Combining packages

Combining packages

[Preben Randhol]

Hi

I have made a generic package called Double_Linked_List. I have also a
package called Wordgroups which has the type Wordgroup and several
functions/procedures connected with the type.

Now I want to have a List of Wordgroups. 

First I made a child package Wordgroups.List of the Wordgroups pacakge
like this:

with Double_Linked_List;
with Wordgroups;

   package Wordgroups.List is
         new Double_Linked_List (Data_Type => Wordgroups.Wordgroup_Type);


Now I relized that it would be nice to have a procedure like:

   procedure Add (List        : in out  List_Type;
                  Word        : in      String;
                  Explanation : in      String) is

      Wordgroup : Wordgroup_Type;

   begin
      Create (Wordgroup, Word, Explanation);
      Append_Element (List, Wordgroup);
   end Add;

so that I don't have to do:

   Create (Wordgroup, Word, Explanation);
   Append_Element (List, Wordgroup);

in the rest of the program, only Add.

But I cannot add this to Wordgroups.List.

I would appreciate some hints on how to do something like this. Thanks
in advance.

Preben Randhol
-- 
�.., chaos is found in greatest abundance wherever order is being
sought. It always defeats order, because it is better organized.�
                            -- Interesting Times, Terry Pratchett

Re: Combining packages

[Matthew Heaney]

"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrn9u0jr0.5nn.randhol+abuse@kiuk0156.chembio.ntnu.no...
> But I cannot add this to Wordgroups.List.

If you mean you can't make Add a child of Wordgroups.List, that's true.  But
what's wrong with simply making Add a child of Wordgroups?

Re: Combining packages

[Preben Randhol]

On Wed, 31 Oct 2001 13:31:47 -0500, Matthew Heaney wrote:
> 
> "Preben Randhol" <randhol+abuse@pvv.org> wrote in message
> news:slrn9u0jr0.5nn.randhol+abuse@kiuk0156.chembio.ntnu.no...
>> But I cannot add this to Wordgroups.List.
> 
> If you mean you can't make Add a child of Wordgroups.List, that's true.  But
> what's wrong with simply making Add a child of Wordgroups?

you mean put the Add procedure in another child package?

Preben

Re: Combining packages

[Matthew Heaney]

"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrn9u0rij.du.randhol+abuse@kiuk0156.chembio.ntnu.no...
> you mean put the Add procedure in another child package?

No.  I mean make the procedure itself a child:

procedure Workgroups.Add (...);

Child units can be packages or subprograms, and they can be either public or
private.  In fact, creating a child subprogram is the intended way to extend
an abstraction without having to resort to inheritance.

Re: Combining packages

[Preben Randhol]

On Wed, 31 Oct 2001 15:41:13 -0500, Matthew Heaney wrote:
> 
> "Preben Randhol" <randhol+abuse@pvv.org> wrote in message
> news:slrn9u0rij.du.randhol+abuse@kiuk0156.chembio.ntnu.no...
>> you mean put the Add procedure in another child package?
> 
> No.  I mean make the procedure itself a child:
> 
> procedure Workgroups.Add (...);
> 
> Child units can be packages or subprograms, and they can be either public or
> private.  In fact, creating a child subprogram is the intended way to extend
> an abstraction without having to resort to inheritance.

Ah. Thanks. Didn't know you could do that.

Preben
-- 
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