Re: GNU Guile 1.9.6 released (alpha)

[Linas Vepstas <linasvepstas@gmail.com>]

2009/12/15 Ludovic Courtès <ludo@gnu.org>:

> Changes since the 1.9.5 pre-release:

>  *** Simplify representation of primitive procedures
>
>  It used to be that there were something like 12 different typecodes
>  allocated to primitive procedures, each with its own calling convention.
>  Now there is only one, the gsubr. This may affect user code if you were
>  defining a procedure using scm_c_make_subr rather scm_c_make_gsubr. The
>  solution is to switch to use scm_c_make_gsubr. This solution works well
>  both with the old 1.8 and and with the current 1.9 branch.

I have a new feature request -- it would be useful, in a variety of situations,
to be able to provide an opaque (void *) pointer when calling make_gsubr,
and then getting that pointer back again whenever the primitive is called.

I've needed this on multiple occasions. Each time, I eventually found
reasonably elegant alternative solutions, but not before some fair amount
of cursing, agonizing, exploring, and general pain.  (each alternative solution
required several hundred lines of carefully documented code, because it
did non-obvious things to find the needed data.)

--linas