如何从前瞻转换正则表达式 [英] How to convert regexp from lookahead
问题描述
我在PHP和其他出色的代码中拥有以下正则表达式.
I have the following Regex in PHP and other code that is doing a great job.
/^(?:(?=[^ ]+\d)(?:[A-Z0-9]+))|(?:[A-Z0-9]+) +?(?=.*\d)(?:[A-Z0-9]+)?
事实证明，Go不支持headheads，我对如何将其转换一无所知.
It turns out that Go doesn't support lookheads and I'm at a loss on how to convert it across.
Debuggex链接中包含一些我用来验证代码的测试数据.
The Debuggex link has some test data I was using to qualify the code before.
推荐答案
首先，交替/^...的左侧不匹配任何内容，因为/永远不会在输入开始之前出现.
Firstly, the left hand side of the alternation /^... matches nothing, because / can never appear before start of input.
仅留下(?:[A-Z0-9]+) +?(?=.*\d)，可以表示为:
((?:[A-Z0-9]+) ).*\d.*
所使用的术语" +?"实际上与" "相同.
The term " +?" as used is identical in effect to just " ".
但是请注意，这消耗了比原始输入更多的输入，这是不可避免的.您原来的比赛现在在第1组中.
Note however that this consumes more input than the original, which is unavoidable. Your original match is now in group 1.
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