Why should I learn Lisp? [closed]

Question

I really feel that I should learn Lisp and there are plenty of good resources out there to help me do it.

I'm not put off by the complicated syntax, but where in "traditional commercial programming" would I find places it would make sense to use it instead of a procedural language.

Is there a commercial killer-app out there that's been written in Lisp ?

Answer 1

Killer app? The flight search engine by ITA Software is one.

As for "why", it will most probably make you a better developer and is extremnely unlikely to make you a worse one. It may, however, make you prefer lisp dialects to other languages.

Answer 2

One of the main uses for Lisp is in Artificial Intelligence. A friend of mine at college took a graduate AI course and for his main project he wrote a "Lights Out" solver in Lisp. Multiple versions of his program utilized slightly different AI routines and testing on 40 or so computers yielded some pretty neat results (I wish it was online somewhere for me to link to, but I don't think it is).

Two semesters ago I used Scheme (a language based on Lisp) to write an interactive program that simulated Abbott and Costello's "Who's on First" routine. Input from the user was matched against some pretty complicated data structures (resembling maps in other languages, but much more flexible) to choose what an appropriate response would be. I also wrote a routine to solve a 3x3 slide puzzle (an algorithm which could easily be extended to larger slide puzzles).

In summary, learning Lisp (or Scheme) may not yield many practical applications beyond AI but it is an extremely valuable learning experience, as many others have stated. Programming in a functional language like Lisp will also help you think recursively (if you've had trouble with recursion in other languages, this could be a great help).

Answer 3

I took a "lisp class" in college back in the eighties. Despite grokking all the concepts presented in the class, I was left without any appreciation for what makes lisp great. I'm afraid that a lot of people look at lisp as just another programming language, which is what that course in college did for me so many years ago. If you see someone complaining about lisp syntax (or lack thereof), there's a good chance that they're one of those people who has failed to grasp lisp's greatness. I was one of those people for a very long time.

It wasn't until two decades later, when I rekindled my interest in lisp, that I began to "get" what makes lisp interesting--for me anyway. If you manage to learn lisp without having your mind blown by closures and lisp macros, you've probably missed the point.

Answer 4

This is a topic i myself have pondered for a while but I have not really come to a decision, as usual time is the main problem... ;)

And since I can´t find these links sofar in this post i add them for public interest:

Success and Failure story: Lisping at JPL

Really impressive success story: Lisp in use at the Orbitz corporation

Comparison and analysis of whether to use Lisp instead of Java: Lisp as an Alternative to Java

Answer 5

Killer app? Franz Inc. has a long list of success stories, but this list only includes users of AllegroCL... There are probably others. My favourite is the story about Naughty Dog, since I was a big fan of the Crash Bandicoot games.

For learning Common Lisp, I'd recommend Practical Common Lisp. It has a hands-on approach that at least for me made it easier than other books I've looked at.

Answer 6

From http://www.gigamonkeys.com/book/introduction-why-lisp.html

One of the most commonly repeated myths about Lisp is that it's "dead." While it's true that Common Lisp isn't as widely used as, say, Visual Basic or Java, it seems strange to describe a language that continues to be used for new development and that continues to attract new users as "dead." Some recent Lisp success stories include Paul Graham's Viaweb, which became Yahoo Store when Yahoo bought his company; ITA Software's airfare pricing and shopping system, QPX, used by the online ticket seller Orbitz and others; Naughty Dog's game for the PlayStation 2, Jak and Daxter, which is largely written in a domain-specific Lisp dialect Naughty Dog invented called GOAL, whose compiler is itself written in Common Lisp; and the Roomba, the autonomous robotic vacuum cleaner, whose software is written in L, a downwardly compatible subset of Common Lisp. Perhaps even more telling is the growth of the Common-Lisp.net Web site, which hosts open-source Common Lisp projects, and the number of local Lisp user groups that have sprung up in the past couple of years.