luatex examples - Traversing TeX nodes

luatex examples - Traversing TeX nodes

[Piotr Kopszak]

Hello,

I am trying to compile luatex examples from http://luatex.bluwiki.com
. How could I make it work with ConTeXt? The following fails.
-----------------------------------------------------------------------------------------------------------------------------------
\directlua0{
 local glyph = node.id('glyph')
 local hlist = node.id('hlist')
 local vlist = node.id('vlist')

 function gothru(h,prof)
   for t in node.traverse(h) do
     texio.write_nl(string.rep("...",prof) .. 'NODE type=' ..
node.type(t.id) .. ' subtype=' .. t.subtype )
     if t.id == hlist or t.id == vlist then
       texio.write(' w=' .. t.width .. ' h=' .. t.height .. ' d=' ..
t.depth .. ' s=' .. t.shift )
	   gothru(t.list,prof+1)
     end
     if t.id == glyph then
       texio.write(' font=' .. t.font .. ' char=' .. t.char .. '
width=' font.fonts[t.font].characters[t.char]['width'])
     end
   end
 end

 callback.register('pre_linebreak_filter',
   function(h)
      gothru(h,0)
      return true
   end
   )
}

\starttext
bla bla bla bla
\stoptext
-------------------------------------------------------------------------------------------------------

best

Piotr

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http://okle.pl
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___________________________________________________________________________________

Re: luatex examples - Traversing TeX nodes

[Hans Hagen]

Piotr Kopszak wrote:
> Hello,
> 
> I am trying to compile luatex examples from http://luatex.bluwiki.com

i have no time to look into it now but be aware of the fact that if you 
set a callback like this you're likely to overload one that context 
itself sets and that can result in problems elsewhere

there are user hooks but i need to describe them (as one should be very 
careful in doing thinsg that interfere)

a safe way to play with node is is

\setbox0=\vbox{....}

and the look at tex.box[0].list




-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
      tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
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://tex.aanhet.net
archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________

Re: luatex examples - Traversing TeX nodes

[Piotr Kopszak]

Great thanks for your hint.

Ever onward!

Piotr

2009/6/1 Hans Hagen <pragma@wxs.nl>:
> Piotr Kopszak wrote:
>>
>> Hello,
>>
>> I am trying to compile luatex examples from http://luatex.bluwiki.com
>
> i have no time to look into it now but be aware of the fact that if you set
> a callback like this you're likely to overload one that context itself sets
> and that can result in problems elsewhere
>
> there are user hooks but i need to describe them (as one should be very
> careful in doing thinsg that interfere)
>
> a safe way to play with node is is
>
> \setbox0=\vbox{....}
>
> and the look at tex.box[0].list
>
>
>
>
> -----------------------------------------------------------------
>                                          Hans Hagen | PRAGMA ADE
>              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
>     tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
>                                             | www.pragma-pod.nl
> -----------------------------------------------------------------
> ___________________________________________________________________________________
> 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://tex.aanhet.net
> archive  : https://foundry.supelec.fr/projects/contextrev/
> wiki     : http://contextgarden.net
> ___________________________________________________________________________________
>



-- 
http://okle.pl
___________________________________________________________________________________
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://tex.aanhet.net
archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________