How to grok a complicated regex?

[martin rudalics]

> so I have this monstrosity [note: I know, there are much worse ones,
> too!]:
>
> "\\`\\(?:\\\\[([]\\|\\$+\\)?\\(.*?\\)\\(?:\\\\[])]\\|\\$+\\)?\\'"
>
> (it's in the org-latex--script-size function in ox-latex.el, if you're
> curious).
>
> I'm not asking “what does this match” – I can read it myself.  But it
> comes with a considerable effort.  Are you aware of any tools that might
> help to understand such regexen?

You might want to try regexp-lock.el which you can find here:

https://lists.gnu.org/archive/html/emacs-devel/2014-10/msg00688.html

Eventually it should also appear on ELPA but I have to polish up some
things first.

Sincerely, martin