How to Determine the Current File Name and Line Number in the ConTeXt Source?

How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Tad Ashlock]

Is there a convenient way within a Lua block to determine the current 
file name and line number of the source file being processed by ConTeXt?

For example: (test.tex)
---------------------------------
\def\ShowLineNumber{%
    \ctxlua{print('current line number:', tex.current_line_number())
               print('current file:', tex.current_file_name())}}
\starttext
a line
\ShowLineNumber
another line

\ShowLineNumber
\stoptext
---------------------------------

With the following displayed:
---------------------------------
current line number: 6
current file: test.tex
current line number: 9
current file: test.tex
---------------------------------

I've considered hooking into the open_read_file callback and tracking 
the file name and line number (via reader) myself.  But that seems a bit 
heavy handed if the file name and line number information are available 
more directly.  And since that information is needed for error 
reporting, I'm thinking there's a good chance it is accessible.

(Just in case you're interested, the purpose of this is to be able to 
assemble code segments during the ConTeXt processing into external files 
with #line directives ala the C preprocessor.  That way if the 
subsequent compilation of the external file results in an error, the 
error message can refer back to the line of code in the ConTeXt source 
file.  This is part of the literate programming module that Kevin 
Robbins has been describing in another thread.)

Thanks,
Tad
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___________________________________________________________________________________

Re: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Hans Hagen]

Tad Ashlock wrote:
> Is there a convenient way within a Lua block to determine the current 
> file name and line number of the source file being processed by ConTeXt?
> 
> For example: (test.tex)
> ---------------------------------
> \def\ShowLineNumber{%
>    \ctxlua{print('current line number:', tex.current_line_number())
>               print('current file:', tex.current_file_name())}}
> \starttext
> a line
> \ShowLineNumber
> another line
> 
> \ShowLineNumber
> \stoptext
> ---------------------------------
> 
> With the following displayed:
> ---------------------------------
> current line number: 6
> current file: test.tex
> current line number: 9
> current file: test.tex
> ---------------------------------
> 
> I've considered hooking into the open_read_file callback and tracking 
> the file name and line number (via reader) myself.  But that seems a bit 
> heavy handed if the file name and line number information are available 
> more directly.  And since that information is needed for error 
> reporting, I'm thinking there's a good chance it is accessible.
> 
> (Just in case you're interested, the purpose of this is to be able to 
> assemble code segments during the ConTeXt processing into external files 
> with #line directives ala the C preprocessor.  That way if the 
> subsequent compilation of the external file results in an error, the 
> error message can refer back to the line of code in the ConTeXt source 
> file.  This is part of the literate programming module that Kevin 
> Robbins has been describing in another thread.)

i have no time now to figure out while filenames are not known but 
here's a (wikifyable) hack:

\starttext

% needs to be added to buff-ini.lua
%
% function buffers.raw(name)
%     return data[name] or { }
% end

\startluacode
     local locations = { }

     function document.set_number(name)
         locations[name] = {
             line = status.linenumber,
             file = status.filename
         }
     end

     function document.add_number(name)
         local b, l = buffers.raw(name), locations[name]
         if b and l then
             for i=1,#b do
                 b[i] = string.gsub(b[i],"# line: <number>","# line: " 
.. l.line + 2)
             end
         end
     end
\stopluacode

\ctxlua{document.set_number("oeps")}
\startbuffer[oeps]
# line: <number>

test
test
\stopbuffer
\ctxlua{document.add_number("oeps")}

\typebuffer[oeps]

\stoptext

when i have time (or reason) i'll think about a more integrated approach 
with hooks

-----------------------------------------------------------------
                                           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
-----------------------------------------------------------------
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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Taco Hoekwater]

Tad Ashlock wrote:
> 
> Now you say that ConTeXt may not be reading from a file at that level.
> That I can accept (being a non-expert), but status.linenumber always
> returns the correct line number for the ConTeXt file being processed
> (even if the file is being \input from another file).  It seems to me
> that if the line number within the source file is accurate, then the
> file's name should be accurate, too.

I've patched status.filename so that it will behave like that starting
with the next beta.

Best wishes,
Taco

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___________________________________________________________________________________

Re: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Tad Ashlock]

Taco Hoekwater wrote:
> Tad Ashlock wrote:
> >
> > Looks like we're always getting the xstrdup() branch of the conditional.
>
> Probably because you are not reading from a file at that level,
> but from a token list. Do you want filename to be a file even
> if the current input is not directly from a file at all
> (doable, but less meaningful)?
>
> Best wishes,
> Taco

Hi Taco,

I'm far from an expert in this realm, but since you asked what *I* 
want... :)

My intention is to associate status.filename and status.linenumber 
together.  That is, I would read and save their values consecutively in 
the same Lua function so that they would refer to the ConTeXt source 
line currently being processed by the ConTeXt engine.

Now you say that ConTeXt may not be reading from a file at that level. 
That I can accept (being a non-expert), but status.linenumber always 
returns the correct line number for the ConTeXt file being processed 
(even if the file is being \input from another file).  It seems to me 
that if the line number within the source file is accurate, then the 
file's name should be accurate, too.

Thank you,
Tad



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maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Taco Hoekwater]

Tad Ashlock wrote:
> 
> Looks like we're always getting the xstrdup() branch of the conditional.

Probably because you are not reading from a file at that level,
but from a token list. Do you want filename to be a file even
if the current input is not directly from a file at all
(doable, but less meaningful)?

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: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Hans Hagen]

Tad Ashlock wrote:
> Hans Hagen wrote:
>  > Tad Ashlock wrote:
>  > > Is there a convenient way within a Lua block to determine the current
>  > > file name and line number of the source file being processed by 
> ConTeXt?
> 
> [snip]
> 
>  > i have no time now to figure out while filenames are not known but
>  > here's a (wikifyable) hack:
> [snip]
>  > line = status.linenumber,
>  > file = status.filename
> 
>  From the luatex 0.40.6 sources
> (luatex/source/texk/web2c/luatexdir/lua/lstatslib.c):
> ----------------------------------------------------------
> /* hack, I really should implement the makecstring */
> char *getfilename(void)
> {
>    integer t;
>    t = get_current_name();
>    if (t > (1 << 21))
>        return makecstring(t);
>    else
>        return xstrdup("");
> }
> ----------------------------------------------------------
> 
> Looks like we're always getting the xstrdup() branch of the conditional.
> 
> Hans, would you like me to submit this as a luatex bug?

taco reads this mail anyway so this suits as bug report

Hans

-----------------------------------------------------------------
                                           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: How to Determine the Current File Name and Line Number in the ConTeXt Source?

[Tad Ashlock]

Hans Hagen wrote:
 > Tad Ashlock wrote:
 > > Is there a convenient way within a Lua block to determine the current
 > > file name and line number of the source file being processed by 
ConTeXt?

[snip]

 > i have no time now to figure out while filenames are not known but
 > here's a (wikifyable) hack:
[snip]
 > line = status.linenumber,
 > file = status.filename

 From the luatex 0.40.6 sources
(luatex/source/texk/web2c/luatexdir/lua/lstatslib.c):
----------------------------------------------------------
/* hack, I really should implement the makecstring */
char *getfilename(void)
{
    integer t;
    t = get_current_name();
    if (t > (1 << 21))
        return makecstring(t);
    else
        return xstrdup("");
}
----------------------------------------------------------

Looks like we're always getting the xstrdup() branch of the conditional.

Hans, would you like me to submit this as a luatex bug?

Tad

___________________________________________________________________________________
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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
___________________________________________________________________________________