YAML 新手：不在 Swift 中解析

Question

这是我生成的一些 yaml ：

byTeam:
    - t0: { description: "Find a video of an object being selected and deselected", bestAnswer: [ 0 ]}
    - t1: { description: "Reveal and hide numeric controls", bestAnswer: [ 1 ]}
    - t2: { description: "Reveal and hide the tools", bestAnswer: [ 2 ]}

解析此错误时遇到的错误是：

no decode typeMismatch(Yams.Node.Mapping, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "assignments", intValue: nil), _YAMLCodingKey(stringValue: "Index 1", intValue: 1), CodingKeys(stringValue: "challenges", intValue: nil), _YAMLCodingKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "byTeam", intValue: nil)], debugDescription: "Expected to decode Mapping but found Node instead.", underlyingError: nil))

这是新数据，进一步嵌套到已经工作的 yaml 文件中。它最终会被解析成这个结构：

    struct CodableChallenge : Codable {
        var title :                     String
        var type :                      String
        var description :               String
        var uuid :                      UUID
        var videos :                    Array<String>
        var bestAnswer :                Array<Int>
        var userAnswer :                Array<Int>?
        var byTeam :                    Dictionary<String, TeamChallenge>?
    }
    
    struct TeamChallenge : Codable {
        var description :               String
        var bestAnswer :                Array<Int>
    }

产生错误的代码是

 do {
            let decoded = try decoder.decode(MenuScreenVC.CodableCurriculum.self, from: src)
            manifestObsolete = curriculum == nil || decoded.referenceDate! > curriculum!.referenceDate!
            self.newManifest = decoded
            NotificationCenter.default.post(name: NSNotification.Name("gotManifest"), object: nil)
            return
        } catch {
            print("no decode \(error)")
        }

我对 yaml 并不完全陌生，我很多年前就在 RoR 中使用过它。但我认为我没有注意到的是更深层次的嵌套。该错误似乎表明它获取的数据看起来不像简单的映射，但为什么呢？

Answer 1

您以一种没有意义的方式混合数组和字典，并且与您的代码所期望的不匹配。

每个刻度线都会启动一个新对象。每个带有冒号后缀的标签都标记对象中的一个键。所以你写的已经生效了：

byTeam: [
    { t0: { ... } },
    { t1: { ... } },
    { t2: { ... } },
]

您只需删除这些

tN

值即可：

byTeam:
    - { description: "Find a video of an object being selected and deselected", bestAnswer: [ 0 ]}
    - { description: "Reveal and hide numeric controls", bestAnswer: [ 1 ]}
    - { description: "Reveal and hide the tools", bestAnswer: [ 2 ]}