Getting Started With Clojure

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My first steps in learning Clojure and setting things up.

Get inspired

Start with Leiningen

Since Clojure is a Jar file there is no Clojure binary to install. You just need a Java JVM and Leiningen.

Leiningen is like Gemfile and Rakefile in Ruby, plus much more.

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brew install leiningen

(or use your preferred package manager)

Start a new project

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lien project new playground

By default a command-line app is generated. You can get a different starting point by specifying a template, for example Figwheel for ClojureScript, Play for dekstop and mobile games, or Luminus for websites.

A commandline app is packaged as an uberjar, that is a jar file which includes all it’s dependencies.

You can build the uberjar:

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lein uberjar

and run it using java -jar playground-0.1.0-standalone.jar.

REPL

The REPL (Read Eval Print Loop), like Irb in Ruby, can be started with lein:

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lien repl

In the REPL we can requie and run our newly created app:

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(require 'playground.core) ; require the app
(playground.core/-main)    ; run the app

In the source playground.core is a namespace and -main is a function. The -main function is used as an entry point for the uberjar, it is passed the commandline arguments as its arguments.

The REPL is the best place to start experimenting with Clojure syntax.

Tests

This is just here for compleness, I don’t intend to write any tests for quite a while.

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lien test

Run

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lien run

For more detailed information about Lein see the leiningen tutorial.

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