探検！SwiftyJSON演習

// 詳しい解説は下記
// https://trifort.jp/blog/development/%E6%8E%A2%E6%A4%9C%EF%BC%81swiftyjson-%E5%89%8D%E7%B7%A8/

struct SampleStruct {
    var object:Any?
}

// ここに実装を追加していきます
// [] を実装
extension SampleStruct {
    subscript(key: String) -> SampleStruct {
        get {
            return self
        }
        set {
            object = key
        }
    }
}

extension SampleStruct : SequenceType {
    // イテレータのようなもの
    typealias Generator = SampleGenerator
    func generate() -> Generator {
        return Generator()
    }
}

struct SampleGenerator : GeneratorType {
    typealias Element = Int

    var index = 0
    mutating func next() -> Element? {
        // 次がない場合は nil を返します
        if (index > 10) { return nil }
        return index++
    }
}

extension SampleStruct : CollectionType {
    typealias Index = Int
    var startIndex: Index { return 0 }
    var endIndex: Index { return 10 }

    subscript (position: Index) -> Generator.Element {
        return position
    }
}

extension SampleStruct : BooleanType {
    var boolValue:Bool { return true }
}

let sampleStruct = SampleStruct()

// try1
sampleStruct["sample"]
sampleStruct["sample"]["sample"]

// try2
sampleStruct.map({ $0 })
for element in sampleStruct { print(element) }

// try3
sampleStruct.first
for _ in sampleStruct.startIndex ..< sampleStruct.endIndex {}

// try4
if (sampleStruct) {}
while (!sampleStruct) {}