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From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Discriminant of a limited type object
Date: Wed, 28 Feb 2018 17:10:22 -0600
Date: 2018-02-28T17:10:22-06:00	[thread overview]
Message-ID: <p77csu$4i8$1@franka.jacob-sparre.dk> (raw)
In-Reply-To: p74nge$1oto$1@gioia.aioe.org

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:p74nge$1oto$1@gioia.aioe.org...
...
> The problem is passing state between calls to the function. The code in 
> mind is a loop over array elements. The loop body gutted and its parts 
> moved into the function.
>
>    A : T (1..N);
> begin
>    for Index in A'Range loop
>       do-init of A (Index)
>    end loop;
>
>         |
>         V
>
>    Index : Positive := 1;
>    function F return Element is
>    begin
>       Index := Index + 1;
>       return do-init of A (Index - 1);
>    end F;
>    A : T (1..N) := (others => F)
>
> Quite ugly. In the end I decided to flatten record variants and make the 
> discriminant a plain record member. The memory loss is not big enough to 
> justify the code above.

Ada 2020 has you covered:

    function F(Index : Natural) return Element is
    begin
       return do-init of A (Index - 1);
    end F;
    A : T (1..N) := (for I in 1 .. N  => F(I));

Note the new iterator choice in the aggregate.

                                           Randy.




  parent reply	other threads:[~2018-02-28 23:10 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-27 17:54 Discriminant of a limited type object Dmitry A. Kazakov
2018-02-27 22:20 ` Randy Brukardt
2018-02-27 22:53   ` Dmitry A. Kazakov
2018-02-28  6:36     ` J-P. Rosen
2018-02-28  8:42       ` Dmitry A. Kazakov
2018-02-28  9:07         ` J-P. Rosen
2018-02-28 17:16       ` Jeffrey R. Carter
2018-02-28 23:10     ` Randy Brukardt [this message]
2018-03-01  8:43       ` Dmitry A. Kazakov
2018-03-01 22:00         ` Randy Brukardt
2018-03-02 10:30           ` Dmitry A. Kazakov
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