Edsger Dijkstra said: "It is practically impossible to teach good programming style to students that have had prior exposure to Basic; as potential programmers, they are mentally mutilated beyond all recognition."One look at most people's OO code and I feel like applying the phrase
"mentally mutilated beyond recognition" to OOP practitioners as well. Congealed, booger-like masses of heavily-coupled classes (rendering useless the whole reason for using them in the first place!!!) and superfluous inheritance hierarchies are the norm.
Good old functions are a perfectly good abstraction in many many cases, but clearly, a new generation of programmers has been trained to believe that they are committing a mortal sin if they do not immediately think in terms of classes and objects when trying to solve a problem.
[ They should ponder this fact over and over again:
Linux, the most successful open source project of all time - with a codebase worth several million lines and teeming with daily activity involving thousands of people - does not make use of classes and objects. ]
Good OO design is extremely hard such that for all but the most experienced programmers, I believe the correct design decision is to actually
refrain from designing your own classes. I've come to realize that classes, because they are intended to be heavily reused, require design skills, taste and subtlety on a level approaching that required for
language design and are thus not for mere mortals to dabble with. Unfortunately, most of today's popular languages, through a lack of better alternative high level facilities, force everyone working in them to become class designers.
Happily, there are environments, like Python, which allow average programmers to effectively reuse reifications of abstractions (classes included) done by those with the necessary design skills/expertise, largely dispensing with the need to do such work themselves. A good thing, since for the most part, the end results of most such efforts are U-G-L-Y, those based on classes consistently being the worst offenders. In fact, one of the characteristics of the better-designed python 'objects' is that they save you from having to engage in the gobbledygook of object think and talk, delivering not only on the promise of
"usage without knowledge of implementation details", but usage without having to
master an entire paradigm. This is the promise of scripting taken to a higher level.
So, to all budding Python programmers out there, please keep in mind that you can do a lot of powerful things in this language just sticking to functions and for loops and try to avoid inflicting your class designs on others until you're up to the task of designing elegant ones.
Also realize that there are much neater non-OO abstractions in the language such that classes, and specifically class hierarchies, should be considered an evil to be resorted to only out of sheer desperation. The increasing popularity of interfaces and similar mechanisms nowadays proves that inheritance - IS-A relationships - are only useful in a minority of situations and nowhere near as universally applicable as the OO snake oil salesmen of yore (mid-to-late 90s) like to tout.
Expect more traditional OO concepts to crumble or mutate as time passes to the point where what you thought of as object oriented today will become completely unrecognizable. Come to think of it, 'traditional OO' could be an oxymoron... OO is a
circus: friend classes, abstract classes, refactoring, patterns, "cross-cutting concerns", interfaces, members, methods, messages, yada yada yada. The monkey-mind comes up with a new concept every 6 months...
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