From: bruniau@cenatls.cena.dgac.fr (Christophe Bruniau)
Subject: Re: Ada 9X _has_ "class"
Date: Thu, 25 Mar 1993 10:27:30 GMT
Date: 1993-03-25T10:27:30+00:00 [thread overview]
Message-ID: <1993Mar25.102730.10202@cenatls.cena.dgac.fr> (raw)
In-Reply-To: 1993Mar24.164424@lglsun.epfl.ch
In article <1993Mar24.164424@lglsun.epfl.ch>, magnus@lglsun.epfl.ch (Magnus Kempe) writes:
|> jgg@evb.com (John Goodsen) quotes a lot and writes:
|> :
|> : The 'CLASS attribute is not what you will see in marketing literature.
|> : What you will see in Marketing literature is "tagged types".
|>
|> I have seen a lot of marketing literature touting "inheritance" and
|> "polymorphism", although the programming languages involved did not have
|> such keywords. In addition, I have never seen any ad revolving around
|> "int" for C, "VAR" for Pascal, or "!" for PROLOG.
|>
...
|> The primary goal w.r.t. Ada's syntax is to have a readable and
|> understandable language. It has been explained several times that Ada
|> 9X provides both specific types and classes (a set of related types).
|> These constructs are _so_ different that they should each be subsumed
|> by a specific concept, and these concepts should not be randomly
|> mixed.
|>
|> Since a specific type is _not_ a class, it is quite reasonable to _not_
|> call it a "class". If you think the distinction does not matter, or is
|> "merely technical", think twice. A tagged type T is _not_ a class: it
|> is _in_ a class (T'class) as well as in the superclasses of T'class
|> (e.g. T_First'class).
|>
If find this quite amazing (if not disturbing).
What does an instance of a class look like ?
It seems to me that, in order to agree with the object paradigm,
a class instance should be an object. I don't think this is true in
that case, if a class is some kind of a type set.
|> --
|> Magnus Kempe "No nation was ever drunk when wine was cheap."
|> magnus@lglsun.epfl.ch -- Thomas Jefferson
Christophe BRUNIAU bruniau@cenatls.cena.dgac.fr
next prev parent reply other threads:[~1993-03-25 10:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
1993-03-19 21:34 Ada 9X _has_ "class" John Goodsen
1993-03-24 16:16 ` Magnus Kempe
1993-03-25 10:27 ` Christophe Bruniau [this message]
1993-03-29 7:11 ` Magnus Kempe
-- strict thread matches above, loose matches on Subject: below --
1993-03-18 17:34 Magnus Kempe
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