Interesting take on Paradigms (OO vs Procedural)
in [Cobol]
|
From: Rick Smith on 29 Mar 2008 10:24 "Richard" <riplin(a)azonic.co.nz> wrote in message news:c1715df2-76a5-4502-bdd7-23e4ae8f7551(a)d4g2000prg.googlegroups.com... > On Mar 29, 1:51 pm, "Rick Smith" <ricksm...(a)mfi.net> wrote: [snip] > > The book "Simulation Using GPSS", Thomas J. Schriber, > > 1974, covers the use of General Purpose Simulation System > > to accomplish discrete event simulation. I find no mention of > > "class", "object", or "method" in this book; thus, apparently, > > these terms are not in the jargon of GPSS users. The author > > uses procedural languages as a model for explaining the use > > of GPSS. > > Turning to my* copy of "Programming Languages. NATO Advanced Study > Institute, edited by F Genuys 1968" it has an article "Discrete Event > Simulation Languages" by Ole-Johan Dahl. This apparently was given as > a series of lectures around 1966. It discusses simulation in general > and how some computer simulation languages map onto the process. [snip] > After a few pages of these concepts there is a section that indicates > the terminology of several programs and how the concepts relate to the > terminology used by the programs. The programs are GPSS, SOL, > SIMSCRIPT, CSL and SIMULA. For example in GPSS an 'attribute' is > called a 'parameter', an 'object' is called a 'transaction', GPSS > doesn't implement anything related to 'class'. Thanks for the information. I was hoping to find in my GPSS book a discussion of the OO terms in the context of simulation; but I guess that ain't going to happen.
From: Alistair on 29 Mar 2008 15:01 On 29 Mar, 06:18, tim <T...(a)internet.com> wrote: > On Sat, 29 Mar 2008 01:15:20 +0000, docdwarf wrote: > > > 'Technically' there is even less difference between what you cite and > > between A-negative and B-positive human blood... now I'd appreciate it if > > you'd keep away from dealing with transfusions. > > > DD > > Ditto. No more than one bit might separate a program that works correctly > and one that fails catastrophically. This is a relevant analogy, because > DNA is code. > Well said Tim. Most DNA is in fact what is called 'Junk DNA' with no discernable function and with sections repeated without rhyme or reason.
From: Pete Dashwood on 29 Mar 2008 15:59 "Alistair" <alistair(a)ld50macca.demon.co.uk> wrote in message news:6ee2259e-8acb-4822-b0fb-922006515356(a)s19g2000prg.googlegroups.com... > On 28 Mar, 21:16, "Pete Dashwood" > >> "Structures" are NOT "objects" and there therefore is a good reason for >> not >> retaining the procedural nomenclature; neither are "procedures" >> "methods", >> just because on the surface they appear to be similar. >> >> A horse is not a camel, despite both of them having a leg at each corner >> and >> being used for transport. >> > > Technically, there is very little difference between an earthworm, a > frog and a human (except for what theBible has to say about morphology > and anatomy). Camels and horses are virtually identical. However, "virtually" is NOT identical. Try not watering a horse for 6 weeks and see how long it lasts. Try riding a horse over sand dunes for weeks on end and see how long it lasts or the distance it covers, compared to a camel. Try making turkish delight out of camel hooves... Differences are important, (sometimes even critical...) And THAT was my point. Pete. -- "I used to write COBOL...now I can do anything."
From: Pete Dashwood on 29 Mar 2008 16:05 "Alistair" <alistair(a)ld50macca.demon.co.uk> wrote in message news:69c88c59-3e42-484a-8321-67452c60d5fd(a)s12g2000prg.googlegroups.com... > On 29 Mar, 06:18, tim <T...(a)internet.com> wrote: >> On Sat, 29 Mar 2008 01:15:20 +0000, docdwarf wrote: >> >> > 'Technically' there is even less difference between what you cite and >> > between A-negative and B-positive human blood... now I'd appreciate it >> > if >> > you'd keep away from dealing with transfusions. >> >> > DD >> >> Ditto. No more than one bit might separate a program that works correctly >> and one that fails catastrophically. This is a relevant analogy, because >> DNA is code. >> > > Well said Tim. Most DNA is in fact what is called 'Junk DNA' with no > discernable function and with sections repeated without rhyme or > reason. I think you need to qualify that to "without rhyme or reason that we can discern at this time." While it may be that much of what is there is left over from previous failed evolutionary attempts (much as some maintenance programmers don't remove code that has become irrelevant "just in case it is ever needed again"), and is not required for the organism to function in its present incarnation, that certainly doesn't mean we can decisively state it is there without rhyme or reason. We know that people can function "normally" even when quite large pieces of their brains are removed, but we don't advocate removing brain parts in the interest of general efficiency...:-) Pete. -- "I used to write COBOL...now I can do anything."
From: Pete Dashwood on 29 Mar 2008 16:22
"Rick Smith" <ricksmith(a)mfi.net> wrote in message news:13ur5tg3con5ja4(a)corp.supernews.com... > > "Pete Dashwood" <dashwood(a)removethis.enternet.co.nz> wrote in message > news:65553nF2cjsrhU1(a)mid.individual.net... >> >> >> "Rick Smith" <ricksmith(a)mfi.net> wrote in message >> news:13uq9i0e2sfdd1a(a)corp.supernews.com... >> > >> > < http://www.cs.berkeley.edu/~jrs/4/lec/14 > >> > ----- >> > Why did the originators of object orientation rename "structures" to >> > "objects" >> > and "procedures" to "methods"? Hubris and arrogance, in my opinion. >> >> This simply says that the writer has not really understood the essential >> differences. I read the full article and he/she does a good job of >> listing >> the differences, but identifying differences and actually understanding > the >> implications of those differences are two different things. >> >> The comment above implies that the commentator sees no difference between > a >> "structure" and an "object", yet anyone who has worked with these things > in >> the real world would understand the essential difference. This is the >> difference between Acadaemia and Reality. > > H'm! Structure, in procedural, is accessed through a pointer. > Object, in object-based, is accessed through a reference. > Object, in object-oriented, is accessed through a reference; > but also holds a "vtable" to accommodate inheritance and > polymorphism. > > The essential difference seems to be the extension of the > structure to add the "vtable" making the object a bigger > structure. > You are looking only at the mechanics of an implementation. The conceptual use of objects is WAY more important. But you only come to appreciate that when you start using them for systems in the real world, and not just to describe some academic argument. Whether objects implement inheritance through a vtable or not is completely irrelevant to the use of objects. For you, an object is just a structure in memory; for me, it is much more than that. I visualise objects as representing a real world entity and having attributes and behaviours that a structure alone can never have. Perhaps it comes down to imagination and vision. Pete. -- "I used to write COBOL...now I can do anything." |