luatexing

luatexing

[Wolfgang Werners-Lucchini]

Hallo,

I have a few silly questions about

  tex.print()

To produce 

  $\sqrt{2}=1.4142135623731$

it should be enough to write

  tex.print("$\\sqrt{2}=" .. math.sqrt(2) .. "$")

or better

  tex.print([[$\sqrt{2}=]] .. math.sqrt(2) .. "$")

but that's both not working. The following instead does the job:

  tex.print("$\string\\sqrt{2}=" .. math.sqrt(2) .. "$")

why?

Another question:

What is the differenz between 'tex.sprint()' and 'tex.write()'?

Wolfgang
___________________________________________________________________________________
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: luatexing

[Hans Hagen]

Wolfgang Werners-Lucchini wrote:
> Hallo,
> 
> I have a few silly questions about
> 
>   tex.print()
> 
> To produce 
> 
>   $\sqrt{2}=1.4142135623731$
> 
> it should be enough to write
> 
>   tex.print("$\\sqrt{2}=" .. math.sqrt(2) .. "$")

this is because \\ can mean anything, for instance it may expand to \par 
or \crlf or ..

there is a \luaescapestring primitive which catches things like quotes

tex.print("\detokenize{$\sqrt{2}=}" .. math.sqrt(2) .. "$")

may also work ok

> or better
> 
>   tex.print([[$\sqrt{2}=]] .. math.sqrt(2) .. "$")
> 
> but that's both not working. The following instead does the job:
> 
>   tex.print("$\string\\sqrt{2}=" .. math.sqrt(2) .. "$")
> 
> why?
 >
> Another question:
> 
> What is the differenz between 'tex.sprint()' and 'tex.write()'?

tokenization under a catcode regime versus writing strings

-----------------------------------------------------------------
                                           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: luatexing

[Hans Hagen]

Wolfgang Werners-Lucchini wrote:
> On 12 Apr 2008 at 9:39, ntg-context-request@ntg.nl wrote:
> 
>>> I have a few silly questions about
>>>
>>>   tex.print()
>>>
>>> To produce 
>>>
>>>   $\sqrt{2}=1.4142135623731$
>>>
>>> it should be enough to write
>>>
>>>   tex.print("$\\sqrt{2}=" .. math.sqrt(2) .. "$")
>> this is because \\ can mean anything, for instance it may expand to
>> \par  or \crlf or ..
> 
> May be I do not understand this right, but I thought that '\' is luas 
> escape character and tex.print() returns '\' not '\\'. So TeX sees no 
> macro '\\' which could expand to whatever.

it depends on where you code lives ... in a lua file, then \\ is an 
escape, in \directlua (or \ctxlua cum suis), then it's a tex cs

your mail only shows the one line of code so we have to guess

>> there is a \luaescapestring primitive which catches things like
>> quotes
> 
> Can you make a little example of usage?
> 
>> tex.print("\detokenize{$\sqrt{2}=}" .. math.sqrt(2) .. "$")

well, if you put that in your document, you'l get a typeset tex.sprint, 
so i assume that tis is wrapped in \directlua or so?

> Could not find the definition of \detokenize.

an etex primitive

-----------------------------------------------------------------
                                           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: luatexing

[Taco Hoekwater]

Wolfgang Werners-Lucchini wrote:
> 
> May be I do not understand this right, but I thought that '\' is luas 
> escape character and tex.print() returns '\' not '\\'. So TeX sees no 
> macro '\\' which could expand to whatever.

This depends on how exactly you have input that line (which
in turn nicely demonstrates why you should post minimal examples,
instead of out-of-context questions).

I tried:

   % engine=luatex
   \starttext
   \directlua0 {tex.print('$\\sqrt{2}=1.4142135623731$')}
   \ctxlua{tex.print('$\\sqrt{2}=1.4142135623731$')}
   \startluacode
   tex.print('$\\sqrt{2}=1.4142135623731$')
   \stopluacode
   \stoptext

And all three work as they should. So what did you input, exactly, that
gave wrong results?

Best wishes,
Taco


___________________________________________________________________________________
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: luatexing

[Wolfgang Werners-Lucchini]

On 12 Apr 2008 at 9:39, ntg-context-request@ntg.nl wrote:

> > I have a few silly questions about
> > 
> >   tex.print()
> > 
> > To produce 
> > 
> >   $\sqrt{2}=1.4142135623731$
> > 
> > it should be enough to write
> > 
> >   tex.print("$\\sqrt{2}=" .. math.sqrt(2) .. "$")
> 
> this is because \\ can mean anything, for instance it may expand to
> \par  or \crlf or ..

May be I do not understand this right, but I thought that '\' is luas 
escape character and tex.print() returns '\' not '\\'. So TeX sees no 
macro '\\' which could expand to whatever.
 
> there is a \luaescapestring primitive which catches things like
> quotes

Can you make a little example of usage?

> tex.print("\detokenize{$\sqrt{2}=}" .. math.sqrt(2) .. "$")

Could not find the definition of \detokenize.

Wolfgang
___________________________________________________________________________________
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
___________________________________________________________________________________