Validators5.swift

func validatedEmail(_ value: String) throws -> String {
    do {
        if try NSRegularExpression(pattern: "^[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}$", options: .caseInsensitive).firstMatch(in: value, options: [], range: NSRange(location: 0, length: value.count)) == nil {
            throw ValidationError("Invalid e-mail Address")
        }
    } catch {
        throw ValidationError("Invalid e-mail Address")
    }
    return value
}