Andreas Rottmann <a.rottm...@gmx.at> writes:
> Mark H Weaver <m...@netris.org> writes:
>
>> Why not leave the API as-is, and in the event of an error, just raise
>> the proper R6RS exception from within 'scm_get_string_n_x'?
>>
> The problem here is that we have no easy way to raise R6RS exceptions
> from C code, AFAICT. It is certainly possible, but if it involves
> convoluted code of doing imports of condition types and appropriate
> constructors, then constructing a proper invocation, all in C, I'd
> rather avoid it.
It's not that bad. In Guile 2.0 we have some convenient procedures for
accessing arbitrary Scheme variables from C.
Looking at your patch, I see that if '%get-string-n!' returned an error,
then you did:
(raise (make-i/o-decoding-error port))
This can be written in C as follows:
scm_call_1 (scm_c_public_ref ("rnrs exceptions", "raise"),
scm_call_1 (scm_c_public_ref ("rnrs io ports",
"make-i/o-decoding-error")));
Alternatively, you could write one or more private helper procedures in
Scheme to raise R6RS exceptions, and call those private helpers from C
using 'scm_c_private_ref' instead of 'scm_c_public_ref'.
What do you think?
Regards,
Mark
