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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Community Input for the Maintenance and Revision of the Ada
 Programming Language
Date: Sat, 2 Sep 2017 13:04:27 +0200
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Date: 2017-09-02T13:04:27+02:00
List-Id: <comp.lang.ada>

On 2017-09-02 12:49, Vincent DIEMUNSCH wrote:

> Regarding arrays I propose the following evolutions :
> 
> 1. Allow discriminants in array types (if they are not unconstrained array types).
> type Matrix (M,N : Positive) is array (1 .. M, 1 .. N) of Long_Float.

Yes, all types must be allowed to have discriminants. However, I would 
treat array bounds as discriminants too.

The problem is removing discriminants upond constraining. This seems to 
be why discriminants were not allowed in the first place.

> 2. Allow a special indexing syntax, that I called relative indexing.
> Adding a Unary + operator (that has no other purpose ! :-) ) in front of
> an index expression means starting from A'First. Unary plus would then
> become the ordinal operator.
> 
>   A(+i) simply means A(A'First +i).

A better approach is to allow positional indexing by universal integer 
offset (0-based) or position (1-based).

    A [N] means N-th element
    A'Span would be a positional equivalent to A'Range

Offset vs. position is up to debate.

And C-freaks will finally have their ugly square brackets back! (:-))

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de