(with-dyn-lib "./query.so"
  (deffi query "query" void (closure)))

(with-dyn-lib nil
  (deffi memcpy "memcpy" cptr (cptr str size-t)))

(deffi-cb query-cb int (cptr (ptr (array 1 size-t))))

(query (query-cb (lambda (buf sizeptr)              ;  int lambda(void *buf, siz
                   (symacrolet ((size [sizeptr 0])) ;  { #define size sizeptr[0]
                     (let* ((s "Here am I")         ;    char *s = "Here am I";
                            (l (length s)))         ;    size_t l = strlen(s);
                       (cond                        ;    if (length > size)
                         ((> l size) 0)             ;    { return 0; } else
                         (t (memcpy buf s l)        ;    { memcpy(buf, s, l);
                            (set size l))))))))     ;      return size = l; } }