On Thu, Feb 08, 2018 at 09:30:48AM +0100, Thomas A. Schmitz wrote:

On 02/07/2018 06:39 PM, Rudolf Bahr wrote:

...

Sometimes the necessity could arise to send data from lua to context and answers back to lua. I tried this by using "read" and "immediate\write" commands in context. These commands are described in chapter 21 and 22 of Donald E. Knuth's "The TeXbook".

My question is: Do there exist better and more simple solutions?

You can print (typeset) information from inside lua code with the "context" function. Have you seen the manual cld-mkiv.pdf? It's in the minimals.

Thomas

Yes, thank you. I tried "context()" several times, but without success. Could be, that I have a false meaning how to use it: If I transfer data from context to lua and vice versa then in my imagination there must be variables in both languages where the sent data is to be found. With the use of "\immediate\write" and "\read" in context and the read and write functions in lua I know exactly from where to where the data goes. How to do the same with "context()"? Rudolf

On 2/8/2018 3:34 PM, Rudolf Bahr wrote:

On Thu, Feb 08, 2018 at 09:30:48AM +0100, Thomas A. Schmitz wrote:

...

On 02/07/2018 06:39 PM, Rudolf Bahr wrote:

...

Sometimes the necessity could arise to send data from lua to context and answers back to lua. I tried this by using "read" and "immediate\write" commands in context. These commands are described in chapter 21 and 22 of Donald E. Knuth's "The TeXbook".

My question is: Do there exist better and more simple solutions?

You can print (typeset) information from inside lua code with the "context" function. Have you seen the manual cld-mkiv.pdf? It's in the minimals.

Thomas

Yes, thank you. I tried "context()" several times, but without success. Could be, that I have a false meaning how to use it: If I transfer data from context to lua and vice versa then in my imagination there must be variables in both languages where the sent data is to be found.

With the use of "\immediate\write" and "\read" in context and the read and write functions in lua I know exactly from where to where the data goes. How to do the same with "context()"? I have no clue what you want to achieve but Thomas means:

\setupwhitespace[line] \starttext \startluacode context("Here is lua.") context.par() context("I'm sending some picture names to Context in order to get back their sizes.") local imageA = "2007-01-01---Intro.png" local imageB = "2007-01-01---Neujahrsballade---1.png" local imageC = "2007-01-01---Neujahrsballade---2.png" local f = io.open("contextin.txt", "w") f:write(imageA,"\n",imageB,"\n",imageC) f:close() \stopluacode \openin15=contextin.txt \read15 to \zeileA \read15 to \zeileB \read15 to \zeileC \closein15 Here is \CONTEXT\ and what I got from Lua: \startlines \zeileA \zeileB \zeileC \stoplines Now I'm working ... and write my answers to a file for lua: \startlines \zeileA\ width=3000pt height=2000pt \zeileB\ width=1200pt height=900pt \zeileC\ width=1600pt height=1200pt \stoplines \immediate\openout7=contextout.txt \immediate\write7{\zeileA\ width=3000pt height=2000pt \\} \immediate\write7{\zeileB\ width=1200pt height=900pt \\} \immediate\write7{\zeileC\ width=1600pt height=1200pt \\} \immediate\closeout7 \startluacode context("Here is lua again and what I got back from Context:") context.par() context(io.loaddata("contextout.txt")) \stopluacode \stoptext ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

On Thu, Feb 08, 2018 at 04:26:16PM +0100, Henning Hraban Ramm wrote:

Am 2018-02-08 um 15:34 schrieb Rudolf Bahr :

...

On Thu, Feb 08, 2018 at 09:30:48AM +0100, Thomas A. Schmitz wrote:

...

On 02/07/2018 06:39 PM, Rudolf Bahr wrote:

...

Sometimes the necessity could arise to send data from lua to context and answers back to lua. I tried this by using "read" and "immediate\write" commands in context. These commands are described in chapter 21 and 22 of Donald E. Knuth's "The TeXbook".

My question is: Do there exist better and more simple solutions?

You can print (typeset) information from inside lua code with the "context" function. Have you seen the manual cld-mkiv.pdf? It's in the minimals.

Thomas

Yes, thank you. I tried "context()" several times, but without success. Could be, that I have a false meaning how to use it: If I transfer data from context to lua and vice versa then in my imagination there must be variables in both languages where the sent data is to be found.

With the use of "\immediate\write" and "\read" in context and the read and write functions in lua I know exactly from where to where the data goes. How to do the same with "context()"?

\startluacode

function SomeFunction() context("Value") end

\stopluacode

\def\MyVar{\ctxlua{SomeFunction()}}

YES! That's what I needed to get back data from lua to context! Many thanks to Hraban, Hans and Thomas for your help! Rudolf