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 = "[e-mail]"

if matcher.match(maybeMailAddress) 

{  

println("有效的邮箱地址")

}

// 输出:

// 有效的邮箱地址