Basic Morse Code translator - letters

Morse.swift

//
//  Morse.swift
//  Morse
//
//  Created by Roshan Nindrai on 9/30/18.
//  Copyright © 2018 Roshan Nindrai. All rights reserved.
//
import Foundation


enum MorseCode {
    case dot
    case dash
}

final class MorseCodeNode<Element> {
    var data: Element?
    var dot: MorseCodeNode<Element>?
    var dash: MorseCodeNode<Element>?
    
    init() {
        data = nil
        dot = nil
        dash = nil
    }
    
    convenience init(_ data: Element) {
        self.init()
        self.data = data
    }
}

extension MorseCodeNode {
    
    func insert(_ element: Element) {
        var queue = [self]
        while !queue.isEmpty {
            let node = queue.removeFirst()
            
            if node.dot == nil {
                node.dot = MorseCodeNode(element)
                break
            } else {
                queue.append(node.dot!)
            }
            
            if node.dash == nil {
                node.dash = MorseCodeNode(element)
                break
            } else {
                queue.append(node.dash!)
            }
        }
    }
    
    func constructTree(_ data: [Element]) {
        for element in data {
            self.insert(element)
        }
    }
    
}

final class MorseCodeLetterTraslator {
    private let root = MorseCodeNode<String>()
    
    init() {
        root.constructTree([
            "e", "t",
            "i", "a", "n", "m",
            "s", "u", "r", "w", "d", "k", "g", "o",
            "h", "v", "f", "u", "l", "a", "p", "j", "b", "x", "c", "y", "z", "q"
            ])
    }
    
    func translate(_ codes: [MorseCode]) -> String? {
        var currentNode: MorseCodeNode<String>? = root
        for code in codes {
            switch code {
            case .dot:
                currentNode = currentNode?.dot
            case .dash:
                currentNode = currentNode?.dash
            }
        }
        return currentNode?.data
    }
    
    func translate(_ codes: [[MorseCode]]) -> String {
        return codes.compactMap { translate($0) }.reduce("") { result, code in
            return result.appending(code)
        }
    }
    
}

let translator = MorseCodeLetterTraslator()
translator.translate([[.dot, .dot, .dot], [.dash, .dash, .dash], [.dot, .dot, .dot]]) // SOS
translator.translate([.dash, .dot, .dash, .dash]) // Y