Re: C Interface question

[dewar@cs.nyu.edu (Robert Dewar)]

T.E.D. said

Cool!! That was one of my favorite DECisms. The best part was the "mechanisims",
field, which allowed "thin" bindings to use ADTs, rather than just integers
or access types. That almost makes thin C bindings usable.


Indeed. It is true that the Ada 95 rules (or rather implementation advice)
if followed, allows more consistent and portable interface to C, but the
Import pragma allows precise control, and GNAT does indeed fully implement
the whole pragma (well to be precise, certain very VMS'y features like
First_Optional_Parameter and pass by Descriptor are available on VMS
only, since they make no sense elsewhere, but most of the pragma makes
good sense. Actually come to think of it, maybe we should allow
First_Optional_Parameter and ignore it? well probably it's not worth it,
since it is only really of use for DEC packages like Starlet.

But the important point is that the Value and Reference mechanisms work
fine, and I think that is what Ted is really referring to in his "Cool!!"