(?:pattern)
(?=pattern)
(?!pattern)
(?<=pattern)
(?<！pattern)
https://blog.csdn.net/csm0912/article/details/81206848
https://www.cnblogs.com/dogecheng/p/11466687.html
正则表达式中?=和?:和?!的理解
原文：https://www.cnblogs.com/come202011/p/12709683.html
