Thanks for the review. Attached patch fixes these and a few other
little things.

Mattias Engdegård <mattias.engdegard@gmail.com> writes:

> Some observations about the recently added lua-mode.el:
>
>  394   "A regexp that matches Lua builtin functions & variables.
>  395 
>  396 This is a compilation of 5.1, 5.2 and 5.3 builtins taken from the
>  397 index of respective Lua reference manuals.")
>
> Clearly meant as a doc string. Bracket error?

Fixed.

> 1266            (or
>
> This `or` has only a single operand. Simple oversight or indication of something worse?

Looks like there used to be a second part but it got refactored up
into the first part and the ‘or’ just hung around.

> 1270                (save-excursion
> 1271                  (and (goto-char prev-line)
> 1272                       ;; Check last token of previous nonblank line
> 1273                       (lua-last-token-continues-p)))))
>
> `goto-char` never returns nil, but its presence as a condition
> here suggest that the author may have thought otherwise.

Removed the ‘and’ here.

> (Line 996 is similar.)

Wrapped it and the recursive call to lua-find-matching-token-word
on the next line in progn to make it clear the goto-char is for
side-effect and not return value.

> 2099         for type = (if (string-match-p "\\`(E" msg) :error :warning)
>
> A regexp is overkill here; `string-prefix-p` is simpler.

The plan is to merge the common parts between the lua modes. The
lua-ts-mode flymake backend uses string-prefix-p there so I left
this for now and it’ll get replaced with the lua-ts flymake code.

> 1821       (while (re-search-forward "[\"'\\\t\\\n]" nil t)
>
> This regexp is a bit muddled; too many backslashes here.
> You could even rewrite the whole function using `replace-regexp-in-string`, maybe
>
>   (concat "'"
>           (replace-regexp-in-string
>            (rx (or ?\" ?' ?\t ?\n ?\\))
>            (lambda (s)
>              (cdr (assq (aref s 0) '((?\" . "\\\"")
>                                      (?\\ . "\\\\")
>                                      (?\n . "\\n")
>                                      (?\t . "\\t")
>                                      (?'  . "\\'")))))
>            str t t)
>           "'"))
>
> without any need for a temporary buffer.

That works.