How to convert hexadecimal string representations to unicode. For example "The 0x1f511 to 0x1f48e is turning 0x1f34b into 0x1f379" becomes "The 🔑 to 💎 is turning 🍋 into 🍹"

NSString+Hex.swift

extension NSString {
  func stringByConvertingHexToUnicode() -> NSString {
    var replaced = ""
    var scanned: NSString?

    let scanner = NSScanner(string: self as String)
    while !scanner.atEnd {
      if scanner.scanUpToString("0x", intoString: &scanned), let s = scanned {
        replaced.appendContentsOf(s as String)
      }
      var scalar: UInt32 = 0
      if scanner.scanHexInt(&scalar) && scalar.isValidUnicodeScalar() {
        let unicodeString = String(UnicodeScalar(scalar))
        replaced.appendContentsOf(unicodeString)
      }
    }
    return replaced
  }
}

extension UInt32 {
  func isValidUnicodeScalar() -> Bool {
    return 0x0000...0xD7FF ~= self || 0xE000...0x10FFFF ~= self
  }
}

Glad if you could do its vice versa ??