String regex

String+Regex.swift

extension String {
    /// 是否为合法邮箱地址
    var isValidEmail: Bool {
        // https://stackoverflow.com/a/41782027/5211544
        let firstPart = "[A-Z0-9a-z]([A-Z0-9a-z._%+-]{0,30}[A-Z0-9a-z])?"
        let serverPart = "([A-Z0-9a-z]([A-Z0-9a-z-]{0,30}[A-Z0-9a-z])?\\.){1,5}"
        let regex = "\(firstPart)@\(serverPart)[A-Za-z]{2,8}"

        let predicate = NSPredicate(format: "SELF MATCHES %@", regex)
        return predicate.evaluate(with: self)
    }
    
    /// 将 hex 字符组成的字符串按照字面值转换为 16 进制数据
    var literalAsBytes: [UInt8] {
        guard count % 2 == 0 else {
            fatalError("count of \(self) must be even.")
        }

        var result = [UInt8]()
        for i in 0 ..< (count / 2) {
            let start = index(startIndex, offsetBy: 2 * i)
            let end = index(start, offsetBy: 1)
            let temp = String(self[start...end])
            let piece = UInt8(temp, radix: 16)!
            result.append(piece)
        }
        return result
    }

    /// 将 hex 字符组成的字符串按照字面值转换为二进制数据
    var binaryData: Data {
        return Data(literalAsBytes)
    }
}

String+Unclassified.swift

/// 打 call
func call() -> Bool {
    let result = components(separatedBy: CharacterSet.init(charactersIn: "0123456789-+()").inverted).joined(separator: "")
    if let url = URL(string: "tel:\(result)"),
       UIApplication.shared.canOpenURL(url) {
        UIApplication.shared.open(url, options: [:], completionHandler: nil)
        return true
    }

    return false
}