Thank you for all your work and the time to answer my questions. Liam Healy <lnp@healy.washington.dc.us> writes:
Willem,
Thanks for the report.
My thinking is that with-foreign-slots is intended to expose the value (and not the pointer), and therefore, expands to foreign-slot-value, so the behavior you're seeing is correct. Your fix to your code is the correct way to access the pointer. I think with-foreign-slots is provided as a convenient shortcut to get all the values; since it doesn't do what you need, you need to use the actual access form (foreign-slot-pointer in your case).
Ah, ok, I am a bit struggling to convert the old way to the new way. It probably has nothing to do with (with-foreign-slots ...), but just my mis understanding and trying to quickly convert old code to new.
For your second question: if the argument is actually a pointer to the structure, :pointer is the right thing to use. Are you sure it is a pointer argument? Check the .h file where it is defined.
Liam
Ah, I do not have an issue with passing it to the c library. What I meant was that in my mind the following confused me: (let ((c-oid (foreing-alloc '(:struct git-oid)))) ;;; I think of c-oid, conceptually as type ;;; (:pointer (:struct git-oid)) ;;;; later: (foreign-slot-pointer c-oid '(:struct git-oid) 'id) ;;; I thought that because c-oid is of type ;;; (:pointer (:struct git-oid)) ;;; I thought I needed to put here ;;; '(:pointer (:struct git-oid)) instead of ;;; '(:struct git-oid) Does this make sense? Now I have a small additional question. I have a struct like: (defcstruct (git-index-time :class index-time-struct) ....) Now the (translate-from-foreign value (type index-time-struct)) works if I use as type: (:struct git-index-time) So everyting works. However, if I do: (defctype struct-index-time (:struct git-index-time)) And use as type: struct-index-time The `translate-from-foreign` is not called and I end up with untranslated values. I thought that (defctype ...) worked as a typedef and naively expected the type translation to still work. Is this as expected? I probably should use (define-parse-method ...) to get the behaviour as I expect. Hm, some more digging to do. Kind regards, Wim Oudshoorn.