Agreed. It's "funny" how common 1000+ character uncommented oneliner regular expressions are, while in any other programming language even things like `if (flag) return;` would get rejected for being dangerous, unreadable, uncommented, brace style violations and possibly even for being too long if indentation and length of the flag name make this exceed just 80 characters.

Is this because people think of a regex as an atomic blackbox instead of a program or function that can be read and modified? For example when a regex is incorrect, they don't say "This regex is incorrect. How can it be corrected?" like they would for a program or function, but "This is the incorrect regex. Which one is the correct regex."

Free-spacing mode (where you can add whitespace, newlines and comments to a regex) would at least help a little. (Although even then I think a function with early returns is often more appropriate. Possibly using very small regular expressions for some of the individual checks.) But I rarely even see free-spacing modes mentioned. Maybe because most programmers using regex actually prefer an atomic blackbox?