Hello, thanks Henri and Hans for all solutions! On 2020-05-28 10:34, Hans Hagen wrote:
On 5/28/2020 12:42 AM, context@vivaldi.net wrote:
Hello,
is it possible to check whether a macro exists (or - is it a non-\undefined control sequence) with Lua? Suppose:
---- \starttext \def\MyMacro{Ahoj} \def\MyMac#1#2{Something}
\startluacode IsDefined = function(ctl_seq) print("CS " .. ctl_seq .. (tex.IsCS(ctl_seq) -- Or what to come here? "is defined" or "is unknown") .. ".") end
-- So the function should print to the console:
IsDefined("MyMacro") --> "CS MyMacro is defined." IsDefined("MyMac") --> "CS MyMac is defined." IsDefined("bf") --> "CS bf is defined." IsDefined("dummy") --> "CS dummy is unknown."
\stopluacode \stoptext ----
Is it possible? A lot is possible. Take this:
\def\MyMacroA{Ahoj A} \unexpanded\def\MyMacroB{Ahoj B} \frozen \def\MyMacroC{Ahoj C} % in lmtx % \def\MyMacroC{Ahoj C} % barks
At the tex end you can check for several properties:
\ifusercmd \hbox Y\else N\fi % in lmtx \iffrozen \hbox Y\else N\fi % in lmtx \ifusercmd \MyMacroA Y\else N\fi % in lmtx \iffrozen \MyMacroA Y\else N\fi % in lmtx \iffrozen \MyMacroC Y\else N\fi % in lmtx
At the Lua end you can check for being defined:
\startluacode local function whatever(s) context.type("\\" .. s) context(" is %s", tokens.defined(s) and "defined" or "undefined") context.par() end whatever("MyMacroA") whatever("MyMacroD") whatever(" ") whatever("-") \stopluacode
alternatively you can say:
\startluacode local t = token.create("MyMacro") print(t.cmdname == "undefined_cs") \stopluacode
which is less efficient unless you want to access more properties.
Hans
(@Hans: I'm using vivaldi's mail account in "good will" - I didn't suppose it would cause any unwanted actions, like resending mails or whatever.) Bets regards, Lukas