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From: "Gene" <gene.ressler@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: Surprise in array concatenation
Date: 1 Sep 2005 14:42:22 -0700
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Date: 2005-09-01T14:42:22-07:00
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Ok.  Thanks.  And Jean-Pierre too.

I completely agree with the marginal utility of other-than-1 least
array indices.

Still it makes complete sense for your code

    X: String(-99 .. -10_000); -- empty string
    Y: constant String := X & "Hello world."

to generate an exception because the dest index range starts at -99.

I have a much bigger problem with

   A : Int_Array(1..i - 1);
   B:  Int_Array(i+1..10);
...
... := A & B;

producing an array indexed from 1 when i = 2 and from 2 when i = 1.
This still makes my head hurt.

The starting point of a range of length zero is a perfectly logical
concept.  It's easy to draw such a range on a number line, for example.
 The fact that A'First is always defined is a tacit verification!

So I'm still interested in an example that shows why the defined
behavior makes sense.

Gene