Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!samsung!uunet!mcsun!ukc!edcastle!sean From: sean@castle.ed.ac.uk (S Matthews) Newsgroups: comp.software-eng Subject: Re: Reuse and Abstraction (was: reu Message-ID: <4483@castle.ed.ac.uk> Date: 4 Jun 90 23:26:28 GMT References: <4979@stpstn.UUCP> <102100009@p.cs.uiuc.edu> <19820@duke.cs.duke.edu> <12085@june.cs.washington.edu> <81111@tut.cis.ohio-state.edu> <5152@stpstn.UUCP> <81153@tut.cis.ohio-state.edu> Reply-To: sean@castle.ed.ac.uk (S Matthews) Organization: Edinburgh University Computing Service Lines: 36 In article <81153@tut.cis.ohio-state.edu> Bruce Weide writes: >In article <5152@stpstn.UUCP> cox@stpstn.UUCP (Brad Cox) writes >regarding whether formal specifications are a pain: > >>-------- >> >>"Most" people (certainly not myself) aren't saying that they're a big pain >>for stacks. A lot of them *are* saying that their usefulness is less obvious >>than their costs for bigger objects like Sets (see Ralph London's article), >>word processors, or hamburgers. >> >>-------- > If you want to see a formal specification of a word processor look at Sufrin's spec in specification case studies by Ian Hayes. It is actually for a display oriented editor, rather than a full word processor and to be frank it is a crummy design, but then it was a piece of reverse engineering, so that is not a fair criticism of the quality of the specification *as a specification*. It is certainly not complex or a pain, and it is very readable, and highlights nicely some of the differences between a specification and a program because of the intention. It would be interesting to see how it would be extended into a full editor. Sean P.S. there is another (new---there is also an older, out of print, book by Bjorner and him) book in the same series that gives examples of VDM specifications as well, edited by Jones. Why don't some of you read them so that you know what formal specs of (semi) real systems look like. You would also be able to compare notes on the same specs!