i18n.swift

var translations: [String: [String:String]]  = [
  "en": [
    "title": "Title English",
    "content": "Hello World"
  ],
  "de": [
    "title": "Title Deutsch",
    "content": "Hallo Welt"
  ]
]

struct I18n {
  static func translate(_ key: String, locale: String) -> String {
    translations[locale]?[key] ?? "<missing-translation: \(locale):\(key)>"
  }

  static func translate(_ key: String) -> String {
    let locale = "en" // Find default locale
    return translate(key, locale: locale)
  }

  static func t(_ key: String, locale: String) -> String {
    translate(key, locale: locale)
  }

  static func t(_ key: String) -> String {
    translate(key)
  }
}

I18n.t("title")
I18n.translate("title", locale: "de")
I18n.t("unknown-key")
I18n.t("title", locale: "en_GB")