* Inheriting from foreign objects @ 2002-04-09 18:21 Andreas Rottmann 2002-04-10 19:47 ` Neil Jerram 0 siblings, 1 reply; 5+ messages in thread From: Andreas Rottmann @ 2002-04-09 18:21 UTC (permalink / raw) Hi! I have run into a problem: I create classes from C (C++) using scm_make_class(). These classes all get the SCM_CLASSF_FOREIGN bit set to treat them as foreign objects (like invoke the constructor & desctructor supplied). So far, so good. However, when I derive from these classes (on the Scheme level), the new class has also the FOREIGN bit set (it's inherited in scm_sys_inherit_magic_x(), AFAICT), but the constructor set NULL, which causes %allocate-instance bails out when trying to instantiate the class. Is there a way I can cleanly derive from C-created classes? BTW, I'm using the current CVS code. Regards, Andy -- Andreas Rottmann | Dru@ICQ | 118634484@ICQ | a.rottmann@gmx.at http://www.8ung.at/rotty | GnuPG Key: http://www.8ung.at/rotty/gpg.asc Fingerprint | DFB4 4EB4 78A4 5EEE 6219 F228 F92F CFC5 01FD 5B62 _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Inheriting from foreign objects 2002-04-09 18:21 Inheriting from foreign objects Andreas Rottmann @ 2002-04-10 19:47 ` Neil Jerram 2002-04-23 20:43 ` Thien-Thi Nguyen 0 siblings, 1 reply; 5+ messages in thread From: Neil Jerram @ 2002-04-10 19:47 UTC (permalink / raw) Cc: guile-devel >>>>> "Andreas" == Andreas Rottmann <a.rottmann@gmx.at> writes: Andreas> Hi! Andreas> I have run into a problem: I create classes from C (C++) using Andreas> scm_make_class(). These classes all get the SCM_CLASSF_FOREIGN bit set Andreas> to treat them as foreign objects (like invoke the constructor & Andreas> desctructor supplied). Andreas> So far, so good. However, when I derive from these classes (on the Andreas> Scheme level), the new class has also the FOREIGN bit set (it's Andreas> inherited in scm_sys_inherit_magic_x(), AFAICT), but the constructor Andreas> set NULL, which causes %allocate-instance bails out when trying to Andreas> instantiate the class. Andreas> Is there a way I can cleanly derive from C-created classes? I'd say you're in virgin territory here, and that any advice you can give on such problems, and on defining a C API for GOOPS, would be very useful. (Sorry that wasn't much help! Good luck.) Neil _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Inheriting from foreign objects 2002-04-10 19:47 ` Neil Jerram @ 2002-04-23 20:43 ` Thien-Thi Nguyen 2002-04-30 10:23 ` Andreas Rottmann 0 siblings, 1 reply; 5+ messages in thread From: Thien-Thi Nguyen @ 2002-04-23 20:43 UTC (permalink / raw) Cc: guile-devel, guile-user From: Neil Jerram <neil@ossau.uklinux.net> Date: 10 Apr 2002 20:47:13 +0100 Andreas> Is there a way I can cleanly derive from C-created classes? I'd say you're in virgin territory here, and that any advice you can give on such problems, and on defining a C API for GOOPS, would be very useful. it looks like foreign bit is set when superclass list is empty. perhaps a good guideline would be to use at least `(list <object>)' for `supers' for normal operation. btw, it doesn't look like user-supplied ctor/dtor are suppressed based on foreign bit in any case. [cc guile-user in order to ask survey question: which goops-related C functions do people use now? the answer to this helps shape definition of the C interface to goops -- thanks!] thi _______________________________ SCM scm_make_class (SCM meta, char *s_name, SCM supers, size_t size, void * (*constructor) (SCM initargs), size_t (*destructor) (void *)) { SCM name, class; name = scm_str2symbol (s_name); if (SCM_NULLP (supers)) supers = scm_list_1 (scm_class_foreign_object); class = scm_basic_basic_make_class (meta, name, supers, SCM_EOL); scm_sys_inherit_magic_x (class, supers); if (destructor != 0) { SCM_SET_SLOT (class, scm_si_destructor, (SCM) destructor); SCM_SET_CLASS_DESTRUCTOR (class, scm_free_foreign_object); } else if (size > 0) { SCM_SET_CLASS_DESTRUCTOR (class, scm_struct_free_light); SCM_SET_CLASS_INSTANCE_SIZE (class, size); } SCM_SET_SLOT (class, scm_si_layout, scm_str2symbol ("")); SCM_SET_SLOT (class, scm_si_constructor, (SCM) constructor); return class; } _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Inheriting from foreign objects 2002-04-23 20:43 ` Thien-Thi Nguyen @ 2002-04-30 10:23 ` Andreas Rottmann 2002-05-15 12:30 ` Thien-Thi Nguyen 0 siblings, 1 reply; 5+ messages in thread From: Andreas Rottmann @ 2002-04-30 10:23 UTC (permalink / raw) Thien-Thi Nguyen <ttn@giblet.glug.org> writes: > From: Neil Jerram <neil@ossau.uklinux.net> > Date: 10 Apr 2002 20:47:13 +0100 > > Andreas> Is there a way I can cleanly derive from C-created classes? > > I'd say you're in virgin territory here, and that any advice you can > give on such problems, and on defining a C API for GOOPS, would be > very useful. > > it looks like foreign bit is set when superclass list is empty. perhaps > a good guideline would be to use at least `(list <object>)' for `supers' > for normal operation. I can't test your statement, since I have switched to create a 'normal' class and have a special slot being a smob containing the pointer to the C++ object. > btw, it doesn't look like user-supplied ctor/dtor > are suppressed based on foreign bit in any case. > When you inherit from a 'foreign' class, the constructor/destructor fields of the new class are set NULL. I suggest you write some 'test' code that uses the various goops-related C functions, as that would both make them easier to understand and they can be validated this way. > [cc guile-user in order to ask survey question: which goops-related C > functions do people use now? the answer to this helps shape definition > of the C interface to goops -- thanks!] > I use, in my C++ <-> GOOPS bindings: scm_load_goops() scm_make() scm_basic_make_class() scm_sys_allocate_instance() scm_sys_initialize_object() scm_slot_set_x() SCM_IS_A_P() scm_add_method() scm_generic_function_methods() scm_method_procedure() scm_method_specializers() scm_slot_exists_p() scm_slot_ref() I may have overlooked some. BTW: Has anybody of the developers looked at my GOOPS-related bugreport yet? Since I have included a program documenting the bug it shouldn't be too hard to investigate... Regards, Andy -- Andreas Rottmann | Dru@ICQ | 118634484@ICQ | a.rottmann@gmx.at http://www.8ung.at/rotty | GnuPG Key: http://www.8ung.at/rotty/gpg.asc Fingerprint | DFB4 4EB4 78A4 5EEE 6219 F228 F92F CFC5 01FD 5B62 _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Inheriting from foreign objects 2002-04-30 10:23 ` Andreas Rottmann @ 2002-05-15 12:30 ` Thien-Thi Nguyen 0 siblings, 0 replies; 5+ messages in thread From: Thien-Thi Nguyen @ 2002-05-15 12:30 UTC (permalink / raw) Cc: guile-devel, guile-user From: Andreas Rottmann <a.rottmann@gmx.at> Date: 30 Apr 2002 12:23:06 +0200 I suggest you write some 'test' code that uses the various goops-related C functions, as that would both make them easier to understand and they can be validated this way. i've added "write goops test cases in C" under "Eventually" in the TODO. > [cc guile-user in order to ask survey question: which goops-related C > functions do people use now? the answer to this helps shape definition > of the C interface to goops -- thanks!] > I use, in my C++ <-> GOOPS bindings: [...] recorded in $workbook/policy/api.text -- thanks. BTW: Has anybody of the developers looked at my GOOPS-related bugreport yet? Since I have included a program documenting the bug it shouldn't be too hard to investigate... i believe this is bug `goops-1'. thi _______________________________________________ Guile-devel mailing list Guile-devel@gnu.org http://mail.gnu.org/mailman/listinfo/guile-devel ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2002-05-15 12:30 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2002-04-09 18:21 Inheriting from foreign objects Andreas Rottmann 2002-04-10 19:47 ` Neil Jerram 2002-04-23 20:43 ` Thien-Thi Nguyen 2002-04-30 10:23 ` Andreas Rottmann 2002-05-15 12:30 ` Thien-Thi Nguyen
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