正则表达式

struct RegexHelper {

let regex : NSRegularExpression

init(_ pattern: String) throws {

try regex = NSRegularExpression(pattern: pattern, options: .caseInsensitive)

}

func match(_ input: String) -> Bool{

let matches = regex.matches(in: input, options: [], range: NSMakeRange(0, input.utf8.count))

return matches.count > 0

}

}

func checkEmail() -> Bool{

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

guard let matcher = try? RegexHelper(mailPattern) else {

return false

}

let maybeMainlAddress = "[email protected]"

if matcher.match(maybeMainlAddress) == true {

print("有效的邮箱地址")

return true

}

return false

}

// 定义优先级

precedencegroup MatchPrecedence {

associativity: none

higherThan: DefaultPrecedence

}

// 定义“中位”操作

infix operator =~: MatchPrecedence

// 定义操作符

func =~(lhs: String, rhs: String) -> Bool{

do {

return try RegexHelper(rhs).match(lhs)

} catch _ {

return false

}

}

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

print("有效的邮箱地址")

}