[texhax] dotfill leaders on first line of paragraph only ?

[Philip TAYLOR]

Philip TAYLOR wrote:

> As I wrote to Herb, I have now cracked this,
> and will post my solution once it is in a fit state
> for publication.

and here it is.  Please treat it as "proof of concept" only --
it records (but does not make use of) \lastskip and \lastpenalty,
and obviously these should be re-inserted into the re-built
\vtop if it is to be a perfect replica of the one with which
we started.

** Phil.
--------
% !TeX Program=XeTeX

\font \Text = "Palatino Linotype" at 11.25 pt
\font \Vietnamese = "Palatino Linotype: color=0000FF" at 11.25 pt
\font \English = "Palatino Linotype: color=003F00" at 11.25 pt
\font \Seqno = "Palatino Linotype: color=FF0000" at 11.25 pt
\font \Price = "Palatino Linotype: color=0000FF" at 11.25 pt

\newif \ifmore
\newskip \Lastskip
\newcount \Lastpenalty
\tabskip = 0 pt plus 1 fil
\hsize = 25pc
\catcode `\~ = \catcode `\@
\parindent = 0 pt
\parskip = 3 ex

\def \Note #1{{\Text #1} \vskip 1 ex }

\def \Shewsample #1{\halign to \hsize {&##\hfil \cr {\Seqno 1. }&\copy #1& {\Price £9-99}\cr}}

\def \Sample #1%
	{
		\setbox 0 = \vtop
			\bgroup
				\parindent = 0 pt
				\raggedright
				\emergencystretch = 1 pt
				\multiply \tolerance by 8
				\hsize = 247pt
				#1
			\egroup
	}

\def \Dotfilllineone
	{
		\vtop
			\bgroup
				\global \setbox 4 = \vtop {}
				\parindent = 0 pt
				\showboxbreadth = 400
				\showboxdepth = 3
				\unvbox 0
				\loop
					\setbox 0 = \lastbox
				\ifvoid 0
					\morefalse
					\global \setbox 4 = \vtop {\hsize = 247 pt \unhbox 2 \unskip \ \dotfill \break \box 4 }
				\else
					\moretrue
					\Lastskip = \lastskip \unskip
					\Lastpenalty = \lastpenalty \unpenalty
					\ifvoid 2 \else \global \setbox 4 = \vtop {\hsize = 227 pt \box 2 \box 4 }\fi
					\setbox 2 = \box 0
				\fi
				\ifmore
				\repeat
			\egroup
	}

\Note {First test : one-line item}

\Sample {{\Vietnamese Heo nồi đất} \English ~ Minced pork hot pot}
\Shewsample 0
\Dotfilllineone
\Shewsample 4

\Note {Second test : two-line item}

\Sample {{\Vietnamese Heo nồi đất} \English ~ Minced pork hot pot with tofu and aubergine}
\Shewsample 0
\Dotfilllineone
\Shewsample 4

\end