Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!samsung!crackers!jjmhome!smds!rh
From: rh@smds.UUCP (Richard Harter)
Newsgroups: comp.software-eng
Subject: Re: recap so far
Summary: layering, decomposition, pluses and minuses
Message-ID: <116@smds.UUCP>
Date: 16 Jul 90 08:34:52 GMT
References: <268462df> <39400111@m.cs.uiuc.edu> <114@smds.UUCP> <269b7b9d.5643@petunia.CalPoly.EDU>
Organization: SMDS Inc., Concord, MA
Lines: 30

In article <269b7b9d.5643@petunia.CalPoly.EDU>, jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) writes:

> What you call the "layering effect" is a negative aspect of what is the
> otherwise highly desirable goal of decomposition of a problem into
> cohesive, loosely-coupled chunks.  The more we can increase the
> independence, generality, and ultimately the reusability of our code,
> the more advantages we gain in terms of programmer efficiency on the
> long term, maintainability, etc.  On the other hand, each layer of
> abstraction involves adding a layer of indirection to the code.

One can scarcely argue with your list of goals.  However the whole matter
is not exactly as simple as it seems.  Barring the occasional circumstance
where one is "programming down to the bare iron" we are using packages and
facilities that are pre-existent all of the time.  We use OS calls and
facilities.  We write in languages that are compiled and interpreted.  We
use routines from libraries (and pre-defined classes, etc.)  None of these
facilities and abstractions were created with our particular problems in
mind.  Sometimes the fit is good; sometimes people create the most Godawful
kludges using off the shelf components.

I guess all that says that is that people can write bad programs regardless
of the languages and tools available.  However I would like to make the
point that efficiency and "good programming" are not antonyms.  One can
usually have your cake and eat it too.  The only problem is that there is
a price for doing it.
-- 
Richard Harter, Software Maintenance and Development Systems, Inc.
Net address: jjmhome!smds!rh Phone: 508-369-7398 
US Mail: SMDS Inc., PO Box 555, Concord MA 01742
This sentence no verb.  This sentence short.  This signature done.