The #regex IRC channel had an IRC bot with a quiz with 28 levels.
All sensibility ended after level 14 or so. At that point it was just "how deep does the PCRE rabbit-hole go?"
But there was a lot of useful, non-trivial stuff, too. Most specifically, look-aheads/lookbehinds, non-greedy matching, back-references, named capture-groups, character classes, anchors,
When I learned jq, I went much the same way: Started hanging out on #jq IRC channels and started trying to answer jq questions on StackOverflow. Sadly, I got outperformed the first six months, until it finally clicked.
The resources from Jan Goyvaerts / Just Great Software are great! His guides and to some extent tools is how I learned it too. Today I tend to often be the Regex go-to guy among colleagues, all seemingly because I learned to properly get the hang of the basics via Jan's resources.
I only used the bare minimum for years.
I also hung out on a #regex IRC channel, so I got exposed to questions and answers by many people.
Later I read up on https://www.regular-expressions.info/ which has a lot of very good explanations.
The #regex IRC channel had an IRC bot with a quiz with 28 levels.
All sensibility ended after level 14 or so. At that point it was just "how deep does the PCRE rabbit-hole go?"
But there was a lot of useful, non-trivial stuff, too. Most specifically, look-aheads/lookbehinds, non-greedy matching, back-references, named capture-groups, character classes, anchors,
When I learned jq, I went much the same way: Started hanging out on #jq IRC channels and started trying to answer jq questions on StackOverflow. Sadly, I got outperformed the first six months, until it finally clicked.