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From: Chris.Holt@newcastle.ac.uk (Chris Holt)
Newsgroups: comp.lang.misc
Subject: Re: REFs or aliases?
Message-ID: <1990Nov1.204843.18771@newcastle.ac.uk>
Date: 1 Nov 90 20:48:43 GMT
References: <1990Oct28.165903.9627@newcastle.ac.uk> <8960021@hpfcso.HP.COM>
Sender: news@newcastle.ac.uk
Organization: Computing Laboratory, U of Newcastle upon Tyne, UK NE1 7RU.
Lines: 22

This whole discussion of pointers (REFs) seems too concerned with the
wrong things to me (but then, I'm more concerned with semantics; people
worried about efficiency can hit "n" now).

Given an arbitrary domain, e.g. sets of integers, it is always
possible to introduce a monadic operation f that extends that
domain.  So, given a value such as {1,3,4}, we can apply f to
it to obtain a new value f{1,3,4}; and we can apply f to that
new value to obtain f(f{1,3,4}).  We also introduce an inverse
operation f' such that f'(f(x)) = x.  [Obviously, one might
spell f as REF, and f' as DEREF or whatever.]

The question is, why bother?  Forget about machine addresses and
locations and pointers right now; the point is that introducing
such an additional operation complicates the domain, and I can't
see any redeeming social value in so doing (at least that has been
presented yet).  But then, I prefer programs to be as simple as
possible...
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 Chris.Holt@newcastle.ac.uk      Computing Lab, U of Newcastle upon Tyne, UK
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 "He either fears his fate too much, or his programming tools are small..."