Re: advice on package design

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 12 Mar 2005 14:57:17 -0500, Robert A Duff wrote:

> If I were [re]designing Ada, I would make 'use' transitive. That is,
> if Foo says "use Linked_List" that would make the contents of
> Linked_List directly visible in Foo, and anything that says "use Foo;"
> would have direct visibility on everything directly visible in Foo --
> not just the things *declared* in Foo.  Or something like that.

Yes, I really miss it. What about:

   use all <package-name>;

or

  use package <package-name>;

with the effect importing the specification of the package? Also,
differently to use, it should prevent hiding. So:

package A is
   Foo (X : Integer);
end A;

with A;
package B is
   use all A;
   Foo (X : out Integer); -- Illegal, can't hide A.Foo
end B;

It could be also used for testing if a child package is parent-friendly:

package Foo.Child is
   ... -- Lot of stuff
private
   use all Foo; -- Fails if Child hides something in Foo
   ...
end Foo;

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de