[WaitWaitWha]

It is unclear if the short note is about regular expression refers to pattern matching techniques, an application like regex, or an internal command in some coding language like =~ and !~ in Perl.

I can use regular expression to parse CSV, it is just not pretty. Regex solutions do not need to be single runs.

I frequently use regex in multiple iterations to clean up the data be it in code or command line, then process it for one off scenarios.

> This is because a regular expression doesn’t store state.

This depends on how much state I need to store and in what context (see first sentence).