physics2-code.src.base.dtx

% \DeclareSourceFile{base}
%
%
%
% This file describes \texttt{physics2.sty}.
%
%
%
% \section{The \pkg{physics2} package}
%    \begin{macrocode}
%<*package>
\NeedsTeXFormat{LaTeX2e}[2020/10/01]
\ProvidesPackage{physics2}
  [2024/06/06 v1.1.1 Tools for typesetting math for physics.]
%    \end{macrocode}
% \subsection{Common variables}
% \begin{variable}{\phy@temp..}
%   \begin{syntax}
%     \cs{phy@temp}\meta{register type}\meta{a or b}
%   \end{syntax}
%   Some \LaTeXe\ variables starting with ``|\phy@temp|''. 
%   These variables can be shared by any module of \pkg{physics2}.
% \end{variable}
%    \begin{macrocode}
\newcount  \phy@tempcnta
\newdimen  \phy@tempdima
\newdimen  \phy@tempdimb
\newskip   \phy@tempskipa
\newmuskip \phy@tempmuskipa
\newbox    \phy@tempboxa
\newif     \ifphy@tempswa
\newtoks   \phy@toksa
%    \end{macrocode}
% \subsection{Package requirements and module-loading methods}
% \pkg{physics2} requires \pkg{keyval} (part of the graphics bundle) to 
% process options of modules.
%    \begin{macrocode}
\RequirePackage{keyval}
\def\phy@true{true}
\def\phy@false{false}
%    \end{macrocode}
% \begin{function}{\phy@define@key, \phy@setkeys, \phy@processkeyopt}
%   \begin{syntax}
%     \cs{phy@define@key} \marg{module} \marg{key} \oarg{default value} \marg{code}
%     \cs{phy@setkeys} \marg{module} \marg{key-val list}
%     \cs{phy@processkeyopt} \marg{module}
%   \end{syntax}
%   The position of \cs{phy@processkeyopt} in a \pkg{physics2} module is just the same
%   as the position of \cs{ProcessOptions} in a regular \LaTeX\ package.
% \end{function}
%    \begin{macrocode}
\long\def\phy@define@key#1{\define@key{phy-#1}}
\long\def\phy@setkeys#1{\setkeys{phy-#1}}
\def\phy@processkeyopt#1{\let\reserved@a\@empty%
  \edef\reserved@a{\@ptionlist{\@currname.\@currext}}%
  \edef\reserved@a{\noexpand\phy@setkeys{#1}{\reserved@a}}%
  \reserved@a
  \AtEndOfPackage{\let\@unprocessedoptions\relax}}
%    \end{macrocode}
% We use almost the same way to load \pkg{physics2} modules as \LaTeXe\ kernel
% does. We use a lot of kernel commands in \LaTeXe.
% 
% \begin{function}{\usephysicsmodule, \phy@requiremodule}
%   \begin{syntax}
%     \cs{usephysicsmodule} \oarg{key-val options} \marg{module} \oarg{key-val options}
%     \cs{phy@requiremodule} \oarg{key-val options} \marg{module} \oarg{key-val options}
%   \end{syntax}
%   \cs{usephysicsmodule} is a user command, and \cs{phy@requiremodule} is a developer
%   command.
% \end{function}
%    \begin{macrocode}
\def\usephysicsmodule{\phy@FWoptions\@pkgextension}
\let\phy@requiremodule\usephysicsmodule
\@onlypreamble\usephysicsmodule
\def\phy@FWoptions#1{\@ifnextchar[%]
  {\phy@FW@ptions#1}{\phy@FW@ptions#1[]}}
\@onlypreamble\phy@FWoptions
\def\phy@FW@ptions#1[#2]#3{\@ifnextchar[%]
  {\phy@FW@pti@ns#1[{#2}]#3}{\phy@FW@pti@ns#1[{#2}]#3[]}}
\@onlypreamble\phy@FW@ptions
\def\phy@FW@pti@ns#1[#2]#3[#4]{%
  \def\reserved@b##1,{%
    \ifx\@nnil##1\relax\else
      \ifx\@nnil##1\@nnil\else
       \noexpand\@onefilewithoptions{phy-##1}[{\unexpanded{#2}}][{#4}]%
       \noexpand\@pkgextension
      \fi
      \expandafter\reserved@b
    \fi}%
    \edef\reserved@a{\zap@space#3 \@empty}%
    \edef\reserved@a{\expandafter\reserved@b\reserved@a,\@nnil,}%
  \reserved@a}
\@onlypreamble\phy@FW@pti@ns
%    \end{macrocode}
% \subsection{Common package-defined commands}
% The code below used to be the automatically-loaded \modu{common} module,
% but now we load it together with \pkg{physics2}'s code. This change may
% bring better performance in Windows system.
% 
% Check if \pkg{unicode-math} loaded and (re)define the vert symbols.
% The \cs{relax}'s at the ends of \cs{vert} and \cs{Vert}'s definitions must not be
% removed. They are for \cs{ifx} to compare. \pkg{unicode-math} sets these symbols
% \cs{fam}1, \cs{symoperators} is equal to 1 in \LaTeXe\ kernel. Moreover, we make
% \cs{mid} as a delimiter but it may not work.
%    \begin{macrocode}
\AtBeginDocument{\ifcsname symrm\endcsname
  \protected\def\|{\Udelimiter 0 \symoperators "2016 }%
  \protected\def\vert{\Udelimiter 0 \symoperators "007C\relax}%
  \protected\def\Vert{\Udelimiter 0 \symoperators "2016\relax}%
  \protected\def\mid{\Udelimiter 3 \symoperators "007C }%
\fi}
\protected\def\Vert{\delimiter"026B30D\relax}
\protected\def\mid{\delimiter"326A30C }
%    \end{macrocode}
% \begin{function}{\delopen, \delclose}
%   \begin{syntax}
%     \cs{delopen} \meta{left delimiter}
%     \cs{delclose} \meta{right delimiter}
%   \end{syntax}
%   Actually in \TeX, \cs{left} and \cs{right} will enclose the subformula as ``inner'',
%   but \cs{delopen} and \cs{delclose} will make the subformula an empty open node and
%   a non-empty close node.
% \end{function}
%    \begin{macrocode}
\DeclareRobustCommand\delopen{\mathopen{}\mathclose\bgroup\left}
\DeclareRobustCommand\delclose{\aftergroup\egroup\right}
%    \end{macrocode}
% \begin{function}{\DeclareBiggg}
%   \begin{syntax}
%     \cs{DeclareBiggg} \meta{biggg command} \marg{ratio}
%   \end{syntax}
% \end{function}
% \cs{bBigg@} is a command from \pkg{amsmath}. The code below should
% update with \pkg{amsmath} together.
%    \begin{macrocode}
\expandafter\def\csname phy@ab@chk\string*\endcsname{}
\expandafter\def\csname phy@ab@chk\string\big\endcsname{}
\expandafter\def\csname phy@ab@chk\string\Big\endcsname{}
\expandafter\def\csname phy@ab@chk\string\bigg\endcsname{}
\expandafter\def\csname phy@ab@chk\string\Bigg\endcsname{}
\ifdefined\bBigg@
  \def\DeclareBiggg#1#2{%
    \DeclareRobustCommand#1{\bBigg@{#2}}%
    \edef\phy@tempa{\expandafter\@gobble\string#1}%
    \ifcsname\phy@tempa m\endcsname\else
      \expandafter\DeclareRobustCommand\csname\phy@tempa l\endcsname{\mathopen#1}%
      \expandafter\DeclareRobustCommand\csname\phy@tempa m\endcsname{\mathrel#1}%
      \expandafter\DeclareRobustCommand\csname\phy@tempa r\endcsname{\mathclose#1}%
    \fi
    \expandafter\def\csname phy@ab@chk\string#1\endcsname{}%
  }
\else
  \PackageInfo{physics2}{It is recommended to load `amsmath' before `physics2'}%
  \def\DeclareBiggg#1#2{%
    \phy@tempdima=6pt
    \phy@tempdima=#2\phy@tempdima
    \advance\phy@tempdima 3.5pt\relax
    \DeclareRobustCommand#1[1]{\leavevmode@ifvmode
      {\hbox{$\left#1\vbox to \phy@tempdima{}\right.\n@space$}}}
    \AtBeginDocument{\ifdefined\bBigg@\DeclareRobustCommand#1{\bBigg@{#2}}\fi}%
    \edef\phy@tempa{\expandafter\@gobble\string#1}%
    \ifcsname\phy@tempa m\endcsname\else
      \expandafter\DeclareRobustCommand\csname\phy@tempa l\endcsname{\mathopen#1}%
      \expandafter\DeclareRobustCommand\csname\phy@tempa m\endcsname{\mathrel#1}%
      \expandafter\DeclareRobustCommand\csname\phy@tempa r\endcsname{\mathclose#1}%
    \fi
    \expandafter\def\csname phy@ab@chk\string#1\endcsname{}%
  }
\fi
\DeclareBiggg\biggg{3}
\DeclareBiggg\Biggg{3.5}
%    \end{macrocode}
% \begin{function}{\phy@mathvphantom}
%   \begin{syntax}
%     \cs{phy@mathvphantom} \marg{math mode material}
%   \end{syntax}
%   This command is just like \cs{vphantom} in \LaTeXe\ kernel but only works
%   in math mode.
% \end{function}
%    \begin{macrocode}
\def\phy@mathvphantom#1{\setbox\phy@tempboxa=\hbox{}%
  \mathchoice
    {\setbox\@tempboxa\hbox{$\displaystyle#1$}%
      \ht\phy@tempboxa=\ht\@tempboxa
      \dp\phy@tempboxa=\dp\@tempboxa
      \box\phy@tempboxa}
    {\setbox\@tempboxa\hbox{$\textstyle#1$}%
      \ht\phy@tempboxa=\ht\@tempboxa
      \dp\phy@tempboxa=\dp\@tempboxa
      \box\phy@tempboxa}
    {\setbox\@tempboxa\hbox{$\scriptstyle#1$}%
      \ht\phy@tempboxa=\ht\@tempboxa
      \dp\phy@tempboxa=\dp\@tempboxa
      \box\phy@tempboxa}
    {\setbox\@tempboxa\hbox{$\scriptscriptstyle#1$}%
      \ht\phy@tempboxa=\ht\@tempboxa
      \dp\phy@tempboxa=\dp\@tempboxa
      \box\phy@tempboxa}%
}
%    \end{macrocode}
% \subsection{\LaTeX3 variables}
% Some common variables and functions for experimental \LaTeX3 syntax.
%    \begin{macrocode}
%<@@=phy>
\ExplSyntaxOn
\int_new:N \l_@@_tmpa_int
\int_new:N \l_@@_tmpb_int
\tl_new:N \l_@@_tmpa_tl
\tl_new:N \l_@@_tmpb_tl
\cs_new:Npn \_@@_gobble_i:n #1 { }
\ExplSyntaxOff
%<@@=>
%</package>
%    \end{macrocode}
\endinput