commit 791ade53da1a3bd37bc055ebe956fc0c8f3adfd5
parent 14fc068001e2f1ca829fff47a24f8a2e3f84a188
Author: robert <robertrussell.72001@gmail.com>
Date: Sun, 16 Jan 2022 10:31:14 -0800
Add versatile, low-level list macros
Some reorganization is required. The r3tex core should not make any
style decisions. It should merely provide the low-level tools for, in
this case, making lists of various styles. Then style files should
define appropriate list macros based on the low-level macros provided by
r3tex. Of course, multiple styles may wish to use the same types of
lists, in which case styles can be composed.
Diffstat:
| A | list.tex | | | 73 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| M | r3tex.tex | | | 2 | +- |
2 files changed, 74 insertions(+), 1 deletion(-)
diff --git a/list.tex b/list.tex
@@ -0,0 +1,73 @@
+% Derive bullet from \Lfmt based on \Lcnt, which is incremented per item.
+
+\newcount\Lcnt % item number within current list
+\newcount\Llvl \Llvl=0 % list nesting level
+
+\newdimen\Lindent % indent of first paragraph in item
+\newdimen\Lmaxprotrusion % max protrusion of item label
+\newdimen\Llmargin % bring left margin in by this amount
+\newdimen\Lrmargin % bring right margin in by this amount
+\newskip\Ltopskip % vskip above list
+\newskip\Lmidskip % vskip between items
+\newskip\Lbotskip % vskip below list
+\newcount\Ltoppenalty
+\newcount\Lmidpenalty
+\newcount\Lbotpenalty
+
+\def\@Lbeg{%
+ \par
+ \begingroup
+ \Lcnt=0
+ \incr\Llvl
+ \let\Lfmt=\empty
+ \advance\leftskip\Llmargin
+ \advance\rightskip\Lrmargin
+ \penalty\Ltoppenalty
+ \vskip\Ltopskip
+}
+
+\def\@Lend{%
+ \par
+ \endgroup
+ \penalty\Lbotpenalty
+ \vskip\Lbotskip
+ \tmpparindent0pt
+}
+
+\def\item{\@Litem\Lfmt}
+\def\xitem#1{\@Litem{#1\enspace}\ignorespaces}
+\def\@Litem#1{%
+ \par
+ \ifnum\Lcnt>0 \penalty\Lmidpenalty \vskip\Lmidskip \fi
+ \incr\Lcnt
+ \setbox0=\hbox{#1}%
+ \dimen1=\dimexpr\wd0-\Lmaxprotrusion\relax
+ \dimen0=\ifdim\Lindent<\dimen1 \dimen1 \else \Lindent \fi
+ \noindent\hbox to\dimen0{\hss\box0}%
+}
+
+% Common list types
+% TODO: some of these belong in style
+\newdimen\@Lpwd
+\def\begxlist#{\@Lbeg\def\Lfmt}
+\def\begplist#1#2#3{%
+ \@Lbeg
+ \def\csA{#3}%
+ \ifx\csA\empty
+ \def\Lfmt{\rm(#1\/)#2}% TODO: use robust italic correction
+ \else
+ \maxwd\@Lpwd={#3}%
+ \def\Lfmt{\rm(\hbox to\@Lpwd{\hss#1\/\hss})#2}%
+ \fi
+}
+\def\begnlist{\begxlist{\rm\number\Lcnt.\enspace}} % 1. 2. 3. ...
+\def\begrlist{\begplist{\rm\romannumeral\Lcnt}{\enspace}} % (i) (ii) (iii) ...
+\def\begalist{\begplist{\rm\char\numexpr\Lcnt+96\relax}{\enspace}} % (a) (b) (c) ...
+\def\begblist{\begxlist{$\m@th\bullet$\enspace}} % bullets
+
+\def\begol{\begnlist}
+\def\endol{\@Lend}
+\def\begul{\begblist}
+\def\endul{\@Lend}
+
+\endinput
diff --git a/r3tex.tex b/r3tex.tex
@@ -10,7 +10,7 @@
% \input margin
% \input font
% \input section
-% \input list
+\input list
% \input verbatim
% \input hyphen
% \input graphics
