%D \module
%D   [       file=math-dif,
%D        version=2022.05.31, % moved code
%D          title=\CONTEXT\ Math Macros,
%D       subtitle=Differentials,
%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.

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

\unprotect

%D The shapes are defined in \type {char-def.lua} where they get the right class
%D too.
%D
%D \starttyping
%D \setupmathematics
%D   [differentiald=upright]
%D \stoptyping

%D Alternatively we can handle this by an attribute and do the remapping at the
%D \LUA\ end but we're only talking of a few variables and we already had one
%D done at the \TEX\ end.

\def\math_upright_constant#1#2#3%
  {\ifcstok{\mathematicsparameter#1}\s!upright
     \begingroup
       \attribute\mathalphabetattribute\attributeunsetvalue
       \attribute\mathgreekattribute   \attributeunsetvalue
       #2%
     \endgroup
   \else
     #3%
   \fi}

\setupmathematics
  [\s!differentiald=\mathematicsparameter\c!mathconstants,
    \s!exponentiale=\mathematicsparameter\c!mathconstants,
      \s!imaginaryi=\mathematicsparameter\c!mathconstants,
      \s!imaginaryj=\mathematicsparameter\c!mathconstants,
              \s!pi=\mathematicsparameter\c!mathconstants]

% \setupmathematics
%   [\c!mathconstants=\s!upright]

\permanent\protected\def\dd{\math_upright_constant\s!differentiald\mathduprightshape \mathditalicshape }
\permanent\protected\def\DD{\math_upright_constant\s!differentiald\mathDuprightshape \mathDitalicshape }
\permanent\protected\def\ee{\math_upright_constant\s!exponentiale \matheuprightshape \matheitalicshape }
\permanent\protected\def\ii{\math_upright_constant\s!imaginaryi   \mathiuprightshape \mathiitalicshape }
\permanent\protected\def\ij{\math_upright_constant\s!imaginaryj   \mathjuprightshape \mathjitalicshape }
\permanent\protected\def\pi{\math_upright_constant\s!pi           \mathpiuprightshape\mathpiitalicshape}

\protect

