Builder Pattern - Block

BuilderBlock.swift

// We reuse the above SportCarBuilder, we just change some interface
// Notice we instead are using the block for update the necessary properties
class SportCar {
  typealias Builder = (builder: SportCarBuilder) -> Void

  private init(builder: SportCarBuilder) {
    super.init(doors: Door(2), engine: Engine(V85000), wheel: builder.wheel, color: builder.color)
  }

  static func make(with builderBlock: Builder) -> SportCar {
    let builder = SportCarBuilder()
    builderBlock(builder)
    return SportCar(builder: builder)
  }
}

// This is the way we will use by defining the properties inside the block
let sportCar = SportCar.make { builder in
  builder.color = .red
  builder.wheel = .racing
}