bug#60830: 30.0.50; The *Compilation* buffer does not recognize Lua errors

["Rudolf Adamkovič via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> For true "regular expressions", you'd use conjunction and negation and
> Bob's your uncle, but sadly, our regexps don't support conjunction nor
> negation, so you're stuck doing it by hand, e.g.:
>
>     "\\|\\[\\|[^[].*\\|\\[C\\|\\[[^C].*\\|\\[C[^]].*\\|\\[C].+"
>
> Yes, it's hideous and it suffers from a really bad size-explosion
> syndrome.  I don't even want to think about how to encode "this group
> can match neither "joe" nor "henry".

After a bit of thinking, I used a shy group

  \\(?:\\[C\\]\\|.......\\)
       ^^^^^^^   ^^^^^^^  
       NEGATIVE  POSITIVE

This either matches nothing or the groups in the POSITIVE alternative.

Rudy
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Rudolf Adamkovič <salutis@me.com> [he/him]
Studenohorská 25
84103 Bratislava
Slovakia