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From: freeman@argosy.UUCP (Jay R. Freeman)
Newsgroups: comp.lang.scheme
Subject: Re: Order of evaluation (was Re: evaluating () should be an error
Message-ID: <1055@argosy.UUCP>
Date: 27 Mar 91 19:04:33 GMT
References: <2977@kraftbus.cs.tu-berlin.de> <1991Mar26.155905.12906@daffy.cs.wisc.edu> <kiran.670017354@copper> <1991Mar26.224805.23381@cs.ubc.ca> <harlan.670038398@copper> <1991Mar27.101357.20383@news.cs.indiana.edu>
Sender: news@argosy.UUCP
Reply-To: freeman@cleo.UUCP (Jay R. Freeman)
Organization: MasPar Computer Corporation, Sunnyvale, CA
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Possibly one reason for not specifying the order of evaluation of
arguments to a procedure is to make one step toward an implementation
that can run on an asynchronous MIMD processor -- the idea is to farm
out each argument evaluation to its own processor and collect the
results as they come in.  Such an implementation would quite likely
evaluate the arguments in different orders each time the same code
was run.

(I'm *not* saying that that's *all* you have to do to make a Scheme
that can run on an asynchronous MIMD processor -- but "a journey of
1000 MIPS, er, miles, begins with a single step.")

                                          -- Jay Freeman

	  <canonical disclaimer -- I speak only for myself>