[wonnage]

I personally had the most trouble with regexes because I didn't have a good mental model of how they worked. The hard part wasn't finding the correct symbol/character class I was trying to match, but coming to grips with repetition, greedy/nongreedy, etc.

I took a compilers class in college where one of the projects was to implement a simple regex matcher using NFAs. Bashing my head against this for a week really helped with being able to "read" a regex. Not sure if this was due to finally understanding the algorithm, or the fact that I was just constantly staring at broken regex matches all day.

IMO it was a fairly small time investment for something that is so widely used.

I'll recommend this post that's been on HN many times: https://swtch.com/~rsc/regexp/regexp1.html

[the-pigeon]

I'm not sure how to explain it but the most important thing I've learned in over a decade of programming experience is to not use regular expressions for many things they may seem like a regular expression problem.

For example, even something as simple a phone number can have all sorts of weird but valid variants. Be sure you really need to even validate it's format and not just that it's present.

Trying to handle all of those variants via regex expression is doable but a pain. And in practice you as the programmer should not be defining those variants that are valid as it's up to the business itself to define what type of data it considers to be valid for the field.

That said I've also worked for companies with small engineering teams where the goal has always been to be as efficient with development time as possible, as opposed to making a near ideal system. Software has different needs when it's used by a thousand people than when it's used by millions.

[btilly]

I think it is understanding the algorithm that does it.

I also recommend that people learn how to read a regex by writing a small recursive program to match specific regexes. After you look at a regex and think about how it might work, intuition follows.

Actually writing the bit that turns the regex expression into said program isn't as important though. Doing that by hand 5 times is enough IMO.