\documentclass{article} \usepackage{luamplib} \begin{document} \tracingcommands1 A% \begin{mplibcode} %% test all printable ascii chars in comments %% ( 2 < F P Z d n x %% ) 3 = G Q [ e o y %% * 4 > H R \ f p z %% ! + 5 ? I S ] g q { %% " , 6 @ J T ^ h r | %% # - 7 A K U _ i s } %% $ . 8 B L V ` j t ~ %% % / 9 C M W a k u DEL %% & 0 : D N X b l v %% ยด 1 ; E O Y c m w beginfig(1); fill fullcircle scaled 20; %% actual to make sure it works endfig; \end{mplibcode} B\par \end{document}