feat(fold)!: handle comment specially

This removes folding of multiline comments. I may add it back later if
requested by users.

refer: #2882

autoload/vimtex/fold.vim

@@ -54,31 +54,37 @@ function! vimtex#fold#init_state(state) abort " {{{1
         \ . '|^\s*\]\s*%(\{|$)'
         \ . '|^\s*}'
   let a:state.fold_re_next = ''
+  let a:state.fold_re_comment = ''
   for l:name in [
-        \ 'comment_pkg',
         \ 'preamble',
         \ 'cmd_single',
         \ 'cmd_single_opt',
         \ 'cmd_multi',
         \ 'cmd_addplot',
         \ 'sections',
         \ 'markers',
-        \ 'comments',
         \ 'items',
         \ 'envs',
         \ 'env_options',
         \]
     let l:type = get(a:state.fold_types_dict, l:name, {})
-    if !empty(l:type)
-      call add(a:state.fold_types_ordered, l:type)
-      if exists('l:type.re.fold_re')
-        let a:state.fold_re .= '|' . l:type.re.fold_re
-      endif
-      if exists('l:type.re.fold_re_next')
-        let a:state.fold_re_next .=
-              \ (empty(a:state.fold_re_next) ? '\v' : '|')
-              \ . l:type.re.fold_re_next
-      endif
+    if empty(l:type) | continue | endif
+
+    call add(a:state.fold_types_ordered, l:type)
+    if exists('l:type.re.fold_re')
+      let a:state.fold_re .= '|' .. l:type.re.fold_re
+    endif
+
+    if exists('l:type.re.fold_re_next')
+      let a:state.fold_re_next .=
+            \ (empty(a:state.fold_re_next) ? '\v' : '|')
+            \ .. l:type.re.fold_re_next
+    endif
+
+    if exists('l:type.re.fold_re_comment')
+      let a:state.fold_re_comment .=
+            \ (empty(a:state.fold_re_comment) ? '\v' : '|')
+            \ .. l:type.re.fold_re_comment
     endif
   endfor
 endfunction
@@ -110,6 +116,18 @@ function! vimtex#fold#level(lnum) abort " {{{1
     return '='
   endif
 
+  " Handle comments by considering the syntax
+  if vimtex#syntax#in_comment(a:lnum, 1)
+        \ && l:line !~# b:vimtex.fold_re_comment
+    if l:line =~# '^\s*\\begin\s*{comment}'
+      return 'a1'
+    elseif l:line =~# '^\s*\\end\s*{comment}'
+      return 's1'
+    else
+      return '='
+    endif
+  endif
+
   for l:type in b:vimtex.fold_types_ordered
     let l:value = l:type.level(l:line, a:lnum)
     if !empty(l:value) | return l:value | endif

autoload/vimtex/fold/markers.vim

@@ -27,7 +27,8 @@ function! s:folder.init() abort dict " {{{1
         \ ['^.*\ze\s*%', ''],
         \]
 
-  let self.re.fold_re = escape(self.open . '|' . self.close, '{}%+*.')
+  let self.re.fold_re = escape(self.open .. '|' .. self.close, '{}%+*.')
+  let self.re.fold_re_comment = escape(self.open .. '|' .. self.close, '{}%+*.')
 
   return self
 endfunction

autoload/vimtex/fold/sections.vim

@@ -35,7 +35,8 @@ function! s:folder.init() abort dict " {{{1
   let self.re.secpat1 = self.re.sections . '\*?\s*\{\zs.*'
   let self.re.secpat2 = self.re.sections . '\*?\s*\[\zs.*'
 
-  let self.re.fold_re = '\\%(' . join(self.parts + self.sections, '|') . ')'
+  let self.re.fold_re = '\\%(' .. join(self.parts + self.sections, '|') .. ')'
+  let self.re.fold_re_comment = '^\s*\% Fake'
 
   return self
 endfunction

autoload/vimtex/options.vim

@@ -95,8 +95,6 @@ function! vimtex#options#init() abort " {{{1
   call s:init_option('vimtex_fold_types_defaults', {
         \ 'preamble' : {},
         \ 'items' : {},
-        \ 'comment_pkg' : {},
-        \ 'comments' : { 'enabled' : 0 },
         \ 'envs' : {
         \   'blacklist' : [],
         \   'whitelist' : [],

doc/vimtex.txt

@@ -1851,11 +1851,6 @@ OPTIONS                                                        *vimtex-options*
                         corresponding "real" sections. The fold title is the
                         provided title with the `Fake...` part prepended.
 
-    <comment_pkg>       Fold `\begin{comments} ... \end{comments}` and disable
-                        folding inside the environment.
-
-    <comments>          Fold multiline comments. This is disabled by default.
-
     <markers>           Fold on vim-style markers inside comments, that is,
                         pairs of e.g. `{{{` and `}}}` (the default markers).
                         |regex| patterns for the opening and closing markers

test/test-folding/test-comment.tex

@@ -0,0 +1,16 @@
+\documentclass{article}
+\usepackage{comment}
+
+\begin{document}
+
+\section{test 1}
+
+\begin{comment}
+  f(x) = 1
+  \begin{equation}
+    f(x) = 1
+  \end{equation}
+  \label{sec:test1}
+\end{comment}
+
+\end{document}

test/test-folding/test-comment.vim

@@ -0,0 +1,23 @@
+set nocompatible
+let &rtp = '../..,' . &rtp
+filetype plugin on
+syntax enable
+
+set fillchars=fold:\ 
+set number
+set foldcolumn=4
+
+nnoremap q :qall!<cr>
+
+call vimtex#log#set_silent()
+
+let g:vimtex_fold_enabled = 1
+
+silent edit test-comment.tex
+
+if empty($INMAKE) | finish | endif
+
+call assert_equal(2, foldlevel(9))
+call assert_equal(2, foldlevel(11))
+
+call vimtex#test#finished()

test/test-folding/test-other.vim

@@ -11,15 +11,14 @@ nnoremap q :qall!<cr>
 call vimtex#log#set_silent()
 
 let g:vimtex_fold_enabled = 1
-let g:vimtex_fold_types = {'comments' : {'enabled': 1}}
 
 silent edit test-other.tex
 
 if empty($INMAKE) | finish | endif
 
 
 call assert_equal(1, foldlevel(1))
-call assert_equal(2, foldlevel(2))
+call assert_equal(1, foldlevel(2))
 call assert_equal(2, foldlevel(34))
 call assert_equal(2, foldlevel(48))
 call assert_equal(3, foldlevel(128))