FFI: Allocating an array of doubles and initializing it

FFI: Allocating an array of doubles and initializing it

[Kaspar Rohrer]

Hello,

I'm currently trying to allocate an array of doubles to pass some  
values back to Ocaml. However, documentation on this specific topic  
seems relatively sparse, and thus I'm not sure if the following is  
correct:

CAMLprim value ml_create_float_array (value n, value fill)
{
	CAMLparam2(n, fill);
	CAMLlocal1(arr);

	long i;
	long N = Long_val(n);
	double D = Double_val(fill);
	
	arr = caml_alloc_shr(N * Double_wosize, Double_array_tag);
	for (i = 0; i < N; ++i) {
	   Store_double_field(arr, i, D);
	}
	
	CAMLreturn(arr);
}

Any help appreciated.
	Kaspar Rohrer

PS: I'm using Ocaml 3.09.

Re: [Caml-list] FFI: Allocating an array of doubles and initializing it

[Olivier Andrieu]

Hi,

On 6/20/07, Kaspar Rohrer <krohrer@student.ethz.ch> wrote:
> I'm currently trying to allocate an array of doubles to pass some
> values back to Ocaml. However, documentation on this specific topic
> seems relatively sparse, and thus I'm not sure if the following is
> correct:

it is, except it'd simply use caml_alloc instead of caml_alloc_shr and
let the GC decide in which generation it should allocate the array.

> CAMLprim value ml_create_float_array (value n, value fill)
> {
>         CAMLparam2(n, fill);
>         CAMLlocal1(arr);
>
>         long i;
>         long N = Long_val(n);
>         double D = Double_val(fill);
>
>         arr = caml_alloc_shr(N * Double_wosize, Double_array_tag);
>         for (i = 0; i < N; ++i) {
>            Store_double_field(arr, i, D);
>         }
>
>         CAMLreturn(arr);
> }
>
> Any help appreciated.
>         Kaspar Rohrer
>
> PS: I'm using Ocaml 3.09.

-- 
  Olivier