Re: Reprise: 'in out' parameters for functions

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

Wojtek Narczynski wrote:

>>> You silently refused to say what abstraction inversion is according
>>> to you :-)
> 
>> We can use your definition if you want. (:-))
> 
> My impression was that, according to you, mine was wrong. Certainly, I
> would prefer to use the right one.

I did not disagree with your definition. I did with your statement that
Ada's protected objects are wrong way. They might have problems, though.
But it appeared, as you treating them as completely wrong.

>>> Then we're talking about two distinct things. I am talking about a
>>> compile time solution only.
>  
>> Why should they be distinct?
> 
> Checking physical units statically would be helpful for high integrity
> software. I don't see any practical use for runtime unit checks.

Only because I see no smiley... How would you implement:

procedure Put (Stream : File, Value : Measurement);
procedure Get (Stream : File, Value : out Measurement);

For example, a requirement of one of our customer was to have a button in
his MMI to switch between European and American units in all visual
elements and printouts. Now go, figure out, how would you solve that using
templates. BTW, European /= SI, because of km/h, ps, Celsius degree etc.
Not to forget dozens of external devices all working with units of their
own, all need to be hot pluggable etc.

>> I didn't say that (2) is not solvable. I just invited you to think about
>> it more deeply, before making some final statements.
> 
> It is unclear to me what final statements you are referring to.

That Ada exception model should be replaced by some other.
 
-- 
Regards,
Dmitry A. Kazakov
www.dmitry-kazakov.de