
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{etex}
%        [1997/08/12 v0.1 eTeX basic definition package (DPC)]
         [1998/03/26 v2.0 eTeX basic definition package (PEB)]

\DeclareOption{grouptypes}{\catcode`\G=9}
\DeclareOption{interactionmodes}{\catcode`\I=9}
\DeclareOption{nodetypes}{\catcode`\N=9}
\DeclareOption{iftypes}{\catcode`\C=9}
\DeclareOption{localalloclog}{\let\et@xwlog\wlog} % the default
\DeclareOption{localallocnolog}{\let\et@xwlog\@gobble} % be quiet
\DeclareOption{localallocshow}{\let\et@xwlog\typeout} % debugging

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% A basic interface to some etex primitives, closely modeled on
%% etex.src and etexdefs.lib provided by the core etex team.

%% The etex.src `module' system is not copied here, the standard
%% LaTeX package option mechanism is used instead,
%% however the package options match the module names.
%% (Currently grouptypes, interactionmodes, nodetypes, iftypes.)
%% The individual type names are different too: We use, e.g.,
%%
%% `\bottomleveltype' and `\simplegrouptype' instead of
%% `\grouptypes{bottomlevel}' and `\grouptypes{simple}'.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% Other Comments...

%% The names of the `interactionmodes' are not too good.
%% In particular \scroll and \batch are likely to clash with existing
%% uses. These names have been changed into \batchinteractionmode,
%% \scrollinteractionmode etc.
%% Similarly, the names of the `groupetypes' have been changed, in
%% particular \mathgroup would conflict with the LaTeX kernel.

%% \etex logo could have the same trick as \LaTeXe to pick up a bold
%% epsilon when needed. (Not done here, I hate wasting tokens on logos.)
%% This version does have a \m@th not in the original.

%% The \globcountvector, \loccountvector, etc. allocation macros are
%% not (yet) implemented.

%% Currently if run on a standard TeX, the package generates an error.
%% Perhaps it should instead load some code to try to fake
%% the new etex primitives in that case???
%% Likewise, the package generates an error when used with e-TeX V 1

%% The etex.src language mechanism is not copied here. That facility
%% does not use any of the etex features. LaTeX should be customised
%% using the same hyphen.cfg mechanism as for a format built with a
%% standard TeX.

%% David Carlisle

%% Upgraded for e-TeX V 2.0
%% Peter Breitenlohner

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



\ifx\eTeXversion\@undefined
  \PackageError{etex}
    {This package may only be run using an\MessageBreak
     etex in extended mode}
    {Perhaps you forgot the `*' when making the format with (e)initex.%
    }
\fi

\ifnum\eTeXversion<2
  \PackageError{etex}
    {This package requires e-TeX V 2}
    {You are probably using the obsolete e-TeX V 1.%
    }
\fi

\def\eTeX{%
  $\m@th\varepsilon$-\TeX}

\def\tracingall{%
  \tracingcommands\thr@@        % etex
  \tracingstats\tw@
  \tracingpages\@ne
  \tracinglostchars\tw@         % etex
  \tracingmacros\tw@
  \tracingparagraphs\@ne
  \tracingrestores\@ne
  \tracinggroups\@ne            % etex
  \tracingifs\@ne               % etex
  \tracingscantokens\@ne        % etex
  \tracingnesting\@ne           % etex
  \tracingassigns\@ne           % etex
  \errorcontextlines\maxdimen
  \showoutput}

\def\loggingall{%
  \tracingall
  \tracingonline\z@}

\def\tracingnone{%
  \tracingonline\z@
  \showboxdepth\m@ne
  \showboxbreadth\m@ne
  \tracingoutput\z@
  \errorcontextlines\m@ne
  \tracingassigns\z@
  \tracingnesting\z@
  \tracingscantokens\z@
  \tracingifs\z@
  \tracinggroups\z@
  \tracingrestores\z@
  \tracingparagraphs\z@
  \tracingmacros\z@
  \tracinglostchars\@ne
  \tracingpages\z@
  \tracingstats\z@
  \tracingcommands\z@}

%% Register allocation
%% We have to adjust the Plain TeX / LaTeX register allocation counts
%% for our slightly modified book-keeping, but first we allocate our
%% insertion counter \et@xins, because \insc@ount of Plain TeX / LaTeX
%% will be used differently.

\newcount\et@xins

\advance\count10 by 1 % \count10=23 % allocates \count registers 23, 24, ...
\advance\count11 by 1 % \count11=10 % allocates \dimen registers 10, 11, ...
\advance\count12 by 1 % \count12=10 % allocates \skip registers 10, 11, ...
\advance\count13 by 1 % \count13=10 % allocates \muskip registers 10, 11, ...
\advance\count14 by 1 % \count14=10 % allocates \box registers 10, 11, ...
\advance\count15 by 1 % \count15=10 % allocates \toks registers 10, 11, ...
\advance\count16 by 1 % \count16=0 % allocates input streams 0, 1, ...
\advance\count17 by 1 % \count17=0 % allocates output streams 0, 1, ...
\advance\count18 by 1 % \count18=4 % allocates math families 4, 5, ...
\advance\count19 by 1 % \count19=0 % allocates \language codes 0, 1, ...

\et@xins=\insc@unt % \et@xins=255 % allocates insertions 254, 253, ...

%% We don't change the LaTeX definitions of \newcount, etc., but the
%% \alloc@ macro doing the actual work is redefined.

%% When the normal register pool for \count, \dimen, \skip, \muskip,
%% \box, or \toks registers is exhausted, we switch to the extended pool.

\def\alloc@#1#2#3#4#5%
 {\ifnum\count1#1<#4% make sure there's still room
    \allocationnumber\count1#1
    \global\advance\count1#1\@ne
    \global#3#5\allocationnumber
    \wlog{\string#5=\string#2\the\allocationnumber}%
  \else\ifnum#1<6
    \begingroup \escapechar\m@ne
    \expandafter\alloc@@\expandafter{\string#2}#5%
  \else\errmessage{No room for a new #2}\fi\fi
 }

%% The \expandafter construction used here allows the generation of
%% \newcount and \globcount from #1=count.

\def\alloc@@#1#2%
 {\endgroup % restore \escapechar
  \wlog{Normal \csname#1\endcsname register pool exhausted,
    switching to extended pool.}%
  \global\expandafter\let
    \csname new#1\expandafter\endcsname
    \csname glob#1\endcsname
  \csname new#1\endcsname#2%
 }

%% We do change the LaTeX definition of \newinsert

\def\newinsert#1{% make sure there's still room for ...
  \ch@ck0\et@xins\count{% ... a \count, ...
    \ch@ck1\et@xins\dimen{% ... \dimen, ...
      \ch@ck2\et@xins\skip{% ... \skip, ...
        \ch@ck4\et@xins\box{% ... and \box register
  \global\advance\et@xins\m@ne
  \unless\ifnum\insc@unt<\et@xins \global\insc@unt\et@xins \fi
  \allocationnumber\et@xins
  \global\chardef#1\allocationnumber
  \wlog{\string#1=\string\insert\the\allocationnumber}}}}}}

\def\ch@ck#1#2#3#4%
 {\ifnum\count1#1<#2#4\else\errmessage{No room for a new #3}\fi}

%% And we define \reserveinserts, so that you can say \reserveinserts{17}
%% in order to reserve room for up to 17 additional insertion classes, that
%% will not be taken away by \newcount, \newdimen, \newskip, or \newbox.

\outer\def \reserveinserts#1%
 {\global\insc@unt\numexpr \et@xins \ifnum#1>\z@ -#1\fi \relax}

% Now, we define \globcount, \globbox, etc., so that you can say
% \globcount\foo and \foo will be defined (with \countdef) to be the
% next count register from the vastly larger but somewhat less efficient
% extended register pool. We also define \loccount, etc., but these
% register definitions are local to the current group.

\count260=277 % globally allocates \count registers 277, 278, ...
\count261=256 % globally allocates \dimen registers 256, 257, ...
\count262=256 % globally allocates \skip registers 256, 257, ...
\count263=256 % globally allocates \muskip registers 256, 257, ...
\count264=256 % globally allocates \box registers 256, 257, ...
\count265=256 % globally allocates \toks registers 256, 257, ...
\count266=1 % globally allocates \marks classes 1, 2, ...

\count270=32768 % locally allocates \count registers 32767, 32766, ...
\count271=32768 % ditto for \dimen registers
\count272=32768 % ditto for \skip registers
\count273=32768 % ditto for \muskip registers
\count274=32768 % ditto for \box registers
\count275=32768 % ditto for \toks registers
\count276=32768 % ditto for \marks classes

% \count registers 256-259 and 267-269 are not (yet) used

% \def \et@xglob #1#2#3#4% <offset>, <type>, <method>, <register>
% \def \et@xloc #1#2#3#4% <offset>, <type>, <method>, <register>

\def \globcount  {\et@xglob 0\count  \countdef}
\def \loccount   {\et@xloc  0\count  \countdef}
\def \globdimen  {\et@xglob 1\dimen  \dimendef}
\def \locdimen   {\et@xloc  1\dimen  \dimendef}
\def \globskip   {\et@xglob 2\skip   \skipdef}
\def \locskip    {\et@xloc  2\skip   \skipdef}
\def \globmuskip {\et@xglob 3\muskip \muskipdef}
\def \locmuskip  {\et@xloc  3\muskip \muskipdef}
\def \globbox    {\et@xglob 4\box    \mathchardef}
\def \locbox     {\et@xloc  4\box    \mathchardef}
\def \globtoks   {\et@xglob 5\toks   \toksdef}
\def \loctoks    {\et@xloc  5\toks   \toksdef}
\def \globmarks  {\et@xglob 6\marks  \mathchardef}
\def \locmarks   {\et@xloc  6\marks  \mathchardef}

\let\newmarks=\globmarks %% this used to be \newmark for e-TeX V 1.1

\def\et@xglob#1#2#3#4%
 {\et@xchk#1#2{% make sure there's still room
  \allocationnumber=\count26#1%
  \global\advance\count26#1\@ne
  \global#3#4\allocationnumber
  \wlog{\string#4=\string#2\the\allocationnumber}}%
 }

\def\et@xloc#1#2#3#4%
 {\et@xchk#1#2{% make sure there's still room
  \advance\count27#1by\m@ne
  \allocationnumber=\count27#1%
  #3#4=\allocationnumber
  \et@xwlog{\string#4=\string#2\the\allocationnumber\space(local)}}%
 }

%% The allocation messages for local allocations use \et@xwlog, such that
%% these messages can easily be switched on/off

\let\et@xwlog=\wlog

\def\et@xchk#1#2#3%
 {\ifnum\count26#1<\count27#1 #3\else\errmessage{No room for a new #2}\fi}

% Next we define \globcountblk, \loccountblk, etc., so that you can
% say \globcountblk\foo{17} and \foo will be defined (with \mathchardef)
% as the first (the zeroth?) of a block of 17 consecutive registers.
% Thus the user is intended to reference elements <\foo+0> to <\foo+n-1>,
% where n is the length of the block allocated.

% \def \et@xgblk #1#2#3#4% <offset>, <type>, <register>, <size>
% \def \et@xlblk #1#2#3#4% <offset>, <type>, <register>, <size>

\def\globcountblk  {\et@xgblk 0\count  }
\def\loccountblk   {\et@xlblk 0\count  }
\def\globdimenblk  {\et@xgblk 1\dimen  }
\def\locdimenblk   {\et@xlblk 1\dimen  }
\def\globskipblk   {\et@xgblk 2\skip   }
\def\locskipblk    {\et@xlblk 2\skip   }
\def\globmuskipblk {\et@xgblk 3\muskip }
\def\locmuskipblk  {\et@xlblk 3\muskip }
\def\globboxblk    {\et@xgblk 4\box    }
\def\locboxblk     {\et@xlblk 4\box    }
\def\globtoksblk   {\et@xgblk 5\toks   }
\def\loctoksblk    {\et@xlblk 5\toks   }
\def\globmarksblk  {\et@xgblk 6\marks  }
\def\locmarksblk   {\et@xlblk 6\marks  }

% \def\et@xchkblk#1#1#3#4% <offset>, <type>, <size>, <action>

\def\et@xgblk#1#2#3#4%
 {\et@xchkblk#1#2{#4}% make sure there's still room
   {\allocationnumber\count26#1%
    \global\advance\count26#1by#4%
    \global\mathchardef#3\allocationnumber
    \wlog{\string#3=\string#2blk{\number#4} at
      \the\allocationnumber}%
   }%
 }

\def\et@xlblk#1#2#3#4%
 {\et@xchkblk#1#2{#4}% make sure there's still room
   {\advance\count27#1-#4%
    \allocationnumber\count27#1%
    \mathchardef#3\allocationnumber
    \et@xwlog{\string#3=\string#2blk{\number#4} at
      \the\allocationnumber\space(local)}%
   }%
 }

\def\et@xchkblk#1#2#3#4%
 {\ifnum#3<\z@
    \errmessage{Negative register block size \number#3}%
  \else\ifnum\numexpr\count26#1+#3>\count27#1%
    \errmessage{No room for new #2block of size \number#3}%
  \else #4\fi \fi
 }

\catcode`\G=14
\catcode`\I=14
\catcode`\N=14
\catcode`\C=14

\ProcessOptions

%% Declare names for `grouptypes'

G \chardef \bottomleveltype       =  0 % for the outside world
G \chardef \simplegrouptype       =  1 % for local structure only
G \chardef \hboxgrouptype         =  2 % for `\hbox{}'
G \chardef \adjustedhboxgrouptype =  3 % for `\hbox{}' in vertical mode
G \chardef \vboxgrouptype         =  4 % for `\vbox{}'
G \chardef \vtopgrouptype         =  5 % for `\vtop{}'
G \chardef \aligngrouptype        =  6 % for `\halign{}', `\valign{}'
G \chardef \noaligngrouptype      =  7 % for `\noalign{}'
G \chardef \outputgrouptype       =  8 % for output routine
G \chardef \mathgrouptype         =  9 % for, e.g, `^{}'
G \chardef \discgrouptype         = 10 % for `\discretionary{}{}{}'
G \chardef \insertgrouptype       = 11 % for `\insert{}', `\vadjust{}'
G \chardef \vcentergrouptype      = 12 % for `\vcenter{}'
G \chardef \mathchoicegrouptype   = 13 % for `\mathchoice{}{}{}{}'
G \chardef \semisimplegrouptype   = 14 % for `\begingroup...\endgroup'
G \chardef \mathshiftgrouptype    = 15 % for `$...$'
G \chardef \mathleftgrouptype     = 16 % for `\left...\right'

%% Declare names for `interactionmodes'

I \chardef \batchinteractionmode     = 0 % omits all stops and omits terminal output
I \chardef \nonstopinteractionmode   = 1 % omits all stops
I \chardef \scrollinteractionmode    = 2 % omits error stops
I \chardef \errorstopinteractionmode = 3 % stops at every opportunity to interact

%% Declare names for `nodetypes'

N \chardef \charnode     =  0 % character nodes
N \chardef \hlistnode    =  1 % hlist nodes
N \chardef \vlistnode    =  2 % vlist nodes
N \chardef \rulenode     =  3 % rule nodes
N \chardef \insnode      =  4 % insertion nodes
N \chardef \marknode     =  5 % a mark node
N \chardef \adjustnode   =  6 % an adjust node
N \chardef \ligaturenode =  7 % a ligature node
N \chardef \discnode     =  8 % a discretionary node
N \chardef \whatsitnode  =  9 % special extension nodes
N \chardef \mathnode     = 10 % a math node
N \chardef \gluenode     = 11 % node that points to a glue specification
N \chardef \kernnode     = 12 % a kern node
N \chardef \penaltynode  = 13 % a penalty node
N \chardef \unsetnode    = 14 % an unset node
N \chardef \mathsnodes   = 15 % nodes that occur only in maths mode

%% Declare names for `iftypes'

C \chardef \charif     =  1 % \if
C \chardef \catif      =  2 % \ifcat
C \chardef \numif      =  3 % \ifnum
C \chardef \dimif      =  4 % \ifdim
C \chardef \oddif      =  5 % \ifodd
C \chardef \vmodeif    =  6 % \ifvmode
C \chardef \hmodeif    =  7 % \ifhmode
C \chardef \mmodeif    =  8 % \ifmmode
C \chardef \innerif    =  9 % \ifinner
C \chardef \voidif     = 10 % \ifvoid
C \chardef \hboxif     = 11 % \ifhbox
C \chardef \vboxif     = 12 % \ifvbox
C \chardef \xif        = 13 % \ifx
C \chardef \eofif      = 14 % \ifeof
C \chardef \trueif     = 15 % \iftrue
C \chardef \falseif    = 16 % \iffalse
C \chardef \caseif     = 17 % \ifcase
C \chardef \definedif  = 18 % \ifdefined
C \chardef \csnameif   = 19 % \ifcsname
C \chardef \fontcharif = 20 % \iffontchar

\catcode`\G=11
\catcode`\I=11
\catcode`\N=11
\catcode`\C=11

