Re: Graphical octave frontend

[Paul Kienzle]

Ulrich Kuettler wrote:

> I hope you share my enthusiasm about it because to go further I need
> your kind help and support. My aim is to link against out of the box
> octave libraries. But there might be a few changes necessary. For
There are a number of projects which want a
'headless' octave, such as a windows port,
a tcl extension, a perl extension, an R extension,
and various parallel octave implementations which
need to take over from the read-eval-print loop.
Lots of ambition but not much time.

An alternative approach is to run octave in a
separate process and use pipes (e.g., octave-forge
extra/engine) or TCP/IP sockets (e.g., octave-forge
main/miscellaneous/listen.cc).  Neither interface is
complete, but both have been used successfully in
some projects.

> example could the build process be much smoother if octave's config.h
> had another name. (I'm also very much in favour of John Eaton's
> suggestion to introduce an "octave" namespace.) Another issue I
> haven't solved yet is how a library's user finds the error messages
> when error_state != 0.
Look in listen.cc:

   bind_global_error_variable();
   octave_value def = get_builtin_value("__error_text__");
   std::string str = def.string_value();

I also have:

   clear_gloabl_error_variable(NULL);

but I don't think it is needed.

The function get_builtin_value is not (yet) in
variables.cc.  It is defined as follows:

octave_value
get_builtin_value (const std::string& nm)
{
 octave_value retval;
 symbol_record *sr = fbi_sym_tab->lookup (nm);
 if (sr) {
   octave_value sr_def = sr->def ();
   if (sr_def.is_undefined())
     error ("get_builtin_value: undefined symbol `%s'", nm.c_str ());
   else
     retval = sr_def;
 } else error("get_builtin_value: unkonwn_symbol %s",nm.c_str());
}

Paul Kienzle
address@hidden