ayanonagon

import Foundation

extension String {
    func s_n_a_k_e_c_a_s_e_d() -> String { // OK, you can name it just “snakecased” if you prefer… :)
        var charactersToRemove = CharacterSet.alphanumerics.inverted
        charactersToRemove.remove(charactersIn: " ")
        let result = components(separatedBy: charactersToRemove).joined(separator: "")
        return result.replacingOccurrences(of: " ", with: "_").lowercased()
    }
}

ayanonagon

import Foundation

var nonAlphaNumeric = CharacterSet.alphanumerics.inverted
nonAlphaNumeric.remove(charactersIn: " ")

ayanonagon

import UIKit

protocol Coordinator {
    func start()
}

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

ayanonagon

struct Item {
    let name: String
    var price: UInt

    init(name: String, price: UInt) {
        self.name = name
        self.price = price
    }
}

ayanonagon

class Cart {
    let items: [Item]

    var total: UInt {
        return items.reduce(0) { sum, item in
            sum + item.price
        }
    }

    init(items: [Item]) {

ayanonagon

class Item {
    let name: String
    var price: UInt

    init(name: String, price: UInt) {
        self.name = name
        self.price = price
    }
}

ayanonagon

func listUsers(completion: Result<[User]> -> Void) {
    // Get the list of users
    // If success, call completion(Result.Success(users))
    // If error, call completion(Result.Error(error))
}

ayanonagon

enum Result<T> {
    case Success(T)
    case Error(NSError)
}

func listMessages(completion: Result<[Message]> -> Void) {
    // Get the list of messages
    // If success, call completion(Result.Success(messages))
    // If error, call completion(Result.Error(error))
}

ayanonagon

func listMessages(completion: Result -> Void) {
    // Get the list of messages
    // If success, call completion(.Success(messages: messages))
    // If error, call completion(.Error(error: error))
}

ayanonagon

enum Result {
    case Success(messages: [Message])
    case Error(error: NSError)
}