如何在Go语言中编写正则验证IPv6子网掩码？

以下是有效的IPv6子网掩码列表：

8000::
c000::
e000::
f000::
f800::
fc00::
fe00::
ff00::
ff80::
ffc0::
ffe0::
fff0::
fff8::
fffc::
fffe::
ffff::
ffff:8000::
ffff:c000::
ffff:e000::
ffff:f000::
ffff:f800::
ffff:fc00::
ffff:fe00::
ffff:ff00::
ffff:ff80::
ffff:ffc0::
ffff:ffe0::
ffff:fff0::
ffff:fff8::
ffff:fffc::
ffff:fffe::
ffff:ffff::
ffff:ffff:8000::
ffff:ffff:c000::
ffff:ffff:e000::
ffff:ffff:f000::
ffff:ffff:f800::
ffff:ffff:fc00::
ffff:ffff:fe00::
ffff:ffff:ff00::
ffff:ffff:ff80::
ffff:ffff:ffc0::
ffff:ffff:ffe0::
ffff:ffff:fff0::
ffff:ffff:fff8::
ffff:ffff:fffc::
ffff:ffff:fffe::
ffff:ffff:ffff::
ffff:ffff:ffff:8000::
ffff:ffff:ffff:c000::
ffff:ffff:ffff:e000::
ffff:ffff:ffff:f000::
ffff:ffff:ffff:f800::
ffff:ffff:ffff:fc00::
ffff:ffff:ffff:fe00::
ffff:ffff:ffff:ff00::
ffff:ffff:ffff:ff80::
ffff:ffff:ffff:ffc0::
ffff:ffff:ffff:ffe0::
ffff:ffff:ffff:fff0::
ffff:ffff:ffff:fff8::
ffff:ffff:ffff:fffc::
ffff:ffff:ffff:fffe::
ffff:ffff:ffff:ffff::
ffff:ffff:ffff:ffff:8000::
ffff:ffff:ffff:ffff:c000::
ffff:ffff:ffff:ffff:e000::
ffff:ffff:ffff:ffff:f000::
ffff:ffff:ffff:ffff:f800::
ffff:ffff:ffff:ffff:fc00::
ffff:ffff:ffff:ffff:fe00::
ffff:ffff:ffff:ffff:ff00::
ffff:ffff:ffff:ffff:ff80::
ffff:ffff:ffff:ffff:ffc0::
ffff:ffff:ffff:ffff:ffe0::
ffff:ffff:ffff:ffff:fff0::
ffff:ffff:ffff:ffff:fff8::
ffff:ffff:ffff:ffff:fffc::
ffff:ffff:ffff:ffff:fffe::
ffff:ffff:ffff:ffff:ffff::
ffff:ffff:ffff:ffff:ffff:8000::
ffff:ffff:ffff:ffff:ffff:c000::
ffff:ffff:ffff:ffff:ffff:e000::
ffff:ffff:ffff:ffff:ffff:f000::
ffff:ffff:ffff:ffff:ffff:f800::
ffff:ffff:ffff:ffff:ffff:fc00::
ffff:ffff:ffff:ffff:ffff:fe00::
ffff:ffff:ffff:ffff:ffff:ff00::
ffff:ffff:ffff:ffff:ffff:ff80::
ffff:ffff:ffff:ffff:ffff:ffc0::
ffff:ffff:ffff:ffff:ffff:ffe0::
ffff:ffff:ffff:ffff:ffff:fff0::
ffff:ffff:ffff:ffff:ffff:fff8::
ffff:ffff:ffff:ffff:ffff:fffc::
ffff:ffff:ffff:ffff:ffff:fffe::
ffff:ffff:ffff:ffff:ffff:ffff::
ffff:ffff:ffff:ffff:ffff:ffff:8000:0
ffff:ffff:ffff:ffff:ffff:ffff:c000:0
ffff:ffff:ffff:ffff:ffff:ffff:e000:0
ffff:ffff:ffff:ffff:ffff:ffff:f000:0
ffff:ffff:ffff:ffff:ffff:ffff:f800:0
ffff:ffff:ffff:ffff:ffff:ffff:fc00:0
ffff:ffff:ffff:ffff:ffff:ffff:fe00:0
ffff:ffff:ffff:ffff:ffff:ffff:ff00:0
ffff:ffff:ffff:ffff:ffff:ffff:ff80:0
ffff:ffff:ffff:ffff:ffff:ffff:ffc0:0
ffff:ffff:ffff:ffff:ffff:ffff:ffe0:0
ffff:ffff:ffff:ffff:ffff:ffff:fff0:0
ffff:ffff:ffff:ffff:ffff:ffff:fff8:0
ffff:ffff:ffff:ffff:ffff:ffff:fffc:0
ffff:ffff:ffff:ffff:ffff:ffff:fffe:0
ffff:ffff:ffff:ffff:ffff:ffff:ffff:0
ffff:ffff:ffff:ffff:ffff:ffff:ffff:8000
ffff:ffff:ffff:ffff:ffff:ffff:ffff:c000
ffff:ffff:ffff:ffff:ffff:ffff:ffff:e000
ffff:ffff:ffff:ffff:ffff:ffff:ffff:f000
ffff:ffff:ffff:ffff:ffff:ffff:ffff:f800
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fc00
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fe00
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ff00
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ff80
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffc0
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffe0
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fff0
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fff8
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffc
ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff

我需要编写验证上述格式IPv6子网掩码的正则表达式，想知道是否可以用单个正则实现该验证？

我了解到可以通过两个独立正则实现，但希望合并成一个：

• 第一个正则确保输入由一系列冒号和F组成，后跟8/C/E/F之一，再跟一串零，可选择后跟::或:0：

^[fF:]*[8cCeEfF]0*(?::[0:])?$

• 第二个正则要求冒号出现在固定位置：

^(?:(?:[^:]{4}:){1,6}:|(?:[^:]{4}:){7}(?:0|[^:]{4}))$

原本可以用前瞻合并这两个正则，但Go语言不支持前瞻。是否有其他方法合并这两个正则，或有其他实现方式？

内容的提问来源于stack exchange，提问作者Rupesh Choudhary