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From: "Peter Münster" <pmlists@free.fr>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Re: arguments to ctxlua
Date: Tue, 30 Mar 2010 20:30:42 +0200	[thread overview]
Message-ID: <20100330183042.GA15195@gaston.couberia.bzh> (raw)
In-Reply-To: <A5FF035D-B4C4-444D-99C2-D438F34F808D@uva.nl>

On Tue, Mar 30 2010, Hans van der Meer wrote:

> called through:
> 	\def\callf#1#2{\ctxlua{f("#1","#2")}}
>
> and do this actually with one argument:
> 	\callf{one}
>
> then I find that the absent argument b in f(a,b) is not nil but a string of 
> length 1.

Hello Hans,

You want probably something like this:

\startluacode
userdata = userdata or {}
function userdata.f(a, b)
	b = b or "default value"
	tex.print(string.format("a = '%s' and b = '%s'\\par", a, b))
end
\stopluacode
\def\callf{\dodoubleempty\docallf}
\def\docallf[#1][#2]{\ctxlua{userdata.f("#1"\ifsecondargument, "#2"\fi)}}
\starttext
\callf[one]
\callf[one][two]
\callf[one][]
\callf[][]
\callf[][two]
\callf[]
\stoptext

Cheers, Peter

-- 
Contact information: http://pmrb.free.fr/contact/


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      parent reply	other threads:[~2010-03-30 18:30 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-30 17:45 Hans van der Meer
2010-03-30 17:52 ` Hans Hagen
2010-03-30 18:30 ` Peter Münster [this message]

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