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let  swift:  Race? Jack Nutting @jacknutting jacknutting@mac.com

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let  swift:  Race?

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struct  Sun  {          let  swift:  Race?          let  strong:  Battle?          let  wise:  Bread?          let  intelligent:  Riches?          let  knowledgeable:  Favor?        init()  {                  swift                  =  TimeAndChance()  ?  Race()      :  .None                  strong                =  TimeAndChance()  ?  Battle()  :  .None                  wise                    =  TimeAndChance()  ?  Bread()    :  .None                  intelligent      =  TimeAndChance()  ?  Riches()  :  .None                  knowledgeable  =  TimeAndChance()  ?  Favor()    :  .None          }   }

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let  swift:  Race?

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No content

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[[somePeople  like:ObjectiveC]  evenIn:2015]

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[[[[[[receiver  method]  method]  method]          method]  method]  method]; receiver.method().method().method()          .method().method().method()

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Static fixed, stable, steady, consistent motionless, frozen, inert, lifeless

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enum

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enum  Button  {          case  Rectangular(bounds:  CGRect,  title:  String,  font:  UIFont)          case  RoundedCorners(bounds:  CGRect,  title:  String,  font:  UIFont,                  radius:  CGFloat)   }  

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extension  Button  {          func  draw()  {                  switch  self  {                  case  let  .Rectangular(bounds,  title,  font):                          drawRectangleButton(bounds,  title,  font)                  case  let  .RoundedCorners(bounds,  title,  font,  radius):                          drawRoundedRectangleButton(bounds,  title,  font,  radius)                  }          }   }

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extension  Button  {          func  buttonOfPreferredSize()  -­‐>  CGSize  {                  switch  self  {                  case  let  .Rectangular(bounds,  title,  font):                          return  preferredSizeForRectangleButton(bounds,                                  title,  font)                  case  let  .RoundedCorners(bounds,  title,  font,  radius):                          return  preferredSizeForRoundedRectangleButton(bounds,                                  title,  font,  radius)                  }          }   }

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• My Way or the Highway • Eternal Vigilance • Boilerplate

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If a huge chunk of your enum’s code is just switching on the type, maybe you should just use a set of classes.

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Using struct instead of class Marking classes as final Marking methods as final

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Future developers will want the flexibility to extend your system in ways you can’t foresee.

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–Sir Tony Hoare “Premature optimization is the root of all evil.”

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C++

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–Jack Nutting “All of C++ is premature optimization.”

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Functional Programming is not a silver bullet

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http://chris.eidhof.nl/ posts/lenses-in-swift.html

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https://www.destroyallsoftware.com/ talks/boundaries

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Conclusions Sometimes enums aren’t the answer. Static has drawbacks. All of C++ is premature optimization. FP is not a silver bullet.

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Jack Nutting @jacknutting jacknutting@mac.com let  swift:  Race?