comp.lang.ada
 help / color / mirror / Atom feed
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Constructors with multiple inheritance
Date: Fri, 30 Sep 2011 09:36:20 +0200
Date: 2011-09-30T09:36:20+02:00	[thread overview]
Message-ID: <2pu3h5hqltxi$.ze4yrf1f2y8z.dlg@40tude.net> (raw)
In-Reply-To: 4976045.4489.1317352313370.JavaMail.geo-discussion-forums@yqjw35

On Thu, 29 Sep 2011 20:11:53 -0700 (PDT), Rego, P. wrote:

>> This is equivalent to:
>> 
>>     Obj := Construct (Obj.all);
>> 
>> But Obj is null.

> Yes, I agree. But that's the point. I want to reserve the address (so I
> can build my queues from there).

The problem is not the result, but the argument of Construct.

>>> So, how can I fix this?
>> 
>> I don't understand your design, but a constructing function of a
>> non-limited type is just:
>> 
>>    function Construct return Parent_Class;

> It works (and the current code utilizes this approach), but I cannot name
> it a method,

"method" is not an Ada term, but from the OO point of view Construct is a
method, because it is covariant in the result.

> since I cannot call the funtion from inside the class, using
> something like Object.Method.

X.Op is just a syntactic sugar for Op (X). It has nothing to do with an
operation being a method or not, except that in Ada the sugar is allowed
only for certain types of methods, rather than universally.

(The operation Op is a method of the type T in one of its arguments or the
result, when the type of that argument or result is T and Op is covariant
in it.)

> So I need to fix the
> package.function_constructor call and use a call of type
> object.method_constructor.

Why?

What is wrong with the abstract factory pattern?

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



  reply	other threads:[~2011-09-30  7:35 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-29 19:40 Constructors with multiple inheritance Rego, P.
2011-09-29 20:20 ` Dmitry A. Kazakov
2011-09-30  3:11   ` Rego, P.
2011-09-30  7:36     ` Dmitry A. Kazakov [this message]
2011-09-30 14:04       ` Rego, P.
2011-09-30 16:29         ` Robert A Duff
2011-09-30 19:14           ` Rego, P.
2011-09-30 16:42         ` Dmitry A. Kazakov
2011-09-30 19:42           ` Rego, P.
2011-10-06 12:46             ` Julian Leyh
2011-11-09  2:24           ` Rego, P.
2011-11-09  8:39             ` Dmitry A. Kazakov
2011-11-10  3:47               ` Rego, P.
2011-11-10  7:09                 ` AdaMagica
2011-11-10  7:20                   ` AdaMagica
2011-11-10  8:35                   ` Dmitry A. Kazakov
2011-11-12 15:16                     ` Rego, P.
2011-11-12 15:30                   ` Rego, P.
2011-11-12 16:28                     ` Dmitry A. Kazakov
2011-11-12 17:41                       ` Rego, P.
2011-11-10  8:33                 ` Simon Wright
2011-11-10  9:01                 ` Georg Bauhaus
2011-11-10  9:09                   ` Georg Bauhaus
2011-11-10 18:16                 ` Jeffrey Carter
2011-11-10 19:39                   ` Dmitry A. Kazakov
2011-11-09  9:00             ` Simon Wright
2011-11-10  3:54               ` Rego, P.
2011-10-07  0:08 ` Shark8
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox