Regular expression options in Swift

let data = "AaaA\r\naaaA";
let pattern = "^(a+)$"
let options: NSRegularExpressionOptions =
[NSRegularExpressionOptions.CaseInsensitive, NSRegularExpressionOptions.AnchorsMatchLines]
let regex = tryNSRegularExpression(pattern: pattern, options: options)
let results = regex.matchesInString(data, options: NSMatchingOptions.ReportProgress, range: NSMakeRange(0, data.characters.count))
let range = results[0].range
let value = NSString(string: data).substringWithRange(range)
//value is "AaaA"