Re: A little trouble with very large arrays.

[Jacob Sparre Andersen <jacob@jacob-sparre.dk>]

Shark8 <onewingedshark@gmail.com> writes:

> The main-problem right now is the "Primary Data Array" which can have
> a dimensionality in 1..999, each itself with some non-zero range. (In
> the files these are specified by keywords in the file like NAXIS = n,
> NAXIS1 = n_1, NAXIS2 = n_2, and so on until the NAXISn = n_n
> keyword/value pair is encountered.)

Ouch. :-(

Something like this will work, but it doesn't look nice:

package Variable_Dimensionality is

   type Raw is array (Positive range <>,
                      Positive range <>,
                      Positive range <>) of Boolean;

   type Nice (Dim_1, Dim_2, Dim_3 : Positive) is
      record
         Data : Raw (1 .. Dim_1,
                     1 .. Dim_2,
                     1 .. Dim_3);
      end record;

end Variable_Dimensionality;

> (As another interesting constraint, the file-format mandates a sort of
> block-structure of 2880 bytes [23040 bits], and while I don't
> anticipate this being an issue, something that might be relevant.)

Ada.Sequential_IO and Ada.Direct_IO can both be instantiated with types
of any size, so you could simply use a 2880 character String, or a 2880
element Storage_Element_Array (remember to assert that
Storage_Element'Size = 8).

Greetings,

Jacob
-- 
»Verbing weirds language.«                         -- Calvin