From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Generic Library Units?
Date: Wed, 15 Oct 2014 09:21:06 +0200
Date: 2014-10-15T09:21:06+02:00 [thread overview]
Message-ID: <1e3dumb4ql0xb$.1reo7fz5y3vyl.dlg@40tude.net> (raw)
In-Reply-To: ca5teuFqcvkU1@mid.individual.net
On Tue, 14 Oct 2014 21:29:16 -0300, hreba wrote:
> On 10/13/2014 04:45 AM, Dmitry A. Kazakov wrote:
>>
>> with Gui;
>> with GuiGtk.SimpleGad;
>> with Gui.SimpleGad;
>> package MainAux is
>> package Toolkit is new GuiGtk;
>> package SimpleGad is new Toolkit.SimpleGad;
>> package GuiTK is new Gui (Toolkit, SimpleGad);
>> end MainAux;
>>
> Ok, did that too, and the error message disappeared.
>
> Now in the package body of Gui.SimpleGad I have
>
> function Get (gad: BoolGadget) return boolean is
> begin
> return TKSG.GetBool (gad.widget.all);
> end Get;
>
> and get the error message
>
> gui-simplegad.adb:78:39: expected type "GuiGtk.GadWidgets" defined at
> guigtk.ads:38
> gui-simplegad.adb:78:39: found type "TK.GadWidgets" defined at
> guigtk.ads:38, instance at gui.ads:10
>
> So the compiler isn't aware that GuiGtk is the actual value to the
> formal package TK. How do I tell him?
You can't. GuiGtk is a generic package. It cannot be actual of anything.
Actuals are *real* things. E.g. an instance of a generic package can be
actual of a formal package.
> ( The Gui package header is
>
> generic
> with package TK is new GuiGtk(<>); -- this is gui.ads:10
> with package TKSG is new GuiGtk.SimpleGad;
> package Gui is
> ...
> )
Which has nothing to do with GuiGtk and GuiGtk.SimpleGad. Generic packages
know nothing about any instances of. That is the basic idea of being
"generic".
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2014-10-15 7:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-12 14:38 Generic Library Units? hreba
2014-10-12 15:47 ` Dmitry A. Kazakov
2014-10-12 22:39 ` hreba
2014-10-13 7:45 ` Dmitry A. Kazakov
2014-10-15 0:29 ` hreba
2014-10-15 7:21 ` Dmitry A. Kazakov [this message]
2014-10-16 1:21 ` hreba
2014-10-16 7:04 ` Dmitry A. Kazakov
2014-10-16 7:54 ` Simon Wright
2014-10-17 12:46 ` hreba
2014-10-16 10:36 ` AdaMagica
2014-10-17 12:57 ` hreba
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