Hi Myles!
In your case, you've announced int array in your C code, so you shouldn't
use u8vector, the correct one is (u32vector 0 1 2 3 4 5 6 7 8 9)
Please notice that 0 is the placeholder since your array starts from 1.
On Thu, Mar 12, 2020 at 4:22 AM Myles English <mylesengl...@gmail.com>
wrote:
> Hi Nala,
>
> On Tue, 10 Mar 2020, 18:50 Nala Ginrut, <nalagin...@gmail.com> wrote:
>
>> If I understand your question correctly, the arg_type should be (list
>> int '*)
>>
>> On Tue, Mar 10, 2020 at 10:25 PM Myles English <mylesengl...@gmail.com>
>> wrote:
>>
> I am trying to call a C function with this signature from Guile:
>>
>>>
>>> void the_test(int n, const int the_array[]);
>>>
>>> in pointer->procedure what should arg_types be?
>>>
>>
> Thank you for reply, it does indeed answer my original question. Now, how
> do I call the guile procedure to use the C function? I thought this might
> work but it doesn't:
>
> In file main.scm:
>
> (use-modules (system foreign)
> (rnrs bytevectors))
>
> (define libarray (dynamic-link "/path/to/libarray.so"))
>
> (define the-test
> (pointer->procedure void
> (dynamic-func "the_test" libarray)
> (list int '*)))
>
> (define (call-the-test)
> (let* ((bv (u8-list->bytevector '(1 2 3 4 5 6 7 8 9)))
> (bv_p (bytevector->pointer bv)))
> (display bv) (newline)
> (the-test 9 bv_p)))
>
> (call-the-test)
>
> In file array.c:
>
> #include <stdio.h>
> void the_test(int n, const int the_array[])
> {
> int i, k;
> for (k = 1; k <= n; k++)
> {
> i = the_array[k];
> printf("the_array [%d] = %d\n", k, i);
> }
> return;
> }
>
> compiled with:
>
> gcc -c -Wall -fpic array.c && gcc -shared -o libarray.so array.o
>
> This is the result of calling the guile module, (I was hoping to get the
> numbers 1 to 9):
>
> $ guile main.scm
> #vu8(1 2 3 4 5 6 7 8 9)
> the_array [1] = 134678021
> the_array [2] = 9
> the_array [3] = 0
> the_array [4] = 0
> the_array [5] = 0
> the_array [6] = 0
> the_array [7] = 0
> the_array [8] = 27
> the_array [9] = 0
>
> In addition to the main question above, the C function expects a 1-based
> index for the array, how would the guile procedure accommodate this?
>
> Thanks,
> Myles
>
>>
