Comment by codetrotter

I use regexes a lot. The main thing that always trips me up is dealing with escaping, because different tools I use – vim, sed, rg, and so on – sometimes have different meanings for when to escape or not.

In one tool you’ll use + to match one or more times, and \+ to mean literal plus sign.

In another tool you’ll use \+ to match one or more time, and + to mean literal plus sign.

In one tool you’ll use ( and ) to create a match group, and \( and \) to mean literal open and close parentheses.

In another tool you’ll use \( and \) to create a match group, and ( and ) to mean literal open and close parentheses.

This is basically the only problem I have when writing regexes, for the kinds of regexes I write.

Also, one thing that’s not a problem per se but something that leads me to write my regexes with more characters than strictly necessary is that I rarely use shorthand for groups of characters. For example the tool might have a shorthand for digit but I always write [0-9] when I need to match a digit. Also probably because the shorthand might or might not be different for different tools.

Regexes are also known to be “write once read never”, in that writing a regex is relatively easy, but revisiting a semi-complicated regex you or someone else wrote in the past takes a little bit of extra effort to figure out what it’s matching and what edits one should make to it. In this case, tools like https://regex101.com/ or https://www.debuggex.com/ help a lot.