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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Are there noticable differences in Ada acceptance by country?
Date: Thu, 20 Mar 2008 21:48:14 +0100
Date: 2008-03-20T21:48:16+01:00	[thread overview]
Message-ID: <1kv438li1fcvq.ox99qnglkog5.dlg@40tude.net> (raw)
In-Reply-To: m2eja5cfi9.fsf@mac.com

On Thu, 20 Mar 2008 20:22:22 +0000, Simon Wright wrote:

> gpriv@axonx.com writes:
> 
>> I think strong typing should not be dismissed.  Unfortunately Java-
>> based (and C/C++/C#) courses don't explain to students that X and Y
>> coordinates being fundamentally integer (or float) types are not the
>> same thing.
> 
> I always disliked an X binding which had (sub)types for X, Y
> coordinates. Wrong level of abstraction, I thought: use something like
> 
>    type Position is record
>       X : Float;
>       Y : Float;
>    end record;
> 
> and you get a _lot_ less scope for confusion.

If no rotations involved I would suggest:

   type Horizontal_Coordinate is new Float;
   type Vertical_Coordinate is new Float;
   type Position is record
       X : Horizontal_Coordinate;
       Y : Vertical_Coordinate;
   end record;

In some cases I would consider making absolute positions and relative
offsets different types, similar to Time and Duration.

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



  reply	other threads:[~2008-03-20 20:48 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-18 19:08 Are there noticable differences in Ada acceptance by country? Mike Silva
2008-03-18 20:41 ` Pascal Obry
2008-03-18 22:58   ` Phaedrus
2008-03-18 22:25     ` Mike Silva
2008-03-18 22:50 ` Ludovic Brenta
2008-03-19 11:42   ` Thomas
2008-03-19 12:09     ` Ludovic Brenta
2008-03-19 12:51       ` framefritti
2008-03-20  4:37         ` gpriv
2008-03-19 12:16     ` Ludovic Brenta
2008-03-19 19:04       ` Tero Koskinen
2008-03-20  8:57         ` Jean-Pierre Rosen
2008-03-25 18:02           ` Tero Koskinen
2008-03-25 19:57             ` Gautier
2008-03-19 19:55     ` svaa
2008-03-19 21:14       ` Phaedrus
2008-03-20  4:52         ` gpriv
2008-03-20 20:22           ` Simon Wright
2008-03-20 20:48             ` Dmitry A. Kazakov [this message]
2008-03-20 22:17               ` Simon Wright
2008-03-20 22:59                 ` gpriv
2008-03-21  1:54                   ` tmoran
2008-03-21  4:16                   ` Jeffrey R. Carter
2008-03-21 16:41                     ` Simon Wright
2008-03-21 19:15                     ` gpriv
2008-03-22 14:00                       ` Maciej Sobczak
2008-03-21 16:39                   ` Simon Wright
2008-03-21 19:21                     ` gpriv
2008-03-21 21:11                       ` Adam Beneschan
2008-03-22  7:02                         ` Simon Wright
2008-03-24 18:01                           ` gpriv
2008-03-21  7:52                 ` Dmitry A. Kazakov
2008-03-22 17:16                   ` Subtypes to represent coordinate charts Eric Hughes
2008-03-21 16:44                 ` Are there noticable differences in Ada acceptance by country? Simon Wright
2008-03-20 21:17             ` gpriv
2008-03-20  1:34       ` Ivan Levashew
2008-03-19  7:42 ` Thomas
2008-03-19 10:35   ` Peter C. Chapin
2008-03-19 21:21     ` Phaedrus
     [not found]       ` <13u3vq728nidu3b@corp.supernews.com>
2008-03-31  4:27         ` David Thompson
2008-03-31  5:40           ` DScott
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