At the 16:43 mark of WWDC20 session 10189 is this code snippet:
func handleIncomingFile(_ incomingResourceURL: URL, with name: String, from fromID: String) {
guard
case let safeFileName = name.lastPathComponent,
safeFileName.count > 0,
safeFileName != "..", safeFileName != "." else { return }
let destinationFileURL = URL(fileURLWithPath: NSTemporaryDirectory())
.appendingPathComponent(safeFileName)
// Copy the file into a temporary directory
try! FileManager.default.copyItem(at: incomingResourceURL, to: destinationFileURL)
}
There is no documentation of guard case let
in the official language guide. All resources I found online are dated about 4 years back, written for Swift 2. The best one I found is this write-up that covers if case let
, guard case let
, and for case let
.
Because there were a lot of source breaking changes between Swift 2 and 5, and because these expressions are not documented in the language guide, I wonder if they have been replaced by other expressions?