Am 05.09.2021 um 13:01 schrieb Hans Hagen :

On 9/5/2021 12:01 PM, Henning Hraban Ramm via ntg-context wrote:

...

* How translates \ifodd\realpageno ? This doesn’t work: if ((tex.getcount("realpageno") mod 2) == 1) then a = 1 end

we're talking lua: 9 % 2 == 0

Oops. Too many languages...

...

TeX: \def\Something{1cm} Lua: context.Something()

yes (assuming you're in scope)

Then I’m out of scope. \def is in my environment, directly before I load the Lua functions with \loadluafile. How can I access the macros from the environment there?

...

Is tex.strut and tex.par supposed to work? Or how should I access these?

\strut is not is primitive

context.strut() and context.par() should just work

It does. I thought I had tried that...

0) I don’t understand what “permanent” does and why I should maybe disable it. (cld-mkiv, p.146)

overload protection

\permanent\def\Whatever{?} \overloadmode=0 %\overloadmode=3 %\overloadmode=4 \def\Whatever{!}

try 3 and 4 (actually, try to run your documents with overloadmode set and you might see where you replace core macros)

%enabledirectives[overloadmode=warning] \enabledirectives[overloadmode=error]

btw, you can temporary do

\pushoverloadmode potentially risky definitions \popoverloadmode

Thank you, I’ll try. (While I’m quite sure I never overload core macros.)

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1) The parameter y is actually supposed to be a dimension, but if I declare it "dimen", ConTeXt says there wasn’t a number at "1cm". Or is a measure like that not a dimension?

if you want to use {} around it use "dimenargument"

...

2) The original interface of \MyFun had two optional parameters. I couldn’t find how to do that with interfaces.implement. cld-mkiv, p.151 (12.7) shows how to do lists or key=value, but not single optional args.

there is "optional"

and ... cld is not yet updated to lmtx in this respect so some newer features are missing

Thank you! Must I then declare "string optional" etc.? Hraban

On 9/6/2021 6:20 PM, Henning Hraban Ramm via ntg-context wrote:

Another question:

I think I understood the need for function arguments. My macro, defined with interfaces.implement, works while I call "Image" below, but if I call "ClippedImage" (one level of indirection more), I get:

""" tex error > tex error on line 28 in file virtual://page.nopage.1: Missing { inserted ...(no helpful output here)... A left brace was mandatory here, so I've put one in. """

I can’t imagine where to put that brace.

function Image(Width, Height, filename) context.externalfigure( { filename }, { width = todimen(Width), } ) end

function ClippedImage(Width, Height, filename) context.clip( { width = todimen(Width), height = todimen(Height), }, Image(Width, Height, filename)

function() Image(Width, Height, filename) end

) end

Am 05.09.2021 um 16:27 schrieb Henning Hraban Ramm via ntg-context :

...

...

TeX: \def\Something{1cm} Lua: context.Something()

yes (assuming you're in scope)

Then I’m out of scope.

\def is in my environment, directly before I load the Lua functions with \loadluafile. How can I access the macros from the environment there?

...

...

2) The original interface of \MyFun had two optional parameters. I couldn’t find how to do that with interfaces.implement. cld-mkiv, p.151 (12.7) shows how to do lists or key=value, but not single optional args.

there is "optional"

and ... cld is not yet updated to lmtx in this respect so some newer features are missing

Must I then declare "string optional" etc.?

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