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Newsgroups: comp.lang.ada
Subject: Re: Using Ada for device drivers? (Was: the Ada mandate, and why
 it collapsed and died)
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Xref: archiver1.google.com comp.lang.ada:37310
Date: 2003-05-14T05:00:12+00:00
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Stephen Leake wrote:

> Ok. But now you are in the solution space, not the problem space :).
> Even professors get to be a little inconsistent :). 
> Perhaps you should write: 
> function Mod (I : in Card_Index_Type) return Card_Index_Type;
> which does what you want.

First of all I would have to define:

    function "Mod" (I : Card_Index_Type) return Card_Index_Type;

But I found the existing "mod" operator to be perfectly fine.  However, 
what you are missing is the deeper truth that for enties that have this 
sort of behavior are best represented as modular types.  If I had been 
able to write the program in Ada 95--this was written while working on 
the Ada 9X standard--I could have written:

type Card_Index_Type is mod 52;

Deck: array (Card_Index_Type) of Card;

Would that make you happier?