Re: Private discrete type as index

["AG" <ang@xtra.co.nz>]

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
news:b0435c$la5bg$1@ID-77047.news.dfncis.de...
> tmoran@acm.org wrote:
>
> >>   type x is limited private;
> >>   type test is array(x) of boolean;
> >   The "array" abstraction has certain characteristics, among them
> > sequential indexing.
>
> Why so? Array is just a mapping index->element, so if no index ranges
> required then the array index need not to be ordered (have "<" and "="),
> only "=" is required.

I suppose the answer will be that index ranges *are* required
by the array semantics (in Ada, at least). But, as you pointed out:

> Anyway a limited type is allowed to have both.

So, it should be able to meet the range requirements too.
At least if the provider of the type also provides the minimum
set of operations.