From: Henri Menke <henrimenke@gmail.com>
To: ConTeXt <ntg-context@ntg.nl>
Subject: Re: Checking existence of a macro (control sequence) by Lua
Date: Thu, 28 May 2020 18:50:52 +1200 [thread overview]
Message-ID: <20200528065052.3xgw67gs4epukvvv@vento15post8> (raw)
In-Reply-To: <b58899c80e0ea1da906ac3a00e427faf@vivaldi.net>
On 28/05/20, 00:42, 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?
Yes, that is what the token library is there for.
\starttext
\def\MyMacro{Ahoj}
\def\MyMac#1#2{Something}
\startluacode
local str = { [true] = "defined", [false] = "undefined" }
for _, macro in ipairs({ "MyMacro", "MyMac", "bf", "dummy" }) do
context(macro .. " is " .. str[token.is_defined(macro)] .. "\\par")
end
\stopluacode
\stoptext
Cheers, Henri
>
> Best regards,
>
> Lukas
> ___________________________________________________________________________________
> 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
> ___________________________________________________________________________________
___________________________________________________________________________________
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
___________________________________________________________________________________
next prev parent reply other threads:[~2020-05-28 6:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 22:42 context
2020-05-27 22:49 ` luigi scarso
2020-05-28 7:56 ` Hans Hagen
2020-05-28 6:50 ` Henri Menke [this message]
2020-05-28 8:34 ` Hans Hagen
2020-05-28 11:24 ` context
2020-05-28 21:24 ` context
2020-05-29 7:36 ` Hans Hagen
2020-05-29 21:21 ` context
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