Re: Allocation questions

[Martin <martin.dowie@btopenworld.com>]

On May 28, 1:32 pm, Olivier Scalbert <olivier.scalb...@algosyn.com>
wrote:
> Martin wrote:
> > On May 28, 11:05 am, "Dmitry A. Kazakov" <mail...@dmitry-kazakov.de>
>
> > p.s. here's a demo:
>
> > with Ada.Text_IO; use Ada.Text_IO;
> > procedure Demo is
> >    package D is
> >       type No_Of_Samples is range 0 .. 1_000;
> >       type A_of_F is array (No_Of_Samples range <>) of Float;
> >       type R (S : No_Of_Samples := 0) is private;
> >       function Create (N : No_Of_Samples) return R;
> >       procedure Put_Line (This_R : R);
> >    private
> >       type R (S : No_Of_Samples := 0) is
> >          record
> >             I : Integer;
> >             B : Boolean;
> >             A : A_Of_F (1 .. S);
> >          end record;
> >    end D;
> >    package body D is
> >       function Create (N : No_Of_Samples) return R is
> >       begin
> >          return (S => N,
> >                  I => 0,
> >                  B => False,
> >                  A => (others => 0.0));
> >       end Create;
> >       procedure Put_Line (This_R : R) is
> >       begin
> >          Put_Line (Integer'Image (This_R.I));
> >          Put_Line (Boolean'Image (This_R.B));
> >          Put_Line (No_Of_Samples'Image (This_R.S));
> >          for I in This_R.A'Range loop
> >             Put_Line (Float'Image (This_R.A (I)));
> >          end loop;
> >       end Put_Line;
> >    end D;
>
> >    R_1 : D.R := D.Create (1);
> >    R_5 : D.R := D.Create (5);
> > begin
> >    D.Put_Line (R_1);
> >    D.Put_Line (R_5);
> > end Demo;
>
> Thanks Martin, it works!
>
> 2 more questions:
>
> 1) In fact (due to my background!), I would like to use the dot notation:
> object.method.
> So I have add "tagged":
>
>      type Delay_Type (Size : Nb_Of_Samples := 0) is tagged private;
>      ...
> private
>      type Delay_Type (Size : Nb_Of_Samples :=0) is tagged record
>       ...
>
> When I compile, I have:
> "discriminants of tagged type cannot have defaults"
> How can I fix it ?

Just remove the " := 0" bit.

> 2) If Nb_Of_Samples range is too large, around 1..5_000_000, I have a
> nice Segmentation fault. How can I fix that ?

Works fine with 2_000_00 with GNAT GPL 2009 Win32... ;-)

What OS are you using?

Cheers
-- Martin