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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Ada is getting more popular!
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Date: Sun, 31 Oct 2010 11:54:22 +0100
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Date: 2010-10-31T11:54:24+01:00
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On Sun, 31 Oct 2010 11:38:02 +0100, J-P. Rosen wrote:

> FWIW, here are my criteria for using inheritance:
> 1) you have several types, that are too different to be modelled as
> variations of a single type (use discriminated types otherwise);
> 2) however, these types have some common logical properties, with
> different implementations
> 3) you have to maintain an heterogenous container of these various types
> 4) you want to call the common operations on all objects in the container

5) you want to postpone some design decision/implementation to a later
point. So you describe/implement what you know for certain right now, in
the form of an abstract type, and let a derived type to define the rest
when more information becomes available.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de