Re: Checking existence of a macro (control sequence) by Lua - problem after updating MkIV

[Hans van der Meer <havdmeer@ziggo.nl>]

[-- Attachment #1.1: Type: text/plain, Size: 2259 bytes --]

Why can you not simply use one of the doifundefined macro's? Something for example:
\doifundefined{ExitStatus}{\gdef\ExitStatus{0}}	% default to ok as in UNIX

dr. Hans van der Meer


> On 18 Jun 2020, at 10:27, Lukas/ConTeXt <lpr.context@email.cz> wrote:
> 
> Hello,
> I'm using Hans' macro suggested some time before.
> I've just updated Ctx MkIV and my sample code:
> 
> ----
> \starttext
>  \def\MyMacro{Ahoj}
> 
>  \def\MyMacWithPars#1#2{Something}
> 
>  \def\Undefined{}
>  \let\Undefined\undefined
> 
>  \def\DoNothing{}
>  \let\DoNothing\donothing
> 
>  \startluacode
>    if CONTEXTLMTXMODE == 0 then
>        local d = tokens.defined
>        local c = tokens.create
> 
>        function tokens.defined(s,b)
>            if b then
>                return d(s)
>            else
>                return c(s).cmd_name == "undefined_cmd"
>            end
>        end
>    end
> 
>    --
> 
>    local defined = tokens.defined
> 
>    for _, v in ipairs{ "MyMacro", "MyMacWithPars", "Undefined", "DoNothing", "NonExisting" } do
>      print(string.format("\letterpercent-12s", v), defined(v), defined(v, true), defined(v, false))
>    end
>  \stopluacode
> 
>  Aaa
> \stoptext
> ----
> 
> gives:
> "
> MyMacro         false   false   false
> MyMacWithPars   false   false   false
> Undefined       false   false   false
> DoNothing       false   false   false
> NonExisting     false   false   false
> "
> 
> IOW, I'm not able to determine whether a control sequence has not been defined (or has \undefined value) or not.
> 
> Am I doing a trivial mistake or has anything changed?
> 
> Thank you for patience...
> 
> Lukas<IsMacDef3.log><IsMacDef3.mkiv><IsMacDef3.log_>___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
> 
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
> archive  : https://bitbucket.org/phg/context-mirror/commits/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________


[-- Attachment #1.2: Type: text/html, Size: 6058 bytes --]

[-- Attachment #2: Type: text/plain, Size: 493 bytes --]

___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
archive  : https://bitbucket.org/phg/context-mirror/commits/
wiki     : http://contextgarden.net
___________________________________________________________________________________