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From: "markww" <markww@gmail.com>
Subject: Re: how to import a package
Date: 10 Dec 2006 22:16:00 -0800
Date: 2006-12-10T22:16:00-08:00	[thread overview]
Message-ID: <1165817760.736164.218530@73g2000cwn.googlegroups.com> (raw)
In-Reply-To: <7ft8le.vk1.ln@hunter.axlog.fr>

Ok I still don't understand why this assignment is illegal though -
here's a test I have:

    generic
        type T is private;
    package GenericNode is
        type Node;
        type Node_Ptr is access Node;
        type Node is record
            Data     : T;           -- the generic data we want to
store in a node.
            Prev_Rec : access Node_Ptr; -- points to the next record or
null if none exists.
            Next_Rec : access Node_Ptr; -- points to the previous
record or null if none exists.
        end record;
    end GenericNode;

now later...

    package gNode is new GenericNode(T => PERSON_REC);
    use gNode;

    function Test(whatever : INTEGER) return INTEGER is
    Temp : gNode.Node_Ptr;
    begin
        Temp := Temp.Next_Rec; -- no!!!!!!!!!!!!!!!!
        return 0;
    end Test;

Why is the Temp assignment not possible? The compiler says: expected
type Node_Ptr defined in genericnode.ads. But I have defined it as type
Node_Ptr.

Thanks,
Mark



Jean-Pierre Rosen wrote:
> Stuart a écrit :
> >    package body P is
> >       type T is array(0..5) of integer;
> >       A, B : array(0..5) of integer;
> >       C, D : T;
> >    begin
> >       A := B;
> >       -- Not allowed because types don't match!
> >       C := D;
> >       -- Types match!
> >    end P;
> >
> > [...]
> > However, both C and D are of the same named type - even though the type T
> > has an anonymous type as an index range.  I think it is better to avoid
> > anonymous types - so the declaration of T might be better written as:
> >       type T_index is range 0..5;
> >       type T is array(T_index) of integer;
> >
> Just nit-picking, the index type of T is not anonymous, it is
> Standard.Integer by default, therefore the aboved declaration is not
> equivalent.
>
> Agreed, it is best to avoid hidden use of Standard.Integer. If you need
> Integer as the index type, better use:
> type T is array (Integer range 0..5) of Integer;
>
> Note that this remark is also applicable to loops. Rather than:
> for I in 1..10 loop
>
> write:
> for I in Integer range 1..10 loop
>
> (small plug: there is a rule in AdaControl to check the above)
> --
> ---------------------------------------------------------
>             J-P. Rosen (rosen@adalog.fr)
> Visit Adalog's web site at http://www.adalog.fr




  reply	other threads:[~2006-12-11  6:16 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-06  2:14 how to import a package markww
2006-12-06  3:06 ` Adam Beneschan
2006-12-06  3:34   ` markww
2006-12-06  9:18     ` Simon Wright
2006-12-06 19:47 ` Jeffrey R. Carter
2006-12-06 23:56   ` markww
2006-12-07  1:18     ` Björn Persson
2006-12-07  1:26     ` Brian May
2006-12-07  4:14       ` markww
2006-12-07  4:40         ` Brian May
2006-12-07  9:32           ` Stuart
2006-12-07 11:21             ` Jean-Pierre Rosen
2006-12-11  6:16               ` markww [this message]
2006-12-11  6:50                 ` markww
2006-12-11  9:40                   ` Georg Bauhaus
2006-12-11 14:19                     ` markww
2006-12-11 15:03                       ` Dmitry A. Kazakov
2006-12-11 16:22                       ` Adam Beneschan
2006-12-11 20:28                       ` Jeffrey R. Carter
2006-12-12  3:19                         ` markww
2006-12-12  3:31                           ` Jeffrey R. Carter
2006-12-12  9:03                           ` Stuart
2006-12-12 10:56                           ` Georg Bauhaus
2006-12-11  7:00                 ` Simon Wright
2006-12-07  4:06     ` Jeffrey R. Carter
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