Re: Zoo question

[Ted Dennison <dennison@escmail.orl.mmc.com>]

Bob Gilbert wrote:
> 
> In article <3211C9C6.41C67EA6@escmail.orl.mmc.com>, Ted Dennison <dennison@escmail.orl.mmc.com> writes:
> > where integer_type is an ananoymous base type, snd predefined_integer_type
> > can be any predefined integer type the compiler wants, as long as it
> > includes 1 and 5.
> >
> > Thus the base type is NOT integer.
> 
> I guess I should have said that the base type of Animal_ID is *equivalent* to
> or derived from type integer, at least as far as the constraints are concerned.

Close. However, integer is not the only predefined "integer type" allowed.
Thus it could well be something like Short_Integer that the compiler 
chooses to derive Animal_ID's base type from.

Of course this is a nit upon a nit. In effect if not in detail, you were
correct (and at a certian level of detail, we are all incorrect).

> 
> > However, the base type's range may well be the same as integer's.
> 
> As I would expect it to be.

It may also be 1/2 the range, or 1/4, or 2*, or some bizzare unrelated 
range.

>>(more of my prattling deleted)
> 
> That's what I said (I think).  The attribute 'Succ is not constrained to
> the specified range 1 .. 5, but I think I would expect a constraint check
> to raise an exception when making the assignment back to Next_Animal.

Yes, that is what you said. The part that got me was saying that the base type
was integer. But the effect is (probably) the same.

However, I should (and did) point out that the constraint check does NOT have
to happen (and does not have to happen within the begin block). That is why 
Ada (95) now has the 'valid attribute.

-- 
T.E.D.          
                |  Work - mailto:dennison@escmail.orl.mmc.com  |
                |  Home - mailto:dennison@iag.net              |
                |  URL  - http://www.iag.net/~dennison         |