Obtaining Closure with Anonymous Functions

Transcript

1. Obtaining Closure with Anonymous Functions @alc277

2. Functions&! Lambdas&! Anonymous&! Closures&! Fun.

3. Named Functions

4. Named Functions

5. Functions&! Lambdas&! Anonymous&! Closures&! Fun.

6. NAMED LAMBDA

7. Lambda Functions

8. None

9. Lambda Functions

10. Lambda Functions

11. Type Hinting

12. Wow much useful such amaze ! very programmer

13. Functions&! Lambdas&! Anonymous&! Closures&! Fun.

14. None

15. Anonymous Functions

16. Functions&! Lambdas&! Anonymous&! Closures&! Fun.

17. λ Closures Rasmus’s Throne Room

18. None

19. Lambda Variable Scope

20. Closure Variable Scope & “use”

21. Tricky Bit

22. Passing a Variable to a Lambda or Closure

23. None

24. Passing a Variable by Reference to a Lambda or Closure

25. None
26. None

27. Closure Class

28. Closure! {! ! /* Methods */! ! public bindTo ()

    { }! ! ! ! ! ! ! ! } PHP Closure Class ! ! ! ! public static bind () {}! ! ! ** double-secret function __invoke() { }! !
29. None

30. Reasons to use Closures • Variable Scope and Binding! •

    Don’t Pollute Namespace With Functions! • Map/Reduce/Filter! • Data Output! • Retrieving Records from Database

31. • Currying! • Fixed-point Combinators (Y- Combinator)! • Improved Performance

    (Memoization)! • Monads! • Dependency Injection Reasons to use Closures

32. Things to Avoid • create_function! • Closure::bind()

33. Map/Reduce/Filter

34. Map/Reduce/Filter with Lambda Credit: Fabien Potencier

35. Map/Reduce/Filter Credit: Fabien Potencier Map/Reduce/Filter with Closure

36. Currying Photo: Penn State Office of Research Communications.

37. Currying

38. DATA OUTPUT

39. Data Output

40. Data Output

41. Database Records

42. Data Output

43. Y-Combinator

44. Y-Combinator

45. Y-Combinator

46. None

47. Memoization

48. fib(5) = fib(3) + fib(4)! fib(3) = fib(1) + fib(2)!

    fib(1) = 1! fib(2) = fib(1) + fib(0)! fib(1) = 1! fib(0) = 0! fib(2) = 1 + 0 = 1! fib(3) = 1 + 1 = 2! fib(4) = fib(3) + fib(2)! fib(3) = fib(1) + fib(2)! fib(1) = 1! fib(2) = fib(1) + fib(0)! fib(1) = 1! fib(0) = 0! fib(2) = 1 + 0 = 1! fib(3) = 1 + 1 = 2! fib(2) = fib(1) + fib(0)! fib(1) = 1! fib(0) = 0! fib(2) = 1 + 0 = 1! fib(4) = 2 + 1 = 3! fib(5) = 3 + 2 = 5

49. Memoization

50. 1 1 2 1 3 2 4 3 5 5

    6 8 7 13 8 21 9 34 10 55 11 89 12 144 13 233 14 377 15 610 16 987

51. Memoization

52. None

53. Monads

54. MonadPHP Anthony Ferrara

55. Monads Credit: Anthony Ferrara

56. Monads Credit: Anthony Ferrara

57. Monads Credit: Anthony Ferrara

58. $posts = [! [“title" => "foo", "author" => [“name" =>

    "Bob", "email" => “bob@example.com”]],! [“title" => "bar", "author" => array("name" => "Tom", "email" => “tom@example.com”]],! [“title" => “baz"],! [“title" => "biz", "author" => array("name" => "Mark", "email" => “mark@example.com”]],! ]; Monads Credit: Anthony Ferrara

59. Monads Credit: Anthony Ferrara

60. Dependency! Injection

61. Dependency Injection

62. Dependency Injection

63. Dependency Injection

64. Dependency Injection

65. Dependency Injection