neovim/runtime/ftplugin/lua.vim

" Vim filetype plugin file.
" Language:	        Lua
" Maintainer:		Doug Kearns <dougkearns@gmail.com>
" Previous Maintainer:	Max Ischenko <mfi@ukr.net>
" Last Change:	        2021 Nov 15

" Only do this when not done yet for this buffer
if exists("b:did_ftplugin")
  finish
endif

" Don't load another plugin for this buffer
let b:did_ftplugin = 1

let s:cpo_save = &cpo
set cpo&vim

" Set 'formatoptions' to break comment lines but not other lines, and insert
" the comment leader when hitting <CR> or using "o".
setlocal formatoptions-=t formatoptions+=croql

setlocal comments=:--
setlocal commentstring=--%s
setlocal suffixesadd=.lua

let b:undo_ftplugin = "setlocal fo< com< cms< sua<"

if exists("loaded_matchit") && !exists("b:match_words")
  let b:match_ignorecase = 0
  let b:match_words =
        \ '\<\%(do\|function\|if\)\>:' .
        \ '\<\%(return\|else\|elseif\)\>:' .
        \ '\<end\>,' .
        \ '\<repeat\>:\<until\>,' .
        \ '\%(--\)\=\[\(=*\)\[:]\1]'
  let b:undo_ftplugin .= " | unlet! b:match_words b:match_ignorecase"
endif

if (has("gui_win32") || has("gui_gtk")) && !exists("b:browsefilter")
  let b:browsefilter = "Lua Source Files (*.lua)\t*.lua\n" .
	\              "All Files (*.*)\t*.*\n"
  let b:undo_ftplugin .= " | unlet! b:browsefilter"
endif

let &cpo = s:cpo_save
unlet s:cpo_save