%D \module
%D   [       file=spac-chr,
%D        version=2011.05.24, % code moved from core-spa.mkiv
%D          title=\CONTEXT\ Spacing Macros,
%D       subtitle=Characters,
%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 Spacing Macros / Characters}

\unprotect

\registerctxluafile{spac-chr}{optimize}

\definesystemattribute[characters][public]

%D The nobreakspace is special as it needs to keep track of the space being
%D flexible. Another option is to use space (glue) nodes and tag them as characters
%D instead. No big deal but takes a moment of coding. So, as a prelude we
%D tag the nobreakspace only. Interesting is that it also fits better in the
%D tagging mechanism.
%D
%D But we need to do some checking as from then on we no longer can compare
%D them in a string. So this needs thinking. Not that we can compare the
%D nobreakspace now anyway.

% \unexpanded\def\specialspacecharacter#1{\begingroup\attribute\charactersattribute#1\ \endgroup}
%
% \unexpanded\edef\nobreakspace            {\specialspacecharacter{"00A0}} % 1 = left
% \unexpanded\edef\ideographicspace        {\specialspacecharacter{"2000}}
% \unexpanded\edef\ideographichalffillspace{\specialspacecharacter{"2001}}
% \unexpanded\edef\twoperemspace           {\specialspacecharacter{"2002}}
% \unexpanded\edef\threeperemspace         {\specialspacecharacter{"2004}}
% \unexpanded\edef\fourperemspace          {\specialspacecharacter{"2005}}
% \unexpanded\edef\sixperemspace           {\specialspacecharacter{"2006}}
% \unexpanded\edef\figurespace             {\specialspacecharacter{"2007}}
% \unexpanded\edef\punctuationspace        {\specialspacecharacter{"2008}}
% \unexpanded\edef\breakablethinspace      {\specialspacecharacter{"2009}}
% \unexpanded\edef\hairspace               {\specialspacecharacter{"200A}}
% \unexpanded\edef\zerowidthspace          {\specialspacecharacter{"200B}}
% \unexpanded\edef\zwnj                    {\specialspacecharacter{"200C}}
% \unexpanded\edef\zwj                     {\specialspacecharacter{"200D}}
% \unexpanded\edef\narrownobreakspace      {\specialspacecharacter{"202F}}

% This does not work as spaceskip is only inserted in the case of raggedleft
% and we need to be able to figure out all of them. Which makes me wonder ...
% can't we just always set spaceskip to some value?

% Making them active is also not an option unless we do that in every
% catcode vector.

%    \nobreakspace            {\begingroup\setalignstateattribute\normalUchar"00A0\endgroup} % 1 = left
\edef\nobreakspace            {\normalUchar"00A0} % space
\edef\softhyphen              {\normalUchar"00AD} % softhyohen
\edef\enquad                  {\normalUchar"2000} % quad/2
\edef\emquad                  {\normalUchar"2001} % quad

\let\ideographicspace         \enquad
\let\ideographichalffillspace \emquad

\edef\twoperemspace           {\normalUchar"2002} % quad/2
%                             %            "2003  % quad == \quad == \hskip\emwidth
\edef\threeperemspace         {\normalUchar"2004} % quad/3
\edef\fourperemspace          {\normalUchar"2005} % quad/4
%edef\fiveperemspace          {\normalUchar"001E} % quad/5 (bonus)
\edef\sixperemspace           {\normalUchar"2006} % quad/6
\edef\figurespace             {\normalUchar"2007} % width of zero
\edef\punctuationspace        {\normalUchar"2008} % width of period
\edef\breakablethinspace      {\normalUchar"2009} % quad/8
\edef\hairspace               {\normalUchar"200A} % quad/8
\edef\zerowidthspace          {\normalUchar"200B} % 0
\edef\zerowidthnonjoiner      {\normalUchar"200C} % 0
\edef\zerowidthjoiner         {\normalUchar"200D} % 0
\edef\narrownobreakspace      {\normalUchar"202F} % quad/8
%edef\mediummathspace         {\normalUchar"205F} % space/8 (math)
%edef\zerowidthnobreakspace   {\normalUchar"FEFF}
%edef\fiveperemspace          {\normalUchar"001E}

\udef\zerowidthnobreakspace   {\penalty\plustenthousand\kern\zeropoint}
\udef\fiveperemspace          {\hskip\dimexpr\emwidth/5\relax}

\let\zwnj                     \zerowidthnonjoiner
\let\zwj                      \zerowidthjoiner
\let\nbsp                     \nobreakspace

\chardef\optionalspace"1F % will be space unless before punctuation

% Shortcuts:

% unexpanded as otherwise we need to intercept / cleanup a lot

\unexpanded\def~{\nobreakspace}

\protect \endinput