在swift如何写正则匹配

 struct RegexHelper {

        let regex: NSRegularExpression?

        init(_ pattern:String)

        {

            var error:NSError?

            regex = NSRegularExpression(pattern: pattern, options:.CaseInsensitive , error: &error)

        }

        func match(input:String) -> Bool

        {

            if let matches = regex?.matchesInString(input, options: nil, range: NSMakeRange(0, count(input)))

            {

                return matches.count > 0

            }else{

                return false

            }

        }

    }

let mailPattern = "^([a-z0-9_\\.-]+)@([\\da-z\\.-]+)\\.([a-z\\.]{2,6})$"

let matcher = RegexHelper (mailPattern)

let maybeMailAddress = "[email protected]"

if matcher.match(maybeMailAddress) 

{  

println ( "有效的邮箱地址" )

}

// 输出:

// 有效的邮箱地址