Dear list, Recently I answered a question on TeX.SX where it was necessary to go through an already typeset vbox and examine it line by line. Therefore I used the macro \eatlines from Viktor Eijkhout's "TeX by Topic", here a version tailored to my needs: \def\eatlines{% \setbox\scratchbox=\lastbox \ifvoid\scratchbox\else \unskip\unpenalty {\eatlines}% \setbox\scratchbox=\hbox{\unhbox\scratchbox}% % Do something with scratchbox, e.g. examine width \fi } It is then used like \vbox{ ... some content ... \par\eatlines} The macro goes through all hboxes (lines) in the vertical list until there is none left (\ifvoid) and unpacks each hbox into a new one. I was wondering, can the same thing be done in Lua (with probably less and more readable code)? Kind regards, Henri