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From: Oliver Kellogg on 4 Mar 2010 00:37
Referring back to
http://groups.google.com/group/comp.lang.ada/msg/c14a79f7d21f5ebf ,

On Mar 29 2002, 2:05 pm, Oliver Kellogg wrote:

> Sergey Koshcheyev <serk...(a)hotmail.com> wrote:
> > Just a quick idea - maybe using "is separate" in some right places
> > would solve it? Like having the spec of A.B.Impl inside A.B, and
> > having the body separate.
>
> That's definitely possible, but still only a workaround solution.

I have to correct myself. It's not so definitely possible:

-- file: a.ads
package A is -- module A
package B is -- interface B
package Impl is
procedure X;
end Impl;
end B;
end A;

-- file: a.adb
package body A is
package body B is
-- Implementation for interface B,
-- body to be provided by user
package body Impl is separate;
end B;
end A;


$ gcc -c a.adb
a.adb:6:07: stub cannot appear in an inner scope
From: Admin - Do Not Email on 4 Mar 2010 09:55
On Mar 4, 12:37 am, Oliver Kellogg <okell...(a)users.sourceforge.net>
wrote:
> Referring back tohttp://groups.google.com/group/comp.lang.ada/msg/c14a79f7d21f5ebf,
>
> Hello CLA,
>
> How come child packages are only possible for library level packages?
>
> I now encountered a situation where I'd like to create a child
> package of a nested package:
>
> -- file: pkg.ads
> package Pkg is
> package Nested is
> type Object is tagged null record;
> end Nested;
> end Pkg;
>
> -- file: pkg-nested-child.ads
> package Pkg.Nested.Child is
> type Derived is new Object with null record;
> end Pkg.Nested.Child;

I can't tell you *why* that's not allowed, but your supposition about
additional work for the compiler makes sense. In this case, would the
following work for you?:

-- file: nested_child.ads
with Pkg; use Pkg;
use Pkg.Nested;

package Nested_Child is
type Derived is new Object with null record;
end Nested_Child;
From: Adam Beneschan on 4 Mar 2010 11:12
On Mar 3, 9:37 pm, Oliver Kellogg <okell...(a)users.sourceforge.net>
wrote:
> Referring back tohttp://groups.google.com/group/comp.lang.ada/msg/c14a79f7d21f5ebf,
>
> On Mar 29 2002, 2:05 pm, Oliver Kellogg wrote:
>
> > Sergey Koshcheyev <serk...(a)hotmail.com> wrote:
> > > Just a quick idea - maybe using "is separate" in some right places
> > > would solve it? Like having the spec of A.B.Impl inside A.B, and
> > > having the body separate.
>
> > That's definitely possible, but still only a workaround solution.
>
> I have to correct myself. It's not so definitely possible:
>
> -- file: a.ads
> package A is  -- module A
>    package B is     -- interface B
>       package Impl is
>          procedure X;
>       end Impl;
>    end B;
> end A;
>
> -- file: a.adb
> package body A is
>    package body B is
>       -- Implementation for interface B,
>       -- body to be provided by user
>       package body Impl is separate;
>    end B;
> end A;
>
> $ gcc -c a.adb
> a.adb:6:07: stub cannot appear in an inner scope

You can do it if you make B separate:

package body A is
package body B is separate;
end A;

separate(A)
package body B is
package body Impl is separate;
end B;

I'm not really familiar with the original problem so I don't know
whether this helps you any.

-- Adam
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