%D \module
%D   [       file=core-two, % moved from core-uti
%D        version=1997.03.31,
%D          title=\CONTEXT\ Core Macros,
%D       subtitle=Two Pass Data,
%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 Core Macros / Two Pass Data}

%D This is a rather old mechanism which has not changed much over time, apart from
%D adding a few more selectors. This code used to be part of \type {core-uti}. The
%D following examples demonstrate the interface.
%D
%D \startbuffer
%D \definetwopasslist{test-1}
%D
%D \gettwopassdatalist{test-1} [\twopassdatalist=]
%D \checktwopassdata  {test-1} [\twopassdata=]
%D \checktwopassdata  {test-1} [\twopassdata=]
%D \gettwopassdata    {test-1} [\twopassdata=]
%D \gettwopassdata    {test-1} [\twopassdata=]
%D
%D \definetwopasslist{test-2}
%D
%D \lazysavetwopassdata{test-2}{1}{x}
%D \lazysavetwopassdata{test-2}{2}{y}
%D \lazysavetwopassdata{test-2}{3}{z}
%D
%D \gettwopassdatalist{test-2} [\twopassdatalist=x,y,z]
%D \checktwopassdata  {test-2} [\twopassdata=x]
%D \checktwopassdata  {test-2} [\twopassdata=x]
%D \gettwopassdata    {test-2} [\twopassdata=x]
%D \gettwopassdata    {test-2} [\twopassdata=y]
%D \gettwopassdata    {test-2} [\twopassdata=z]
%D \gettwopassdata    {test-2} [\twopassdata=]
%D
%D \definetwopasslist{test-3}
%D
%D \lazysavetaggedtwopassdata{test-3}{1}{x}{a}
%D \lazysavetaggedtwopassdata{test-3}{2}{y}{b}
%D \lazysavetaggedtwopassdata{test-3}{3}{z}{c}
%D
%D \findtwopassdata{test-3}{x} [\twopassdata=a]
%D \findtwopassdata{test-3}{y} [\twopassdata=b]
%D \findtwopassdata{test-3}{z} [\twopassdata=c]
%D \findtwopassdata{test-3}{w} [\twopassdata=]
%D
%D \definetwopasslist{test-4}
%D
%D \lazysavetwopassdata{test-4}{1}{A}
%D \lazysavetwopassdata{test-4}{2}{B}
%D \lazysavetwopassdata{test-4}{3}{C}
%D
%D \getfirsttwopassdata{test-4}    [\twopassdata=A]
%D \getlasttwopassdata {test-4}    [\twopassdata=C]
%D \getfirsttwopassdata{test-4}    [\twopassdata=A]
%D \getlasttwopassdata {test-4}    [\twopassdata=C]
%D \getfromtwopassdata {test-4}{1} [\twopassdata=A]
%D \getfromtwopassdata {test-4}{3} [\twopassdata=C]
%D \getfromtwopassdata {test-4}{2} [\twopassdata=B]
%D \stopbuffer
%D
%D \getbuffer \typebuffer

\unprotect

\registerctxluafile{core-two}{}

\permanent\def\immediatesavetwopassdata   #1#2#3{\normalexpanded{\noexpand\clf_savetwopassdata{#1}{#3}}}
\permanent\def     \lazysavetwopassdata   #1#2#3{\normalexpanded{\noexpand\ctxlatecommand{savetwopassdata("#1","#3")}}}
\permanent\let         \savetwopassdata          \lazysavetwopassdata
\permanent\def    \savetaggedtwopassdata#1#2#3#4{\normalexpanded{\noexpand\clf_savetaggedtwopassdata{#1}{#3}{#4}}}
\permanent\def\lazysavetaggedtwopassdata#1#2#3#4{\normalexpanded{\noexpand\ctxlatecommand{savetaggedtwopassdata("#1",'#3',"#4")}}}

% temp hack: needs a proper \starteverytimeluacode

\setfalse\twopassdatafound

\mutable\let\twopassdata    \empty
\mutable\let\twopassdatalist\empty
\mutable\let\noftwopassitems\!!zeropoint

\def\syst_twopass_check % can be delegated to lua once obsolete is gone
  {\ifempty\twopassdata
     \setfalse\twopassdatafound
   \else
     \settrue\twopassdatafound
   \fi}

\permanent\protected\def\definetwopasslist        #1{\clf_definetwopasslist{#1}}
\permanent\protected\def\gettwopassdata           #1{\edef\twopassdata    {\clf_gettwopassdata      {#1}}\syst_twopass_check}
\permanent\protected\def\checktwopassdata         #1{\edef\twopassdata    {\clf_checktwopassdata    {#1}}\syst_twopass_check}
\permanent\protected\def\findtwopassdata        #1#2{\edef\twopassdata    {\clf_findtwopassdata {#1}{#2}}\syst_twopass_check}
\permanent\protected\def\getfirsttwopassdata      #1{\edef\twopassdata    {\clf_getfirsttwopassdata {#1}}\syst_twopass_check}
\permanent\protected\def\getlasttwopassdata       #1{\edef\twopassdata    {\clf_getlasttwopassdata  {#1}}%
                                                     \edef\noftwopassitems{\clf_counttwopassdata    {#1}}\syst_twopass_check}
\permanent\protected\def\getnamedtwopassdatalist#1#2{\edef              #1{\clf_gettwopassdatalist  {#2}}}
\permanent\protected\def\gettwopassdatalist       #1{\edef\twopassdatalist{\clf_gettwopassdatalist  {#1}}}

\permanent\protected\def\doifelseintwopassdata  #1#2{\clf_doifelseintwopassdata{#1}{#2}}

\aliased\let\doifintwopassdataelse\doifelseintwopassdata
\aliased\let\getfromtwopassdata   \findtwopassdata

\protect \endinput