String.stringByFormattingPhoneNumbers()

phoneformat.swift

extension String {
    static let phoneDetector = NSDataDetector(types: NSTextCheckingType.PhoneNumber.rawValue, error: nil)!
    func stringByFormattingPhoneNumbers() -> String {
        var mutableString = self
        String.phoneDetector.enumerateMatchesInString(self, options: NSMatchingOptions.allZeros, range: NSRange(location: 0, length: count(self))) { result, flags, stop in
            if let
                range = self.rangeFromNSRange(result.range),
                phoneNumber = result.phoneNumber.flatMap(PhoneManager.sanitizedPhoneNumber) {
                    mutableString.replaceRange(range, with: PhoneManager.formattedPhoneNumber(phoneNumber))
            }
        }
        return mutableString
    }
    func rangeFromNSRange(nsRange : NSRange) -> Range<String.Index>? {
        if let
            from = String.Index(self.utf16.startIndex + nsRange.location, within: self),
            to = String.Index(self.utf16.startIndex + nsRange.location + nsRange.length, within: self) {
                return from ..< to
        }
        return nil
    }
}