 public enum StringsFileParserError: Error, CustomStringConvertible {
   case failureOnLoading(path: String)
   case invalidFormat
+  case invalidPlaceholder(previous: StringsFileParser.PlaceholderType, new: StringsFileParser.PlaceholderType)
 
   public var description: String {
     switch self {

          while list.count <= insertionPos-1 {
            list.append(.unknown)
          }
          list[insertionPos-1] = p
        }
      }

      return "Failed to load a file at \"\(path)\""
    case .invalidFormat:
      return "Invalid strings file"
    case .invalidPlaceholder(let previous, let new):
      return "Invalid placeholder type \(new) (previous: \(previous))"
    }
  }
}
