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From: "Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>
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Subject: Re: Lower bounds of Strings
Date: Wed, 13 Jan 2021 15:08:04 +0100
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On 1/12/21 9:12 AM, Randy Brukardt wrote:
>        N2 : String(314 .. 25);
> 
> And it takes code to figure this out at runtime if either bound is nonstatic
> (which is usually the case with slices). And you still have to store the
> bounds (you can still ask for the bounds of N2, and one better get 314 and
> 25, but the length is still zero).

I don't think I have ever cared what values 'First and 'Last return for a null 
array. While I was aware that such super-null ranges were possible, I presumed 
that some canonical values were used for the bounds of a null array, regardless 
of the actual bounds given.

For a 1-D array X with X'Length = 0, my uses of the bounds of X are usually one of

I in X'range
-----
I := X'First;
followed by comparison to X'Last
-----
comparison of X'Length to zero
-----
if X is a string type, comparison of X to ""

Are there real-world cases where retrieving the actual bounds given is necessary?

-- 
Jeff Carter
"Your mother was a hamster and your father smelt of elderberries."
Monty Python & the Holy Grail
06