My talk at Geek2Geek, where i gave little talk about first steps into Clojure.

2. (apply fun clojure)
Geek<->Geek

3. {:name “Timo Sulg”
:from “VersionEye”
:at “Geek2Geek”
:twitter “@timgluz”}

4. Path to Clojure

5. Formal introduction

6. Clojure

7. Clojure philosophy
source: “The Joy of Clojure”, M.Fogus

8. Language basics

9. Primitives
integers 42, -107, 0x7f,
2r01011001, 32r3V
floats 1.17, -2. , 366e7, 32e-14,
10.7e-3
rationals 22/2 , -7/22 , -103/4
symbols sym + def
keywords :2 :chumby :?
characters a space 0042
strings “this is string”

10. Functions
+ inplace functions
#(say %1)
+ anonymous functions
(fn [x y] (+ x y))
+ named-functions
(def add2 (fn [x y] (+ x y)))
(defn add2 (+ x y))
(defn addN
([] 0) ([x] x) ([x y] (+ x y)))) ;; function arity

11. Seq(uence)
“It is better to have 100 functions operate on
one data structure than to have 10 function
operate on 10 data structures”,
Alan J. Perlis

12. Clojure Collections
+ Lists
(:yankee :hotel :foxtrot)
+ Vectors
[1 :a 2 :b] (vector 1 2 4) (apply vector ‘(1 3 4))
+ Hash-maps
{1 :one, 2 :two 3 :three}
+ Sets
#{:first :second :third}

13. Loops
high-order functions
(map sqr [1 2 3])
(reduce + [1,2,3])
list comprehensions
(for [word [“the” “quick”
“tutorial”]]
(format “<p>%s</p>”
word))
recursion
(defn print-down-from [x]
(when (?pos x)
(println x)
(recur (dec x))))

14. STM
“STM - what, why, how” - http://sw1nn.com/blog/2012/04/11/clojure-stm-what-why-how/

15. Mutation primitives and concurreny
“Refs and transactions, STM” http://clojure.org/refs
REF Agent Atom Var
Coordinated
✓
Asynchronous
✓
Retriable
✓ ✓
Thread-local
✓

16. Interoperability
“Programming Clojure”, C.Emerick, p.44

17. Bla-bla, it’s all here

18. Little reality check

20. Ugly side and why it’s okay.
- clumzy lazyness
- dynamic typing
- microbenchmarks
- exception vomit
- young ecosystem
- lack of good docs

21. Vox Populi
survey by Chas Emerick
3 most important graphs
Results: http://java.dzone.com/articles/results-2012-state-clojure

26. Quil - processing in Clojure

27. Overtone - rock on REPL
checkout: meta-ex.com

28. Incanter - hammer your statistics

29. Datomic

30. Other Rockstars
data processing
(Storm, Cascalog, Incanter, Core.logic)
data pipelining
(Aleph, Plumbing, Core/async)
Web
(Hiccup, Ring, Dommy, Luminus, Pedestal)
Graphs
(d2, quil)
Music
(overtone, checkout meta-ex.com)

31. Hands on REPL

32. Installing lein
1. Download the lein script
(or on Windows lein.bat)
2. Place it on your $PATH
(eg. ~/bin)
3. Set it to be executable
(chmod a+x ~/bin/lein)

33. Editors
Clooj / Catnip
ps: there’s plugins for all mainstream IDEs

34. Sample workflow
> lein new geek2geek
> cd & geek2geek
> ls -a
> vim project.clj
> lein deps
> lein repl

35. tryClojure
online REPL http://tryclj.com/
download Android App
homebrew
lein-try
Shortcuts to Clojure

36. Demos
On REPL
File IO
API access
Quil

37. Demo 1 - FoxyEye

38. Demo 1 - FoxyEye
Experimental
Firefox OS
App
Clojure
ClojureScript

39. Sources

40. Books
1. “Clojure Programming” by Chas Emerick
http://shop.oreilly.com/product/0636920013754.do
2. “Joy of Clojure”, by Micheal Fogus & Chris Houser
http://shop.oreilly.com/product/0636920013754.do
3. Clojure Cookbook, by community
http://clojure-cookbook.com/

41. Websites
quick ref:
http://clojuredocs.org/quickref/Clojure%20Core
Cheetsheet:
http://clojure.org/cheatsheet
Clojure page on VersionEye:
http://versioneye.com/clojure
Talks:
http://www.youtube.com/user/clojuretv

42. AFAIK
Clojure Berlin’s meetup, 4th September: http:
//www.meetup.com/Clojure-
Berlin/events/123414852/
ClojureCup - end of September, http:
//clojurecup.com/
EuroClojure - 14/15th October, http:
//euroclojure.com/2013/

43. Thank you!