On Sun 27 Apr 2014 18:00, Mark H Weaver <mhw@netris.org> writes:

> Andy Wingo <wingo@pobox.com> writes:
>
>> I propose to provide a new interface that will eventually make SMOBs
>> obsolete.  This new interface is based on structs with raw fields -- the
>> 'u' fields.  (See
>> http://www.gnu.org/software/guile/docs/master/guile.html/Vtables.html#Vtables
>> for description of 'u' fields.  Note that the documentation is wrong --
>> these fields are indeed traced by the GC.)
>
> Sounds like a good idea, in general.

Thanks; with this note, Ludo's approbation, and a doc update I feel OK
with pushing to stable-2.0.  Let's hammer out the details there.

>>     SCM scm_make_foreign_object_1 (SCM type, scm_t_bits val0);
>>     SCM scm_make_foreign_object_2 (SCM type, scm_t_bits val0,
>>                                     scm_t_bits val1);
>>     SCM scm_make_foreign_object_3 (SCM type, scm_t_bits val0,
>>                                     scm_t_bits val1, scm_t_bits val2);
>
> If we include an interface like this, I think we should have more of
> these, but see below.

I changed this interface to take void* pointers, with the idea that
that's the common thing.  Same with scm_foreign_object_ref.  But I added
scm_foreign_object_signed_ref, unsigned_set_x, etc, with notes in the
manual that you can indeed provide fewer initializers than fields, and
then initialize the fields yourself later.

> #ifndef __GNUC__
>   if (bits > SCM_T_SIGNED_BITS_MAX)
>     return -1 - (scm_t_signed_bits) ~bits;
> #endif
>   return (scm_t_signed_bits) bits;
> }

I think I forgot to actually implement this bit though :P

Tutorial-style documentation (in the Programming in C chapter, replacing
the SMOB tutorial) attached.  There is also reference-style
documentation in the API chapter.

Andy