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From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: operation can be dispatching in only one type
Date: Tue, 24 Nov 2015 22:25:39 +0200
Organization: Tidorum Ltd
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Xref: news.eternal-september.org comp.lang.ada:28528
Date: 2015-11-24T22:25:39+02:00
List-Id: <comp.lang.ada>

On 15-11-24 19:09 , Jeffrey R. Carter wrote:

> Note that the Ada construct that most closely matches a "class" is a protected type.

Huh? What have mutual exclusion and interrupt-handling to do with "class"?

Ok, some languages have "synchronized" classes, mixing the two concepts.

Perhaps you mean that there is a syntactic resemblance, in that the 
operations and data of a protected type are indeed enclosed in dedicated 
"is" .. "end" brackets?

> The only thing you *need* tagged types for in Ada is finalization.

Tagged types and finalization are never "needed" in the Turing sense :-)

I find that tagged types are a huge help in decoupling dependencies 
between packages. The root type (and 'Class type) can often have many 
fewer dependencies than the child types, greatly helping to localize 
cross-package dependencies. YMMV of course.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .