Considere usar Clojure/ClojureScript na sua próxima web App

1. Considere usar
Clojure/ClojureScript na
sua próxima web App
What is it and why is it interesting?

2. About me
devpaulomarques@gmail.com
in/devpaulomarques
fb/devpaulomarques
ADS Senac-RS
DomTI

3. “APRENDER UMA NOVA
LINGUAGEM DE
PROGRAMAÇÃO É SÓ
APRENDER A SINTAXE”
Algum amigo seu.

5. Timeline
● Lisp 1958
● Clojure 2007
● Clojure 1.0 2009
● Clojure 1.8 2016

6. What is Clojure?
Clojure is a functional Lisp
that targets the JVM and
enables simpler software
design.

7. Clojure is a Lisp

8. Clojure is a Lisp

9. Clojure is a Lisp
Code as data

10. Clojure is a Lisp
No sintax

11. It looks like this
(def a 1)
(def f (fn [x] (* 2 x)))
(f a) ;; 2
(f (+ a 10)) ;; 22

12. Clojure is a Lisp

13. REPL
Read-Eval-Print-Loop

14. Macros
(defmacro expect [value to|!to matcher match]
(let [assertion (if (= matcher 'be)
`(= ~value ~match)
`(~matcher value match))]
(if (= to|!to 'not-to)
`(is (not ~assertion))
`(is ~assertion))))
;; isso expande para:
(testing "Sum is working"
(is (not (= (+ 2 2) 3)))
(is (= (+ 2 1) 3)))

15. Macros
????

17. Macros
(defmacro expect [value to|!to matcher match]
(let [assertion (if (= matcher 'be)
`(= ~value ~match)
`(~matcher value match))]
(if (= to|!to 'not-to)
`(is (not ~assertion))
`(is ~assertion))))
;; isso expande para:
(testing "Sum is working"
(is (not (= (+ 2 2) 3)))
(is (= (+ 2 1) 3)))

18. Paradigms as Libraries
Design by Contract - core.contracts
Logic Programming - core.logic
Lightweight threads + channels -
core.async
Optional/Gradual Type system -
core.typed

19. What is Clojure?
Clojure is a functional Lisp
that targets the JVM and
enables simpler software
design.

20. Targets the JVM
Constructor
new Person("Paulo");
(Person. "Paulo")
Static Member
Math.PI // 3.141592653589793
Math/PI ;; 3.141592653589793
Instance Method
" Hello world! ".trim(); //Hello world!
(.trim " Hello world! ") ;;Hello world!

21. Targets the JVM
Chained Access
person.getAddress().getState().getCode();
(.. person getAddress getState getCode)

22. Targets the JVM
Chained Access
person.getAddress().getState().getCode();
(.. person getAddress getState getCode)
(macroexpand '(.. person getAddress getState getCode))
(. (. (. person getAddress) getState) getCode)

23. Targets the JVM
Multiple Updates
person.setFirstName("Ben");
person.setLastName("Mabey");
person.makePresenter();
(doto person (.setFirstName "Ben") (.setLastName "Mabey")
.makePresenter)

24. What is Clojure?
Clojure is a functional Lisp
that targets the JVM and
enables simpler software
design.

25. Clojure is functional
Avoid state changes
First class functions
High order functions

26. Why is Clojure interesting?
● Succinct

27. Why is Clojure interesting?
● Succinct
● Java Interop

28. Why is Clojure interesting?
● Succinct
● Java Interop
● Multi-threaded

29. Why is Clojure interesting?
● Succinct
● Java Interop
● Multi-threaded
● Lazy

30. Why is Clojure interesting?
● Succinct
● Java Interop
● Multi-threaded
● Lazy
● Fun
● ...

32. ClojureScript
JavaScript

33. ClojureScript

34. ClojureScript

35. Why ClojureScript
Google closure compiler

36. Why ClojureScript
Google closure compiler
Modularity

37. Why ClojureScript
Google closure compiler
Modularity
Immutability

38. Why ClojureScript
Google closure compiler
Modularity
Immutability
And...

39. REPL

40. React

41. Cljs + Reagent
Reagent
minimalistic interface between ClojureScript and React
Hiccup
Hiccup is a library for representing HTML in Clojure

42. Reagent

43. Reagent

44. Add
some
style

45. Garden

47. Cljs + Reagent + Garden

48. Thanks