Hello ConTeXist. I hope that my crazy questions not much bother. This time I needed to get to the fair value of the parameter, delivering to lua function over the content macros. Obviously it's my misunderstanding of the functioning of expansion in case maker with optional parameters, or you really can not explain the functioning of the transmission values. It seems that is passed to a sort of reference as to the actual contents of the macro perhaps can not even get through Lua. Or did they? The following minimal example, perhaps explain what going on. The question ultimately: Is there any alternative how using Lua somehow easily evaluate the macro content? For example to determine whether two different macros have the same content? Jaroslav Hajtmar here is minimal example: \starttext This works as expected: \def\makrowithAAAAcontent{AAAA} \edef\testparameter#1{% \startluacode local parameter='#1' if parameter=='AAAA' then context('TRUE. ') else context('FALSE. ') end context('Parameter '..parameter..' has length '..string.len(parameter)) \stopluacode }% \type{\makrowithAAAAcontent} -- \makrowithAAAAcontent Test is \testparameter{BBBB} Test is \testparameter{AAAA} % OK Test is \testparameter{\makrowithAAAAcontent} % OK But what about with this: ??? % initialize values \startluacode A={} for i=1,50 do A[i]='Record '..tostring(i) end A[25]='AAAA' \stopluacode \def\makrowithAAAAcontent{AAAA} \def\lastname{\dosingleempty\dolastname}% \def\dolastname[#1]{\doifsomethingelse{#1}{\ctxlua{context(A[#1])}}{\makrowithAAAAcontent}}% \type{\lastname} - \lastname \type{\lastname[2]} - \lastname[2] \type{\lastname[5]} - \lastname[5] \type{\lastname[25]} - \lastname[25] \edef\readandprocessparameters#1#2{% \startluacode local parameter1='#1' if parameter1=='AAAA' then context('Test '..parameter1..' = AAAA is TRUE. ') else context('Test '..parameter1..' = AAAA is FALSE. ') end context('Parameter 1 = '..parameter1..' has length '..string.len(parameter1)) context('\\crlf') local parameter2='#2' if parameter2=='AAAA' then context('Test '..parameter2..' = AAAA is TRUE. ') else context('Test '..parameter2..' = AAAA is FALSE. ') end context('Parameter 2 = '..parameter2..' has length '..string.len(parameter2)) context('\\crlf') \stopluacode }% \readandprocessparameters{AAAA}{BBBB} %Test is \readandprocessparameters{\lastname[25]}{\lastname} % Crashed \readandprocessparameters{\\lastname[25]}{\\lastname} \stoptext