Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!ut-sally!utah-cs!utah-orion!shebs 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