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From: math1205@waikato.ac.nz
Newsgroups: comp.lang.scheme.c
Subject: Implicit Forcing
Message-ID: <1525.26ece66a@waikato.ac.nz>
Date: 11 Sep 90 01:28:10 GMT
Organization: University of Waikato, Hamilton, New Zealand
Lines: 18

How would one go about making forces implicit in a Scheme implementation?
From R3RS it seems such a thing is permissible and indeed implemented in
some versions. Does any know of such a version?

Would it be necessary to modify all primitive procedures such as car, + to
check for the presence of a promise where by default promises would be
self-evaluating. I suspect most primitive procedure require actual values,
the only ones I can think of that don't are: cons, list, 2nd arg of append,
set! and  user-defined procedure calls.

Also are there any nasty suprises install for somebody implementing the above,
like special cases, incompatiblity with other language features (e.g. garbage
collector, continuations)? Has anyone considered added this feature to
Scheme->C ?

Thanks in advance to replies.
Wayne Schou
MATH1205@waikato.ac.nz