Is there a way of producing a playground app? - swift-playground

Question

Xcode newbie.(me.dumb)
First time poster.
I have the following code and it tested flawlessly in Xcode Playground(h/t D.Budd Data Science).
I want to turn the code into a MacOS app and I cannot fathom the correct Project and Settings
to do this or do I need to import the Playground into a Project and modify it?
Also this app needs to run in the background (ie, no Window/UI) as this would destroy the current window scene(MagicMirror), sort of like an Automater app can do. It would have an app icon, of course.
Thanks so much for any help.
import Cocoa
extension String{
// get the file name from string
func fileName() -> String{
return URL(fileURLWithPath: self).deletingPathExtension().lastPathComponent
}
// get the file extension from a string
func fileExtension() -> String{
return URL(fileURLWithPath: self).pathExtension
}
}
func readFile(inputFile: String) -> String{
//split the file extension and file name
let fileExtension = inputFile.fileExtension()
let fileName = inputFile.fileName()
//get the file URL
let fileURL = try! FileManager.default.url(for: .desktopDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let inputFile = fileURL.appendingPathComponent(fileName).appendingPathExtension(fileExtension)
//get the data
do{
let saveData = try String(contentsOf: inputFile)
return saveData
} catch {
return error.localizedDescription
}
}
func writeFile(outputFile: String, stringData: String){
let fileExtension = outputFile.fileExtension()
let fileName = outputFile.fileName()
//get the fileURL
let fileURL = try! FileManager.default.url(for: .desktopDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let outputFile = fileURL.appendingPathComponent(fileName).appendingPathExtension(fileExtension)
//save the data
guard let data = stringData.data(using: .utf8) else {
print("No Can Do")
return
}
do {
try data.write(to: outputFile)
print("data written: /data")
} catch {
print(error .localizedDescription)
}
let myData = readFile(inputFile: "test.txt")
writeFile(outputFile: "output.txt", stringData: myData)
}