(wrong list, forwarded)
Von: Frank Mittelbach
Betreff: [lltx] linebreak_filter problems
Datum: 10. Juni 2012 16:50:26 MESZ
An:
Hi folks,
can somebody help me to identify if I do something wrong or if there is a bug with linebreak_filter.
Th problem is documented at length in
http://tex.stackexchange.com/questions/59176/lastnodetype-not-working-as-exp...
In a nutshell I try to replace (at certain times) TeX's linebreaking algorithm and replace it with a simple version that just packs up the hlist into an hbox and returns that.
If I do that the resulting box appears on the current vertical list (ie is seen via \showlists) but at the same time
\lastnotetype returns -1
\lastbox picks up a void box
ie to some parts of TeX the list appears to be empty. Here is an MWE
\def\partest{%
\directlua{%
function hpackparagraph (head)
return node.hpack(head)
end
callback.register("linebreak_filter", hpackparagraph)
}%
\par
}
\setbox0\vbox{ABC\par
{\tracingonline1\showboxbreadth\maxdimen\showboxdepth\maxdimen\showlists}%
\showthe\lastnodetype
}
\setbox0\vbox{ABC\partest
{\tracingonline1\showboxbreadth\maxdimen\showboxdepth\maxdimen\showlists}%
\showthe\lastnodetype
}
Any ideas what goes wrong or how I should alter things to make this possible?
thanks
frank
