How to do it...

If you are implementing this in a new playground, enter the following:

struct PersonName { 
    let givenName: String 
    let middleName: String 
    var familyName: String 
     
    func fullName() -> String { 
        return "\(givenName) \(middleName) \(familyName)" 
    } 
     
    mutating func change(familyName: String) { 
        self.familyName = familyName 
    } 
} 

class Person { 
     
    let birthName: PersonName 
    var currentName: PersonName 
    var countryOfResidence: String 
     
    init(name: PersonName, countryOfResidence: String = "UK") { 
        birthName = name 
        currentName = name 
        self.countryOfResidence = countryOfResidence 
    } 
     
    var displayString: String { 
        return "\(currentName.fullName()) - Location: \(countryOfResidence)" 
    } 
} 

You will need to go back over the previous recipes to see how these were created.

Now, let's put a number of closure types in the playground so we examine them:

// No input, no output 
let printAuthorsDetails: () -> Void = { 
    let name = PersonName(givenName: "Keith", middleName: "David", familyName: "Moon") 
    let author = Person(name: name) 
    print(author.displayString) 
} 
printAuthorsDetails() // "Keith David Moon - Location: UK" 
 
// No input, Person output 
let createAuthor: () -> Person = { 
    let name = PersonName(givenName: "Keith", middleName: "David", familyName: "Moon") 
    let author = Person(name: name) 
    return author 
} 
let author = createAuthor() 
print(author.displayString) // "Keith David Moon - Location: UK" 
 
// String inputs, no output 
let printPersonsDetails: (String, String, String) -> Void = { givenName, middleName, familyName in 
    let name = PersonName(givenName: givenName, middleName: middleName, familyName: familyName) 
    let author = Person(name: name) 
    print(author.displayString) 
} 
printPersonsDetails("Kathyleen", "Mary", "Moon") // "Kathleen Mary Moon - Location: UK" 
 
// String inputs, Person output 
let createPerson: (String, String, String) -> Person = { givenName, middleName, familyName in 
    let name = PersonName(givenName: givenName, middleName: middleName, familyName: familyName) 
    let person = Person(name: name) 
    return person 
} 
let melody = createPerson("Melody", "Margaret", "Moon") 
print(melody.displayString) // "Melody Margaret Moon - Location: UK"