Swift Ordered Dictionary

Swift Ordered Dictionary

public class OrderedDictionary <K: Hashable, V> {
    
    typealias Key = K
    typealias Value = V
    
    private final var dictionary = [K: V]()
    private final var orderedKeys = [K]()
    
    init() {
    }
    
    subscript(key: K) -> V? {
        get {
            return dictionary[key]
        }
        
        set (newValue) {
            if (orderedKeys.filter({$0 == key}).count == 0) {
                orderedKeys.append(key)
            }
            
            dictionary[key] = newValue
        }
    }
    
    subscript(index: Int) -> V? {
        get {
            var key = orderedKeys[index]
            return dictionary[key]
        }
        
        set (newValue) {
            var key = orderedKeys[index]
            dictionary[key] = newValue
        }
    }
}