On Saturday, October 19, 2013 2:02:24 AM UTC+5:30, Peter Cacioppi wrote: > > I still say that object-based is a distinct and meaningful subset of > object-oriented programming.
Yes that is what is asserted by http://www-public.int-evry.fr/~gibson/Teaching/CSC7322/ReadingMaterial/Wegner87.pdf -- a classic though old reference > The former can be implemented elegantly in a wide range of languages without > much in the way of specific language support, the latter needs to designed > into the language to allow a modicum of polymorhpic readability. 3 examples were given (1) python's C implementation (2) OS/2 (3) Linux kernel About 2 I dont know anything though I believe gdk and gobject are more contemporary examples. About 1 I have reservations -- see below IMO the linux kernel is the closest approx to what you are asking: The details are here http://lwn.net/Articles/444910/ The top level summary is in the opening paras of http://lwn.net/Articles/446317/ > It's an important distinction, because a project that is constrained to C > should (IMHO) target an object-based design pattern but not an > object-oriented one. That said, I'm open to disputation-by-example on this > point, provided the example is reasonably small and pretty. (If the only > polymorphic C code is ugly and non-small, it sort of proves my point). Yes this is an important point though hard to argue in a definitive way -- I call such arguments philosophical rather than scientific; ie it is important but it cant really be settled once and for all. To see this one can start with two extremes: Extreme 1: Computability (aka Turing) theory. From this pov every language/system/computer is equivalent to every other and people designing 'newer' and 'better' ones are wasting their's and other's time just like fashion designers who keep alternating pant-hems from Elvis Presley to narrow. Extreme 2: Semicolon as separator differs from semicolon as terminator; P4 processor is different from P2 etc etc -- essentially treating any difference as a substantive difference. Clearly both extremes are unsatisfactory: the first lands us into the Turing-tarpit. The second makes a discussion of close-but-different impossible. Just as the study of algorithms arose out of a desire to study program efficiency but with the nitty-gritty details of machines abstracted away, in the same way programming language semantics arose in order to study broad classes of languages with details hidden away. Unfortunately, even after 50 years of trying, semantics has been a dismal failure in defining the what and where and whither of OOP. In a sane world this would have signified that perhaps OOP as a concept(s) needs to be questioned. Considering that the opposite has happened -- programming language semantics as an area has become distinctly 'old-fashioned' and not-so-respectable-- I can only conclude that the world is not sane. Well the tide is slowly turning -- here's a growing bunch of people questioning the validity of OOP: http://en.wikipedia.org/wiki/Object-oriented_programming#Criticism Of these I find two noteworthy: 1. Stepanov who is next to Stroustrup in C++ circles, calls OOP a hoax. 2. Carnegie Mellon university has eliminated OOP as "unsuitable for a modern CS curriculum" And which is why I sympathize with Mark Janssen's passion to clean up the OOP act. -- https://mail.python.org/mailman/listinfo/python-list
