%D \module
%D   [       file=core-env, % was core-new
%D        version=1995.01.01, % wrong
%D          title=\CONTEXT\ Core Macros,
%D       subtitle=New ones,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
%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 Core Macros / Environments}

\unprotect

%D Modes:
%D
%D \starttyping
%D \enablemode[screen,paper,bound]
%D
%D \doifmodeelse {paper}        {this} {that}
%D \doifmode     {paper,screen} {this}
%D \doifnotmode  {paper,bound}  {that}
%D
%D \startmode [list]
%D \stopmode
%D
%D \startnotmode [list]
%D \stopnotmode
%D \stoptyping
%D
%D system modes have a * as prefix
%D
%D Sometimes, we want to prevent a mode for being set. Think
%D of situations where a style enables a mode, but an outer
%D level style does not want that. Preventing can be
%D considered a permanent disabling on forehand.

\def\@mode@{@md@}

\def\systemmodeprefix{*}

\def\disabledmode {0} % no chardefs
\def\enabledmode  {1}
\def\preventedmode{2}

% fast internal ones

\def\setmode  #1{\@EA\let\csname\@mode@#1\endcsname\enabledmode }
\def\resetmode#1{\@EA\let\csname\@mode@#1\endcsname\disabledmode}

\def\setsystemmode  #1{\@EA\let\csname\@mode@\systemmodeprefix#1\endcsname\enabledmode }
\def\resetsystemmode#1{\@EA\let\csname\@mode@\systemmodeprefix#1\endcsname\disabledmode}

% user ones

\def\preventmode{\unprotect\dopreventmode}
\def\enablemode {\unprotect\doenablemode }
\def\disablemode{\unprotect\dodisablemode}

\def\dopreventmode[#1]{\protect\rawprocesscommacommand[#1]\dodopreventmode}
\def\doenablemode [#1]{\protect\rawprocesscommacommand[#1]\dodoenablemode }
\def\dodisablemode[#1]{\protect\rawprocesscommacommand[#1]\dododisablemode}

\def\dodopreventmode#1%
  {\@EA\let\csname\@mode@#1\endcsname\preventedmode}

\def\dodoenablemode#1% mode can be relax
  {\ifcase0\csname\@mode@#1\endcsname\relax
     \@EA\let\csname\@mode@#1\endcsname\enabledmode
   \fi}

\def\dododisablemode#1%
  {\ifcase0\csname\@mode@#1\endcsname\or
     \@EA\let\csname\@mode@#1\endcsname\disabledmode
   \fi}

% handy for mp

\def\booleanmodevalue#1% can be \relax
  {\expandafter\ifx\csname\@mode@#1\endcsname\relax
     fals%
   \else\ifnum0\csname\@mode@#1\endcsname=0
     fals%
   \else
     tru%
   \fi\fi e}

% check macros

\newif\ifcheckedmode

\def\dodocheckformode#1%
  {\ifcase0\csname\@mode@#1\endcsname\or\checkedmodetrue\fi}

\def\docheckformode#1#2#3% will be sped up with a quit
  {\protect\checkedmodefalse\rawprocesscommacommand[#3]\dodocheckformode
   \ifcheckedmode\@EA#1\else\@EA#2\fi}

\def\dodocheckforallmodes#1%
  {\ifcase0\csname\@mode@#1\endcsname\relax\checkedmodefalse\or\or\checkedmodefalse\fi}

\def\docheckforallmodes#1#2#3% will be sped up with a quit
  {\protect\checkedmodetrue\rawprocesscommacommand[#3]\dodocheckforallmodes
   \ifcheckedmode\@EA#1\else\@EA#2\fi}

% simple ones

\unexpanded\def\doifmodeelse{\unprotect\dodoifmodeelse}
\unexpanded\def\doifmode    {\unprotect\dodoifmode}
\unexpanded\def\doifnotmode {\unprotect\dodoifnotmode}
\unexpanded\def\startmode   {\unprotect\dostartmode}
\unexpanded\def\startnotmode{\unprotect\dostartnotmode}

\def\dodoifmodeelse
  {\docheckformode\firstoftwoarguments\secondoftwoarguments}

\def\dodoifmode
  {\docheckformode\firstofoneargument\gobbleoneargument}

\def\dodoifnotmode
  {\docheckformode\gobbleoneargument\firstofoneargument}

\long\unexpanded\def\dostartmode[#1]%
  {\docheckformode\donothing\dostopmode{#1}}

\long\def\dostartnotmode[#1]%
  {\docheckformode\dostopnotmode\donothing{#1}}

\unexpanded\def\stopmode   {} % no relax
\unexpanded\def\stopnotmode{} % no relax

\long\def\dostopmode   #1\stopmode   {}
\long\def\dostopnotmode#1\stopnotmode{}

\unexpanded\def\doifallmodeselse{\unprotect\dodoifallmodeselse}
\unexpanded\def\doifallmodes    {\unprotect\dodoifallmodes}
\unexpanded\def\doifnotallmodes {\unprotect\dodoifnotallmodes}
\unexpanded\def\startallmodes   {\unprotect\dostartallmodes}
\unexpanded\def\startnotallmodes{\unprotect\dostartnotallmodes}

\def\dodoifallmodeselse
  {\docheckforallmodes\firstoftwoarguments\secondoftwoarguments}

\def\dodoifallmodes
  {\docheckforallmodes\firstofoneargument\gobbleoneargument}

\def\dodoifnotallmodes
  {\docheckforallmodes\gobbleoneargument\firstofoneargument}

\long\def\dostartallmodes[#1]%
  {\docheckforallmodes\donothing\dostopallmodes{#1}}

\long\def\dostartnotallmodes[#1]%
  {\docheckforallmodes\dostopnotallmodes\donothing{#1}}

\unexpanded\def\stopallmodes   {} % no relax
\unexpanded\def\stopnotallmodes{} % no relax

\long\def\dostopallmodes   #1\stopallmodes   {}
\long\def\dostopnotallmodes#1\stopnotallmodes{}

%D Lets now set a mode:

\enablemode[mkiv] \setsystemmode{mkiv}

%D Setups:

\unexpanded\def\startsetups{} % to please dep checker
\unexpanded\def\stopsetups {} % to please dep checker

\expanded
  {\long\def\@EA\noexpand\csname\e!start\v!setups\endcsname
     {\begingroup\noexpand\doifnextoptionalelse
        {\noexpand\dostartsetupsA\@EA\noexpand\csname\e!stop\v!setups\endcsname}
        {\noexpand\dostartsetupsB\@EA\noexpand\csname\e!stop\v!setups\endcsname}}}

\letvalue{\e!stop\v!setups}\relax

\unexpanded\def\setups{\doifnextbgroupelse\dosetupsA\dosetupsB} % {..} or [..]
\unexpanded\def\setup {\doifnextbgroupelse\dosetups \dosetupsC} % {..} or [..]

\def\dosetupsA  #1{\processcommacommand[#1]\dosetups} % {..}
\def\dosetupsB[#1]{\processcommacommand[#1]\dosetups} % [..]
\def\dosetupsC[#1]{\dosetups{#1}} % [..]

\letvalue{\??su:\letterpercent}\gobbleoneargument

\def\dosetups#1% the grid option will be extended to other main modes
  {\csname\??su
     \ifgridsnapping
       \ifcsname\??su\v!grid:#1\endcsname\v!grid:#1\else\ifcsname\??su:#1\endcsname:#1\else:\letterpercent\fi\fi
     \else
                                                        \ifcsname\??su:#1\endcsname:#1\else:\letterpercent\fi
     \fi
   \endcsname\empty} % takes one argument

% the next one is meant for \c!setups situations, hence the check for
% a shortcut

\def\doprocesslocalsetups#1%
  {\edef\tobeprocessedsetups{#1}%
   \ifx\tobeprocessedsetups\empty\else
     \dodoprocesslocalsetups
   \fi}

\def\dodoprocesslocalsetups
  {\@EA\processcommalist\@EA[\tobeprocessedsetups]\dosetups}

\edef\setupwithargument#1% saves a few expansions
  {\noexpand\csname\??su:\noexpand\ifcsname\??su:#1\endcsname#1\noexpand\else\letterpercent\noexpand\fi\endcsname}

\let\directsetup\dosetups

\def\doifsetupselse#1% to be done: grid
  {\doifdefinedelse{\??su:#1}}

\chardef\setupseolmode\plusone

\unexpanded\def\startsetups     {\xxstartsetups\plusone  \stopsetups     } \let\stopsetups     \relax
\unexpanded\def\startlocalsetups{\xxstartsetups\plusone  \stoplocalsetups} \let\stoplocalsetups\relax
\unexpanded\def\startrawsetups  {\xxstartsetups\zerocount\stoprawsetups  } \let\stoprawsetups  \relax
\unexpanded\def\startxmlsetups  {\xxstartsetups\plustwo  \stopxmlsetups  } \let\stopxmlsetups  \relax

\def\xxstartsetups#1#2%
  {\begingroup\let\setupseolmode#1\doifnextoptionalelse{\dostartsetupsA#2}{\dostartsetupsB#2}}

\def\dostartsetupsA#1% [ ] delimited
  {\ifcase\setupseolmode\or\catcode`\^^M\@@ignore\or\catcode`\^^M\@@ignore\catcode`\|\@@other\fi
   \dotripleempty\dostartsetups[#1]}

\def\dostartsetupsB#1#2 % space delimited
  {\ifcase\setupseolmode\or\catcode`\^^M\@@ignore\or\catcode`\^^M\@@ignore\catcode`\|\@@other\fi
   \dodostartsetups#1\empty{#2}}

\def\dostartsetupsC[#1][#2][#3]{\dodostartsetups#1{#2}{#3}}   % [..] [..]
\def\dostartsetupsD[#1][#2][#3]{\dodostartsetups#1\empty{#2}} % [..]

\def\dostartsetups
  {\ifthirdargument\@EA\dostartsetupsC\else\@EA\dostartsetupsD\fi}

\long\def\dodostartsetups#1#2#3%
  {\long\def\dododostartsetups##1#1%
     {\endgroup
      \dodoglobal % bah
      \long\expandafter\def\csname\??su#2:#3\expandafter\endcsname\expandafter####\expandafter1\expandafter{##1}}%
   \dododostartsetups\empty} % the empty trick prevents the { } in {arg} from being eaten up

\def\systemsetupsprefix{*}

\def\systemsetups#1{\dosetups{\systemsetupsprefix#1}}

\def\resetsetups[#1]% see x-fo for usage
  {\ifcsname\??su\ifgridsnapping\v!grid\fi:#1\endcsname
     \dodoglobal\letbeundefined{\??su\ifgridsnapping\v!grid\fi:#1}%
   \else
     \dodoglobal\letbeundefined{\??su:#1}%
   \fi}

%D \macros
%D   {setvariables,getvariable,getvariabledefault}
%D
%D \starttyping
%D \setvariables[xx][title=]
%D \setvariables[xx][title=test test]
%D \setvariables[xx][title=test $x=1$ test]   % fatal error reported
%D \setvariables[xx][title=test {$x=1$} test]
%D \setvariables[xx][title]                   % fatal error reported
%D \setvariables[xx][titletitel=e]
%D \stoptyping

\def\??vars{@@vars}

\def\setvariables {\dotripleargument\dosetvariables[\getrawparameters ]}
\def\setevariables{\dotripleargument\dosetvariables[\getraweparameters]}
\def\setgvariables{\dotripleargument\dosetvariables[\getrawgparameters]}
\def\setxvariables{\dotripleargument\dosetvariables[\getrawxparameters]}

\def\globalsetvariables % obsolete
  {\dotripleargument\dosetvariables[\globalgetrawparameters]}

\long\def\dosetvariables[#1][#2][#3]% tricky, test on s-pre-60
  {\errorisfataltrue
   \doifelse{#2}\currentvariableclass
     {#1[\??vars:#2:][#3]}%
     {\pushmacro\currentvariableclass
      \def\currentvariableclass{#2}%
      \getvariable{#2}\s!reset
      #1[\??vars:#2:][#3]%
      \getvariable{#2}\s!set
      \popmacro\currentvariableclass}%
   \errorisfatalfalse}

\long\def\setvariable #1#2#3{\long\expandafter\def \csname\??vars:#1:#2\endcsname{#3}}
\long\def\setevariable#1#2#3{\long\expandafter\edef\csname\??vars:#1:#2\endcsname{#3}}
\long\def\setgvariable#1#2#3{\long\expandafter\gdef\csname\??vars:#1:#2\endcsname{#3}}
\long\def\setxvariable#1#2#3{\long\expandafter\xdef\csname\??vars:#1:#2\endcsname{#3}}

\def\getvariable#1#2%
  {\csname
     \ifcsname\??vars:#1:#2\endcsname\??vars:#1:#2\else\s!empty\fi
   \endcsname}

\def\showvariable#1#2%
  {\showvalue{\ifcsname\??vars:#1:#2\endcsname\??vars:#1:#2\else\s!empty\fi}}

\let\currentvariableclass\empty

%D \macros
%D   {checkvariables}
%D
%D I'll probably forget that this on exists.

\def\checkvariables
  {\dodoubleargument\docheckvariables}

\def\docheckvariables
  {\dogetparameters\docheckrawvalue}

\long\def\docheckrawvalue#1#2#3%
  {\ifcsname\??vars:#1:#2\endcsname
     \edef\checkedrawvalue{\csname\??vars:#1:#2\endcsname}%
     \ifx\checkedrawvalue\empty
       \long\expandafter\def\csname\??vars:#1:#2\endcsname{#3}%
     \fi
   \else
     \long\expandafter\def\csname\??vars:#1:#2\endcsname{#3}%
   \fi}

%D \macros
%D   {doifelsevariable,doifvariable,doifnotvariable}
%D
%D A few trivial macros:

\def\doifelsevariable#1#2%
  {\ifcsname\??vars:#1:#2\endcsname
     \expandafter\firstoftwoarguments
   \else
     \expandafter\secondoftwoarguments
   \fi}

\def\doifvariable#1#2%
  {\ifcsname\??vars:#1:#2\endcsname
     \expandafter\firstofoneargument
   \else
     \expandafter\gobbleoneargument
   \fi}

\def\doifnotvariable#1#2%
  {\ifcsname\??vars:#1:#2\endcsname
     \expandafter\gobbleoneargument
   \else
     \expandafter\firstofoneargument
   \fi}

\def\getvariabledefault#1#2% #3% can be command, so no ifcsname here
  {\executeifdefined{\??vars:#1:#2}}% {#3}

% \unexpanded\def\setupenv{\dodoubleargument\rawgetparameters[\??en]}
%
% \def\doifenvelse#1{\doifdefinedelse{\??en#1}} % speed up
% \def\doifenv    #1{\doifdefined    {\??en#1}} % speed up
% \def\doifnotenv #1{\doifundefined  {\??en#1}} % speed up
%
% \def\env#1{\csname\??en#1\endcsname}
%
% \def\envvar#1#2%
%   {\ifcsname\??en#1\endcsname
%      \csname\??en#1\endcsname\else#2%
%    \fi}
%
% low level change, now also accessible as \getvariable
% {environment}{...}; the next macros will become obsolete
% some day in favor of normal variables in the environment
% namespace

\def\s!environment{environment}

\unexpanded\def\setupenv   {\dotripleargument\dosetvariables[\getrawparameters][\s!environment]}
\def\doifenvelse{\doifelsevariable  \s!environment}
\def\doifenv    {\doifvariable      \s!environment}
\def\doifnotenv {\doifnotvariable   \s!environment}
\def\env        {\getvariable       \s!environment}
\def\envvar     {\getvariabledefault\s!environment}

\protect \endinput