0x1 有序集合diff
//bird [b,i,r,d]
//bear [b,e,a,r]
let diff = bird.difference(from:bear)
let newBird = bear.applying(diff) //[b,i,r,d]
0x2数据连续性
struct Data使用protocol ContiguousBytes 做了内存数据连续性优化
public protocol ContiguousBytes {
func withUnsafeBytes(_ body: (UnsafeRawBufferPointer) throws -> R) rethrows -> R
}
对于其他类型使用了下面的某个协议做了优化
public protocol DataProtocol: RandomAccessCollection where Element == UInt8, ... { }
public protocol MutableDataProtocol : DataProtocol, MutableCollection, RangeReplaceableCollection { }
已适配protocol的类型 Data [UInt8] DispatchData
0x3数据压缩
let compressed = try data.compressed(using: .lzfse)
public enum CompressionAlgorithm : Int { case lzfse
case lz4
case lzma
case zlib
}
0x4单位
UnitDuration
- Added milliseconds, microseconds, nanoseconds, and picoseconds
UnitFrequency
- Added framesPerSecond
UnitInformationStorage
- bits, bytes, nibbles for common usage
- SI- and binary-prefixed units (kilo, kibi, ... yotta, yobi) Format with MeasurementFormatter - and ByteCountFormatter
0x5日期展示
let formatter = RelativeDateTimeFormatter()
let dateString = formatter.localizedString(for: aDate, relativeTo: now)
// en_US: "2 weeks ago"
// es_ES: "hace 2 semanas"
// zh_TW: "2 週前"
let string = ListFormatter.localizedString(byJoining: ["
// en_US: ", , and "
// es_ES: ", y "
// zh_TW: ", 和 "
image.png
let listFormatter = ListFormatter() let dateFormatter = DateFormatter()
listFormatter.itemFormatter = dateFormatter let string = listFormatter.string(from: dates)
// en_US: "8/15/19, 9/13/19, and 2/1/20"
// es_ES: "15/8/19, 13/9/19 y 1/2/20”
0x6 Operation Queue
- 支持addBarrierBlock
queue.addBarrierBlock {
save()
}
- 进度报告
let queue = OperationQueue()
queue.progress.totalUnitCount = 3
queue.addOperation {
task1() // Finished task: 1 / 3
}
queue.addOperation {
task2() // Finished task: 2 / 3
}
queue.addOperation {
task3() // Finished task: 3 / 3
}
0x7 USB 和 SMB
- 选择存储位置时使用FileManager.SearchPathDirectory.itemReplacementDirectory
- 对于可能挂掉的卷使用Data.ReadingOptions.mappedIfSafe 来安全存储
0x8 swift5 API简化
// Swift 4
var nameNSString: NSString?
if scanner.scanUpToCharacters(from: .newlines, into: &nameNSString) {
let name = nameNSString! as String
}
// Swift 5.1
let nameString = scanner.scanUpToCharacters(from: .newlines)
let matchedString = scanner.scanString(string: "hi, $")
- FileHandle 支持 try
let fileHandle = FileHandle()
let data = try fileHandle.readToEnd()
extension FileHandle {
public func write(contentsOf data: T) throws
}