The LISP Programming Language
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Interest in artificial intelligence first surfaced in the mid 1950. Linguistics, psychology, and mathematics were only some areas of application for AI. Linguists were concerned with natural language processing, while psychologists were interested in modeling human information and retrieval. Mathematicians were more interested in automating the theorem proving process. The common need among all of these applications was a method to allow computers to process symbolic data in lists.
IBM was one of the first companies interested in AI in the 1950s. At the same time, the FORTRAN project was still going on. Because of the high cost associated with producing the first FORTRAN compiler, they decided to include the list processing functionality into FORTRAN. The FORTRAN List Processing Language (FLPL) was designed and implemented as an extention to FORTRAN.
In 1958 John McCarthy took a summer position at the IBM Information Research Department. He was hired to create a set of requirements for doing symbolic computation. The first attempt at this was differentiation of algebraic expressions. This initial experiment produced a list of of language requirements, most notably was recursion and conditional expressions. At the time, not even FORTRAN (the only high-level language in existance) had these functions.
It was at the 1956 Dartmouth Summer Research Project on Artificial Intelligence that John McCarthy first developed the basics behind Lisp. His motivation was to develop a list processing language for Artificial Intelligence. By 1965 the primary dialect of Lisp was created (version 1.5). By 1970 special-purpose computers known as Lisp Machines, were designed to run Lisp programs. 1980 was the year that object-oriented concepts were integrated into the language.
By 1986, the X3J13 group formed to produce a draft for ANSI Common Lisp standard. Finally in 1992, X3J13 group published the American National Standard for Common Lisp.
Significant Language Features
Areas of Application
Lisp totally dominated Artificial Intelligence applications for a quarter of a century, and is still the most widely used language for AI. In addition to its success in AI, Lisp pioneered the process of Functional Programming. Many programming language researchers believe that functional programming is a much better approach to software development, than the use of Imperative Languages (Pascal, C++, etc).
Below is a short list of the areas where Lisp has been used:
Artificial Intelligence
1. AI Robots
2. Computer Games (Craps, Connect-4, BlackJack)
3. Pattern Recognition
Sample Program
Source Code: (Hello World)
;;; HWorld.lsp
;;; ================================================== ;;;
;;; =========== HELLO WORLD SIMULATION ============== ;;;
;;; ================================================== ;;;
;;; This function simply returns the string Hello World that is in quotes.
(DEFUN HELLO ()
"HELLO WORLD"
)
This program was created, tested and run using the XLISP-STAT 2.1, Release 3.45 (Beta) compiler. Copyright (c) 1989-1994, by Luke Tierney.
This program simply demonstrates the return of a string from a function call, in the Lisp programming language. The program will display the message "Hello world" each time the function HELLO is called.
