%
%  T A B L S . S T Y
%
%  Copyright (c) 1989 by Donald Arseneau 
%  from
%  LaTeX, Copyright (c) 1985 by Leslie Lamport
%  
%  Modify LaTeX's table building macros to keep text from touching
%  text or hlines above or below.  See instructions after \endinput.
%
%----------------------------------------------------------------------

%  create registers and default settings:

\newskip\tablelineskip \tablelineskip= 1pt
\newskip\extrarulesep  \extrarulesep = 3pt

\newdimen\@arstdepth \newdimen\@arstheight \newskip\@skip@bove

% Change the initializations to create a smaller strut and include
% my macros in the initialization for the preamble.

\def\@array[#1]#2{%  This works for both tabular and array because of this test:
   \ifx\@classz\@arrayclassz \let\@tarlineskip\z@skip
       \else \let\@tarlineskip\tablelineskip 
%  remember global variables to allow recursion
    \edef\@unrecurse{\global\@skip@bove\the\@skip@bove
      \global\@arstheight\the\@arstheight\global\@arstdepth\the\@arstdepth}%
   \fi 
   \setbox\@arstrutbox=\hbox{% set up smaller strut
     \@tempdima\arraystretch\ht\strutbox \@tempdimb\arraystretch\dp\strutbox 
     \ifdim\@tarlineskip>\z@ \advance\@tempdima-.5\@tarlineskip
        \advance\@tempdimb-.5\@tarlineskip \fi
     \vrule \@height\@tempdima \@depth\@tempdimb \@width\z@}%
   \let\@rememsize\relax \let\@seesize\relax
\@mkpream{#2}\edef\@preamble{\halign \noexpand\@halignto
\bgroup \tabskip\z@ \copy\@arstrutbox \@preamble \tabskip\z@ &\@sharp \cr}%
% I have added an extra column (&\@sharp) to take the smart strut.
\let\@startpbox\@@startpbox \let\@endpbox\@@endpbox
  \if#1t\vtop \else \if#1b\vbox \else \vcenter \fi\fi
  \bgroup \let\par\relax 
  \ifdim\@tarlineskip>\z@ \let\@rememsize\@r@m@msize \let\@seesize\@s@@size\fi
  \global\@arstheight\ht\@arstrutbox \global\@arstdepth\dp\@arstrutbox
  \global\@skip@bove\z@ \advance\extrarulesep.5\arrayrulewidth
  \let\@sharp##\let\protect\relax \lineskip\z@ \baselineskip\z@ \@preamble}

%  Change the meaning of \\ to do the final strut calculation and
%  put in the smart strut

\def\@xtabularcr{\@ifnextchar[{\@argtabularcr}{\@argtabularcr[\z@]}}

\def\@argtabularcr[#1]{\@ifnextchar\hline
   {\@mystrutcr\extrarulesep[#1]}% Note: \@tempc is next char from \@ifnextchar
   {\ifx\@tempc\cline\@mystrutcr\extrarulesep[#1]\else\@mystrutcr\z@[#1]\fi}}

\def\@mystrutcr#1[#2]{\ifnum0=`{\fi}&\omit % end group, new column
  \advance\@arstheight\@skip@bove 
  \ifdim#2>\z@ \advance\@arstdepth#2\fi \advance\@arstdepth#1\relax
  \advance\@arstheight.5\@tarlineskip \advance\@arstdepth.5\@tarlineskip
  \vrule \@height\@arstheight \@depth\@arstdepth \@width\z@
  \global\@arstheight\ht\@arstrutbox \global\@arstdepth\dp\@arstrutbox
  \global\@skip@bove\z@ \cr
  \ifdim#2<\z@ \noalign{\vskip#2}\fi}

% Simulate \crcr at the end of the table, assuming that we are not in 
% vmode once a line of entries has started.  This fails to put in a smart 
% strut if the table ends without \\ while in vmode in a column entry.  
% Use \@unrecurse to simulate grouping of global parameters.

\def\endtabular{\ifvmode\crcr\else\\\fi\egroup\@unrecurse\egroup $\egroup}

% Put \@seesize...\@rememsize in all preamble templates

\def\@tabclassz{\ifcase \@lastchclass \@acolampacol \or \@ampacol \or
   \or \or \@addamp \or
   \@acolampacol \or \@firstampfalse \@acol \fi
\edef\@preamble{\@preamble
  \ifcase \@chnum
     \hfil\@seesize\ignorespaces\@sharp\unskip\@rememsize \hfil
     \or \@seesize\ignorespaces\@sharp\unskip\@rememsize \hfil
     \or \hfil\hskip\z@ \@seesize\ignorespaces\@sharp\unskip\@rememsize\fi}}

\def\@classv{\@addtopreamble{\@seesize\@startpbox{\@nextchar}\ignorespaces
  \@sharp\@endpbox\@rememsize}}

% my macros to keep track of the size of entries.

\def\@s@@size{\setbox\z@\hbox\bgroup}

% using dimen variables to keep track is faster than stringing boxes
% together; and it uses less memory.  Since \cr is hidden in a macro, 
% I can't use the format \testsize{\@sharp}.

\def\@r@m@msize{\egroup % end the \hbox
    \ifdim\ht\z@>\@arstheight \global\@arstheight\ht\z@ \fi
    \ifdim\dp\z@>\@arstdepth  \global\@arstdepth \dp\z@ \fi
    \unhbox\z@}

% Redefine \hline to remove nicks and to allow optional [] skip below

\def\hline{\noalign{\ifnum0=`}\fi\kern-.5\arrayrulewidth
   \hrule \@height \arrayrulewidth \kern-.5\arrayrulewidth
   \futurelet\@tempa\@xhline}

\def\@xhline{\global\@skip@bove\extrarulesep
      \ifx\@tempa\hline\vskip \doublerulesep\else
      \ifx\@tempa[\aftergroup\@yhline\fi\fi
      \ifnum0=`{\fi}}

\def\@yhline[#1]{\noalign{\global\advance\@skip@bove#1}}

% make \cline give the \extrarulesep below

\def\cline#1{\noalign{\global\@skip@bove\extrarulesep}\@cline[#1]}

\endinput
% -----------------------------------------------------------------
%
%  Modify LaTeX's tabular environment macros to keep text from touching
%  other text or hlines above or below.  There are two new parameters:
%
%  \tablelineskip: minimum space between text on successive lines in
%                  a tabular environment.  Negative distances are treated
%                  as zero.  There will also be at least .5\tablelineskip 
%                  between an \hline and text (if \extrarulesep >= 0pt).
%                  The default value is 1pt.
%
%  \extrarulesep : extra space to add above and below each \hline in 
%                  addition to half the lineskip.  Negative values can 
%                  be used, but only until some text touches the hline.
%                  The default value is 3pt.
%
%  The appearance of normal LaTeX tables can be had with
%        \setlength\tablelineskip{0pt}
%        \setlength\extrarulesep{0pt}
%
%  \hline[dimen]:
%
%  \hline has been changed to take an optional length argument just like \\
%  giving the space to insert below.  This space is in addition to the 
%  \extrarulesep and lineskip.  A negative value will reduce the space until
%  the hline touches some text below, and then will have no further effect.
%  E.g., \hline[-9in] draws a horizontal line while suppressing the extrarulesep
%  beneath.  Also, the new \hline FIXES THE NICKS that used to appear at the 
%  junction between horizontal and vertical lines.
%
%  How it works:
%  There are no struts in the preamble entries, rather, there are tests
%  to measure the maximum height and depth of all entries on a line.
%  The maximum values start at the size of LaTeX's \@arstrut minus the
%  appropriate lineskip.  At the \\, a strut is inserted (in its own 
%  column) which is that maximum size plus the lineskip.
%
%  The Downside:
%  Building a table will take about twice as much time as before because 
%  the entries have to be boxed twice (by \@seesize and by \halign itself)
%  instead of just once.  Setting \tablelineskip=0pt will recover this speed,
%  with \extrarulesep still in effect.
%
%  These macros could be made to apply to arrays too (an earlier version did!)
%  but I think it makes more sense to use TeX's normal smart lineskip
%  mechanism there.  Why doesn't LaTeX???
%
%  Send problem reports to asnd@triumfcl.bitnet or Arseneau@mtsg.ubc.ca
%
%  Test integrity of file:
%  brackets: round, square, curly, angle:   () [] {} <>
%  backslash, slash, vertical, hat, tilde:   \ / | ^ ~