NIL (programming language): Difference between revisions

Revision as of 23:22, 12 October 2006

Revision as of 21:02, 15 October 2006

Line 1:

{{dablink|This is about the programming langaugelanguage. For other uses see [[Nil]].}}

'''NIL''' was ana 32-bit<ref name="Gabriel"/> implementation of [[Lisp (programming language)|Lisp]] developed at [[Massachusetts Institute of Technology|MIT]] and intended to be the successor to [[Maclisp|MacLisp]]. <ref name=STEELE>{{cite web | title=The evolution of Lisp| author=Guy L Steele Jr, Richard P Gabriel | url=http://www.dreamsongs.com/NewFiles/HOPL2-Uncut.pdf | accessdate=2006-10-12}}</ref> NIL stood for "New Implementation of LISP", and was in part a response to [[Digital Equipment Corporation|DECDECs]]s [[VAX]] computer. The project was headed by [[Jon L White]] <ref>{{cite web | title=Brief History of the Lisp Language| author=Kent M Pitman | url=http://www.lisp.org/table/Lisp-History.html | accessdate=2006-10-12}}</ref>, with a stated goal of maintaining compatabilitycompatibility with MacLisp whilst fixing many of the problems with the language.

==History==

The [[Lisp (programming language)|Lisp]] language was invented in [[1958]] by [[John McCarthy (computer scientist)|John McCarthy]] while he was at [[Massachusetts Institute of Technology|MIT]]<ref>{{cite web|title=History of LISP|author=Paul McJones|url=http://community.computerhistory.org/scc/projects/LISP/|accessdate=2006-10-12}}</ref>. From its inception, Lisp was closely connected with the [[artificial intelligence]] research community, especially on [[PDP-10]]<ref>The 36-bit word size of the [[PDP-6]]/[[PDP-10]] was influenced by the usefulness of having two Lisp 18-bit pointers in a single word. "The PDP-6 project started in early 1963, as a 24-bit machine. It grew to 36 bits for LISP, a design goal." [http://groups.google.com/group/alt.folklore.computers/browse_thread/thread/6e5602ce733d0ec/17597705ae289112] </ref> systems. Lisp was used as the implementation of the programming language [[Planner programming language|Micro Planner]] that was the foundation for the famous AI system [[SHRDLU]]. Lisp, in particular [[Maclisp|MacLisp]] (so called because it originated at MIT's project MAC) was also used to implement the [[Macsyma]] [[computer algebra system]]. In the [[1970s]], as AI research spawned commercial offshoots, the performance of existing Lisp systems became a growing issue.

Partly because of [[garbage collection (computer science)|garbage collection]] (NIL would use stop-and-copy garbage collection of its single [[Heap (data structure)|heap]] for [[Dynamic memory allocation|memory allocation]]<ref name="gabriel"/>)and partly because of its representation of internal structures, Lisp became difficult to run on the memory-limited stock hardware of the day. This led to the creation of [[LISP machine]]s: dedicated hardware for running Lisp environments and programs. An alternative was to use the more powerful commodity hardware which was becoming available, in particular the [[Digital Equipment Corporation|DEC]] [[VAX]].

NIl was an implementation of [[Lisp]] developed at [[MIT]] in the mid to late 1970s, and intended to be thea modern successor to [[MacLisp]]. that was suitable for running on stock hardware<ref name=STEELE/>, as opposed Since the users of theto [[Macsyma]]Lisp programmachine represented a large potential user base for NIL, it was necessary that NIL would be a large, complex system, and that speed would be imperitive. For example high-speed [[bignumLisp]]s wasfor athe requirementLisp to support Macsyma, since NIL would be a failure with slow bignumsmachines.<ref>{{cite web | titlename=Dan"gabriel">"Originally Weinrebdesigned onas NIL|the url=http://www.paulgraham.com/weinreb.html|accessdate=2006-10-12}}</ref>first modern ConsequentlyLisp NILdialect endedon upstock withhardware aafter largethe basedevelopment of VAXLisp-machine assemblyLisp language.at MIT, Theseit requirementswent ledon to abecome veryone aggressiveof andthe complexmain optimisationinfluences strategyon whichthe wasdesign appliedof prematurely,Common withLisp." negativepg results63/294 onof the final system.<ref name=SHIVERS>{{cite web | title=History of T | author=Olin Shivers | url=http://www.paulgraham.com/thist.html | accessdate=2006-10-12}}</ref>book

| last = Gabriel

| first = Richard P.

| title = Performance and evaluation of Lisp systems

| publisher = [[MIT Press]]; Computer Systems Series

| url = http://www.dreamsongs.com/NewFiles/Timrep.pdf

| date = May 1985

| id = ISBN 0-262-07093-6; LCCN: 85-15161}} <!-- xiv, 285 p. ; 23 cm. Cambridge, Mass. --></ref> Since the users of the [[Macsyma]] program represented a large potential user base for NIL, it was necessary that NIL would be a large, complex system, and that speed would be imperative. For example high-speed [[bignum]]s was a requirement to support Macsyma, since NIL would be a failure with slow bignums.<ref>{{cite web | title=Dan Weinreb on NIL| url=http://www.paulgraham.com/weinreb.html|accessdate=2006-10-12}}</ref> Consequently NIL ended up with a large base of VAX assembly language. These requirements led to a very aggressive and complex optimization strategy which was applied prematurely, with negative results on the final system.<ref name=SHIVERS>{{cite web | title=History of T | author=Olin Shivers | url=http://www.paulgraham.com/thist.html | accessdate=2006-10-12}}</ref>

Concurrently with the effort to write NIL, a research group at [[Stanford University]] and

[[Lawrence Livermore National Laboratory]] headed by [[Richard P. Gabriel]] were investigating the design of a Lisp to run on the S-1 Mark IIA supercomputer., [[S-1 ThisLisp]]. projectS-1 Lisp was never fully functional, but was a test bed for implementing advanced compiler techniques in a Lisp. Eventually the S-1 and NIL groups began to collaborate.

Although not succcessfulsuccessful as a project, NIL was important in a number of ways,: firstly it brought together [[Jon L. White]], [[Guy L. Steele, Jr.]] and Richard P. Gabriel, who were to later to go and define [[Common LISP]] <ref name=STEELE/>.; and Secondlysecondly, Jonathan Rees worked on part of the NIL project during a year away from [[Yale University|Yale]]. On returning to Yale, he was hired by the computer science department to write a new Lisp, which became the optimisingoptimizing, native code [[Scheme (programming language)|Scheme]] system known as [[T (programming language)|T]]. In part NIL begat this name, since "T is not NIL". <ref name=SHIVERS/>

==Quotes about NIL==

Line 20 ⟶ 27:

==References==

<!--<nowiki>

See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for an explanation of how

to generate footnotes using the <ref> and </ref> tags, and the template below

</nowiki>-->

{{FootnotesSmall|resize=92%}}

==DocumentationBibliography==

* Brent T. Hailpern and Bruce L. Hitson. S-1 Architecture Manual. Technical Report 161 (STAN-CS-79-715), Department of Electrical Engineering, Stanford University, January 1979.

* G. Burke. Introduction to NIL. Laboratory for Computer Science, Massachusetts Institute of Technology, March 1983.

Line 34 ⟶ 41:

* Steven Correll. S-1 uniprocessor architecture (sma-4). Volume I, Chapter 4, The S-1 Project 1979 Annual Report, Lawrence Livermore Laboratory, Livermore, California, 1979.

* Jon L. White. Nil: A perspective. Proceedings of 1979 Macsyma Users' Conference, Washington, D.C., June 1979.

* Rodney A. Brooks, Richard P. Gabriel, and Guy L. Steele Jr. S-1 Common Lisp Implementation. Proceedings of the 1982 ACM symposium on LISP and functional programming, Pittsburgh, 1982, pages 108–113108 – 113. ACM DL

* Rodney A. Brooks, Richard P. Gabriel, and Guy L. Steele Jr. An optimizing compiler for a lexically scoped LISP. Proceedings of the 1982 Symposium on Compiler Construction, Boston, June 1982, pages 261-275. ACM DL

* Mark Smotherman. S-1 Supercomputer (1975-1988). Web site, last updated April 24, 2004. http://www.cs.clemson.edu/~mark/s1.html