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From: ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe)
Newsgroups: comp.lang.misc
Subject: Re: Some things that pointer-less languages can't do efficiently
Message-ID: <3976@goanna.cs.rmit.oz.au>
Date: 15 Oct 90 05:41:18 GMT
References: <10397:Oct1212:55:1090@kramden.acf.nyu.edu> <65642@lanl.gov>
Organization: Comp Sci, RMIT, Melbourne, Australia
Lines: 21

In article <65642@lanl.gov>, jlg@lanl.gov (Jim Giles) writes:
> Flipping links (with the 'aliased' attribute on) has the same semantics
> as flipping pointers, _nearly_ the same syntax, and most probably the
> same internal implementation.

Jim Giles is one of the people whose postings I read carefully.
But now I am really puzzled.  If recursive data structures with the
'aliased' attribute have the same semantics as pointers and very nearly
the same syntax, what precisely is the advantage, and in what sense
have pointers been eliminated?

Is the claim that undeclared aliasing is a Bad Thing?  I'll agree,
but then recursive structures in Scheme are Bad Things because there
is implicit aliasing, although there are no programmer-visible pointers.

(Don't run away with the idea that I'm defending pointers.  My favourite
languages include ML, Scheme, and Prolog.  But I do have to say that
handling dynamic data structures in C is considerably easier and the
code far less "contorted" than in Pascal.)
-- 
Fear most of all to be in error.	-- Kierkegaard, quoting Socrates.