Re: Possible Ada deficiency?

["Randy Brukardt" <randy@rrsoftware.com>]

<danmcleran@hotmail.com> wrote in message
news:1105327132.335673.73950@c13g2000cwb.googlegroups.com...
> I don't think it needs to be this complicated an issue. The only
> mechanism I'm proposing is that a parent package can choose to hide
> detail(s) from child packages. There would be 3 areas of visibilty:
> public, private, & concealed.

There are already three areas of visibility: public/private/body, and you're
suggesting to add a fourth (not third). And, as I previously indicated, the
three existing areas of visibility have caused no end of problems, both at
the language definition level, and in implementations.

Moreover, this idea would require a large number of additional rules to
explain, and almost certainly would introduce lots of new bugs.

"I don't think is needs to be this complicated an issue." Visibility is an
extremely complicated issue; changes to it have to be made with extreme
care. Limited with proved to be very, very difficult to get right (mostly
because of obscure issues with use clauses and renames of child packages
that no one would ever try to do in practice). Your suggestion would be much
worse.

It also would make Ada programs harder to read and write, because you'd have
to declare things out of the usual order to put them into the right "part".

In any case, infinite repetition that your solution is "simple" is not going
to make it so. Putting private types in the body is the right solution,
because it hides the information without adding new visibility. But that too
is too big a leap for right now.

                     Randy.