Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!decwrl!uunet!mcsun!ukc!dcl-cs!aber-cs!athene!pcg From: pcg@cs.aber.ac.uk (Piercarlo Grandi) Newsgroups: comp.lang.misc Subject: Re: C's sins of commission Message-ID: Date: 10 Nov 90 15:29:10 GMT References: <2062@aber-cs.UUCP> <1990Oct26.155937.29185@maths.nott.ac.uk> <1990Nov2.172508.6393@maths.nott.ac.uk> <1990Nov8.174042.24789@maths.nott.ac.uk> Sender: pcg@aber-cs.UUCP Organization: Coleg Prifysgol Cymru Lines: 34 Nntp-Posting-Host: odin In-reply-to: anw@maths.nott.ac.uk's message of 8 Nov 90 17:40:42 GMT On 8 Nov 90 17:40:42 GMT, anw@maths.nott.ac.uk (Dr A. N. Walker) said: anw> Furthermore, if I am denied access to the algebra of locations, anw> then some useful ideas like anonymous objects, and like remembering anw> locations, become inexpressible. pcg> They are most definitely not useful at the application level, anw> They most definitely are! When I give people directions to my anw> house, I include things like: "Take the third on the right, ...", anw> "If you get to the Hemlock Stone, you've gone too far, you should anw> ...", and "If you get lost, ask for Priory Island, and try again anw> from there". This is an *implementation*. I think we have very different ideas on what is application design and what is implementation design, and in particular between data design and representation design. More precisely, IMNHO you don't make much distinction between the two aspects. Unfortunately. Just to restate my position, while we are talking past each other: when doing data design pointers are extraneous and therefore unwelcome details (and so Chris Holt is right). When doing representation design they are an invaluable technology (and so you are right too). For application oriented languages (SQL, Hermes) pointers are questionable; for implementation oriented languages (C, Algol 68) pointers are important (and Andy Lowry is somehow right on both accounts too). -- Piercarlo Grandi | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk Dept of CS, UCW Aberystwyth | UUCP: ...!mcsun!ukc!aber-cs!pcg Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk