我有两种结构体,Header
和Session
,都符合协议TimelineItem
。
我的一个Array
由TimelineItem
组成,像这样:
[Header1,SessionA,SessionB,Header2,SessionC,SessionD]
我需要将Session
分组到相关的Header
下,就像这样:
[[Header1:[SessionA,SessionB],[Header2:[SessionC,SessionD]]]
我尝试使用filter
方法检索仅Header
结构,并使用split
方法检索Session
数组的数组。 这些方法都可以正常工作,但我无法管理如何将它们协调起来构建我的最终 [[Header:[Session]]]
对象。
以下是我的示例代码:
enum TimelineItemType: String {
case Header = "header"
case Session = "session"
}
protocol TimelineItem {
var id: Int { get }
var type: TimelineItemType { get }
var startDate: NSDate { get }
}
Header
结构体
struct Header: TimelineItem, Decodable, Hashable, Equatable {
let id: Int
let type: TimelineItemType = .Header
let startDate: NSDate
let text: String
init?(json: JSON) {
guard let id: Int = "id" <~~ json,
let type: TimelineItemType = "type" <~~ json,
let startDate: NSDate = "startDate" <~~ json,
let text: String = "text" <~~ json where type == .Header else {
return nil
}
self.id = id
self.startDate = startDate
self.text = text
}
var hashValue: Int {
// As id is unique, we can use it for hash purpose
return id
}
}
Session
结构体
struct Session: TimelineItem, Decodable, Equatable {
let id: Int
let type: TimelineItemType = .Session
let startDate: NSDate
let name: String
let syllabus: String
let speaker: Speaker
let language: String
let room: String
let duration: Int
init?(json: JSON) {
guard let id: Int = "id" <~~ json,
let type: TimelineItemType = "type" <~~ json,
let startDate: NSDate = Decoder.decodeDateISO8601("startDate")(json),
let name: String = "name" <~~ json,
let speaker: Speaker = "speaker" <~~ json,
let syllabus: String = "syllabus" <~~ json,
let language: String = "language" <~~ json,
let room: String = "room" <~~ json,
let duration: Int = "duration" <~~ json where type == .Session else {
return nil
}
self.id = id
self.startDate = startDate
self.name = name
self.speaker = speaker
self.syllabus = syllabus
self.language = language
self.room = room
self.duration = duration
}
}
最后是我尝试分割数组的代码:
func timelineFromItems(timelineItems: [TimelineItem]) -> [[Header: [Session]]]? {
let slicedSessions = timelineItems.split { $0 is Header }
let sessions = Array(slicedSessions)
let headers = timelineItems.filter { $0.type == .Header }
var timeline = [[Header: [Session]]]()
// HOW TO FILL THE TIMELINE ??
}
HOW TO FILL THE TIMELINE ?
for
语句中缺少开头的{
。 - GULsessions[index]
中出现了Ambiguous reference to subscript
。 - GUL