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From: shebs@utah-orion.UUCP (Stanley T. Shebs)
Newsgroups: comp.lang.lisp
Subject: Re: Recognizing QUOTE deemed harmful to EVAL's laziness
Message-ID: <168@utah-orion.UUCP>
Date: Tue, 21-Jul-87 16:08:23 EDT
Article-I.D.: utah-ori.168
Posted: Tue Jul 21 16:08:23 1987
Date-Received: Thu, 23-Jul-87 04:29:37 EDT
References: <2698@crcge1.UUCP>
Reply-To: shebs@utah-orion.UUCP (Stanley T. Shebs)
Organization: PASS Research Group
Lines: 12
Keywords: LISP denotation quotation

For another view on the significance of quoting structures, check out
Brian Smith's paper in the 84 POPL.  The writing is dense, but the
pictures are informative.  His basic point of view is that quoting
is important to distinguish levels of meta-ness, and so quoted objects
are promoted to first-class types known as handles.  There are operations
UP and DOWN that add and remove handles, since evaluation does not;
(eval '2) => '2.  Also, (+ 2 '3) is an semantic error, like taking the
car of an number.  Fairly unusual, but the result (3-Lisp) is quite elegant,
much more so than Scheme or other functional languages.  No lazy evaluation
though...

							stan shebs