Leiningen's goals are slightly different than clrj's. Leiningen is more like a Maven type project descriptor/build system whereas cljr is more like an easy_install-esque tool. cljr can be used without creating a project.
Yes, but it does have a repl command, and a swank plugin, and I like using it as a virtualenv-type tool even when I'm not working on a project. (And most of the time I am. I find the best way to learn is to attempt to write a real piece of software, and it has the added bonus that I might be able to add something to my portfolio.)
What is Clojure performance like? I checked with http://shootout.alioth.debian.org and haven't found it there. We're doing some lightweight geometrical computations like figure intersections, etc (queued, not real time) and we built them in JRuby just for fun (JVM is a requirement here) so I'm wondering how would Clojure perform there.
I'm asking here because I don't know a bit of Lisp so I can't just quickly code a benchmark. Thanks!!
I tried to convince Isaac to include Clojure in the benchmarks. He will probably include it once Clojure 1.2 (which has implications for performance) is released, provided that all the benchmarks are ready.
Generally speaking, I found the following to be true:
Java < Scala < Clojure < ... < JRuby.
Clojure is relatively fast. It really depends on the program at hand, but in my experience, having to REALLY generalize, it's at least an order of magnitude faster than Ruby/JRuby.
Simplistic idiomatic Clojure is much faster than JRuby, but often a bit slower than Java and Scala depending on how much you rely on reflection.
However, if you push it, Clojure can be as fast as anything else on the JVM; it's just a matter of how much time you spend profiling and optimizing. In many cases you can output the exact same bytecode in Clojure that you'd get from a several-times-more-verbose Java program.
Keep it up Antonio! Even though my comment has nothing to do with Clojure, but I just wanted to let you know that I'm very impressed by quality of your average post. You're like Joel Spolsky of Web 2.0 :)
Ok, I'm totally a noob with Clojure, but I thought all I had to do was java -jar ~/clojure.jar and I got a REPL. Did something change recently? This seems like an awful lot more work than it should be.
