Change latex provider to luatex, closes #476

autoload/vimtex/fold/cmd_single_opt.vim

@@ -0,0 +1,53 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'latex') == -1
+
+" vimtex - LaTeX plugin for Vim
+"
+" Maintainer: Karl Yngve Lervåg
+" Email:      karl.yngve@gmail.com
+"
+
+function! vimtex#fold#cmd_single_opt#new(config) abort " {{{1
+  return extend(deepcopy(s:folder), a:config).init()
+endfunction
+
+" }}}1
+
+
+let s:folder = {
+      \ 'name' : 'cmd_single_opt',
+      \ 're' : {},
+      \ 'opened' : 0,
+      \ 'cmds' : [],
+      \}
+function! s:folder.init() abort dict " {{{1
+  let l:re = '\v^\s*\\%(' . join(self.cmds, '|') . ')\*?'
+
+  let self.re.start = l:re . '\s*\[\s*%($|\%)'
+  let self.re.end = '^\s*\]{'
+  let self.re.text = l:re
+  let self.re.fold_re = '\\%(' . join(self.cmds, '|') . ')'
+
+  return self
+endfunction
+
+" }}}1
+function! s:folder.level(line, lnum) abort dict " {{{1
+  if a:line =~# self.re.start
+    let self.opened = 1
+    return 'a1'
+  elseif self.opened && a:line =~# self.re.end
+    let self.opened = 0
+    return 's1'
+  endif
+endfunction
+
+" }}}1
+function! s:folder.text(line, level) abort dict " {{{1
+  let l:col = strlen(matchstr(a:line, '^\s*')) + 1
+  return matchstr(a:line, self.re.text) . '[...]{'
+        \ . vimtex#cmd#get_at(v:foldstart, l:col).args[0].text . '}'
+endfunction
+
+" }}}1
+
+endif