jgautier@vangogh.ads.com (Jorge Gautier) (04/05/91)
In article <1991Apr4.172417.3266@linus.mitre.org> dmg@retina.mitre.org (David Gursky) writes: > I've heard said that Ada is "Object-based" as opposed to "Object-Oriented". > Now I make no pretentions about knowing some undeniable truth as to what > "Object-Oriented" means (this being the subject of many a discussion at > OOPSLA), but could someone enlighten me on what "Object-based" is suppose to > mean? They're probably using the terminology of Wegner's OOPSLA paper ('86 I believe but I'm not sure) "Dimensions of Object-??? Languge Design." A good paper to make sense out of all the object oriented mumbo jumbo. -- Jorge A. Gautier| "The enemy is at the gate. And the enemy is the human mind jgautier@ads.com| itself--or lack of it--on this planet." -General Boy DISCLAIMER: All statements in this message are false.
dmg@retina.mitre.org (David Gursky) (04/05/91)
I've heard said that Ada is "Object-based" as opposed to "Object-Oriented". Now I make no pretentions about knowing some undeniable truth as to what "Object-Oriented" means (this being the subject of many a discussion at OOPSLA), but could someone enlighten me on what "Object-based" is suppose to mean?
kornfein@uganda.crd.ge.com (Mark M. Kornfein) (04/05/91)
In article <1991Apr4.172417.3266@linus.mitre.org> dmg@retina.mitre.org (David Gursky) writes: >I've heard said that Ada is "Object-based" as opposed to "Object-Oriented". >Now I make no pretentions about knowing some undeniable truth as to what >"Object-Oriented" means (this being the subject of many a discussion at >OOPSLA), but could someone enlighten me on what "Object-based" is suppose to >mean? My understanding of "Object-based" is that it is a system using objects but without inheritence. Object based systems allow you to create objects (at run time) and have methods that apply to that object but the methods can not be used for other objects as can be done with inheritence. Not being familiar with Ada I don't know if it is object based. On a project I am currently on is Object based due to some constraints which due not allow us to use inheritence. I have found it to be a useful approach and more powerful than C which is what the object based system is built on. =============================================================================== Mark Kornfein INET: kornfein@crd.ge.com GE Corporate R&D Center UUCP: uunet!crd.ge.com!kornfein Schenectady, NY
jls@rutabaga.Rational.COM (Jim Showalter) (04/10/91)
>My understanding of "Object-based" is that it is a system using objects but >without inheritence. Object based systems allow you to create objects (at run >time) and have methods that apply to that object but the methods can not be >used for other objects as can be done with inheritence. Exactly. I would have much preferred to have seen the distinction made between object-oriented and inheritance-oriented, which is a lot more intuitive than the distinction between object-based and object-oriented. >Not being familiar with Ada I don't know if it is object based. Indeed it is. It does a very good job of allowing you to encapsulate data, hide information, and abstract objects. It also allows you to compose objects out of other objects, and provides direct support for concurrency among objects. It does not provide for much in the way of inheritance. >On a project I am currently on is Object based due to some >constraints which due not allow us to use inheritence. I have found it to be >a useful approach and more powerful than C which is what the object based >system is built on. Not surprising. Personally, I think it is the ability to create objects and encapsulate abstractions that provides 90% of the actual software engineering value available from object-oriented languages. The other 10% is provided by inheritance. Considering that many of the programmers I've encountered don't even grasp the concept of an interface, it is fairly predictable that they'd realize significant benefits from using objects. -- * The opinions expressed herein are my own, except in the realm of software * * engineering, in which case I borrowed them from incredibly smart people. * * * * Rational: cutting-edge software engineering technology and services. *