Reintroducing LISP

 
 
By Peter Coffee  |  Posted 2006-02-07 Email Print this article Print
 
 
 
 
 
 
 


The man from Mars sees development languages being chosen for the convenience of machines, despite attendant productivity penalties and difficulty of delivering high-quality code, instead of being chosen for the convenience of the developers who are the actual scarce resource. Martian question 3: Arent your machines getting faster much more quickly than your programmers are getting smarter?
Symbolic acts
At this point, one could say, "Enter LISP," except that LISP has already been on the stage longer than any extant programming language other than FORTRAN. With a name that is a contraction of "LISt Processing," LISP represents its programs in exactly the same manner as its data—that is, as linked lists of symbols. It can therefore be used to write programs that write new programs as readily as conventional languages construct a vector or array of data. A subset of such programs includes those that define new programming languages, specifically tailored to solve new problems. Although LISP originated in AI (artificial intelligence), being used to write programs that extended themselves in models of machine learning, LISP has also proved useful in building other customizable systems.
For example, Autodesks AutoCAD drafting tool has always incorporated a LISP-based language and a LISP run-time environment that enable powerful extensions. Autodesk recently tapped operations chief Carl Bass to be the new CEO. Click here to read more. LISPs power in manipulating complex lists of lists has also made it the tool of choice for developing symbolic reasoning systems such as OPS5 and PROLOG (both of which have many commercial and public-domain implementations). OPS5 found fame as the language of XCON, a minicomputer configuration tool that greatly reduced deployment costs for Digital Equipment, while PROLOG engines from providers such as the Swedish Institute of Computer Science are embedded in a wide range of applications. Both OPS5 and PROLOG are actually incorporated as utility languages in the Allegro CL (Common Lisp) 8.0 development suite, released in January by Franz. Click here to read more about Allegro CL 8.0. In addition to the robust and fully supported Franz product, there are numerous open-source and public-domain LISP implementations enabling developers to experiment with the language. That which is no more Like anything thats been around for several decades, LISP carries the baggage of what "everyone knows" about it that is no longer true. "Everyone knows," for example, that LISP is an interpreted language and, therefore, too slow for production applications—except that modern LISPs can compile functions for run-time speeds competitive with those of C or C++ programs in algorithmically complex tasks. Attendees of the C++ Connections conference got a glimpse of the languages future. Click here to read more. The trade-offs are clear. In a study performed in 2000 by Erann Gat, a researcher at the California Institute of Technologys Jet Propulsion Laboratory, programmers writing in LISP produced programs with less variability in performance than more experienced programmers writing in C and C++. The fastest versions of C and C++ programs were faster than most LISP implementations, but the median performance of the LISP implementations was actually twice as good as the median performance of the C and C++ code performing typical tasks (more at www.flownet.com/gat/papers/lisp-java.pdf). For real-world teams, such reduction of technical risk and improved worst-case scenarios arguably outweigh best-case results. The LISP implementations in Gats study were more memory-intensive than those in C and C++, although LISPs memory use was comparable to that of Java while performance was much better. A key point, though, is that applications are increasingly being delivered to users via the Web, and that developers are therefore freer to use tools that maximize their own flexibility at the supply end. "In the near future, when everything you encounter is programmable and everyone wants to program [those devices and environments] the ability to create new programming languages will be paramount," said computational biology researcher Jeff Shrager, in Stanford, Calif., in a conversation with eWEEK Labs. "The combination of AI capability with the ability to create entirely new programming languages make LISP uniquely situated for the near future of computation." Technology Editor Peter Coffee can be reached at peter_coffee@ziffdavis.com. Check out eWEEK.coms for the latest news, reviews and analysis in programming environments and developer tools.


 
 
 
 
Peter Coffee is Director of Platform Research at salesforce.com, where he serves as a liaison with the developer community to define the opportunity and clarify developersÔÇÖ technical requirements on the companyÔÇÖs evolving Apex Platform. Peter previously spent 18 years with eWEEK (formerly PC Week), the national news magazine of enterprise technology practice, where he reviewed software development tools and methods and wrote regular columns on emerging technologies and professional community issues.Before he began writing full-time in 1989, Peter spent eleven years in technical and management positions at Exxon and The Aerospace Corporation, including management of the latter companyÔÇÖs first desktop computing planning team and applied research in applications of artificial intelligence techniques. He holds an engineering degree from MIT and an MBA from Pepperdine University, he has held teaching appointments in computer science, business analytics and information systems management at Pepperdine, UCLA, and Chapman College.
 
 
 
 
 
 
 

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