Re: [Caml-list] C -> CAML linking: loosing values in arrays??

[Damien Doligez <damien.doligez@inria.fr>]

On Saturday, January 11, 2003, at 08:07 PM, Daniel Andor wrote:

> parameters.  Since it's for numerics, I want to pass arrays of doubles.

>   return alloc_array(make_float,p);

You cannot use alloc_array to return a value of type [float array].
This is because arrays of floating-point numbers are not represented
like the other array types in O'Caml: they are allocated in-line,
without the usual pointer indirection.

You will have to allocate the array with [alloc], then fill in the
elements with [Store_double_field]:

#define NUM_DIMS 4
value make_float_array(double *ds)
{
   int i;
   value res;

   res = alloc (NUM_DIMS*Double_wosize, Double_array_tag);
   for (i=0; i<NUM_DIMS; i++){
     Store_double_field (res, i, ds[i]);
   }
   return res;
}


-- Damien

-------------------
To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr
Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/
Beginner's list: http://groups.yahoo.com/group/ocaml_beginners