Where to find valid version numbers for dependencies in Leiningen

I'm new to Cloj开发者_如何学Cure and Leiningen, and I've determined that some of what I'll want to use is located in clojure.contrib.generic.math-functions. I found API information for that at http://richhickey.github.com/clojure-contrib/branch-1.1.x/math-api.html, but I can't find anything that helps me figure out what I should put into my project.clj file for that dependency.

I have tried [clojure.contrib.generic.math-functions "1.1"], [clojure.contrib.generic.math-functions "1.1.x"], and [clojure.contrib.generic.math-functions "1.1.0"]. For each of those, I get something like...

...
Caused by: org.apache.maven.artifact.resolver.MultipleArtifactsNotFoundException: Missing:
----------
1) clojure.contrib.generic.math-functions:clojure.contrib.generic.math-functions:jar:1.1

All clojure-contrib namespaces are shipped within a single jar file, for which the dependency has to be listed like:

[org.clojure/clojure-contrib "1.2.0"]

Please note that there are different versions available of that artifact. The 1.2.0 is the current stable release.

In order to use functions coming from the math-functions namespace in your clojure code, you need to either require or use such namespace, usually done within the ns form at the beginning of your source file:

(ns my.namespace
    (:use [clojure.contrib.generic.math-functions]))

Have a look here to see the differences between use and require.

The next version of Leiningen will have a search task for precisely this purpose. It will search Clojars, Maven Central, and any other repositories your project has listed, provided they offer up downloadable indices. It's already implemented, so if you run Leiningen from git you can use it.

Also, the Leiningen tutorial covers this. Type "lein help tutorial".

You can generally find what you need at clojars.org - it's the default repository for leiningen. The current stable release of Clojure is 1.2.0, so you'd have this in your leiningen project.clj:

[org.clojure/clojure "1.2.0"]
[org.clojure/clojure-contrib "1.2.0"]

To use the generic math functions in your clojure, require or use it in your namespace declaration at the top of your source file:

(ns your-namespace
    (:use [clojure.contrib.generic.math-functions :as mathf]))

This allows you to refer to the functions in that namespace like this:

(mathf/abs -10) ;; => 10

:use-ing namespaces with :as is the preferred way to use functions from other namespaces in your code. require is ok, but you'd have to prefix your functions with the entire namespace (e.g. clojure.contrib.generic.math-functions/abs) so that's not practical. Using a namespace without :as allows you to use these functions without any prefix at all (e.g. abs), but you're more likely to get namespace clashes and it might be difficult to see where functions come from, especially if you :use many libraries.

You can browse all libraries available from the default leiningen repository by checking out http://clojars.org/repo/. The structure of clojure-contrib will change when 1.3.0 is out, so you'll have to include the specific contrib library if you're using version 1.3.0-alpha-xx:

[org.clojure.contrib/generic "1.3.0-alpha4"]

Now that the clojure.contrib has been broken up, the math functions are in something called math.numeric-tower. The lein dependency is specified like this:

[org.clojure/math.numeric-tower "0.0.1"]

You can use or require as seems appropriate, for example

(use '[clojure.math.numeric-tower])