Re: Are there noticable differences in Ada acceptance by country?

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

> gpriv@[EMAIL PROTECTED]
 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