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From: lgm@cbnewsc.att.com (lawrence.g.mayka)
Newsgroups: comp.object
Subject: Re: the need for classes as objects
Message-ID: <1990Aug30.010912.6146@cbnewsc.att.com>
Date: 30 Aug 90 01:09:12 GMT
References: <2259@esquire.UUCP>
Organization: AT&T Bell Laboratories
Lines: 24

In article <2259@esquire.UUCP> yost@esquire.UUCP (David A. Yost) writes:
>support it?  I'm sure dynamic classes must
>make development environments better, but I'm
>particularly interested in examples not
>related to issues of the development
>environment.

Consider a service embracing 1000 offered features, which can be
requested individually or in any combination.  The total number of
service behaviors is therefore (EXPT 2 1000), or 2**1000 in Fortran.
Each feature is fundamentally a protocol and hence neatly expressible
as a class.  Each service behavior is then neatly expressible as a
subclass inheriting from the appropriate features.  It may not be
practical, however, to define a priori all (EXPT 2 1000) service
classes.  The alternative is to define each unique service class only
when actually needed (i.e., requested by a customer) and not before.
This requires dynamic class definition.


	Lawrence G. Mayka
	AT&T Bell Laboratories
	lgm@iexist.att.com

Standard disclaimer.