action_text_str \tl_to_str:N \l_@@_defined_tl }
+ \exp_after:wN \cs_set_eq:NN \l_@@_defined_tl \@@_nullfont:
+ \@@_scan_optional_equals:
+ \@@_scan_font_ident:
+ \@@_assign_token:n { }
+ }
+% \end{macrocode}
+%
+% Changes to numeric registers (\tn{count}, \tn{dimen}, \tn{skip},
+% \tn{muskip}, and commands with a built-in number).
+% \begin{macrocode}
+\@@_prefixed_new:nn { register } % 89
+ { \@@_do_register:N 0 }
+\@@_prefixed_new:nn { advance } % 90
+ { \@@_do_operation:N 1 }
+\@@_prefixed_new:nn { multiply } % 91
+ { \@@_do_operation:N 2 }
+\@@_prefixed_new:nn { divide } % 92
+ { \@@_do_operation:N 3 }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_do_operation:N, \@@_do_operation_fail:w}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_operation:N #1
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_print_action:
+ \@@_get_x_next:
+ \@@_set_cmd:
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int > { \@@_tex_use:n { assign_mu_glue } }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { register } }
+ { \@@_do_register:N #1 }
+ { \@@_do_operation_fail:w }
+ }
+ {
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int < { \@@_tex_use:n { assign_int } }
+ { \@@_do_operation_fail:w }
+ {
+ \@@_prev_input:V \l_@@_head_tl
+ \exp_args:NNf \@@_do_register_set:Nn #1
+ {
+ \int_eval:n
+ {
+ \l_@@_head_cmd_int
+ - \@@_tex_use:n { assign_toks }
+ }
+ }
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_do_operation_fail:w
+ {
+ \@@_error:nnnnn { after-advance } { } { } { } { }
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_omit_after_assignment:w
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_register:N, \@@_do_register_aux:Nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_register:N #1
+ {
+ \exp_args:NNV \@@_do_register_aux:Nn #1
+ \l_@@_head_char_int
+ }
+\cs_new_protected:Npn \@@_do_register_aux:Nn #1#2
+ {
+ \int_compare:nNnTF { \tl_tail:n {#2} } = 0
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_assignment:
+ \@@_scan_int:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_prev_input_silent:V \l_@@_head_tl
+ }
+ {
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_print_assignment:
+ }
+ \tl_set_eq:NN \l_@@_defined_tl \l_@@_head_tl
+ \exp_args:NNf \@@_do_register_set:Nn #1
+ { \int_eval:n { #2 / 1 000 000 } }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_do_register_set:Nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_register_set:Nn #1#2
+ {
+ \int_compare:nNnTF {#1} = 0
+ { % truly register command
+ \@@_scan_optional_equals:
+ }
+ { % \advance, \multiply, \divide
+ \@@_scan_keyword:nF { bByY }
+ { \@@_prev_input_silent:n { by } }
+ }
+ \int_compare:nNnTF {#1} < 2
+ {
+ \int_case:nnF {#2}
+ {
+ { 1 } { \@@_scan_int: } % count
+ { 2 } { \@@_scan_normal_dimen: } % dim
+ { 3 } { \@@_scan_normal_glue: } % glue
+ { 4 } { \@@_scan_mu_glue: } % muglue
+ }
+ { \@@_error:nxxxx { internal } { do-reg=#2 } { } { } { } }
+ }
+ { \@@_scan_int: }
+ \@@_assign_register:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% The following is used for instance when making accents.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_do_assignments:
+ {
+ \@@_get_x_non_relax:
+ \@@_set_cmd:
+ \int_compare:nNnT
+ \l_@@_head_cmd_int
+ > { \@@_tex_use:n { max_non_prefixed_command } }
+ {
+ \bool_gset_false:N \g_@@_set_box_allowed_bool
+ \@@_prev_input_gpush:
+ \@@_prefixed_command:
+ \bool_gset_true:N \g_@@_set_box_allowed_bool
+ \@@_do_assignments:
+ }
+ }
+% \end{macrocode}
+%
+% \subsection{Expandable primitives}
+%
+% This section implements expandable primitives, which have the
+% following command codes:
+% \begin{itemize}
+% \item |undefined_cs=103| for undefined control sequences (not quite a
+% primitive).
+% \item |expand_after=104| for \tn{expandafter} and \tn{unless}.
+% \item |no_expand=105| for \tn{noexpand} and \tn{pdfprimitive}.
+% \item |input=106| for \tn{input}, \tn{endinput} and \tn{scantokens}.
+% \item |if_test=107| for the conditionals, \tn{if}, \tn{ifcat},
+% \tn{ifnum}, \tn{ifdim}, \tn{ifodd}, \tn{ifvmode}, \tn{ifhmode},
+% \tn{ifmmode}, \tn{ifinner}, \tn{ifvoid}, \tn{ifhbox}, \tn{ifvbox},
+% \tn{ifx}, \tn{ifeof}, \tn{iftrue}, \tn{iffalse}, \tn{ifcase},
+% \tn{ifdefined}, \tn{ifcsname}, \tn{iffontchar}, \tn{ifincsname},
+% \tn{ifpdfprimitive}, \tn{ifpdfabsnum}, and \tn{ifpdfabsdim}.
+% \item |fi_or_else=108| for \tn{fi}, \tn{else} and \tn{or}.
+% \item |cs_name=109| for \tn{csname}.
+% \item |convert=110| for \tn{number}, \tn{romannumeral}, \tn{string},
+% \tn{meaning}, \tn{fontname}, \tn{eTeXrevision}, \tn{pdftexrevision},
+% \tn{pdftexbanner}, \tn{pdffontname}, \tn{pdffontobjnum},
+% \tn{pdffontsize}, \tn{pdfpageref}, \tn{pdfxformname},
+% \tn{pdfescapestring}, \tn{pdfescapename}, \tn{leftmarginkern},
+% \tn{rightmarginkern}, \tn{pdfstrcmp}, \tn{pdfcolorstackinit},
+% \tn{pdfescapehex}, \tn{pdfunescapehex}, \tn{pdfcreationdate},
+% \tn{pdffilemoddate}, \tn{pdffilesize}, \tn{pdfmdfivesum},
+% \tn{pdffiledump}, \tn{pdfmatch}, \tn{pdflastmatch},
+% \tn{pdfuniformdeviate}, \tn{pdfnormaldeviate}, \tn{pdfinsertht},
+% \tn{pdfximagebbox}, \tn{jobname}, and in
+% \LuaTeX{} \tn{directlua}, \tn{expanded}, \tn{luaescapestring}.
+% \item |the=111| for \tn{the}, \tn{unexpanded}, and \tn{detokenize}.
+% \item |top_bot_mark=112| \tn{topmark}, \tn{firstmark}, \tn{botmark},
+% \tn{splitfirstmark}, \tn{splitbotmark}, \tn{topmarks},
+% \tn{firstmarks}, \tn{botmarks}, \tn{splitfirstmarks}, and
+% \tn{splitbotmarks}.
+% \item |call=113| for macro calls, implemented by \cs{@@_macro_call:}.
+% \item |end_template=117| for \TeX{}'s end template.
+% \end{itemize}
+%
+% Let \TeX{} trigger an error.
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { undefined_cs } % 103
+ { \tl_use:N \l_@@_head_tl \@@_print_expansion: }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_expandafter:, \@@_unless:, \@@_unless_bad:}
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { expand_after } % 104
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_expandafter:D
+ { \@@_expandafter: } { \@@_unless: }
+ }
+\cs_new_protected:Npn \@@_expandafter:
+ {
+ \gtl_set_eq:NN \l_@@_tmpb_gtl \l_@@_head_gtl
+ \@@_get_next:
+ \gtl_concat:NNN \l_@@_head_gtl
+ \l_@@_tmpb_gtl \l_@@_head_gtl
+ \@@_prev_input_gpush_gtl:N \l_@@_head_gtl
+ \@@_print_expansion:x { \gtl_to_str:N \l_@@_head_gtl }
+ \@@_get_next:
+ \@@_token_if_expandable:NTF \l_@@_head_token
+ { \@@_expand_do:N \prg_do_nothing: }
+ { \@@_back_input: }
+ \@@_prev_input_gpop:N \l_@@_head_gtl
+ \@@_set_action_text:x
+ { back_input: ~ \gtl_to_str:N \l_@@_head_gtl }
+ \gtl_pop_left:N \l_@@_head_gtl
+ \@@_back_input:
+ \@@_print_expansion:
+ }
+\cs_new_protected:Npn \@@_unless:
+ {
+ \@@_get_token:
+ \int_compare:nNnTF
+ \l_@@_head_cmd_int = { \@@_tex_use:n { if_test } }
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_ifcase:D
+ { \@@_unless_bad: }
+ {
+ \tl_put_left:Nn \l_@@_head_tl { \reverse_if:N }
+ % \int_add:Nn \l_@@_head_char_int { 32 }
+ \@@_expand_nonmacro:
+ }
+ }
+ { \@@_unless_bad: }
+ }
+\cs_new_protected:Npn \@@_unless_bad:
+ {
+ \@@_error:nnnnn { bad-unless } { } { } { } { }
+ \@@_back_input:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_noexpand:N, \@@_noexpand_after:, \@@_pdfprimitive:}
+% Currently not fully implemented.
+%
+% The argument of \cs{@@_noexpand:N} is \cs{prg_do_nothing:} when
+% \tn{noexpand} is hit by \tn{expandafter}; otherwise it is one of
+% various loop commands (\cs{@@_get_x_next:},
+% \cs{@@_get_x_or_protected:}, \cs{@@_get_token_xdef:},
+% \cs{@@_get_token_x:}) that would call \cs{@@_get_next:} and possibly
+% expand the token more. For these cases we simply stop after
+% \cs{@@_get_next:} and if the token is expandable we pretend its
+% meaning is \tn{relax}.
+%
+% The case of \tn{expandafter} (so \cs{prg_do_nothing:}) is tougher.
+% Do nothing if the next token is an explicit non-active character
+% (begin-group and end-group characters are detected by
+% \cs{l_@@_head_tl}, the rest by testing if the token is definable).
+% Otherwise the token must be marked with \cs{notexpanded:} (even if
+% the token is currently a non-expandable primitive, as its meaning
+% can be changed by the code skipped over by \tn{expandafter}). That
+% \cs{notexpanded:} marker should be removed if the token is taken as
+% the argument of a macro, but we fail to do that. We set the
+% \cs{notexpanded:\ldots{}} command to be a special \tn{relax} marker
+% to make it quickly recognizable in \cs{@@_get_next:}. This is
+% incidentally the same meaning used by \TeX{} for expandable commands.
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { no_expand } % 105
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \tex_noexpand:D
+ { \@@_noexpand:N }
+ { \@@_pdfprimitive: }
+ }
+\cs_new_protected:Npn \@@_noexpand:N #1
+ {
+ \@@_get_token:
+ \cs_if_eq:NNTF #1 \prg_do_nothing:
+ {
+ \tl_if_empty:NTF \l_@@_head_tl
+ { \@@_back_input: }
+ {
+ \exp_after:wN \@@_token_if_definable:NTF \l_@@_head_tl
+ { \@@_noexpand_after: }
+ { \@@_back_input: }
+ }
+ }
+ {
+ \@@_back_input:
+ \@@_get_next:
+ \@@_token_if_expandable:NT \l_@@_head_token
+ { \cs_set_eq:NN \l_@@_head_token \@@_special_relax: }
+ }
+ }
+\cs_new_protected:Npn \@@_noexpand_after:
+ {
+ \group_begin:
+ \@@_set_escapechar:n { 92 }
+ \exp_args:NNc
+ \group_end:
+ \@@_noexpand_after:N
+ { notexpanded: \exp_after:wN \token_to_str:N \l_@@_head_tl }
+ }
+\cs_new_protected:Npn \@@_noexpand_after:N #1
+ {
+ \cs_gset_eq:NN #1 \@@_special_relax:
+ \@@_back_input:n {#1}
+ }
+\cs_new_protected:Npn \@@_pdfprimitive:
+ { \@@_not_implemented:n { pdfprimitive } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_endinput:, \@@_scantokens:, \@@_input:}
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { input } % 106
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 1 } { \@@_endinput: } % \endinput
+ { 2 } { \@@_scantokens: } % \scantokens
+ }
+ { % 0=\input
+ \bool_if:NTF \g_@@_name_in_progress_bool
+ { \@@_insert_relax: } { \@@_input: }
+ }
+ }
+\cs_new_protected:Npn \@@_endinput:
+ {
+ \group_begin:
+ \msg_warning:nn { unravel } { endinput-ignored }
+ \group_end:
+ \@@_print_expansion:
+ }
+\cs_new_protected:Npn \@@_scantokens:
+ {
+ \@@_prev_input_gpush:
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \tl_set_rescan:Nno \l_@@_head_tl { } \l_@@_tmpa_tl
+ \@@_back_input:V \l_@@_head_tl
+ \@@_print_expansion:x { \tl_to_str:N \l_@@_tmpa_tl }
+ }
+\cs_new_protected:Npn \@@_input:
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_scan_file_name:
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \tl_set:Nx \l_@@_tmpa_tl { \tl_tail:N \l_@@_head_tl }
+ \@@_file_get:nN \l_@@_tmpa_tl \l_@@_tmpa_tl
+ \@@_back_input:V \l_@@_tmpa_tl
+ \@@_print_expansion:x { \tl_to_str:N \l_@@_head_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_csname_loop:}
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { cs_name } % 109
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \@@_csname_loop:
+ \@@_prev_input_silent:V \l_@@_head_tl
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_back_input_tl_o:
+ }
+\cs_new_protected:Npn \@@_csname_loop:
+ {
+ \@@_get_x_next:
+ \@@_gtl_if_head_is_definable:NTF \l_@@_head_gtl
+ {
+ \cs_if_eq:NNF \l_@@_head_token \tex_endcsname:D
+ {
+ \@@_back_input:
+ \@@_tex_error:nV { missing-endcsname } \l_@@_head_tl
+ \tl_set:Nn \l_@@_head_tl { \tex_endcsname:D }
+ }
+ }
+ {
+ \@@_prev_input_silent:x
+ { \@@_token_to_char:N \l_@@_head_token }
+ \@@_csname_loop:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { convert } % 110
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \int_case:nn \l_@@_head_char_int
+ {
+ 0 \@@_scan_int:
+ 1 \@@_scan_int:
+ 2 \@@_convert_string:
+ 3 \@@_convert_meaning:
+ 4 \@@_scan_font_ident:
+ 8 \@@_scan_font_ident:
+ 9 \@@_scan_font_ident:
+ { 10 } \@@_scan_font_ident:
+ { 11 } \@@_scan_int:
+ { 12 } \@@_scan_int:
+ { 13 } \@@_scan_pdf_ext_toks:
+ { 14 } \@@_scan_pdf_ext_toks:
+ { 15 } \@@_scan_int:
+ { 16 } \@@_scan_int:
+ { 17 } \@@_scan_pdfstrcmp:
+ { 18 } \@@_scan_pdfcolorstackinit:
+ { 19 } \@@_scan_pdf_ext_toks:
+ { 20 } \@@_scan_pdf_ext_toks:
+ { 22 } \@@_scan_pdf_ext_toks:
+ { 23 } \@@_scan_pdf_ext_toks:
+ { 24 }
+ {
+ \@@_scan_keyword:n { fFiIlLeE }
+ \@@_scan_pdf_ext_toks:
+ }
+ { 25 } \@@_scan_pdffiledump:
+ { 26 } \@@_scan_pdfmatch:
+ { 27 } \@@_scan_int:
+ { 28 } \@@_scan_int:
+ { 30 } \@@_scan_int:
+ { 31 } \@@_scan_pdfximagebbox:
+ { 33 } \@@_scan_directlua:
+ { 34 } \@@_scan_pdf_ext_toks:
+ { 35 } \@@_scan_pdf_ext_toks:
+ { 40 }
+ {
+ \@@_scan_int:
+ \@@_prev_input_silent:n { ~ }
+ \@@_scan_int:
+ }
+ }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_back_input_tl_o:
+ }
+\cs_new_protected:Npn \@@_convert_string:
+ {
+ \@@_get_next:
+ \tl_if_empty:NTF \l_@@_head_tl
+ { \@@_prev_input:x { \gtl_to_str:N \l_@@_head_gtl } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ }
+\cs_new_protected:Npn \@@_convert_meaning:
+ {
+ \@@_get_next:
+ \tl_if_empty:NTF \l_@@_head_tl
+ { \@@_prev_input:n { \l_@@_head_token } }
+ { \@@_prev_input:V \l_@@_head_tl }
+ }
+\cs_new_protected:Npn \@@_scan_pdfstrcmp:
+ {
+ \@@_scan_toks_to_str:
+ \@@_scan_toks_to_str:
+ }
+\cs_new_protected:Npn \@@_scan_pdfximagebbox:
+ { \@@_scan_int: \@@_scan_int: }
+\cs_new_protected:Npn \@@_scan_pdfcolorstackinit:
+ {
+ \@@_scan_keyword:nTF { pPaAgGeE }
+ { \bool_set_true:N \l_@@_tmpa_bool }
+ { \bool_set_false:N \l_@@_tmpb_bool }
+ \@@_scan_keyword:nF { dDiIrReEcCtT }
+ { \@@_scan_keyword:n { pPaAgGeE } }
+ \@@_scan_toks_to_str:
+ }
+\cs_new_protected:Npn \@@_scan_pdffiledump:
+ {
+ \@@_scan_keyword:nT { oOfFfFsSeEtT } \@@_scan_int:
+ \@@_scan_keyword:nT { lLeEnNgGtThH } \@@_scan_int:
+ \@@_scan_pdf_ext_toks:
+ }
+\cs_new_protected:Npn \@@_scan_pdfmatch:
+ {
+ \@@_scan_keyword:n { iIcCaAsSeE }
+ \@@_scan_keyword:nT { sSuUbBcCoOuUnNtT }
+ { \@@_scan_int: }
+ \@@_scan_pdf_ext_toks:
+ \@@_scan_pdf_ext_toks:
+ }
+\sys_if_engine_luatex:T
+ {
+ \cs_new_protected:Npn \@@_scan_directlua:
+ {
+ \@@_get_x_non_relax:
+ \token_if_eq_catcode:NNTF \l_@@_head_token \c_group_begin_token
+ { \@@_back_input: }
+ {
+ \@@_scan_int:
+ \@@_get_x_non_relax:
+ }
+ \@@_scan_pdf_ext_toks:
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_get_the:N}
+% |#1| is \cs{@@_get_token_xdef:} in \tn{edef} or \tn{xdef},
+% \cs{@@_get_token_x:} in \tn{message} and the like, and can be other
+% commands.
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { the } % 111
+ { \@@_get_the:N }
+\cs_new_protected:Npn \@@_get_the:N #1
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \int_if_odd:nTF \l_@@_head_char_int
+ { % \unexpanded, \detokenize
+ \@@_scan_toks:NN \c_false_bool \c_false_bool
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_set_action_text:x { \tl_to_str:N \l_@@_head_tl }
+ }
+ { % \the
+ \@@_get_x_next:
+ \@@_scan_something_internal:n { 5 }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_set_action_text:x
+ {
+ \tl_head:N \l_@@_head_tl
+ => \tl_tail:N \l_@@_head_tl
+ }
+ \tl_set:Nx \l_@@_head_tl
+ { \exp_not:N \exp_not:n { \tl_tail:N \l_@@_head_tl } }
+ }
+ \cs_if_eq:NNTF #1 \@@_get_token_xdef:
+ {
+ \tl_put_right:NV \l_@@_defining_tl \l_@@_head_tl
+ \@@_prev_input:V \l_@@_head_tl
+ }
+ {
+ \cs_if_eq:NNTF #1 \@@_get_token_x:
+ {
+ \@@_exp_args:NNx \gtl_set:Nn \l_@@_tmpb_gtl { \l_@@_head_tl }
+ \@@_prev_input_gtl:N \l_@@_tmpb_gtl
+ }
+ {
+ \tl_set:Nx \l_@@_tmpa_tl { \exp_args:NV \exp_not:o \l_@@_head_tl }
+ \@@_back_input:V \l_@@_tmpa_tl
+ }
+ \@@_print_expansion:
+ }
+ #1
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { top_bot_mark } % 112
+ { \@@_back_input_tl_o: }
+% \end{macrocode}
+%
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { end_template } % 117
+ {
+ \@@_not_implemented:n { end-template } { } { } { }
+ \@@_back_input_tl_o:
+ }
+% \end{macrocode}
+%
+%
+% \subsubsection{Conditionals}
+%
+% ^^A todo: simply use \cs{@@_input_gpop:N} right away.
+% \begin{macro}{\@@_pass_text:}
+% \begin{macro}{\@@_pass_text_done:w}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_pass_text:
+ {
+ \@@_input_if_empty:TF
+ { \@@_pass_text_empty: }
+ {
+ \@@_input_get:N \l_@@_tmpb_gtl
+ \if_true:
+ \if_case:w \gtl_head_do:NN \l_@@_tmpb_gtl \c_one_int
+ \exp_after:wN \@@_pass_text_done:w
+ \fi:
+ \@@_input_gpop:N \l_@@_tmpb_gtl
+ \exp_after:wN \@@_pass_text:
+ \else:
+ \use:c { fi: }
+ \int_set:Nn \l_@@_if_nesting_int { 1 }
+ \@@_input_gpop:N \l_@@_tmpb_gtl
+ \exp_after:wN \@@_pass_text_nested:
+ \fi:
+ }
+ }
+\cs_new_protected:Npn \@@_pass_text_done:w
+ {
+ \@@_get_next:
+ \token_if_eq_meaning:NNT \l_@@_head_token \fi: { \if_true: }
+ \else:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_pass_text_nested:}
+% Again, if there is no more input we are in trouble. The
+% construction otherwise essentially results in
+% \begin{quote}
+% \cs{if_true:} \cs{if_true:} \cs{else:} \meta{head} \\
+% \cs{int_decr:N} \cs{l_@@_if_nesting_int} \cs{use_none:nnnnn} \cs{fi:} \\
+% \cs{use_none:nnn} \cs{fi:} \\
+% \cs{int_incr:N} \cs{l_@@_if_nesting_int} \cs{fi:}
+% \end{quote}
+% If the \meta{head} is a primitive |\if...|, then the \cs{if_true:}
+% \cs{else:} ends with the second \cs{fi:}, and the nesting integer is
+% incremented before appropriately closing the \cs{if_true:}. If it
+% is a normal token or \tn{or} or \tn{else}, \cs{use_none:nnn} cleans
+% up, leaving the appropriate number of \cs{fi:}. Finally, if it is
+% \cs{fi:}, the nesting integer is decremented before removing most
+% \cs{fi:}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_pass_text_nested:
+ {
+ \@@_input_if_empty:TF
+ { \@@_pass_text_empty: }
+ {
+ \@@_input_get:N \l_@@_tmpb_gtl
+ \if_true:
+ \if_true:
+ \gtl_head_do:NN \l_@@_tmpb_gtl \else:
+ \int_decr:N \l_@@_if_nesting_int
+ \use_none:nnnnn
+ \fi:
+ \use_none:nnn
+ \fi:
+ \int_incr:N \l_@@_if_nesting_int
+ \fi:
+ \@@_input_gpop:N \l_@@_unused_gtl
+ \int_compare:nNnTF \l_@@_if_nesting_int = 0
+ { \@@_pass_text: }
+ { \@@_pass_text_nested: }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_pass_text_empty:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_pass_text_empty:
+ {
+ \@@_error:nnnnn { runaway-if } { } { } { } { }
+ \@@_exit_hard:w
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_cond_push:, \@@_cond_pop:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_cond_push:
+ {
+ \tl_gput_left:Nx \g_@@_if_limit_tl
+ { { \int_use:N \g_@@_if_limit_int } }
+ \int_gincr:N \g_@@_if_depth_int
+ \int_gzero:N \g_@@_if_limit_int
+ }
+\cs_new_protected:Npn \@@_cond_pop:
+ {
+ \int_gset:Nn \g_@@_if_limit_int
+ { \tl_head:N \g_@@_if_limit_tl }
+ \tl_gset:Nx \g_@@_if_limit_tl
+ { \tl_tail:N \g_@@_if_limit_tl }
+ \int_gdecr:N \g_@@_if_depth_int
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_change_if_limit:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_change_if_limit:nn #1#2
+ {
+ \int_compare:nNnTF {#2} = \g_@@_if_depth_int
+ { \int_gset:Nn \g_@@_if_limit_int {#1} }
+ {
+ \tl_clear:N \l_@@_tmpa_tl
+ \prg_replicate:nn { \g_@@_if_depth_int - #2 - 1 }
+ {
+ \tl_put_right:Nx \l_@@_tmpa_tl
+ { { \tl_head:N \g_@@_if_limit_tl } }
+ \tl_gset:Nx \g_@@_if_limit_tl
+ { \tl_tail:N \g_@@_if_limit_tl }
+ }
+ \tl_gset:Nx \g_@@_if_limit_tl
+ { \l_@@_tmpa_tl {#1} \tl_tail:N \g_@@_if_limit_tl }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { if_test } % 107
+ {
+ \@@_cond_push:
+ \exp_args:NV \@@_cond_aux:n \g_@@_if_depth_int
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_cond_aux:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_cond_aux:n #1
+ {
+ \int_case:nnF \l_@@_head_char_int
+ {
+ { 0 } { \@@_test_two_chars:nn { 0 } {#1} } % if
+ { 1 } { \@@_test_two_chars:nn { 1 } {#1} } % ifcat
+ { 12 } { \@@_test_ifx:n {#1} }
+ { 16 } { \@@_test_case:n {#1} }
+ { 21 } { \@@_test_pdfprimitive:n {#1} } % ^^A todo and \unless
+ }
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \int_case:nn \l_@@_head_char_int
+ {
+ { 2 } % ifnum
+ { \@@_test_two_vals:N \@@_scan_int: }
+ { 3 } % ifdim
+ { \@@_test_two_vals:N \@@_scan_normal_dimen: }
+ { 4 } { \@@_scan_int: } % ifodd
+ % { 5 } { } % ifvmode
+ % { 6 } { } % ifhmode
+ % { 7 } { } % ifmmode
+ % { 8 } { } % ifinner
+ { 9 } { \@@_scan_int: } % ifvoid
+ { 10 } { \@@_scan_int: } % ifhbox
+ { 11 } { \@@_scan_int: } % ifvbox
+ { 13 } { \@@_scan_int: } % ifeof
+ % { 14 } { } % iftrue
+ % { 15 } { } % iffalse
+ { 17 } { \@@_test_ifdefined: } % ifdefined
+ { 18 } { \@@_test_ifcsname: } % ifcsname
+ { 19 } % iffontchar
+ { \@@_scan_font_ident: \@@_scan_int: }
+ % { 20 } { } % ifincsname % ^^A todo: something?
+ { 22 } % ifpdfabsnum
+ { \@@_test_two_vals:N \@@_scan_int: }
+ { 23 } % ifpdfabsdim
+ { \@@_test_two_vals:N \@@_scan_normal_dimen: }
+ }
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_set_action_text:x { \tl_to_str:N \l_@@_head_tl }
+ \l_@@_head_tl \scan_stop:
+ \exp_after:wN \@@_cond_true:n
+ \else:
+ \exp_after:wN \@@_cond_false:n
+ \fi:
+ {#1}
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_cond_true:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_cond_true:n #1
+ {
+ \@@_change_if_limit:nn { 3 } {#1} % wait for else/fi
+ \@@_print_expansion:x { \g_@@_action_text_str = true }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_cond_false:n, \@@_cond_false_loop:n, \@@_cond_false_common:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_cond_false:n #1
+ {
+ \@@_cond_false_loop:n {#1}
+ \@@_cond_false_common:
+ \@@_print_expansion:x
+ {
+ \g_@@_action_text_str = false ~
+ => ~ skipped ~ to ~ \iow_char:N\\fi
+ }
+ }
+\cs_new_protected:Npn \@@_cond_false_loop:n #1
+ {
+ \@@_pass_text:
+ \int_compare:nNnTF \g_@@_if_depth_int = {#1}
+ {
+ \token_if_eq_meaning:NNT \l_@@_head_token \or:
+ {
+ \@@_error:nnnnn { extra-or } { } { } { } { }
+ \@@_cond_false_loop:n {#1}
+ }
+ }
+ {
+ \token_if_eq_meaning:NNT \l_@@_head_token \fi:
+ { \@@_cond_pop: }
+ \@@_cond_false_loop:n {#1}
+ }
+ }
+\cs_new_protected:Npn \@@_cond_false_common:
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \fi:
+ { \@@_cond_pop: }
+ { \int_gset:Nn \g_@@_if_limit_int { 2 } } % wait for fi
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_test_two_vals:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_two_vals:N #1
+ {
+ #1
+ \@@_get_x_non_blank:
+ \@@_tl_if_in:ooTF { < = > } \l_@@_head_tl { }
+ {
+ \@@_error:nnnnn { missing-equals } { } { } { } { }
+ \@@_back_input:
+ \tl_set:Nn \l_@@_head_tl { = }
+ }
+ \@@_prev_input:V \l_@@_head_tl
+ #1
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: fix interaction with noexpand and active chars (what interaction?)
+% \begin{macro}{\@@_test_two_chars:nn, \@@_test_two_chars_get:n, \@@_test_two_chars_gtl:N}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_two_chars:nn #1
+ {
+ \@@_prev_input_gpush_gtl:N \l_@@_head_gtl
+ \@@_print_expansion:
+ \@@_test_two_chars_get:n {#1}
+ \@@_test_two_chars_get:n {#1}
+ \@@_prev_input_gpop_gtl:N \l_@@_head_gtl
+ \@@_set_action_text:x { \gtl_to_str:N \l_@@_head_gtl }
+ \gtl_pop_left_item:NNTF \l_@@_head_gtl \l_@@_head_tl { } { }
+ \gtl_pop_left:NN \l_@@_head_gtl \l_@@_tmpb_gtl
+ \@@_test_two_chars_gtl:N \l_@@_tmpb_gtl
+ \@@_test_two_chars_gtl:N \l_@@_head_gtl
+ \l_@@_head_tl \scan_stop:
+ \exp_after:wN \@@_cond_true:n
+ \else:
+ \exp_after:wN \@@_cond_false:n
+ \fi:
+ }
+\cs_new_protected:Npn \@@_test_two_chars_get:n #1
+ {
+ \@@_get_x_next:
+ \int_compare:nNnT {#1} = 0
+ {
+ \gtl_if_head_is_N_type:NF \l_@@_head_gtl
+ { \gtl_set:Nx \l_@@_head_gtl { \gtl_to_str:N \l_@@_head_gtl } }
+ }
+ \@@_prev_input_gtl:N \l_@@_head_gtl
+ \@@_print_action:x { \gtl_to_str:N \l_@@_head_gtl }
+ }
+\cs_new_protected:Npn \@@_test_two_chars_gtl:N #1
+ {
+ \tl_put_right:Nx \l_@@_head_tl
+ {
+ \gtl_if_head_is_group_begin:NTF #1 { \c_group_begin_token }
+ {
+ \gtl_if_head_is_group_end:NTF #1 { \c_group_end_token }
+ { \exp_not:N \exp_not:N \gtl_head_do:NN #1 \exp_not:N }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_test_ifx:n, \@@_test_ifx_str:NN, \@@_test_ifx_aux:NNN, \@@_test_ifx_aux:w}
+% The token equal to \tn{ifx} is pushed as a previous input to show an
+% action nicely, then retrieved as \cs{l_@@_tmpa_tl} after getting the
+% next two tokens as |tmpb| and |head|. Then we call
+% \cs{l_@@_tmpa_tl} followed by these two tokens. A previous
+% implementation made sure to get these tokens from unpacking the
+% |gtl|, presumably (I should have documented, now I might be missing
+% something) to deal nicely with the master counter in case these
+% tokens are braces. On the other hand we must take care of tokens
+% affected by \tn{noexpand} and whose current definition is
+% expandable, in which case the trustworthy \tn{meaning} is that of
+% the \cs{l_@@_head_token} or \cs{l_@@_tmpb_token} rather than that of
+% the token in \cs{l_@@_head_gtl} or \cs{l_@@_tmpb_gtl}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_ifx:n #1
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \@@_get_next:
+ \gtl_set_eq:NN \l_@@_tmpb_gtl \l_@@_head_gtl
+ \cs_set_eq:NN \l_@@_tmpb_token \l_@@_head_token
+ \@@_get_next:
+ \@@_prev_input_gpop:N \l_@@_tmpa_tl
+ \@@_set_action_text:x
+ {
+ Compare:~ \tl_to_str:N \l_@@_tmpa_tl
+ \@@_test_ifx_str:NN \l_@@_tmpb_token \l_@@_tmpb_gtl
+ \@@_test_ifx_str:NN \l_@@_head_token \l_@@_head_gtl
+ }
+ \@@_test_ifx_aux:NNN \l_@@_tmpb_token \l_@@_tmpb_gtl
+ \@@_test_ifx_aux:w
+ \exp_after:wN \@@_cond_true:n
+ \else:
+ \exp_after:wN \@@_cond_false:n
+ \fi:
+ {#1}
+ }
+\cs_new:Npn \@@_test_ifx_str:NN #1#2
+ {
+ \token_if_eq_meaning:NNT #1 \@@_special_relax:
+ { \iow_char:N \\notexpanded: }
+ \gtl_to_str:N #2
+ }
+\cs_new_protected:Npn \@@_test_ifx_aux:NNN #1#2#3
+ {
+ \token_if_eq_meaning:NNTF #1 \@@_special_relax:
+ {
+ \gtl_head_do:NN #2 \@@_token_if_expandable:NTF
+ { #3 #1 } { \gtl_head_do:NN #2 #3 }
+ }
+ { \gtl_head_do:NN #2 #3 }
+ }
+\cs_new:Npn \@@_test_ifx_aux:w
+ {
+ \@@_test_ifx_aux:NNN \l_@@_head_token \l_@@_head_gtl
+ \l_@@_tmpa_tl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_test_case:n, \@@_test_case_aux:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_case:n #1
+ {
+ \@@_prev_input_gpush:N \l_@@_head_tl
+ \@@_print_expansion:
+ \bool_if:NT \g_@@_internal_debug_bool { \iow_term:n { {\ifcase level~#1} } }
+ \@@_scan_int:
+ \@@_prev_input_get:N \l_@@_head_tl
+ \tl_set:Nx \l_@@_head_tl { \tl_tail:N \l_@@_head_tl }
+ % ^^A does text_case_aux use prev_input_seq?
+ \exp_args:No \@@_test_case_aux:nn { \l_@@_head_tl } {#1}
+ \@@_prev_input_gpop:N \l_@@_head_tl
+ \@@_print_expansion:x { \tl_to_str:N \l_@@_head_tl }
+ }
+\cs_new_protected:Npn \@@_test_case_aux:nn #1#2
+ {
+ \int_compare:nNnTF {#1} = 0
+ { \@@_change_if_limit:nn { 4 } {#2} }
+ {
+ \@@_pass_text:
+ \int_compare:nNnTF \g_@@_if_depth_int = {#2}
+ {
+ \token_if_eq_meaning:NNTF \l_@@_head_token \or:
+ {
+ \exp_args:Nf \@@_test_case_aux:nn
+ { \int_eval:n { #1 - 1 } } {#2}
+ }
+ { \@@_cond_false_common: }
+ }
+ {
+ \token_if_eq_meaning:NNT \l_@@_head_token \fi:
+ { \@@_cond_pop: }
+ \@@_test_case_aux:nn {#1} {#2}
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_test_ifdefined:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_ifdefined:
+ {
+ \@@_input_if_empty:TF
+ { \@@_pass_text_empty: }
+ {
+ \@@_input_gpop:N \l_@@_tmpb_gtl
+ \@@_set_action_text:x
+ {
+ Conditional:~ \tl_to_str:N \l_@@_head_tl
+ \gtl_to_str:N \l_@@_tmpb_gtl
+ }
+ \@@_prev_input:x
+ {
+ \gtl_if_tl:NTF \l_@@_tmpb_gtl
+ { \gtl_head:N \l_@@_tmpb_gtl }
+ { \gtl_to_str:N \l_@@_tmpb_gtl }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_test_ifcsname:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_test_ifcsname:
+ {
+ \@@_csname_loop:
+ \@@_prev_input:V \l_@@_head_tl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+\@@_new_tex_expandable:nn { fi_or_else } % 108
+ {
+ \int_compare:nNnTF \l_@@_head_char_int > \g_@@_if_limit_int
+ {
+ \int_compare:nNnTF \g_@@_if_limit_int = 0
+ {
+ \int_compare:nNnTF \g_@@_if_depth_int = 0
+ { \@@_error:nnnnn { extra-fi-or-else } { } { } { } { } }
+ { \@@_insert_relax: }
+ }
+ { \@@_error:nnnnn { extra-fi-or-else } { } { } { } { } }
+ }
+ {
+ \@@_set_action_text:
+ \int_compare:nNnF \l_@@_head_char_int = 2
+ {
+ \@@_fi_or_else_loop:
+ \@@_set_action_text:x
+ {
+ \g_@@_action_text_str \c_space_tl
+ => ~ skipped ~ to ~ \tl_to_str:N \l_@@_head_tl
+ }
+ }
+ % ^^A todo: in the terminal output the token itself is missing.
+ \@@_print_expansion:
+ \@@_cond_pop:
+ }
+ }
+\cs_new_protected:Npn \@@_fi_or_else_loop:
+ {
+ \int_compare:nNnF \l_@@_head_char_int = 2
+ {
+ \@@_pass_text:
+ \@@_set_cmd:
+ \@@_fi_or_else_loop:
+ }
+ }
+% \end{macrocode}
+%
+% \subsection{User interaction}
+%
+% ^^A Not implemented yet: non-hash-doubling version.
+%
+% \subsubsection{Print}
+%
+% Let us start with the procedure which prints to the terminal: this
+% will help me test the code while I'm writing it.
+%
+% \begin{macro}{\@@_print_normalize_null:}
+% \begin{variable}{\l_@@_print_tl}
+% Change the null character to an explicit |^||^||@| in \LuaTeX{} to
+% avoid a bug whereby a null character ends a string prematurely.
+% \begin{macrocode}
+\tl_new:N \l_@@_print_tl
+\sys_if_engine_luatex:TF
+ {
+ \cs_new_protected:Npx \@@_print_normalize_null:
+ {
+ \tl_replace_all:Nnn \exp_not:N \l_@@_print_tl
+ { \char_generate:nn { 0 } { 12 } }
+ { \tl_to_str:n { ^ ^ @ } }
+ }
+ }
+ { \cs_new_protected:Npn \@@_print_normalize_null: { } }
+% \end{macrocode}
+% \end{variable}
+% \end{macro}
+%
+% \begin{macro}{\@@_print:n, \@@_print:x, \@@_log:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print:n #1
+ {
+ \tl_set:Nn \l_@@_print_tl {#1}
+ \@@_print_normalize_null:
+ \@@_exp_args:Nx \iow_term:n { \l_@@_print_tl }
+ }
+\cs_new_protected:Npn \@@_print:x
+ { \@@_exp_args:Nx \@@_print:n }
+\cs_new_protected:Npn \@@_log:n #1
+ {
+ \tl_set:Nn \l_@@_print_tl {#1}
+ \@@_print_normalize_null:
+ \@@_exp_args:Nx \iow_log:n { \l_@@_print_tl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_message:nn}
+% The message to be printed should come already detokenized, as~|#2|.
+% It will be wrapped to 80 characters per line, with~|#1| before each
+% line. The message is properly suppressed (or sent only to the log)
+% according to \cs{g_@@_online_int}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_message:nn #1 #2
+ {
+ \int_compare:nNnF \g_@@_online_int < 0
+ {
+ \int_compare:nNnTF \g_@@_online_int = 0
+ { \iow_wrap:nnnN { #1 #2 } { #1 } { } \@@_log:n }
+ { \iow_wrap:nnnN { #1 #2 } { #1 } { } \@@_print:n }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_action_text:x}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_action_text:x #1
+ {
+ \group_begin:
+ \@@_set_escapechar:n { 92 }
+ \str_gset:Nx \g_@@_action_text_str {#1}
+ \group_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_set_action_text:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_set_action_text:
+ {
+ \@@_set_action_text:x
+ {
+ \tl_to_str:N \l_@@_head_tl
+ \tl_if_single_token:VT \l_@@_head_tl
+ { = ~ \token_to_meaning:N \l_@@_head_token }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_state:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_state:
+ {
+ \group_begin:
+ \@@_set_escapechar:n { 92 }
+ \tl_use:N \g_@@_before_print_state_tl
+ \int_compare:nNnT \g_@@_online_int > 0
+ {
+ \@@_print_state_output:
+ \@@_print_state_prev:
+ \@@_print_state_input:
+ }
+ \group_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_state_output:, \@@_print_state_output:n}
+% Unless empty, print |#1| with each line starting with \verb*+<|~+.
+% The \cs{@@_str_truncate_left:nn} function trims |#1| if needed, to
+% fit in a maximum of \cs{g_@@_max_output_int} characters.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_state_output:
+ {
+ \@@_exp_args:Nx \@@_print_state_output:n
+ { \gtl_to_str:N \g_@@_output_gtl }
+ }
+\cs_new_protected:Npn \@@_print_state_output:n #1
+ {
+ \tl_if_empty:nF {#1}
+ {
+ \@@_print_message:nn { <| ~ }
+ { \@@_str_truncate_left:nn {#1} { \g_@@_max_output_int } }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_state_prev:}
+% Never trim~|##1|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_state_prev:
+ {
+ \seq_set_map:NNn \l_@@_tmpa_seq \g_@@_prev_input_seq
+ { \@@_to_str:n {##1} }
+ \seq_remove_all:Nn \l_@@_tmpa_seq { }
+ \seq_if_empty:NTF \l_@@_tmpa_seq
+ { \@@_print_message:nn { || ~ } { } }
+ {
+ \seq_map_inline:Nn \l_@@_tmpa_seq
+ {
+ \@@_print_message:nn { || ~ } {##1}
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_state_input:, \@@_print_state_input:n}
+% Print |#1| with each line starting with \verb*+|>~+. The
+% \cs{@@_str_truncate_right:nn} function trims |#1| if needed, to fit
+% in a maximum of \cs{g_@@_max_input_int} characters.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_state_input:
+ {
+ \@@_exp_args:Nx \@@_print_state_input:n
+ { \@@_input_to_str: }
+ }
+\cs_new_protected:Npn \@@_print_state_input:n #1
+ {
+ \@@_print_message:nn { |> ~ }
+ { \@@_str_truncate_right:nn {#1} { \g_@@_max_input_int } }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_meaning:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_meaning:
+ {
+ \@@_input_if_empty:TF
+ { \@@_print_message:nn { } { Empty~input! } }
+ {
+ \@@_input_get:N \l_@@_tmpb_gtl
+ \@@_print_message:nn { }
+ {
+ \gtl_head_do:NN \l_@@_tmpb_gtl \token_to_str:N
+ = \gtl_head_do:NN \l_@@_tmpb_gtl \token_to_meaning:N
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_action:, \@@_print_action:x, \@@_print_assignment:, \@@_print_assignment:x, \@@_print_expansion:, \@@_print_expansion:x, \@@_print_action_aux:N}
+% Some of these commands are currently synonyms but we may decide to
+% make some options act differently on them.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_action:
+ { \@@_print_action_aux:N \g_@@_trace_other_bool }
+\cs_new_protected:Npn \@@_print_action:x #1
+ {
+ \@@_set_action_text:x {#1}
+ \@@_print_action:
+ }
+\cs_new_protected:Npn \@@_print_assignment:
+ { \@@_print_action_aux:N \g_@@_trace_assigns_bool }
+\cs_new_protected:Npn \@@_print_assignment:x #1
+ {
+ \@@_set_action_text:x {#1}
+ \@@_print_assignment:
+ }
+\cs_new_protected:Npn \@@_print_expansion:
+ { \@@_print_action_aux:N \g_@@_trace_expansion_bool }
+\cs_new_protected:Npn \@@_print_expansion:x #1
+ {
+ \@@_set_action_text:x {#1}
+ \@@_print_expansion:
+ }
+\cs_new_protected:Npn \@@_print_action_aux:N #1
+ {
+ \int_gdecr:N \g_@@_nonstop_int
+ \int_gincr:N \g_@@_step_int
+ \bool_if:NT #1
+ {
+ \@@_print:x
+ {
+ [=====
+ \bool_if:NT \g_@@_number_steps_bool
+ { ~ Step ~ \int_to_arabic:n { \g_@@_step_int } ~ }
+ =====]~
+ \int_compare:nNnTF
+ { \str_count:N \g_@@_action_text_str }
+ > { \g_@@_max_action_int }
+ {
+ \str_range:Nnn \g_@@_action_text_str
+ { 1 } { \g_@@_max_action_int - 3 } ...
+ }
+ { \g_@@_action_text_str }
+ }
+ \@@_print_state:
+ \@@_prompt:
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_assigned_token:, \@@_print_assigned_register:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_assigned_token:
+ {
+ \@@_after_assignment: % ^^A todo: simplify
+ \@@_print_assignment:x
+ {
+ Set~ \exp_after:wN \token_to_str:N \l_@@_defined_tl
+ = \exp_after:wN \token_to_meaning:N \l_@@_defined_tl
+ }
+ \@@_omit_after_assignment:w
+ }
+\cs_new_protected:Npn \@@_print_assigned_register:
+ {
+ \@@_after_assignment: % ^^A todo: simplify
+ \@@_exp_args:Nx \@@_print_assignment:x
+ {
+ \exp_not:n
+ {
+ Set~ \exp_after:wN \token_to_str:N \l_@@_defined_tl
+ \tl_if_single:NT \l_@@_defined_tl
+ { ( \exp_after:wN \token_to_meaning:N \l_@@_defined_tl ) }
+ }
+ = \exp_not:N \tl_to_str:n { \@@_the:w \l_@@_defined_tl }
+ }
+ \@@_omit_after_assignment:w
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_welcome:}
+% Welcome message.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_welcome:
+ {
+ \@@_print_message:nn { }
+ {
+ \bool_if:NTF \g_@@_welcome_message_bool
+ {
+ \\
+ ========~ Welcome~ to~ the~ unravel~ package~ ========\\
+ \iow_indent:n
+ {
+ "<|"~ denotes~ the~ output~ to~ TeX's~ stomach. \\
+ "||"~ denotes~ tokens~ waiting~ to~ be~ used. \\
+ "|>"~ denotes~ tokens~ that~ we~ will~ act~ on. \\
+ Press~<enter>~to~continue;~'h'~<enter>~for~help. \\
+ }
+ }
+ { [=====~Start~=====] }
+ }
+ \@@_print_state:
+ \@@_prompt:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_print_outcome:}
+% Final message.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_print_outcome:
+ { \@@_print_message:nn { } { [=====~End~=====] } }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Prompt}
+%
+% \begin{macro}{\@@_ior_str_get:NN, \@@_ior_str_get:Nc}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_ior_str_get:NN #1#2
+ { \tex_readline:D #1 to #2 }
+\cs_generate_variant:Nn \@@_ior_str_get:NN { Nc }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_prompt:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_prompt:
+ {
+ \int_compare:nNnF \g_@@_nonstop_int > 0
+ {
+ \group_begin:
+ \@@_set_escapechar:n { -1 }
+ \int_set:Nn \tex_endlinechar:D { -1 }
+ \tl_use:N \g_@@_before_prompt_tl
+ \@@_prompt_aux:
+ \group_end:
+ }
+ }
+\cs_new_protected:Npn \@@_prompt_aux:
+ {
+ \int_compare:nNnT { \tex_interactionmode:D } = { 3 }
+ {
+ \bool_if:NTF \g_@@_explicit_prompt_bool
+ { \@@_ior_str_get:Nc \c_@@_prompt_ior }
+ { \@@_ior_str_get:Nc \c_@@_noprompt_ior }
+ { Your~input }
+ \exp_args:Nv \@@_prompt_treat:n { Your~input }
+ }
+ }
+\cs_new_protected:Npn \@@_prompt_treat:n #1
+ {
+ \tl_if_empty:nF {#1}
+ {
+ \@@_exp_args:Nx \str_case:nnF { \tl_head:n {#1} }
+ {
+ { m } { \@@_print_meaning: \@@_prompt_aux: }
+ { q }
+ {
+ \int_gset:Nn \g_@@_online_int { -1 }
+ \int_gzero:N \g_@@_nonstop_int
+ }
+ { x }
+ {
+ \group_end:
+ \@@_exit_hard:w
+ }
+ { X } { \tex_batchmode:D \tex_end:D }
+ { s } { \@@_prompt_scan_int:nn {#1}
+ \@@_prompt_silent_steps:n }
+ { o } { \@@_prompt_scan_int:nn {#1}
+ { \int_gset:Nn \g_@@_online_int } }
+ { C }
+ {
+ \@@_exp_args:Nx \use:n
+ {
+ \tl_gset_rescan:Nnn \exp_not:N \g_@@_tmpc_tl
+ { \exp_not:N \ExplSyntaxOn } { \tl_tail:n {#1} }
+ }
+ \tl_gput_left:Nn \g_@@_tmpc_tl
+ { \tl_gclear:N \g_@@_tmpc_tl }
+ \group_insert_after:N \g_@@_tmpc_tl
+ \group_insert_after:N \@@_prompt:
+ }
+ { | } { \@@_prompt_scan_int:nn {#1}
+ \@@_prompt_vert:n }
+ { u } { \@@_prompt_until:n {#1} }
+ { a } { \@@_prompt_all: }
+ }
+ { \@@_prompt_help: }
+ }
+ }
+\cs_new_protected:Npn \@@_prompt_scan_int:nn #1
+ {
+ \tex_afterassignment:D \@@_prompt_scan_int_after:wn
+ \l_@@_prompt_tmpa_int =
+ \tl_if_head_eq_charcode:fNF { \use_none:n #1 } - { 0 }
+ \use_ii:nn #1 \scan_stop:
+ }
+\cs_new_protected:Npn \@@_prompt_scan_int_after:wn #1 \scan_stop: #2
+ {
+ #2 \l_@@_prompt_tmpa_int
+ \tl_if_blank:nF {#1} { \@@_prompt_treat:n {#1} }
+ }
+\cs_new_protected:Npn \@@_prompt_help:
+ {
+ \@@_print:n { "m":~meaning~of~first~token }
+ \@@_print:n { "a":~print~state~again,~without~truncating }
+ \@@_print:n { "s<num>":~do~<num>~steps~silently }
+ \@@_print:n { "|<num>":~silent~steps~until~<num>~fewer~"||" }
+ \@@_print:n { "u<text>":~silent~steps~until~the~input~starts~with~<text> }
+ \@@_print:n
+ { "o<num>":~1~=>~log~and~terminal,~0~=>~only~log,~-1~=>~neither.}
+ \@@_print:n { "q":~semi-quiet~(same~as~"o-1") }
+ \@@_print:n { "C<code>":~run~some~expl3~code~immediately }
+ \@@_print:n { "x"/"X":~exit~this~instance~of~unravel/TeX }
+ \@@_prompt_aux:
+ }
+\cs_new_protected:Npn \@@_prompt_silent_steps:n #1
+ {
+ \int_compare:nNnF {#1} < 0
+ {
+ \int_gset:Nn \g_@@_online_int { -1 }
+ \tl_gset:Nn \g_@@_before_prompt_tl
+ {
+ \int_gset:Nn \g_@@_online_int { 1 }
+ \tl_gclear:N \g_@@_before_prompt_tl
+ }
+ \int_gset:Nn \g_@@_nonstop_int {#1}
+ }
+ }
+\cs_new_protected:Npn \@@_prompt_vert:n #1
+ {
+ \int_compare:nNnTF {#1} < { 0 }
+ { \@@_prompt_vert:Nn > {#1} }
+ { \@@_prompt_vert:Nn < {#1} }
+ }
+\cs_new_protected:Npn \@@_prompt_vert:Nn #1#2
+ {
+ \int_gset:Nn \g_@@_online_int { -1 }
+ \tl_gset:Nf \g_@@_before_print_state_tl
+ {
+ \exp_args:NNf \exp_stop_f: \int_compare:nNnTF
+ { \int_eval:n { \@@_prev_input_count: - #2 } }
+ #1 { \@@_prev_input_count: }
+ {
+ \int_gset:Nn \g_@@_nonstop_int
+ { \int_max:nn { \g_@@_nonstop_int } { 2 } }
+ }
+ {
+ \int_gset:Nn \g_@@_online_int { 1 }
+ \tl_gclear:N \g_@@_before_print_state_tl
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_prompt_all:
+ {
+ \tl_gset:Nx \g_@@_tmpc_tl
+ {
+ \exp_not:n
+ {
+ \tl_gclear:N \g_@@_tmpc_tl
+ \int_gset_eq:NN \g_@@_max_output_int \c_max_int
+ \int_gset_eq:NN \g_@@_max_input_int \c_max_int
+ \@@_print_state:
+ \int_gdecr:N \g_@@_nonstop_int
+ \@@_prompt:
+ }
+ \@@_prompt_all_aux:N \g_@@_max_output_int
+ \@@_prompt_all_aux:N \g_@@_max_input_int
+ }
+ \group_insert_after:N \g_@@_tmpc_tl
+ }
+\cs_new:Npn \@@_prompt_all_aux:N #1
+ { \exp_not:n { \int_gset:Nn #1 } { \int_use:N #1 } }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: I suspect a bug if given 'a' twice in a row
+%
+% \begin{macro}{\@@_prompt_until:n}
+% \begin{variable}{\g_@@_until_tl}
+% \begin{macrocode}
+\tl_new:N \g_@@_until_tl
+\cs_new_protected:Npn \@@_prompt_until:n #1
+ {
+ \tl_gset:Nx \g_@@_until_tl { \tl_tail:n {#1} }
+ \int_gset:Nn \g_@@_online_int { -1 }
+ \tl_gset:Nn \g_@@_before_print_state_tl
+ {
+ \@@_input_get_left:N \l_@@_tmpa_tl
+ \@@_exp_args:Nx \use:n
+ {
+ \exp_not:N \tl_if_in:nnTF
+ { \exp_not:N \@@:nn \tl_to_str:N \l_@@_tmpa_tl }
+ { \exp_not:N \@@:nn \tl_to_str:N \g_@@_until_tl }
+ }
+ {
+ \int_gset:Nn \g_@@_online_int { 1 }
+ \tl_gclear:N \g_@@_before_print_state_tl
+ }
+ {
+ \int_gset:Nn \g_@@_nonstop_int
+ { \int_max:nn { \g_@@_nonstop_int } { 2 } }
+ }
+ }
+ }
+% \end{macrocode}
+% \end{variable}
+% \end{macro}
+%
+% \subsubsection{Errors}
+%
+% \begin{macro}{\@@_not_implemented:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_not_implemented:n #1
+ { \@@_error:nnnnn { not-implemented } {#1} { } { } { } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_error:nnnnn, \@@_error:nxxxx}
+% Errors within a group to make sure that none of the \pkg{l3msg}
+% variables (or others) that may be currently in use in the code being
+% debugged are modified.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_error:nnnnn #1#2#3#4#5
+ {
+ \group_begin:
+ \msg_error:nnnnnn { unravel } {#1} {#2} {#3} {#4} {#5}
+ \group_end:
+ }
+\cs_new_protected:Npn \@@_error:nxxxx #1#2#3#4#5
+ {
+ \group_begin:
+ \msg_error:nnxxxx { unravel } {#1} {#2} {#3} {#4} {#5}
+ \group_end:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_tex_msg_new:nnn}
+% This stores a \TeX{} error message.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tex_msg_new:nnn #1#2#3
+ {
+ \cs_new:cpn { @@_tex_msg_error_#1: } {#2}
+ \cs_new:cpn { @@_tex_msg_help_#1: } {#3}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_tex_error:nn, \@@_tex_error:nV}
+% Throw the |tex-error| message, with arguments: |#2| which triggered
+% the error, \TeX{}'s error message, and \TeX{}'s help text.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tex_error:nn #1#2
+ {
+ \group_begin:
+ \msg_error:nnxxx { unravel } { tex-error }
+ { \tl_to_str:n {#2} }
+ { \use:c { @@_tex_msg_error_#1: } }
+ { \use:c { @@_tex_msg_help_#1: } }
+ \group_end:
+ }
+\cs_generate_variant:Nn \@@_tex_error:nn { nV }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_tex_fatal_error:nn, \@@_tex_fatal_error:nV}
+% Throw the |tex-fatal| error message, with arguments: |#2| which
+% triggered the fatal error, \TeX{}'s error message, and \TeX{}'s
+% help text.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_tex_fatal_error:nn #1#2
+ {
+ \@@_error:nxxxx { tex-fatal }
+ { \tl_to_str:n {#2} }
+ { \use:c { @@_tex_msg_error_#1: } }
+ { \use:c { @@_tex_msg_help_#1: } }
+ { }
+ }
+\cs_generate_variant:Nn \@@_tex_fatal_error:nn { nV }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Keys}
+%
+% Each key needs to be defined twice: for its default setting and for
+% its setting applying to a single \cs{unravel}. This is due to the
+% fact that we cannot use grouping to keep settings local to a single
+% \cs{unravel} since the \meta{code} argument of \cs{unravel} may open
+% or close groups.
+% \begin{macrocode}
+\keys_define:nn { unravel/defaults }
+ {
+ explicit-prompt .bool_gset:N = \g_@@_default_explicit_prompt_bool ,
+ internal-debug .bool_gset:N = \g_@@_default_internal_debug_bool ,
+ max-action .int_gset:N = \g_@@_default_max_action_int ,
+ max-output .int_gset:N = \g_@@_default_max_output_int ,
+ max-input .int_gset:N = \g_@@_default_max_input_int ,
+ number-steps .bool_gset:N = \g_@@_default_number_steps_bool ,
+ online .int_gset:N = \g_@@_default_online_int ,
+ trace-assigns .bool_gset:N = \g_@@_default_trace_assign_bool ,
+ trace-expansion .bool_gset:N = \g_@@_default_trace_expansion_bool ,
+ trace-other .bool_gset:N = \g_@@_default_trace_other_bool ,
+ welcome-message .bool_gset:N = \g_@@_default_welcome_message_bool ,
+ }
+\keys_define:nn { unravel }
+ {
+ explicit-prompt .bool_gset:N = \g_@@_explicit_prompt_bool ,
+ internal-debug .bool_gset:N = \g_@@_internal_debug_bool ,
+ max-action .int_gset:N = \g_@@_max_action_int ,
+ max-output .int_gset:N = \g_@@_max_output_int ,
+ max-input .int_gset:N = \g_@@_max_input_int ,
+ number-steps .bool_gset:N = \g_@@_number_steps_bool ,
+ online .int_gset:N = \g_@@_online_int ,
+ trace-assigns .bool_gset:N = \g_@@_trace_assigns_bool ,
+ trace-expansion .bool_gset:N = \g_@@_trace_expansion_bool ,
+ trace-other .bool_gset:N = \g_@@_trace_other_bool ,
+ welcome-message .bool_gset:N = \g_@@_welcome_message_bool ,
+ }
+% \end{macrocode}
+%
+% The |machine| and |trace| options are somewhat special so it is
+% clearer to define them separately. The code is identical for
+% |unravel/defaults| and |unravel| keys. To be sure of which options
+% are set, use |.meta:nn| and give the path explicitly.
+% \begin{macrocode}
+\tl_map_inline:nn { { /defaults } { } }
+ {
+ \keys_define:nn { unravel #1 }
+ {
+ machine .meta:nn =
+ { unravel #1 }
+ {
+ explicit-prompt = false ,
+ internal-debug = false ,
+ max-action = \c_max_int ,
+ max-output = \c_max_int ,
+ max-input = \c_max_int ,
+ number-steps = false ,
+ welcome-message = false ,
+ } ,
+ mute .meta:nn =
+ { unravel #1 }
+ {
+ trace-assigns = false ,
+ trace-expansion = false ,
+ trace-other = false ,
+ welcome-message = false ,
+ online = -1 ,
+ }
+ }
+ }
+% \end{macrocode}
+%
+% \subsection{Main command}
+%
+% \begin{macro}{\unravel}
+% Simply call an underlying code-level command.
+% \begin{macrocode}
+\NewDocumentCommand \unravel { O { } +m } { \unravel:nn {#1} {#2} }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\unravelsetup}
+% Simply call an underlying code-level command.
+% \begin{macrocode}
+\NewDocumentCommand \unravelsetup { m } { \unravel_setup:n {#1} }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\unravel_setup:n}
+% Set keys, updating both default values and current values.
+% \begin{macrocode}
+\cs_new_protected:Npn \unravel_setup:n #1
+ {
+ \keys_set:nn { unravel/defaults } {#1}
+ \keys_set:nn { unravel } {#1}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\unravel:nn, \@@:nn, \@@_unravel_marker:}
+% The command starts with \cs{@@_unravel_marker:} to detect nesting of
+% \tn{unravel} in \tn{unravel} and avoid re-initializing important
+% variables.
+% Initialize and setup keys. Initialize and setup other variables
+% including the input. Welcome the user. Then comes the main loop:
+% until the input is exhausted, print the current status and do one
+% step. The main loop is exited by skipping to the first
+% \cs{@@_exit_point:}, while some abort procedures jump to the second
+% (and last) one instead. If the main loop finished correctly, print
+% its outcome and finally test that everything is all right.
+% \begin{macrocode}
+\cs_new_protected:Npn \unravel:nn { \@@_unravel_marker: \@@:nn }
+\cs_new_eq:NN \@@_unravel_marker: \@@_special_relax:
+\cs_new_protected:Npn \@@:nn #1#2
+ {
+ \@@_init_key_vars:
+ \keys_set:nn { unravel } {#1}
+ \@@_init_vars:
+ \@@_input_gset:n {#2}
+ \@@_print_welcome:
+ \@@_main_loop:
+ \@@_exit_point:
+ \@@_print_outcome:
+ \@@_final_test:
+ \@@_exit_point:
+ }
+\cs_new_protected:Npn \unravel_get:nnN #1#2#3
+ {
+ \unravel:nn {#1} {#2}
+ \tl_set:Nx #3 { \gtl_left_tl:N \g_@@_output_gtl }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_init_key_vars:}
+% Give variables that are affected by keys their default values (also
+% controlled by keys).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_init_key_vars:
+ {
+ \bool_gset_eq:NN \g_@@_explicit_prompt_bool \g_@@_default_explicit_prompt_bool
+ \bool_gset_eq:NN \g_@@_internal_debug_bool \g_@@_default_internal_debug_bool
+ \bool_gset_eq:NN \g_@@_number_steps_bool \g_@@_default_number_steps_bool
+ \int_gset_eq:NN \g_@@_online_int \g_@@_default_online_int
+ \bool_gset_eq:NN \g_@@_trace_assigns_bool \g_@@_default_trace_assigns_bool
+ \bool_gset_eq:NN \g_@@_trace_expansion_bool \g_@@_default_trace_expansion_bool
+ \bool_gset_eq:NN \g_@@_trace_other_bool \g_@@_default_trace_other_bool
+ \bool_gset_eq:NN \g_@@_welcome_message_bool \g_@@_default_welcome_message_bool
+ \int_gset_eq:NN \g_@@_max_action_int \g_@@_default_max_action_int
+ \int_gset_eq:NN \g_@@_max_output_int \g_@@_default_max_output_int
+ \int_gset_eq:NN \g_@@_max_input_int \g_@@_default_max_input_int
+ \int_gzero:N \g_@@_nonstop_int
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_init_vars:}
+% Give initial values to variables used during the processing. These
+% have no reason to be modified by the user: neither directly nor
+% through keys.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_init_vars:
+ {
+ \seq_gclear:N \g_@@_prev_input_seq
+ \gtl_gclear:N \g_@@_output_gtl
+ \int_gzero:N \g_@@_step_int
+ \tl_gclear:N \g_@@_if_limit_tl
+ \int_gzero:N \g_@@_if_limit_int
+ \int_gzero:N \g_@@_if_depth_int
+ \gtl_gclear:N \g_@@_after_assignment_gtl
+ \bool_gset_true:N \g_@@_set_box_allowed_bool
+ \bool_gset_false:N \g_@@_name_in_progress_bool
+ \gtl_clear:N \l_@@_after_group_gtl
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_main_loop:, \@@_get_x_next_or_done:}
+% Loop forever, getting the next token (with expansion) and performing
+% the corresponding command. We use \cs{@@_get_x_next_or_done:},
+% which is basically \cs{@@_get_x_next:} but with a different
+% behaviour when there are no more tokens: running out of tokens here
+% is a successful exit of \cs{unravel}. Note that we cannot put the
+% logic into \cs{@@_main_loop:} because \cs{@@_expand_do:N} suppresses
+% the loop when a token is marked with \cs{notexpanded:}, and we don't
+% want that to suppress the main loop, only the expansion loop.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_get_x_next_or_done:
+ {
+ \@@_input_if_empty:TF { \@@_exit:w } { }
+ \@@_get_next:
+ \@@_token_if_expandable:NT \l_@@_head_token
+ { \@@_expand_do:N \@@_get_x_next_or_done: }
+ }
+\cs_new_protected:Npn \@@_main_loop:
+ {
+ \@@_get_x_next_or_done:
+ \@@_set_cmd:
+ \@@_do_step:
+ \@@_main_loop:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% ^^A todo: improve error message
+% \begin{macro}{\@@_final_test:, \@@_final_bad:}
+% Make sure that the \cs{unravel} finished correctly. The error
+% message is a bit primitive.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_final_test:
+ {
+ \bool_if:nTF
+ {
+ \tl_if_empty_p:N \g_@@_if_limit_tl
+ && \int_compare_p:nNn \g_@@_if_limit_int = 0
+ && \int_compare_p:nNn \g_@@_if_depth_int = 0
+ && \seq_if_empty_p:N \g_@@_prev_input_seq
+ }
+ { \@@_input_if_empty:TF { } { \@@_final_bad: } }
+ { \@@_final_bad: }
+ }
+\cs_new_protected:Npn \@@_final_bad:
+ {
+ \@@_error:nnnnn { internal }
+ { the-last-unravel-finished-badly } { } { } { }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Messages}
+%
+% \begin{macrocode}
+\msg_new:nnn { unravel } { unknown-primitive }
+ { Internal~error:~the~primitive~'#1'~is~not~known. }
+\msg_new:nnn { unravel } { extra-fi-or-else }
+ { Extra~fi,~or,~or~else. }
+\msg_new:nnn { unravel } { missing-dollar }
+ { Missing~dollar~inserted. }
+\msg_new:nnn { unravel } { unknown-expandable }
+ { Internal~error:~the~expandable~command~'#1'~is~not~known. }
+\msg_new:nnn { unravel } { missing-font-id }
+ { Missing~font~identifier.~\iow_char:N\\nullfont~inserted. }
+\msg_new:nnn { unravel } { missing-rparen }
+ { Missing~right~parenthesis~inserted~for~expression. }
+\msg_new:nnn { unravel } { missing-cs }
+ { Missing~control~sequence.~\iow_char:N\\inaccessible~inserted. }
+\msg_new:nnn { unravel } { missing-box }
+ { Missing~box~inserted. }
+\msg_new:nnn { unravel } { missing-to }
+ { Missing~keyword~'to'~inserted. }
+\msg_new:nnn { unravel } { improper-leaders }
+ { Leaders~not~followed~by~proper~glue. }
+\msg_new:nnn { unravel } { extra-close }
+ { Extra~right~brace~or~\iow_char:N\\endgroup. }
+\msg_new:nnn { unravel } { off-save }
+ { Something~is~wrong~with~groups. }
+\msg_new:nnn { unravel } { hrule-bad-mode }
+ { \iow_char\\hrule~used~in~wrong~mode. }
+\msg_new:nnn { unravel } { invalid-mode }
+ { Invalid~mode~for~this~command. }
+\msg_new:nnn { unravel } { color-stack-action-missing }
+ { Missing~color~stack~action. }
+\msg_new:nnn { unravel } { action-type-missing }
+ { Missing~action~type. }
+\msg_new:nnn { unravel } { identifier-type-missing }
+ { Missing~identifier~type. }
+\msg_new:nnn { unravel } { destination-type-missing }
+ { Missing~destination~type. }
+\msg_new:nnn { unravel } { erroneous-prefixes }
+ { Prefixes~appplied~to~non-assignment~command. }
+\msg_new:nnn { unravel } { improper-setbox }
+ { \iow_char:N\\setbox~while~fetching~base~of~an~accent. }
+\msg_new:nnn { unravel } { after-advance }
+ {
+ Missing~register~after~\iow_char:N\\advance,~
+ \iow_char:N\\multiply,~or~\iow_char:N\\divide.
+ }
+\msg_new:nnn { unravel } { bad-unless }
+ { \iow_char:N\\unless~not~followed~by~conditional. }
+\msg_new:nnn { unravel } { runaway-if }
+ { Runaway~\iow_char:N\\if... }
+\msg_new:nnn { unravel } { runaway-macro-parameter }
+ {
+ Runaway~macro~parameter~\# #2~after \\\\
+ \iow_indent:n {#1}
+ }
+\msg_new:nnn { unravel } { extra-or }
+ { Extra~\iow_char:N\\or. }
+\msg_new:nnn { unravel } { missing-equals }
+ { Missing~equals~for~\iow_char:N\\ifnum~or~\iow_char:N\\ifdim. }
+\msg_new:nnn { unravel } { internal }
+ { Internal~error:~'#1'.~\ Please~report. }
+\msg_new:nnn { unravel } { not-implemented }
+ { The~following~feature~is~not~implemented:~'#1'. }
+\msg_new:nnn { unravel } { endinput-ignored }
+ { The~primitive~\iow_char:N\\endinput~was~ignored. }
+\msg_new:nnn { unravel } { missing-something }
+ { Something~is~missing,~sorry! }
+\msg_new:nnn { unravel } { nested-unravel }
+ { The~\iow_char:N\\unravel~command~may~not~be~nested. }
+\msg_new:nnnn { unravel } { tex-error }
+ { TeX~sees~"#1"~and~throws~an~error:\\\\ \iow_indent:n {#2} }
+ {
+ \tl_if_empty:nTF {#3}
+ { TeX~provides~no~further~help~for~this~error. }
+ { TeX's~advice~is:\\\\ \iow_indent:n {#3} }
+ }
+\msg_new:nnnn { unravel } { tex-fatal }
+ { TeX~sees~"#1"~and~throws~a~fatal~error:\\\\ \iow_indent:n {#2} }
+ {
+ \tl_if_empty:nTF {#3}
+ { TeX~provides~no~further~help~for~this~error. }
+ { TeX's~advice~is:\\\\ \iow_indent:n {#3} }
+ }
+\msg_new:nnn { unravel } { runaway-unravel }
+ { Runaway~\iow_char:N\\unravel }
+% \end{macrocode}
+%
+% Some error messages from \TeX{} itself.
+% \begin{macrocode}
+\@@_tex_msg_new:nnn { incompatible-mag }
+ {
+ Incompatible~magnification~
+ ( \int_to_arabic:n { \@@_mag: } );~
+ the~previous~value~will~be~retained
+ }
+ {
+ I~can~handle~only~one~magnification~ratio~per~job.~So~I've~
+ reverted~to~the~magnification~you~used~earlier~on~this~run.
+ }
+\@@_tex_msg_new:nnn { illegal-mag }
+ {
+ Illegal~magnification~has~been~changed~to~1000~
+ ( \int_to_arabic:n { \@@_mag: } )
+ }
+ { The~magnification~ratio~must~be~between~1~and~32768. }
+\@@_tex_msg_new:nnn { missing-number }
+ { Missing~number,~treated~as~zero }
+ {
+ A~number~should~have~been~here;~I~inserted~`0'.~
+ If~you~can't~figure~out~why~I~needed~to~see~a~number,~
+ look~up~`weird~error'~in~the~index~to~The~TeXbook.
+ }
+\@@_tex_msg_new:nnn { the-cannot }
+ { You~can't~use~`\tl_to_str:N\l_@@_head_tl'~after~\iow_char:N\\the }
+ { I'm~forgetting~what~you~said~and~using~zero~instead. }
+\@@_tex_msg_new:nnn { incompatible-units }
+ { Incompatible~glue~units }
+ { I'm~going~to~assume~that~1mu=1pt~when~they're~mixed. }
+\@@_tex_msg_new:nnn { missing-mu }
+ { Illegal~unit~of~measure~(mu~inserted) }
+ {
+ The~unit~of~measurement~in~math~glue~must~be~mu.~
+ To~recover~gracefully~from~this~error,~it's~best~to~
+ delete~the~erroneous~units;~e.g.,~type~`2'~to~delete~
+ two~letters.~(See~Chapter~27~of~The~TeXbook.)
+ }
+\@@_tex_msg_new:nnn { missing-pt }
+ { Illegal~unit~of~measure~(pt~inserted) }
+ {
+ Dimensions~can~be~in~units~of~em,~ex,~in,~pt,~pc,~
+ cm,~mm,~dd,~cc,~nd,~nc,~bp,~or~sp;~but~yours~is~a~new~one!~
+ I'll~assume~that~you~meant~to~say~pt,~for~printer's~points.~
+ To~recover~gracefully~from~this~error,~it's~best~to~
+ delete~the~erroneous~units;~e.g.,~type~`2'~to~delete~
+ two~letters.~(See~Chapter~27~of~The~TeXbook.)
+ }
+\@@_tex_msg_new:nnn { missing-lbrace }
+ { Missing~\iow_char:N\{~inserted }
+ {
+ A~left~brace~was~mandatory~here,~so~I've~put~one~in.~
+ You~might~want~to~delete~and/or~insert~some~corrections~
+ so~that~I~will~find~a~matching~right~brace~soon.~
+ (If~you're~confused~by~all~this,~try~typing~`I\iow_char:N\}'~now.)
+ }
+\@@_tex_msg_new:nnn { extra-endcsname }
+ { Extra~\token_to_str:c{endcsname} }
+ { I'm~ignoring~this,~since~I~wasn't~doing~a~\token_to_str:c{csname}. }
+\@@_tex_msg_new:nnn { missing-endcsname }
+ { Missing~\token_to_str:c{endcsname}~inserted }
+ {
+ The~control~sequence~marked~<to~be~read~again>~should~
+ not~appear~between~\token_to_str:c{csname}~and~
+ \token_to_str:c{endcsname}.
+ }
+% \end{macrocode}
+%
+% Fatal \TeX{} error messages.
+% \begin{macrocode}
+\@@_tex_msg_new:nnn { cannot-read }
+ { ***~(cannot~\iow_char:N\\read~from~terminal~in~nonstop~modes) }
+ { }
+\@@_tex_msg_new:nnn { file-error }
+ { ***~(job~aborted,~file~error~in~nonstop~mode) }
+ { }
+\@@_tex_msg_new:nnn { interwoven-preambles }
+ { (interwoven~alignment~preambles~are~not~allowed) }
+ { }
+% \end{macrocode}
+%
+% Restore catcodes to their original values.
+% \begin{macrocode}
+\@@_setup_restore:
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</package>
+% \end{macrocode}
+%
+% \end{implementation}
+%
+% \endinput
diff --git a/macros/latex/contrib/unravel/unravel.ins b/macros/latex/contrib/unravel/unravel.ins
new file mode 100644
index 0000000000..46180f9dea
--- /dev/null
+++ b/macros/latex/contrib/unravel/unravel.ins
@@ -0,0 +1,23 @@
+\input l3docstrip.tex
+\askforoverwritefalse
+
+\preamble
+
+Do not distribute a modified version of this file.
+
+Communicate any suggestions for changing this package
+to Bruno Le Floch (blflatex+unravel@gmail.com).
+
+\endpreamble
+% stop docstrip adding \endinput
+\postamble
+\endpostamble
+
+\keepsilent
+
+% the package
+\generate{%
+ \file{unravel.sty} {\from{unravel.dtx} {package}}%
+}
+
+\endbatchfile
diff --git a/macros/latex/contrib/unravel/unravel.pdf b/macros/latex/contrib/unravel/unravel.pdf
new file mode 100644
index 0000000000..df3f7437be
--- /dev/null
+++ b/macros/latex/contrib/unravel/unravel.pdf
Binary files differ
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 00:21:19 +0000