https://wiki.luatex.org/index.php?action=history&feed=atom&title=Show_the_hyphenation_pointsShow the hyphenation points - Revision history2026-05-21T18:20:51ZRevision history for this page on the wikiMediaWiki 1.31.1https://wiki.luatex.org/index.php?title=Show_the_hyphenation_points&diff=60&oldid=prevPatrick: show the disc nodes2011-01-11T15:35:07Z<p>show the disc nodes</p>
<p><b>New page</b></p><div>This LaTeX example adds a function to the <tt>post_linebreak_filter</tt> callback. The function iterates through all the nodes in the paragraph (and descends into the vlist and hlist nodes) and inserts a small rule where the discretionary nodes are.<br />
<br />
<pre><br />
\documentclass[12pt,a4paper]{scrartcl}<br />
\usepackage[english]{babel}<br />
\usepackage{blindtext}<br />
\usepackage{fontspec}<br />
\directlua{<br />
show_hyph = function(head)<br />
while head do<br />
if head.id == 0 or head.id == 1 then % hlist, vlist<br />
show_hyph(head.list) % should be head.head in a newer luatex than 0.64<br />
elseif head.id == 7 then % disc<br />
local n = node.new("whatsit","pdf_literal")<br />
n.mode = 0<br />
n.data = "q 0.3 w 0 2 m 0 7 l S Q"<br />
n.next = head.next<br />
n.prev = head<br />
head.next = n<br />
head = n<br />
end<br />
head = head.next<br />
end<br />
return true<br />
end<br />
luatexbase.add_to_callback("post_linebreak_filter",show_hyph,"show_hyph")<br />
<br />
}<br />
<br />
\begin{document}<br />
\begin{minipage}{5cm}<br />
\blindtext<br />
\end{minipage}<br />
\end{document}<br />
</pre></div>Patrick