Re: Ada.Strings.Bounded

[Eric Hughes <eric.eh9@gmail.com>]

On Apr 22, 9:41 am, Robert A Duff <bobd...@shell01.TheWorld.com>
wrote:
> The above-quoted paragraph 3.5.4(8) is normative.  It comes right out
> and says in plain language exactly what you were trying to prove in a
> circuitous manner -- that the the set of values is infinite.

Here's the relevant sentence in 3.5.4(8) again:
> The set of values for a signed integer type is the (infinite) set
> of mathematical integers, though only values of the base range of
> the type are fully supported for run-time operations.

So now wait.  When I declare
    type X is range 0 .. 99 ;
does that mean that the value 100 is a value of type X?  Because how
that definition reads in any sort of facially-reasonable way is that
100 is not a value of type X.

> Note that it does not say anything special about root_int or univ_int.
> It applies to ALL signed integer types, including user-defined ones.

Apparently so.

And so now I have developed a Strong Opinion.  This is a travesty.  A
probably-irredeemable travesty. This is so completely counter-
intuitive that I have a hard time believing that competent people came
up with this way of writing the definition.  It's unnecessary.  There
are far better ways of defining this, and they don't break any
existing syntax.

I'm out.  Completely out.  Everything I've said has been predicated on
the assumption that the set of values of a type is what the
declaration says it is, rather than having values that cannot be
assigned to a variable of that type.  In my opinion this means that
assignment and variable definition are broken.  I don't even care what
the details are at this point.

Eric