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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Discriminant of a limited type object
Date: Thu, 1 Mar 2018 16:00:39 -0600
Organization: JSA Research & Innovation
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Date: 2018-03-01T16:00:39-06:00
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:p78een$1jfi$1@gioia.aioe.org...
> On 01/03/2018 00:10, Randy Brukardt wrote:
...
>> 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.
>
> Definitely less ugly than recursion. But does this "loop" guarantee that F 
> will be called in the order?

Nope, it's an aggregate and can be evaluated in any order. No aggregate is 
appropriate for something that has to be done sequentially. (With the 
exception of array delta aggregates; perhaps you could jury-rig something 
using one of them.)

It's not clear that there is much use for streaming of limited objects, as 
streaming is very much like assignment (it makes a copy of the object). One 
would expect that if assignment is a problem, so would streaming be a 
problem. I suppose there are some cases where controlled assignment isn't a 
good solution (I haven't seen one personally, but everything happens 
eventually...), but it seems like a niche need at best.

                                    Randy.