Contributing to Swift

Before Swift was open sourced, our only way to communicate with Apple was through Radar. Filing Radars is an arcane, opaque, and frequently frustrating process. But now we have a whole host of ways to chat directly to Apple engineers, all the way from mailing lists to Twitter messages. Even better than that we can actually dig through large bits of the code we use every day, and see how it works. And then when we find something we think could be better we can fix it! Thats exactly what I did, and last summer a small piece of my code shipped with Xcode 8, and most of you have probably used it. In this talk I’ll tell the story of exactly how that came to be, and explore ways that you can get involved too.

Transcript

1. Contributing
   to Swift
   by @neilkimmett
   

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2. Contributing
   to Swift
   - a little revision
   - story of my contribution
   - ways you can contribute
   - gnarly details
   

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3. struct CGPoint {
   var x: CGFloat
   var y: CGFloat
   }
   struct CGSize {
   var width: CGFloat
   var height: CGFloat
   }
   struct CGRect {
   var origin: CGPoint
   var size: CGSize
   }
   

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4. struct CGPoint {
   static var zero: CGPoint
   }
   struct CGSize {
   static var zero: CGSize
   }
   struct CGRect {
   static var zero: CGRect
   }
   x: 0
   y: 0
   width: 0
   height: 0
   origin: {0, 0}
   size: {0, 0}
   

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5. view.frame.origin =
   let view = UIView()
   …
   .zero
   

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6. struct UIEdgeInsets {
   var top: CGFloat
   var left: CGFloat
   var bottom: CGFloat
   var right: CGFloat
   }
   

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7. view.layoutMargins =
   let view = UIView()
   …
   UIEdgeInsetsZero
   .zero
   
   

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15. http://bugreport.apple.com/
    

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19. http://bugreport.apple.com/
    

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21. https://swift.org
    

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22. https://github.com/apple/swift
    

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33. ‼
    

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36. https://github.com/apple/swift/pull/1323
    

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41. What can I do?
    

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42. “To be a truly great community, Swift.org
    needs to welcome developers from all walks
    of life, with different backgrounds, and with a
    wide range of experience. A diverse and
    friendly community will have more great ideas,
    more unique perspectives, and produce more
    great code. We will work diligently to make the
    Swift community welcoming to everyone.”
    

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43. https://lists.swift.org
    

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44. https://stylemac.com/hirundo/
    

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45. https://apple.github.io/swift-evolution/
    

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46. https://swiftweekly.github.io
    

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47. https://spec.fm/podcasts/swift-unwrapped
    

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48. @jckarter
    Joe Groff
    @UINT_MIN
    Jordan Rose
    @dgregor79
    Doug Gregor
    @tkremenek
    Ted Kremenek
    @ericasadun
    Erica Sadun
    @modocache
    Brian Gesiak
    

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50. https://bugs.swift.org
    

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51. https://github.com/apple/swift
    

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52. Ninja
    

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53. brew install cmake ninja
    

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54. git clone https://github.com/apple/swift.git
    mkdir swift-source
    cd swift-source
    ./swift/utils/update-checkout --clone
    

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56. ./swift/utils/build-script -h
    ./swift/utils/build-script -R -t
    

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57. LLVM
    

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58. LLVM
    IR
    x86
    executable
    clang
    swift
    Haskell
    ARM
    PowerPC
    frontend backend
    

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59. .swift
    AST SIL
    LLVM
    IR
    assembly
    executable
    parse SILGen
    IRGen
    LLVM
    

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60. swiftc
    -dump-ast
    -emit-silgen
    -emit-sil
    -emit-ir
    -emit-assembly
    add.swift
    

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61. let x = 1 + 1
    print(x)
    add.swift
    

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62. swiftc -dump-ast add.swift
    

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63. swiftc -dump-ast add.swift
    

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64. swiftc -emit-silgen add.swift | xcrun swift-demangle
    

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65. swiftc -emit-silgen add.swift | xcrun swift-demangle
    

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66. swiftc -emit-silgen add.swift | xcrun swift-demangle
    

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67. swiftc -emit-silgen add.swift | xcrun swift-demangle
    

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68. swiftc -emit-silgen add.swift | xcrun swift-demangle
    

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69. swiftc -emit-sil add.swift | xcrun swift-demangle
    

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70. swiftc -emit-ir add.swift | xcrun swift-demangle
    

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71. swiftc -emit-assembly add.swift | xcrun swift-demangle
    

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72. https://nicoleorchard.com/blog/compilers
    

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73. https://github.com/apple/swift-evolution
    Swift 5
    

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74. - ABI stability required
    - Generics and String features for stdlib
    - Memory ownership model
    - Source breaking changes have even higher bar than
    Swift 4
    - Every evolution proposal requires working
    implementation with test cases
    Swift 5
    

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75. No-one has any idea
    what they’re doing
    

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76. https://www.youtube.com/watch?v=GnT2ZeHVJe4
    

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77. https://news.realm.io/news/tryswift-jesse-squires-contributing-open-
    source-swift/
    Jesse Squires - Contributing to Open Source Swift
    

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78. https://news.realm.io/news/slug-russ-bishop-contributing-open-
    source-swift-proposal/
    Russ Bishop - Contributing to Swift: From Proposal to Shipped
    

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81. Thanks!
    from @neilkimmett
    

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