Protocols All The Way Down - dotSwift, Paris, January 2018

A talk about the benefits and drawbacks of Protocol Oriented Programming, and protocols with default implementations.

Video:
https://www.dotconferences.com/2018/01/ellen-shapiro-protocols-all-the-way-down

Playground:
https://github.com/designatednerd/ProtocolPlayground

Transcript

1. PROTOCOLS
   ALL THE WAY DOWN
   DOT SWIFT | PARIS, FRANCE | JANUARY 2018
   @DESIGNATEDNERD | BAKKENBAECK.COM | JUSTHUM.COM
   

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3. PROTOCOL-ORIENTED
   PROGRAMMING
   

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6. PROTOCOL-ORIENTED
   PROGRAMMING
   

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7. PROTOCOLS WITH
   DEFAULT IMPLEMENTATIONS
   

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12. DEFAULT PROTOCOL IMPLEMENTATION
    extension
    

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26. CONDITIONAL
    DEFAULT PROTOCOL IMPLEMENTATION
    extension
    

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31. extension
    

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36. where Self:...
    

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39. github.com/designatednerd/
    ProtocolPlayground
    

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46. MULTIPLE
    where CLAUSES
    

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59. SUBCLASS-LIKE BEHAVIOR
    WITHOUT
    THE BAGGAGE OF SUBCLASSING
    

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60. CENTRALIZATION!
    DRY CODE!
    

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61. NO INSANE
    INHERITANCE TREES
    

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62. PROTOCOL-ORIENTED
    ! PITFALLS
    

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63. POP QUIZ
    

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72. TYPE INFERENCE: !
    

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73. TYPE INFERENCE: !
    

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74. TYPE INFERENCE: !
    

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75. SPECIFYING PROTOCOL TYPE: !
    

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76. SPECIFYING PROTOCOL TYPE: !
    

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77. SPECIFYING PROTOCOL TYPE: !
    

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78. SPECIFYING PROTOCOL TYPE: !
    

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79. SPECIFYING PROTOCOL TYPE: !
    

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83. DEFAULT IMPLEMENTATIONS
    VS.
    EXTENSIONS
    VS.
    SUBCLASSES
    

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84. DEFAULT IMPLEMENTATIONS
    **(PLAIN VANILLA OR CONDITIONAL)
    VS.
    EXTENSIONS
    VS.
    SUBCLASSES
    

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85. > Do I need this to work on all instances and/or
    subclasses of a particular thing?
    Extension!
    > Do I need this method to work only when I say it should,
    or in a particular combination of circumstances?
    Default implementation!
    > Does this always need to be called from a particular
    lifecycle or delegate method?
    Subclass!
    

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86. CHOOSE YOUR TOOLS
    WISELY
    

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88. ! MERÇI BEAUCOUP! !
    

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89. LINKS!
    > Protocol-Oriented Programming, WWDC 2015
    developer.apple.com/videos/play/wwdc2015/408
    > The ghost of Swift Bugs Future, Alexandros Salazar
    nomothetis.svbtle.com/the-ghost-of-swift-bugs-
    future
    

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90. PHOTO CREDITS!
    > Businessman, by Daniel X. O'Neil
    flickr.com/photos/juggernautco/6037175371
    > Hammered Screw, by Justin Baeder
    flickr.com/photos/justinbaeder/5317820857
    > Knot, by JP Davidson
    flickr.com/photos/jpdavidsonimages/4677642617
    

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