enum TextAttribute {
  case foregroundColor(NSColor)
  case link(URL)
  case kerning(Int)
  case underline(NSUnderlineStyle)
  case custom(key: String, value: Any)

  var name: String {
    switch self {
      case .foregroundColor:
        return "NSForegroundColorAttributeName"

      case .link:
        return "NSLinkAttributeName"

      case .kerning:
        return "NSKernAttributeName"

      case .underline:
        return "NSUnderlineStyleAttributeName"

      case let .custom(key, _):
        return key

    }
  }
}

let string = NSAttributedString(string: "My underlined link", attributes: [
  .custom(key: "myCustomAttribute", value: 5),
  .link(myWebsiteURL)
])