Example
In computer programming an iterator is an object that enables a programmer to traverse a container, particularly lists. Wikipedia
struct Turtle {
let name: String
}
struct Turtles {
let turtles: [Turtle]
}
struct TurtlesIterator: IteratorProtocol {
private var current = 0
private let turtles: [Turtle]
init(turtles: [Turtle]) {
self.turtles = turtles
}
mutating func next() -> Turtle? {
defer { current += 1 }
return turtles.count > current ? turtles[current] : nil
}
}
extension Turtles: Sequence {
func makeIterator() -> TurtlesIterator {
return TurtlesIterator(turtles: turtles)
}
}
And usage example would be
let ninjaTurtles = Turtles(turtles: [Turtle(name: "Leo"),
Turtle(name: "Mickey"),
Turtle(name: "Raph"),
Turtle(name: "Doney")])
print("Splinter and")
for turtle in ninjaTurtles {
print("The great: \(turtle)")
}
