[XeTeX] \botmark and \firstmark not working for me ...

[Paul Isambert]

Selon Philipp Stephani <st_philipp at yahoo.de>:

>
> Am 01.08.2010 um 09:28 schrieb Ron Aaron:
>
> > On Sunday 01 August 2010 10:16:27 Paul Isambert wrote:
> >
> >> Indeed, the \mark won't end up on the main vertical list. In the latest
> >> TUGboat issue, Hans Hagen writes about this and proposes a nice
> >> solution... but with LuaTeX!
> >
> > Hmm.  I really need XeTeX, since it knows how to typeset complex languages
> > very well (and I really like the font-handling!).
>
> AFAIK LuaTeX can handle OpenType fonts as well (because it can use every Lua
> library). So you might give LuaTeX a try—probably in combination with
> ConTeXt, since LaTeX support for LuaTeX is still in an early stage.

Let's not advertise LuaTeX on the XeTeX list! (I'm a former XeTeX-user who moved
to LuaTeX, but XeTeX remains in my heart because it's the first time I used
True- and OpenType fonts in TeX... for the record, I think the first font was
Comic Sans MS, because it added an improbable twist to a situation I already
couldn't believe! First (and last) time in my life I found those glyphs
beautiful...)

Anyway Hans' code is far from trivial, and can't be duplicated on the fly, I
think.

Ron's problem is acknowledged on page 417 of the TeXbook, where the code for the
two-column index is given: "A more difficult approach would be necessary if the
index contained insertions (e.g., footnotes); fortunately it doesn't.
Furthermore, there is no need to use \mark [...]".

As for \unvbox, Ron, your \vadjust is unnecessary and indeed leads to bad
results. Anyway \unvbox in horizontal mode (your \line) turns to vertical mode,
that's why the columns appear on top of each other. As a replacement, I'd think
of \unvboxing in a vbox (to be shipped out) the first column and then \kern'ing
back to the origin of the box... but then one should \moveright for the right
column, but \moveright takes a \box, not an \unvbox, as its argument, so the
right column won't be unfolded. So it doesn't work.

I'm stuck. But I've learned there always exists a solution in TeX. Although the
code might be quite a hack!

Best,
Paul