feat(toc): support for comment package

refer: #2882

autoload/vimtex/parser/toc.vim

@@ -204,6 +204,7 @@ function! vimtex#parser#toc#get_matchers() abort " {{{1
       let l:re .= '|' . l:matcher.prefilter_re
     endif
   endfor
+  let l:cmds = vimtex#util#uniq_unsorted(l:cmds)
   let l:matchers.prefilter = '\v\\%(' . join(l:cmds, '|') . ')' . l:re
 
   return l:matchers

autoload/vimtex/parser/toc/comment.vim

@@ -0,0 +1,31 @@
+" VimTeX - LaTeX plugin for Vim
+"
+" Maintainer: Karl Yngve Lervåg
+" Email:      [email protected]
+"
+
+function! vimtex#parser#toc#comment#new() abort " {{{1
+  return s:matcher
+endfunction
+
+" }}}1
+
+let s:matcher = {
+      \ 'in_preamble' : 1,
+      \ 'prefilter_cmds': ['begin'],
+      \ 're': '^\s*\\begin{comment}',
+      \ 're_end': '^\s*\\end{comment}',
+      \}
+function! s:matcher.get_entry(context) abort dict " {{{1
+  let a:context.continue = 'comment'
+  return {}
+endfunction
+
+" }}}1
+function! s:matcher.continue(context) abort dict " {{{1
+  if a:context.line =~# self.re_end
+    unlet! a:context.continue
+  endif
+endfunction
+
+" }}}1

test/test-toc/test-comment.tex

@@ -0,0 +1,21 @@
+\documentclass{article}
+\usepackage{comment}
+
+\begin{document}
+
+\section{Real section}
+
+\begin{comment}
+\section{Commented section}
+\subsection{Commented subsection}
+\subsubsection{Commented subsubsection}
+\end{comment}
+
+\begin{comment}
+\begin{figure} \label{fig:commented}
+\end{figure}
+\end{comment}
+
+\section{Next real section}
+
+\end{document}

test/test-toc/test-comment.vim

@@ -0,0 +1,22 @@
+set nocompatible
+let &rtp = '../..,' . &rtp
+filetype plugin on
+
+set nomore
+
+nnoremap q :qall!<cr>
+
+silent edit test-comment.tex
+
+if empty($INMAKE) | finish | endif
+
+let s:toc = vimtex#toc#get_entries()
+call assert_equal(len(s:toc), 3)
+
+" let s:i = 0
+" for s:x in s:toc
+"   echo s:i '--' s:x.title "\n"
+"   let s:i += 1
+" endfor
+
+call vimtex#test#finished()