%D \module
%D   [       file=back-ini,
%D        version=2009.04.15,
%D          title=\CONTEXT\ Backend Macros,
%D       subtitle=Initialization,
%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 Backend Macros / Initialization}

\registerctxluafile{back-ini}{autosuffix}

\unprotect

%D Right from the start \CONTEXT\ had a backend system based on runtime pluggable
%D code. As most backend issues involved specials and since postprocessors had not
%D that much in common, we ended up with a system where we could switch backend as
%D well as output code for multiple backends at the same time.
%D
%D Because \LUATEX\ has the backend built in, and since some backend issues have
%D been moved to the frontend I decided to provide new backend code for \MKIV,
%D starting with what was actually used.
%D
%D At this moment \DVI\ is no longer used for advanced document output and we
%D therefore dropped support for this format. Future versions might support more
%D backends again, but this has a low priority.

%D The exact page model depends on the backend so we just define some variables that
%D are used. A helper at the \LUA\ end will synchronize with the internal variables.
%D We store these in the format.

\ifdefined\everybackendshipout       \else \newtoks\everybackendshipout       \fi
\ifdefined\everylastbackendshipout   \else \newtoks\everylastbackendshipout   \fi
\ifdefined\everybackendlastinshipout \else \newtoks\everybackendlastinshipout \fi

\installcorenamespace{backend}

\installsetuponlycommandhandler \??backend {backend}

%D \starttyping
%D \setupbackend[space=yes]
%D \stoptyping

\appendtoks
    \clf_setrealspaces{\backendparameter\c!space}%
\to \everysetupbackend

\appendtoks
    \clf_setsofthyphens{\backendparameter\c!hyphen}%
\to \everysetupbackend

\setupbackend
  [\c!space=\v!yes, % is now default
   \c!hyphen=\v!yes]

%D For the moment this is an experiment (defauls is pdf, but we also
%D have lua, json and mps).
%D
%D \starttyping
%D % \setupoutput[lua]
%D % \setupoutput[json]
%D % \setupoutput[mps]
%D % \setupoutput[none]  % for testing only
%D % \setupoutput[empty] % for testing only
%D
%D \starttext
%D     \dorecurse{1000}{
%D         {\tf \red   \samplefile{tufte}} \par
%D         {\bf \green \samplefile {ward}} \par
%D         {\sl \blue  \samplefile{davis}} \par
%D     }
%D \stoptext
%D \stoptyping

\permanent\protected\def\setupoutput[#1]%
  {\clf_enabledriver{#1}%
   \clf_setrealspaces{\backendparameter\c!space}}

\protect \endinput
