不能調用從協議擴展斯威夫特

Question

通用的初始化我試圖調用一個struct我從一個協議擴展方法做我也做了：

public struct AdjacentDifferenceArrayGenerator<T: Strideable where T.Stride == T>: GeneratorType { 
    private var array: [T] 
    public init<U: SequenceType where U.Generator.Element == T>(source: U) { 
     self.array = source.adjacentDifference() 
    } 
    public mutating func next() -> [T]? { 
     guard !array.isEmpty else { 
      return nil 
     } 
     defer { 
      self.array = self.array.adjacentDifference() 
     } 
     return self.array 
    } 
} 

public extension SequenceType where Generator.Element: Strideable { 
    public func adjacentDifference() -> [Self.Generator.Element.Stride] { 
     var result: [Self.Generator.Element.Stride] = [] 
     var generator = AdjacentDifferenceGenerator(generator: self.generate()) 
     while let difference = generator.next() { 
      result.append(difference) 
     } 
     return result 
    } 
} 

public extension SequenceType where Generator.Element: Strideable, Generator.Element.Stride: Strideable, Generator.Element.Stride.Stride == Generator.Element.Stride { 
    public func pyramidOfAdjacentDifferences() -> [[Self.Generator.Element.Stride]] { 
     var result: [[Self.Generator.Element.Stride]] = [] 
     var array = self.adjacentDifference() 
     while !array.isEmpty { 
      result.append(array) 
      array = array.adjacentDifference() 
     } 
     //var generator = AdjacentDifferenceArrayGenerator(source: self) 
     //while let differences = generator.next() { 
      //result.append(differences) 
     //} 
     return result 
    } 

正在接近尾聲評論四條線，在替代算法之後，試圖使用與第一個擴展中的方法相同的算法。當我取消註釋掉這些行中的第一行時，遊標在「AdjacentDifferenceArrayGenerator」處等待，並說：「不能調用類型爲'AdjacentDifferenceArrayGenerator < _>'的初始值設定項，其類型爲'（source：Self）'的參數列表'」最後一個「Self 「在錯誤消息中大寫，儘管它在代碼中沒有大寫。在類型和初始化參數之間添加一個顯式的模板括號沒有幫助。有任何想法嗎？

Answer 1

我周圍有通過取出第一次迭代：

public extension SequenceType where Generator.Element: Strideable, Generator.Element.Stride: Strideable, Generator.Element.Stride.Stride == Generator.Element.Stride { 
    public func pyramidOfAdjacentDifferences() -> [[Self.Generator.Element.Stride]] { 
     var result = [self.adjacentDifference()] 
     if result.first!.isEmpty { 
      return [] 
     } 

     var generator = AdjacentDifferenceArrayGenerator(source: result.first!) 
     while let differences = generator.next() { 
      result.append(differences) 
     } 
     return result 
    } 
} 

我要測試，如果是第一次迭代的結果是合法的，因爲服用圈外意味着我失去了自動檢查。我不知道是否使用「self」是問題，或者它是使用通用序列而不是確定性數組是問題所在。在這裏仍然需要幫助....