I’ve got a thing about computer languages. I consider myself to be somewhat of a connoisseur. I have a soft spot in my heart for Lisp but I am also fans of other languages based on the context. I spent ten years more or less as an evangelist for Java. At the time I was fluent in Java, C, BASIC, and Pascal, I was conversant with Lisp, Scheme, Smalltalk, and Ada, and I could read most other languages but in particular COBOL, SNOBOL, Fortran, and Prolog.
While I personally preferred Lisp, I felt that the bulk of the programmers at the time were C or C++ programmers. As such, Lisp looked and behaved weirdly from their perspective. Java represented a huge movement in the right direction while remaining a language accessible to C programmers.
At the time, everybody was impressed by the elegance of Smalltalk and the object oriented, message passing paradigm. Smalltalk was also too esoteric for most C programmers but there was a guy named Doug Cox that came up with a language called Objective-C that captured some of the object oriented flavor of Smalltalk in a syntax that appealed to the C crowd. This was about the same time that Bjarne Stroustrup was experimenting with C++.
Both Objective-C and C++ proved to be overly complicated, especially when it came to managing the dynamic allocation of memory. Consequently, they both gained a reputation for being difficult if powerful. This was the state of affairs when James Gosling was faced with developing a language for a set top box. The requirements were that it be fast, easy to write bug free code in, and it would be well integrated with the network. And, of course, it would be object oriented and have automatic memory management in the guise of garbage collection. In short, Java was no Lisp but it was about as close to it as the programmers of the day could get their minds around
As it turns out, Java did raise the bar to the point that now, some twenty years later, it has itself passed into the conservative end of the spectrum and new languages now fill the spot it once held. In fact, Lisp has had a resurgence in popularity in recent years.
This renewed popularity can probably be best explained by the fact that Lisp has always been a research language. It was conceived as a notation for the discussion of Church’s lambda calculus but it’s simple, homoiconic syntax quickly became a powerful tool for creating derivative languages to explore new programming paradigms.
Consequently, concepts such as structured programming, functional programming, and object oriented programming had their first experimental implementations in Lisp. It has been said that every new feature in every new programming language introduced since Lisp was first created have been done first in Lisp and often better.
Which brings me around to a point of sorts. Since all of these languages have been gravitating toward Lisp for all these years, why hasn’t Lisp just taken over as the language of choice? There are a number of answers to that question, some of them contradictory.
For years Lisp had a reputation as being terrible for problems with a lot of mathematical computation. The truth of the matter was that the implementation of arithmetic in most of the Lisps of the time was good enough for the researchers that were primarily interested in investigating aspects other than numerical computation. When later generations of Lisp implementors took the time to optimize the numerical performance of Lisp it came to rival C and Fortran in both speed and accuracy.
This illustrates the important observation that Lisp has seldom been considered a language for the development of production software. A couple of blatant exceptions have been the use of Lisp in the development of software to predict the performance of stocks on Wall Street and software to predict the most likely places to explore for oil. These domains were willing to accept some rough edges in order to solve these particularly hard problems at all.
At one point it was argued that the automatic garbage collection of Lisp would kick in at the most inopportune time and embarrass the developer mid-demo. Advances in the technology of garbage collection have since made this argument mute.
Another often sited argument used against Lisp is the claim that other, more popular languages have a larger selection of third party libraries available to them than Lisp does. This does remain a challenge to some degree however many Lisp implementations have Foreign Function Interface mechanisms that allow them to call library routines written in other languages.
Another spin on the question is that Lisp has regained popularity especially in revised dialects like Clojure which has taken the opportunity to refactor the architecture of collection types so that the operations on them have similar names when they do similar things. This makes the language easier to learn. Clojure also runs on top of the Java Virtual Machine making interoperation with the vast Java third party libraries one of its attractive features.
Sweet dreams, don’t forget to tell the ones you love that you love them, and most important of all, be kind.