On 9/5/2021 10:14 AM, Hans van der Meer via ntg-context wrote:

There is something I do not understand in the passing of parameters from TeX to LuaTex. This is my TeX definition: \def\ListSort[#1]#2{\directlua{hvdm.listsort([===[#2]===],[===[#1]===])}}

tex haalt de {} rond #2 weg

Calling \ListSort[sep={ + }]{} delivers the string  'sep={ + }' into LuaTeX as the printout in the logfile shows and as intended. However in \ListSort[{ + }]{} the braces have disappeared and transferred is nothing more than '+ '.

Why is the transfer messing up the character string I am passing by removing the outer braces? Is this a bug or is it an unavoidable consequence of the TeX-LuaTeX interface? \starttext \def\foo#1{\detokenize{#1}} \foo{hvdm has to read the tex book}

\def\foo#+{\detokenize{#1}} \foo{hvdm has to read the luametatex manual} \stoptext ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------