Оглавление

Пример

//: Playground - noun: Паттерн Iterator

import UIKit

struct BanksLevel{
    let price:Double
    let time:UInt32
    let comment:String
}

struct Levels {
    let arLevels: [BanksLevel]
}

struct LevelsIterator: IteratorProtocol {
    
    private var current = 0
    private let levels: [BanksLevel]
    
    init(levels: [BanksLevel]) {
        self.levels = levels
    }
    
    mutating func next() -> BanksLevel? {
        defer { current += 1 }
        return levels.count > current ? levels[current] : nil
    }
}

extension Levels: Sequence {
    func makeIterator() -> LevelsIterator {
        return LevelsIterator(levels: arLevels)
    }
}

Применение

let arLevels = Levels(arLevels: [
    BanksLevel(price: 1.06740, time: 1, comment: "Первый банковский уровень"),
    BanksLevel(price: 1.06210, time: 2, comment: "Второй банковский уровень")
] )

for level in arLevels {
    print("Определён: \(level)")
}

Пример 2

import UIKit



class Item{
    let name:String
    
    init(_ name:String){
        self.name = name
    }
}



class IteratableItems{
    var arItems: [Item] = []
    
    init(items:[Item]){
        self.arItems = items
    }
}

class ItemIterator: IteratorProtocol{
    private var current = 0
    private let arItems: [Item]
    
    init(items:[Item]){
        self.arItems = items
    }
    func next()-> Item?{
        defer {
             current += 1
        }
        return arItems.count > current ? arItems[current] : nil
    }
    
}

extension IteratableItems: Sequence {
    
    func makeIterator() -> ItemIterator {
        return ItemIterator(items: arItems)
    }
}

Используем:

let arItems = IteratableItems(items: [Item("One"),Item("Two"),Item("Three")])

for item in arItems{
    print("item: \(item.name)")
}