Introduction to Clojure for Java Devs

http://www.meetup.com/clojure-vienna/events/169764062/

Transcript

1. 4/16/2014 Clojure From A JVM Dev Perspective
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   Why Would You Want To Go From Java To
   Clojure?
   1. Simpler, more elegant
   • Focus on the problem you are trying to solve not the ceremony
   around your implementation language
   2. Dynamic, but good performance
   3. Powerful extensibility
   4. FP and concurrency features
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   What I Am Going To Show You Today
   1. Entry points to get started with Clojure
   2. Basic syntax for people coming from a C-style language
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   To Get a First Taste of Clojure
   1. There are multiple web-based offerings
   • http://tryclj.com/
   • http://clojurescriptkoans.com/
   2. No installation, no hassle
   3. Get to know the basics
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   http://clojurescriptkoans.com
   

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   If You Want To Install It On Your Machine
   1. You need Java. I assume you've got that already
   2. Leiningen is the easiest way to get started
   3. lein new your-new-app
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   http://leiningen.org/
   

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   http://dev.clojure.org
   

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   Let's look at some code
   

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   Java Clojure
   int i = 5 (def i 5)
   if(x == 0)
   return y
   else
   return z
   (cond (zero? x)
   y
   z)
   x * y * z (* x y z)
   foo(x, y, z) (foo x y z)
   foo.bar(x) (. foo bar x)
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    Sources:
    • Rich Hickey: Clojure. An Introduction for Java Programmers. (YouTube)
    • Michael Fogus/Chris Houser: The Joy of Clojure. Manning 2014 (MEAP)
    • Luke VanderHart, Ryan Neufeld: Clojure Cookbook. O'Reilly 2014
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