[Ecls-list] Embedding ECL inside a containing C++ program.

[Andrew Topp]

 --- Juan Jose Garcia-Ripoll <jlr at mpq.mpg.de> wrote: 

> I do not know how you have used setjmp(). Personally
> I recommend the scheme 
> which is used consistently in ECL, and which is
> based on frs_push, cl_throw, 
> etc. For example, the right way to implement a CATCH
> statement
> 
> 	if (frs_push(FRS_CATCH,clSmy_symbol) == 0) {
> 		....
> 		/* Invoke lisp code */
> 		...
> 	}
> 	frs_pop();
> 
> Here clSmy_symbol is the object which you must pass
> to THROW so that this 
> conditional catches the jump. frs_push(), frs_pop()
> and the associated 
> routines take care of calling setjmp() and may be
> subject to important 
> changes in the future.

Nifty, I'll look into it:). setjmp() jumps out of
non-returning functions like FEerror(), well, they
can't return, and using catch/throw in the Lisp
universal-error-handler code causes a spam of frame
stack or bind stack overflow errors. I've also got a
setjmp() breaking out of quit to shut down the main
loop (broadcasts a cscmdQuit event) and return control
to UC so it can shutdown correctly.

> How do you access this virtual file system? Are
> there specialized entry 
> functions?
> 

It uses a completely different set of access methods,
which are performed through an SCF interface (C++
class) called iVFS. Nothing to do with STDIO.

I was thinking of just making a new interface to VFS,
but then things like load won't be able to use it, so
integrating it into the lisp streams would be nice:).

I'd looked into using Boheim's GC on another project
as well, I may give it some experimentation. How it
works is interesting:). Since the plugin completely
wraps around ECL, hiding all internal data
representations (cl_object), there shouldn't be many
references kept floating around.

My prelim plugin was just commited to CVS, you can
have a look at it at

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/unicorp/unicorp/plugins/lisp/lisp.cpp

This isn't production code, its just me fiddling to
get ECL working:). 

Thanks,

>> Andrew (talmakion at yahoo.com.au).


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