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From: dlester@cs.man.ac.uk (David Lester)
Newsgroups: comp.lang.functional
Subject: Re: "Reverse Diff" Arrays
Message-ID: <2807@m1.cs.man.ac.uk>
Date: 28 Jun 91 08:01:36 GMT
References: <591sis-b@massey.ac.nz> <SRA.91Jun27101445@pessoa.ecs.soton.ac.uk>
Sender: news@cs.man.ac.uk
Reply-To: dlester@cs.man.ac.uk (David Lester)
Organization: Department of Computer Science, University of Manchester UK
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In article <SRA.91Jun27101445@pessoa.ecs.soton.ac.uk> sra@ecs.soton.ac.uk
(Stephen Adams) writes:
> 3.  Reverse diffs can be really bad if the data structure
>     is not quite single threaded.  If I make a zillion
>     updates to an array which just happens to have another
>     copy I will wonder where all my memory is going and why
>     it takes so long to look up anything in the original
>     copy.

One might consider this behaviour to be more acceptable than the
equivalent case in an imperative paradigm!

--

David Lester, Manchester University, UK.