Re: 2 Ada 95/05 language design questions

["Adam Beneschan" <adam@irvine.com>]

On Feb 15, 2:59 pm, pnkflyd...@gmail.com wrote:

> You still have to with in the parent tagged types package.

No, I don't think that's correct.  The following program appears to be
legal, and it compiles with GNAT;  the call to A.CW_Op is legal and
refers to the CW_Op defined in pak1, even though pak1 is not visible
and CW_Op isn't implicitly defined (inherited) in pak2 or pak3:

package pak1 is
    type Root is tagged null record;
    procedure CW_Op (X : in out Root'Class);
end pak1;

with pak1;
package pak2 is
    type Child1 is new pak1.Root with null record;
end pak2;

with pak2;
package pak3 is
    type Child2 is new pak2.Child1 with null record;
end pak3;

with pak3;
procedure test is
    A : pak3.Child2;
begin
    A.CW_Op;
end test;

4.1.3 just says about this notation: "The selector_name (i.e. the
subprogram name) shall resolve to denote a view of a subprogram
declared immediately within the declarative region in which an
ancestor of the type T is declared"; there's nothing in there that
says that the ancestor of T, or the subprogram, has to be visible.

So I think Bob was right about "eliminated".

                       -- Adam