Re: friend classes in ada95

["Pascal Obry" <p.obry@der.edf.fr>]

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Jean-Pierre Rosen <rosen.adalog@wanadoo.fr> a �crit dans le message :
8dh37m$qef$2@wanadoo.fr...
> Can't resist to provide my 0.02 on the tagged/class issue, or how I
present
> it in my courses.
>
> A tagged type is not a class. A tagged type is a programming construct
that
> can be used to build classes. This is what the building block approach is
> about.
> A class in the usual OOP sense is a *design pattern*, where you put a
tagged
> type and its associated primitive operations (the methods) in a package
> specification. Ada allows you to build other design patterns, that have no
> equivalent in other languages, like putting several tagged types in a
single
> package (a bit like friends, but not exactly similar).
>

I completly agree with this view. The whole point is "building block" and
this
is how Ada has been design. Then designer can use the flexibility of Ada
to build whatever "design pattern" they need, one of them is the C++ or
Java "class".

This "building block" orientation of Ada has been very well presented by T.
Taft
at a conference in Paris some years ago.

Pascal.

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