Path: utzoo!attcan!utgpu!watmath!att!dptg!rutgers!cs.utexas.edu!uunet!mcvax!ukc!servax0!ese!goss From: goss@ese.essex.ac.uk (Gossain Sanjiv) Newsgroups: comp.software-eng Subject: Re: Attempts to connect SA/D and OOPS(2) Message-ID: <1405@servax0.essex.ac.uk> Date: 8 Aug 89 13:29:14 GMT References: <8908071747.AA03249@mitre.arpa> <538@ajpo.sei.cmu.edu> Sender: news@servax0.essex.ac.uk Reply-To: goss@ese.UUCP (Gossain Sanjiv) Organization: University of Essex, Colchester, UK Lines: 52 In a recent posting, <538@ajpo.sei.cmu.edu> Edward Berard comments: Topic: (CACM May 1989, Volume 32, Number 5, pp608-623) "An Object-Oriented Requirements Specification Method" by Sidney C. Bailin >> As an example he shows that SA separates the reading, sorting, >> and writing of some data into separate processes and a data store, >> whereas an OO structure gathers these inside an object with >> three actions and some data. > This seems strange from an object-oriented point of view, because: > - Reading is a composite operation involving several objects > (the input object, the actual object being read, and at > least one other object), see, e.g., the discussions on > "objectification" on comp.lang.ada, comp.lang.c++, and > others. > > - Sorting is also a composite operation, involving the object > being sorted and the composite object which contains these > objects, and operations from both classes. > > - The same is true for the writing operation. > > At best, you will have a massive amount of undesirable "object > coupling." Reusability and software reliability will be diminished. Yes, it seems to defeat the object (pardon the pun) to have an object oriented approach and yet still adhere to the same, inappropriate principles of a functional approach! I would agree here with Mr. Berard whole-heartedly. It seems to me that too many people try to evolve OO design methods from existing design approaches, when what is really required, IMHO, is to wipe the slate clean and start proposing design approaches that reflect the paradigm shift required when moving to OOP. Methods that arise from peoples experiences in OOD are far better than those that are derived from existing approaches. Sanjiv Gossain goss%ese.essex.ac.uk@nsfnet-relay.ac.uk ---------------------------------------------------------- Sanjiv Gossain Dept. of ESE Universtiy of Essex Colchester CO4 3SQ ENGLAND +44 206 873333 xt:2820