%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Module: ZzTeX Register Facilities
%
% Synopsis: This module provides facilities for defining and manipulating
% TeX registers.
%
% Author: Paul C. Anagnostopoulos
% Created: 13 August 1989
%
% Copyright 1989--2020 by Paul C. Anagnostopoulos
% under The MIT License (opensource.org/licenses/MIT)
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Register Definition
% -------- ----------
% The following constant specifies the number of the first insert register
% set. Such a set is composed of a count, dimen, skip, and box.
\chardef \zfirstinsert = 245
% Establish counters to keep track of the most recently allocated
% registers. The registers are initialized to the first available
% register.
\count10 = 20 % Count registers.
\count11 = 0 % Dimen registers.
\count12 = 0 % Skip registers.
\count13 = 0 % Muskip registers.
\count14 = 1 % Box registers (Plain TeX uses box 0).
\count15 = 0 % Toks registers.
\count16 = 0 % Read streams.
\count17 = 0 % Write streams.
\count18 = 0 % Math families.
\count19 = \zfirstinsert % Insertion register sets.
% There is one macro for each type of register, used to allocate one.
\def \definecount #1#2{% {\name}{initial}
\zalloc{\count}{10}{\zfirstinsert}{\countdef}{#1}%
#1 = #2}
\def \definedimen #1#2{% {\name}{initial}
\zalloc{\dimen}{11}{\zfirstinsert}{\dimendef}{#1}%
#1 = #2}
\def \defineskip #1#2{% {\name}{initial}
\zalloc{\skip}{12}{\zfirstinsert}{\skipdef}{#1}%
#1 = #2}
\def \definemuskip #1#2{% {\name}{initial}
\zalloc{\muskip}{13}{255}{\muskipdef}{#1}% Muskip 255 is scratch.
#1 = #2}
\def \definebox #1{% {\name}
\zalloc{\box}{14}{\zfirstinsert}{\chardef}{#1}}
\def \definetoks #1{% {\name}
\zalloc{\toks}{15}{256}{\toksdef}{#1}%
#1 = {}}
\def \defineread #1{% {\name}
\zalloc{\read}{16}{16}{\chardef}{#1}}
\def \definewrite #1{% {\name}
\zalloc{\write}{17}{16}{\chardef}{#1}}
% Families are not defined directly by the user, but via \definetypestyle.
\def \zdeffam #1{% {\name}
\if \lssp{\count18}{15}%
\zalloc{\fam}{18}{16}{\chardef}{#1}%
\else
\global\chardef #1=\count18
\fi}
\def \defineinsert #1{% {\name}
\zalloc{\insert}{19}{255}{\chardef}{#1}} % Registers 255 are scratch.
\def \zalloc #1#2#3#4#5{% {type}{counter}{limit}{\def-er}{\name}
\if \eqlp{\count#2}{#3}%
\error{noregsleft}{All `\string#1' registers have been allocated}%
\fi
\if \definedp{#5}%
\error{dupreg}{The register `\string#5' is already defined}%
\fi
\global#4 #5=\count#2
\global\increment {\count#2}}
% Register Statistics
% -------- ----------
{\catcode`\_ = \catactive
\gdef \zregstats {%
{\def _{\space}%
\writelog{}%
\writelog{Register Statistics:}%
\writelog{}%
\writelog{Type_____Used / Total}%
\writelog{----_____------------}%
\zrsone{Count_}{10}{\zfirstinsert}{}%
\zrsone{Dimen_}{11}{\zfirstinsert}{}%
\zrsone{Skip__}{12}{\zfirstinsert}{}%
\zrsone{Muskip}{13}{255}{}%
\zrsone{Box___}{14}{\zfirstinsert}{}%
\zrsone{Toks__}{15}{256}{}%
\zrsone{Read__}{16}{16}{}%
\zrsone{Write_}{17}{16}{}%
\zrsone{Family}{18}{256}{(15 for math)}%
\zrsone{Insert}{19}{255}{(starts at \the\zfirstinsert)}%
\writelog{}}}
\gdef \zrsone #1#2#3#4{% {name}{counter}{ex-limit}{comment}
\tcounta = #3
\advance \tcounta by -1
\writelog{#1___\the\count#2 _/_\the\tcounta_#4}}
} % \catcode
% Constant Registers
% -------- ---------
\definecount{\maxcount}{2147483647}
\definecount{\mincount}{-\maxcount}
\zremovePlaindef \maxdimen
\definedimen{\maxdimen}{16383.99999pt}
\definedimen{\mindimen}{-\maxdimen}
\definedimen{\naturalwidth}{\mindimen}
\defineskip{\centerindent}{0pt plus 10000pt}
\let \centering = \centerindent
\defineskip{\normalparfillskip}{0pt plus 1fil}
\definebox{\voidbox} % Permanently void box register.
% Temporary Internal Registers
% --------- -------- ---------
\definecount{\tcounta}{0}
\definecount{\tcountb}{0}
\definecount{\tcountc}{0}
\definedimen{\tdimena}{0pt}
\definedimen{\tdimenb}{0pt}
\definedimen{\tdimenc}{0pt}
\definedimen{\tdimend}{0pt}
\defineskip{\zskipa}{0pt}
\defineskip{\zskipb}{0pt}
\defineskip{\zskipc}{0pt}
\definemuskip{\zmuskipa}{0mu}
\definemuskip{\zmuskipb}{0mu}
\definemuskip{\zmuskipc}{0mu}
\definebox{\zboxa}
\definebox{\zboxb}
\definebox{\zboxc}
\definetoks{\ztoksa}
\definetoks{\ztoksb}
\definetoks{\ztoksc}
\defineread{\zreada}
\definewrite{\zwritea}
% Manipulating Boxes
% ------------ -----
\def \shiftboxbaseline #1#2{% {\box}{amount}
{\tdimena = #2%
\tdimenb = \ht#1%
\advance \tdimenb by \tdimena
\ht#1= \tdimenb
\tdimenb = \dp#1%
\advance \tdimenb by -\tdimena
\dp#1= \tdimenb}}
% Lists
% -----
% These macros support the manipulation of lists in the following format:
%
% \:{<element-0>}\:{<element-1>}\: ...
%
% All lists are global!
% We need two toks registers, which will be used just for lists.
\definetoks{\zlta}
\definetoks{\zltb}
\def \setlist #1=#2{% \listname = {value}
\zlta = \expandafter{#2}%
\xdef #1{\the\zlta}}
\long\def \append #1#2{% {item}{\list-name}
{\zlta = {\:{#1}}%
\zltb = \expandafter{#2}%
\xdef #2{\the\zltb\the\zlta}}}
\long\def \appendlf #1#2{% {\list-name}{item}
{\zlta = {\:{#2}}%
\zltb = \expandafter{#1}%
\xdef #1{\the\zltb\the\zlta}}}
\long\def \prepend #1#2{% {item}{\list-name}
{\zlta = {\:{#1}}%
\zltb = \expandafter{#2}%
\xdef #2{\the\zlta\the\zltb}}}
\let \push = \prepend
\def \pop #1#2{% {\return-macro}{\list-name}
\expandafter\zpop #2\zmark#1#2}
\long\def \zpop \:#1#2\zmark#3#4{%
\def #3{#1}%
\gdef #4{#2}}
\def \listtop #1#2{% {\return-macro}{\list-name}
\expandafter\zlisttop #2\zmark#1}
\long\def \zlisttop \:#1#2\zmark#3{%
\def #3{#1}}
\definecount{\zmapldepth}{0}
\def \maplist #1#2{% {body}{\listname}
\increment \zmapldepth
\withname\let{\zmapl\romannumeral\zmapldepth}=\:%
\long\def \:##1{#1}%
#2%
\expandafter\let
\expandafter\:\csname zmapl\romannumeral\zmapldepth\endcsname
\decrement \zmapldepth}
\def \maplistlf #1#2{% {\listname}{body}
\increment \zmapldepth
\withname\let{\zmapl\romannumeral\zmapldepth}=\:%
\long\def \:##1{#2}%
#1%
\expandafter\let
\expandafter\:\csname zmapl\romannumeral\zmapldepth\endcsname
\decrement \zmapldepth}
\def \exitmaplist {\def \:##1{}}
\def \listlength #1#2{% {\result-count}{\list}
#1= 0
\maplist{\increment #1}{#2}}
\def \member #1#2#3{% {\result-flag}{item}{\list}
\setflag #1= \false
\maplist{\stringeql{#1}{##1}{#2}\if #1\exitmaplist \fi}
{#3}}
\def \commalist #1#2{% {\result-name}{comma-list}
\setlist #1={}%
\expandafter\zcomma #2,\zmark#1}
\def \zcomma #1,#2\zmark#3{%
\if \notp{\emptyargp{#1}}\append{#1}{#3}\fi
\if \notp{\emptyargp{#2}}%
\def \znext {\zcomma #2\zmark#3}%
\else
\let \znext = \relax
\fi
\znext}
\def \inclusionlist #1#2#3{% {\result}{item}{inclusion-list}
\zincla {#1}{#2}#3\zmark}
\let \all = \relax
\let \allbut = \relax
\def \zallname {\all}
\def \zallbutname {\allbut}
\def \zincla #1#2#3#4\zmark{% {\result}{item}{token1}{tokens...}
\def \znext {#3}%
\if \tokeqlp{\znext}{\zallname}%
\setflag #1= \true
\else \if \tokeqlp{\znext}{\zallbutname}%
\commalist{\zincllist}{#4}%
\member{#1}{#2}{\zincllist}%
\setflag #1= {\notp{#1}}%
\else
\commalist{\zincllist}{#3#4}%
\member{#1}{#2}{\zincllist}%
\fi\fi}
% New Expression Evaluation
% --- ---------- ----------
% These macros provide a rudimentary expression evaluation facility.
% The accumulator can be a count, dimen, or skip register. The expression
% is in the form {operand0,op1,operand1,op2,operand2,...}.
%
% WARNING: The \register cannot be used in the expression except possibly
% as the first operand.
\definedimen{\zcalct}{0pt}
\def \calculate #1=#2{% \register = {expression}
\let \zaccum = #1%
\zcalca =,#2,;,,\zmark}
\def \gcalculate #1=#2{% \register = {expression}
\let \zaccum = #1%
\zcalca =,#2,;,,\zmark
\global \zaccum = \zaccum}
\def \zcalca #1,#2,#3\zmark{%
\def \znext{\zcalca #3\zmark}%
\if #1=\zaccum = #2% % Assignment
\else\if #1+\advance \zaccum #2% % Addition
\else\if #1-\advance \zaccum -#2% % Subtraction
\else\if #1*\multiply \zaccum #2% % Multiplication
\else\if #1/\divide \zaccum #2% % Division
\else\if #1N\if \dimlssp{#2}{\zaccum}\zaccum = #2\fi % Minimum
\else\if #1P\divide \zaccum 100 % Percentage
\expandafter\zaccum #2\zaccum
\else\if #1R\zcalct = #2% % Ratio
\divide \zcalct by 4096
\divide \zaccum by \zcalct
\multiply \zaccum by 16\relax
\else\if #1S\zaccum = \thefactor#2\zaccum % Scale
\else\if #1X\if \dimgtrp{#2}{\zaccum}\zaccum = #2\fi % Maximum
\else\if #1;\let \znext = \relax % Done
\else
\error{invoper}{Invalid operator `#1' in expression}%
\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
\znext}
% Calculating Values
% ----------- ------
%%%\defineskip{\zcaccum}{0pt}
%%%\setflag \zexprpos = \true
%%%
%%%\def \calculate #1=#2{% {\reg} = {expression}
%%% \commalist{\zexprlist}{#2}%
%%% \zcaccum = 0pt
%%% \def \zoper {+}%
%%% \setflag \zexprpos = \true
%%% \maplist{\zcalc{##1}}{\zexprlist}%
%%% #1=\zcaccum}
%%%
%%%\def \gcalculate #1=#2{% {\reg} = {expression}
%%% \commalist{\zexprlist}{#2}%
%%% \zcaccum = 0pt
%%% \def \zoper {+}%
%%% \setflag \zexprpos = \true
%%% \maplist{\zcalc{##1}}{\zexprlist}%
%%% \global #1=\zcaccum}
%%%
%%%\def \zcalc #1{% {token}
%%% \if \zexprpos
%%% \zcalcb{#1}%
%%% \setflag \zexprpos = \false
%%% \else
%%% \def \zoper {#1}%
%%% \setflag \zexprpos = \true
%%% \fi}
%%%
%%%\def \zcalcb #1{% {operand}
%%% \if \codeeqlp{\zoper}{+}% % Add.
%%% \advance \zcaccum by #1%
%%% \else\if \codeeqlp{\zoper}{-}% % Subtract.
%%% \advance \zcaccum by -#1%
%%% \else\if \codeeqlp{\zoper}{*}% % Multiply.
%%% \multiply \zcaccum by #1%
%%% \else\if \codeeqlp{\zoper}{/}% % Divide.
%%% \divide \zcaccum by #1%
%%% \else\if \codeeqlp{\zoper}{P}%
%%% \divide \zcaccum by 100
%%% \expandafter \zcaccum #1\zcaccum
%%% \else\if \codeeqlp{\zoper}{R}% % Compute ratio (in points).
%%% \zcalct = #1%
%%% \divide \zcalct by 4096
%%% \divide \zcaccum by \zcalct
%%% \multiply \zcaccum by 16\relax
%%% \else\if \codeeqlp{\zoper}{S}% % Scale (in points).
%%% \zcaccum = \thefactor#1\zcaccum
%%% \else
%%% \error{invoper}{Invalid operator `\zoper' in expression}%
%%% \fi\fi\fi\fi\fi\fi\fi}
% The Vertical Context
% --- -------- -------
% This is in here because we need registers. Otherwise it would be
% in ZZTEX.TEX
\definecount{\zvcontextdepth}{0}
\definetoks{\zeveryvcontext}
\global\zeveryvcontext = {}
\def \zdeclareeveryvcontext #1{%
\global\zeveryvcontext = \expandafter{\the\zeveryvcontext #1}}
\def \zpushvcontext {%
\global\increment \zvcontextdepth
\withname\gdef{\zvcontextstack\romannumeral\zvcontextdepth}{}%
\the\zeveryvcontext}
\def \zpopvcontext {%
{\globaldefs = 1\relax
\name{\zvcontextstack\romannumeral\zvcontextdepth}}%
\global\decrement \zvcontextdepth}
\def \zsavevcontext #1{%
{\ztoksa = \expandafterthrice{%
\name{\zvcontextstack\romannumeral\zvcontextdepth}}%
\withname\xdef{\zvcontextstack\romannumeral\zvcontextdepth}%
{\the\ztoksa #1}}}