%D \module
%D   [       file=math-fen,
%D        version=2012.02.18,
%D          title=\CONTEXT\ Math Macros,
%D       subtitle=Fences,
%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 / Fences}

\unprotect

% todo: mathstyle

% \definemathfence [fancybracket] [bracket] [command=yes,color=blue]
%
% test $|x|$ test \par
% test $||x||$ test (okay) \par
% test $a\left|\frac{1}{b}\right|c$ test \par
% test $a\left||\frac{1}{b}\right||c$ test (not okay) \par
%
% \setupmathfences [color=red]
%
% test $a\fenced[bar]{\frac{1}{b}}c$ test \par
% test $a\fenced[doublebar]{\frac{1}{b}}c$ test \par
% test $a\fenced[bracket]{\frac{1}{b}}c$ test \par
% test $a\fancybracket{\frac{1}{b}}c$ test \par

\installcorenamespace{mathfences}
\installcorenamespace{mathfencesleft}
\installcorenamespace{mathfencesmiddle}
\installcorenamespace{mathfencesright}

\installcommandhandler \??mathfences {mathfence} \??mathfences

\let\setupmathfences\setupmathfence

\setupmathfences
  [\c!left=0x2E,
   \c!right=0x2E,
   \c!middle=0x2E,
   \c!mathstyle=,
   \c!color=,
   \c!command=]

\appendtoks
    \edef\p_command{\mathfenceparameter\c!command}%
    \ifx\p_command\v!yes
        \setuevalue\currentmathfence{\math_fenced_fenced[\currentmathfence]}%
    \fi
\to \everydefinemathfence

\def\math_fenced_left  {\normalleft  \utfchar{\mathfenceparameter\c!left  }} % no Uchar here
\def\math_fenced_middle{\normalmiddle\utfchar{\mathfenceparameter\c!middle}} % no Uchar here
\def\math_fenced_right {\normalright \utfchar{\mathfenceparameter\c!right }} % no Uchar here

\let\fence \relax
\let\fenced\relax

\unexpanded\def\math_fenced_fenced[#1]%
  {\begingroup
   \edef\currentmathfence{#1}%
   \startusemathstyleparameter\mathfenceparameter
   \let\fence\math_fenced_middle
   \edef\p_math_fenced_color{\mathfenceparameter\c!color}%
   \ifx\p_math_fenced_color\empty
     \expandafter\math_fenced_normal
   \else
     \expandafter\math_fenced_colored
   \fi}

\def\math_fenced_normal#1%
  {\math_fenced_left
   #1%
   \math_fenced_right
   \stopusemathstyleparameter
   \endgroup}

\def\math_fenced_colored#1%
  {\pushcolor[\p_math_fenced_color]%
   \math_fenced_left
   \popcolor
   #1%
   \pushcolor[\p_math_fenced_color]%
   \math_fenced_right
   \popcolor
   \stopusemathstyleparameter
   \endgroup}

\appendtoks
    \let\fenced\math_fenced_fenced
\to \everymathematics

\definemathfence [parenthesis] [\c!left=0x28,\c!right=0x29]
\definemathfence [bracket]     [\c!left=0x5B,\c!right=0x5D]
\definemathfence [braces]      [\c!left=0x7B,\c!right=0x7D]
\definemathfence [bar]         [\c!left=0x7C,\c!right=0x7C]
\definemathfence [doublebar]   [\c!left=0x2016,\c!right=0x2016]
\definemathfence [angle]       [\c!left=0x3C,\c!right=0x3E]

%definemathfence [fancybracket] [bracket] [command=yes,color=red]

\protect