Re: Ada2005 temp solo child

Re: Ada2005 temp solo child

[ica2ph]

In article <mailman.1031907902.8367.comp.lang.ada@ada.eu.org> you wrote:
>> While developing an application, I have e.g. a parent.child
>> but not yet a parent package, which may or may come later.
>> Now my compiler forces me to have the parent.
>> I would prefer the ada standard would force the compiler
>> to allow parentless children.
>> Did I ignore some important aspect?

> I do not know, but the request seems silly to me. Why is it so disturbing to create a 
> dummy parent, which is still empty. It has to be created anyway eventually, so 
> why not just now? If there will never be a parent, why have the hierarchy at 
> all?

Haetten Sie meine Anfrage genau durchgelesen,
dann haetten Sie mich nicht gleich beleidigen muessen.

-- 
--Peter Hermann(49)0711-685-3611 fax3758 ica2ph@csv.ica.uni-stuttgart.de
--Pfaffenwaldring 27 Raum 114, D-70569 Stuttgart Uni Computeranwendungen
--http://www.csv.ica.uni-stuttgart.de/homes/ph/
--Team Ada: "C'mon people let the world begin" (Paul McCartney)

Re: Ada2005 temp solo child

[Preben Randhol]

On Fri, 13 Sep 2002 12:24:47 +0200 (MDT),
<ica2ph@csv.ica.uni-stuttgart.de> wrote:

> Haetten Sie meine Anfrage genau durchgelesen, dann haetten Sie mich
> nicht gleich beleidigen muessen.

But if you have a parentless child, why isn't the child then the parent?

Preben

Re: Ada2005 temp solo child

[Peter Hermann]

Preben Randhol <randhol+abuse@pvv.org> wrote:
> But if you have a parentless child, why isn't the child then the parent?

because of a couple of practical aspects:
o  hierarchical grouping (similar to ada.text_io instead of text_io)
o  order of development of the source code
o  parent becoming superfluous in higher versions
o  the concept of far reaching independence of a child is charming, anyway.

-- 
--Peter Hermann(49)0711-685-3611 fax3758 ica2ph@csv.ica.uni-stuttgart.de
--Pfaffenwaldring 27 Raum 114, D-70569 Stuttgart Uni Computeranwendungen
--http://www.csv.ica.uni-stuttgart.de/homes/ph/
--Team Ada: "C'mon people let the world begin" (Paul McCartney)

Re: Ada2005 temp solo child

[Dr. Michael Paus]

Peter Hermann wrote:
> Preben Randhol <randhol+abuse@pvv.org> wrote:
> 
>>But if you have a parentless child, why isn't the child then the parent?
> 
> 
> because of a couple of practical aspects:
> o  hierarchical grouping (similar to ada.text_io instead of text_io)
> o  order of development of the source code
> o  parent becoming superfluous in higher versions
> o  the concept of far reaching independence of a child is charming, anyway.
> 
One might even add that this is common practice in Java for example (where the
problem described here does not exist) to make package names globally unique.
All my packages are child packages of a hierarchy starting at "de.ibpaus" and
these packages are actually empty. Its just Ada which forces me to write two
empty dummy packages to satisfy the compiler.

Michael

Re: Ada2005 temp solo child

[Preben Randhol]

On Fri, 13 Sep 2002 15:50:39 +0200, Dr. Michael Paus wrote:
> One might even add that this is common practice in Java for example (where the
> problem described here does not exist) to make package names globally unique.
> All my packages are child packages of a hierarchy starting at "de.ibpaus" and
> these packages are actually empty. Its just Ada which forces me to write two
> empty dummy packages to satisfy the compiler.
                                      ^^^^^^^^
                                      language ?

Well this makes more sense to me at least. Or you could flip the coin
and say that the compiler must compile two dummy files to satisfy you
;-)

Preben

Re: Ada2005 temp solo child

[Robert A Duff]

Preben Randhol <randhol+abuse@pvv.org> writes:

> But if you have a parentless child, why isn't the child then the parent?

Because it has siblings.  You can't make them *all* be the parent.

- Bob

Re: Ada2005 temp solo child

[Preben Randhol]

On Fri, 13 Sep 2002 16:06:19 GMT, Robert A Duff wrote:
> Preben Randhol <randhol+abuse@pvv.org> writes:
> 
>> But if you have a parentless child, why isn't the child then the parent?
> 
> Because it has siblings.  You can't make them *all* be the parent.

Well then you can simply do a:

package Superparent is

   Pragma Pure (Superparent);

end Superparent;

can't you?

Preben

Re: Ada2005 temp solo child

[Stephen Leake]

Peter Hermann <ica2ph@iris16.csv.ica.uni-stuttgart.de> writes:

> Preben Randhol <randhol+abuse@pvv.org> wrote:
> > But if you have a parentless child, why isn't the child then the parent?
> 
> because of a couple of practical aspects:
> o  hierarchical grouping (similar to ada.text_io instead of text_io)

That's what empty parent packages are for. It's only three lines of code!

-- 
-- Stephe

Re: Ada2005 temp solo child

[Randy Brukardt]

Dr. Michael Paus wrote in message ...
>One might even add that this is common practice in Java for example
(where the
>problem described here does not exist) to make package names globally
unique.
>All my packages are child packages of a hierarchy starting at
"de.ibpaus" and
>these packages are actually empty. Its just Ada which forces me to
write two
>empty dummy packages to satisfy the compiler.


Why would you expect otherwise? The compiler has to look for the
declarations in the parent (in order to determine if the child name is
legal). Ada makes you declare almost everything before use. Why would
this case be different? It doesn't feel much different to me than
saying:

    Int := 10;

and complaining that the compiler shouldn't need a declaration of Int.

               Randy.

Re: Ada2005 temp solo child

[Grein, Christoph]

From: ica2ph@csv.ica.uni-stuttgart.de
> 
> In article <mailman.1031907902.8367.comp.lang.ada@ada.eu.org> you wrote:
> >> While developing an application, I have e.g. a parent.child
> >> but not yet a parent package, which may or may come later.
> >> Now my compiler forces me to have the parent.
> >> I would prefer the ada standard would force the compiler
> >> to allow parentless children.
> >> Did I ignore some important aspect?
> 
> > I do not know, but the request seems silly to me. Why is it so disturbing to 
create a 
> > dummy parent, which is still empty. It has to be created anyway eventually, 
so 
> > why not just now? If there will never be a parent, why have the hierarchy at 
> > all?
> 
> Haetten Sie meine Anfrage genau durchgelesen,
> dann haetten Sie mich nicht gleich beleidigen muessen.

Entschuldigen Sie bitte meine saloppe Ausdrucksweise - das war nicht als 
Beleidigung gedacht. Silly als Übersetzung von unsinnig, nicht blödsinnig... 
Nonesensical wäre vielleicht besser gewesen.

Trotzdem, mein Einwand bleibt bestehen. In meinen Augen macht dieser Vorschlag 
wirklich keinen Sinn.

Mit freundlichen Grüßen
Christoph Grein

Re: Ada2005 temp solo child

[Grein, Christoph]

> ... The compiler has to look for the
> declarations in the parent (in order to determine if the child name is
> legal). Ada makes you declare almost everything before use. Why would
> this case be different? It doesn't feel much different to me than
> saying:
> 
>     Int := 10;
> 
> and complaining that the compiler shouldn't need a declaration of Int.

Another point to consider:

Ada95 removed unneeded library bodies. They were a source of problems when the 
spec was recompiled and the body forgotten.

Your proposal would add a new source of errors of this kind. Imagine there is a 
parent that is somehow lost. The compiler would not know that there should be a 
parent.

> That's what empty parent packages are for. It's only three lines of code!

So where is the problem in declaring empty packages?

Re: Ada2005 temp solo child

[Peter Hermann]

Grein, Christoph <christoph.grein@eurocopter.com> wrote:
> Ada95 removed unneeded library bodies.
> They were a source of problems when the
> spec was recompiled and the body forgotten.
> Your proposal would add a new source of errors of this kind.

I am afraid the arguments for existing parents are stronger   ;-)
Let us hope for more input of the quality of all previous posters.

ps.: apologies for my e-mail-address error: it's ok.

-- 
--Peter Hermann(49)0711-685-3611 fax3758 ica2ph@csv.ica.uni-stuttgart.de
--Pfaffenwaldring 27 Raum 114, D-70569 Stuttgart Uni Computeranwendungen
--http://www.csv.ica.uni-stuttgart.de/homes/ph/
--Team Ada: "C'mon people let the world begin" (Paul McCartney)