     static let commaString = ","
 }
 
-extension NSRegularExpression {
+fileprivate extension NSRegularExpression {
     
     func matches(in input: String) -> [NSTextCheckingResult]? {
         let range = NSRange(0 ..< input.characters.count)

    }
}

extension String {
    func alphabeticalString() -> String {
        let chars =  CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789").inverted
        let string = self.trimmingCharacters(in: .whitespacesAndNewlines)

                let rangeEnd = (line == endLine) ? range.end.column + 1 : lineString.length
                selectionString.append(lineString.substring(with: NSMakeRange(rangeStart, rangeEnd - rangeStart)))
            }
            let isEmptySelection = startLine == endLine && range.start.column == range.end.column
            let indentation = (isEmptySelection) ? "" : "    "
            let result = parse(string: selectionString, indentation: indentation)
            marks.append(MarkTuple(range.end.line, result))
        }
        
