%D \module
%D   [       file=supp-mat,
%D        version=1998.09.10,
%D          title=\CONTEXT\ Support Macros,
%D       subtitle=Math,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

%D For practical reasons, I decided to move some math things to a support module.
%D There is nothing spectacular here. It may move back to math-ini.

\writestatus{loading}{ConTeXt Support Macros / Math}

\unprotect

%D \macros
%D   {mathematics, math, nomathematics, startmathmode}
%D
%D The \type {$} can be both an begin and end math character. This can lead to
%D confusing and errorprone situations when macros insert \type {$}. When for
%D instance we have defined:
%D
%D \starttyping
%D \def\MyPlus{$\,+\,$}
%D \stoptyping
%D
%D the sequence \type{$x^2 \MyPlus y^2 = r^2$} will expand to:
%D
%D \starttyping
%D $x^2 $\,+\,$ y^2 = r^2$
%D \stoptyping
%D
%D Here the \type {\,} are given outside math mode and \TEX\ will definitely
%D complain about this. A more save definition would have been:
%D
%D \starttyping
%D \def\MyPlus{\mathematics{\,+\,}}
%D \stoptyping
%D
%D Which is implemented (in \type{syst-ini.mkiv}) as:

% \permanent\protected\def\Ucheckedstartdisplaymath
%   {\ifinner
%      \ifhmode
%        \normalUstartmath
%        \let\Ucheckedstopdisplaymath\normalUstopmath
%      \else
%        \normalUstartdisplaymath
%        \let\Ucheckedstopdisplaymath\normalUstopdisplaymath
%      \fi
%    \else
%      \normalUstartdisplaymath
%      \let\Ucheckedstopdisplaymath\normalUstopdisplaymath
%    \fi}
%
% \aliased\let\Ucheckedstopdisplaymath\relax

\aliased\let\startimath\Ustartmath
\aliased\let\stopimath \Ustopmath
\aliased\let\startdmath\Ustartdisplaymath  % \Ucheckedstartdisplaymath
\aliased\let\stopdmath \Ustopdisplaymath   % \Ucheckedstopdisplaymath

%permanent\protected\def\displaymath#1{\noindent      \ifmmode#1\else\normalstartdmath#1\normalstopdmath\fi}
%permanent\protected\def\inlinemath #1{\dontleavehmode\ifmmode#1\else\normalstartimath#1\normalstopimath\fi}

\permanent\protected\def\mathematics#1%
  {\relax
   \ifmmode
     #1
   \else
     \normalstartimath#1\normalstopimath
   \fi}

\permanent\protected\def\textmath#1%
  {\dontleavehmode
   \ifmmode
     #1%
   \else
     \begingroup
     \everymathematics\emptytoks         % so \not \everymath
     \normalstartimath#1\normalstopimath % \mathsurround\zeropoint
     \endgroup
   \fi}

\aliased\let\stopmathmode\relax

\permanent\protected\def\startmathmode % nested variant
  {\relax\ifmmode
     \begingroup
     \enforced\let\stopmathmode\endgroup
   \else
     \normalstartimath
     \enforced\let\stopmathmode\normalstopimath
   \fi}

\permanent\protected\def\nomathematics#1%
  {\relax\ifmmode\hbox{#1}\else#1\fi}

\aliased\let\m   \mathematics % \mathematics will be overloaded later
\aliased\let\math\mathematics % \mathematics will be overloaded later

%D \macros
%D   {displaymathematics,inlinemathematics,automathematics}
%D
%D We no longer support native displaymath, which is no big deal because already
%D for many years we abandoned it. We therefore also default differently now. We
%D signal \LUAMETATEX\ that the double dollar mode actually has to be inline
%D display math anyway.

\ifdefined\strc_formulas_start_formula \else
   \def\strc_formulas_start_formula{\normalstartdmath}
   \def\strc_formulas_stop_formula {\normalstopdmath }
\fi

\permanent\protected\def\displaymathematics#1{\relax\ifmmode#1\else\strc_formulas_start_formula{}#1\strc_formulas_stop_formula\fi}
\permanent\protected\def\inlinemathematics   {\dontleavehmode\mathematics}
%permanent\protected\def\automathematics     {\relax\ifhmode\expandafter\inlinemathematics\else\expandafter\displaymathematics\fi}

\aliased\let\displaymath\displaymathematics % we no longer support native displaymath
\aliased\let\inlinemath \inlinemathematics  % we no longer support native displaymath

% better, esp when used in bTABLE ... eTABLE

\permanent\protected\def\automathematics
  {\relax
   \ifhmode
     \expandafter\inlinemathematics
   \orelse\ifintable
     \expandafter\inlinemathematics
   \else
     \expandafter\displaymathematics
   \fi}

%D \macros
%D   {dimension, nodimension}
%D
%D The next few macros are used for typesetting dimensions in such a way that
%D spacing is acceptable. I won't spend much words on these macros, because they
%D will be overloaded in the units module.
%D
%D REPLACED (keep commented):

% \newsignal\dimensionsignal
%
% \mutable\def\dimensiontypeface  {\tf}
% \mutable\def\dimensionhalfspace {\,}
%
% \aliased\let\dodimensionsignal\relax
%
% \permanent\protected\def\dimension#1%
%   {\pushmacro\dodimensionsignal
%    \enforced\gdef\dodimensionsignal{\kern\dimensionsignal}%
%    \ifzeropt\lastskip
%      \ifzeropt\lastkern
%        \ifmmode
%          \mathematics{\dimensionhalfspace\dimensionhalfspace\dimensiontypeface#1}%
%        \else
%          \mathematics{\dimensiontypeface#1}%
%        \fi
%      \orelse\ifdim\lastkern=\dimensionsignal
%        \mathematics{\dimensionhalfspace\dimensiontypeface#1}%
%      \else
%        \unkern\mathematics{\dimensionhalfspace\dimensionhalfspace\dimensiontypeface#1}%
%      \fi
%    \else
%      \unskip\mathematics{\dimensionhalfspace\dimensionhalfspace\dimensiontypeface#1}%
%    \fi
%    \dodimensionsignal
%    \popmacro\dodimensionsignal}
%
% \permanent\protected\def\nodimension#1%
%   {\unskip#1\enforced\glet\dodimensionsignal\relax}

% experiment, not yet to be used

% \protected\def\displaybreak
%   {\ifhmode
%      \removeunwantedspaces
%      \ifcase\raggedstatus\hfill\fi
%      \strut\penalty-9999 % \break fails on case (3)
%    \fi}
%
% \def\startdisplay{\displaybreak\ignorespaces\startpacked}
% \def\stopdisplay {\stoppacked\displaybreak\ignorespaces}

\protect \endinput