 :param: processArguments arguments to pass to new sourcekitten process
 :returns: sourcekitten STDOUT output
 */
-func run_self(processArguments: [String]) -> String {
+func run_self(processArguments: [String]) -> String? {
     let task = NSTask()
     task.launchPath = NSBundle.mainBundle().executablePath!
     task.arguments = processArguments

    let output = NSString(data: file.readDataToEndOfFile(), encoding: NSUTF8StringEncoding)
    file.closeFile()

    return output!
}

/**

                printSTDERR("parsing \(file.lastPathComponent) (\(index + 1)/\(swiftFiles.count))")
                var self_arguments = ["--single-file", file]
                self_arguments.extend(swiftcArguments)
                let selfOutput = run_self(self_arguments)
                println(selfOutput)
                if selfOutput != nil && index < swiftFiles.count-1 {
                    println(",")
                }
            }
