Definition of "property"

[Alan Gauld]

On 31/05/2021 15:59, Dennis Lee Bieber wrote:
> On Sun, 30 May 2021 21:20:24 +0100, Alan Gauld via Python-list
> <python-list at python.org> declaimed the following:
> 
>> On 30/05/2021 17:57, Irv Kalb wrote:
>>> I am doing some writing (for an upcoming book on OOP), and I'm a little stuck.  
>>
>> Oh dear, that's one of myt hot buttons I'm afraid!
>> I hope it really is about OOP and not about classes. Classes
>> are such a minor part of OOP that it is depressing how many

> 	To me, OOP tends to be language specific... 

OOP is supposed to be a programming paradigm in the same way that
Functional or Logic programming are paradigms. Its all about
how you organise your code. It should be based on message
passing between autonomous agents(objects). Classes etc are
language constructs aimed at making OOP easier, but they
are not OOP. It's very easy to build a class/object based
program that is not in any way OOP (in fact I'd go as far
as to say the majority of such programs today come into
that category). It's also possible (but difficult!)
to build an OOP program without classes.

Incidentally, I'm not arguing that classes should not be used
in imperative programming, they can be very powerful there
too. Just that using classes is not necessarily OOP.

> Finding books on OOAD -- which should be language agnostic -- is 
> more difficult, and tend to turn into books about how to use 
> UML rather than how to analyze/design using OO.

That's a fairly modern phenomenon. Most of the early books about
OOAD were language agnostic - even when they used a language for
demonstration purposes.

Books like Grady Booch's classic OOAD, or Peter Coad's series
with Ed Yourdon. The so-called method wars. They all had their own
methodology, but mostly that was just diagrammatic variances. The
underlying techniques and resultant structures were the same.
(And hence the move to UML, which is just a notation - an
extremely useful one, although often abused through over
zealous application.)

Even Rumbaugh's OMT book was meant to be general OOD, although
IMHO it was the least OO of all of them being heavily based
on data modelling.

Sadly, there are very few books today that even attempt to
describe the difference between OOP and the more common
procedural programming paradigm. Discussions of OOP have
degenerated into discussions about OOPL features rather than
how to build worlds of objects passing messages to each other.

-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
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