Improved the simple indent delim method

indent/tex.vim

@@ -15,6 +15,7 @@ if !g:vimtex_indent_enabled | finish | endif
 call vimtex#util#set_default('g:vimtex_indent_ignored_envs', [
       \ 'document',
       \])
+call vimtex#util#set_default('g:vimtex_indent_delims_type', 'simple')
 
 let s:cpo_save = &cpoptions
 set cpoptions&vim
@@ -56,7 +57,8 @@ function! VimtexIndent(lnum) " {{{1
   " Indent environments, delimiters, and tikz
   let l:ind = indent(l:prev_lnum)
   let l:ind += s:indent_envs(l:line, l:prev_line)
-  let l:ind += s:indent_delims(l:line, a:lnum, l:prev_line, l:prev_lnum)
+  let l:ind += s:indent_delims_{g:vimtex_indent_delims_type}(
+        \ l:line, a:lnum, l:prev_line, l:prev_lnum)
   let l:ind += s:indent_tikz(l:prev_lnum, l:prev_line)
   return l:ind
 endfunction
@@ -110,7 +112,48 @@ let s:envs_begitem = s:envs_item . '\|' . s:envs_beglist
 let s:envs_enditem = s:envs_item . '\|' . s:envs_endlist
 
 " }}}1
-function! s:indent_delims(line, lnum, prev_line, prev_lnum) " {{{1
+function! s:indent_delims_simple(line, lnum, prev_line, prev_lnum) " {{{1
+  if empty(s:re_delims) | return 0 | endif
+
+  return &sw*(  max([  s:count(a:prev_line, s:re_open)
+        \            - s:count(a:prev_line, s:re_close), 0])
+        \     - max([  s:count(a:line, s:re_close)
+        \            - s:count(a:line, s:re_open), 0]))
+endfunction
+
+let s:delims_open = [
+      \ '\(',
+      \ '\[',
+      \ '\\\{',
+      \ '\\langle',
+      \ '\\lvert',
+      \ '\\lfloor',
+      \ '\\lceil',
+      \ '\\ulcorner',
+      \]
+let s:delims_close = [
+      \ '\)',
+      \ '\]',
+      \ '\\\}',
+      \ '\\rangle',
+      \ '\\rvert',
+      \ '\\rfloor',
+      \ '\\rceil',
+      \ '\\urcorner',
+      \]
+let s:re_open = '\v'
+      \ . '%(\\left|\\[bB]igg?l?)\s*%(' . join(s:delims_open, '|') . ')'
+      \ . '|\\left\s*\.'
+      \ . '|\{'
+      \ . '|\\\['
+let s:re_close = '\v'
+      \ . '%(\\right|\\[bB]igg?r?)\s*%(' . join(s:delims_close, '|') . ')'
+      \ . '|\\right\s*\.'
+      \ . '|\}'
+      \ . '|\\\]'
+
+" }}}1
+function! s:indent_delims_complex(line, lnum, prev_line, prev_lnum) " {{{1
   if empty(s:re_delims) | return 0 | endif
 
   let l:pre = s:split(a:prev_line, a:prev_lnum)
@@ -132,6 +175,8 @@ endfunction
 "   s:re_delims[1]  == math close
 "   s:re_delims[2]  == text open
 "   s:re_delims[3]  == text close
+"   s:re_delims[4]  == math open only with modifier
+"   s:re_delims[5]  == math close only with modifier
 "
 let s:re_delims = vimtex#delim#get_delim_regexes()
 

test/issues/643/run_test.sh

@@ -0,0 +1 @@
+time vim -Nu test.vim

test/issues/643/test.vim

@@ -0,0 +1,15 @@
+set nocompatible
+let &rtp  = '~/.vim/bundle/vimtex,' . &rtp
+let &rtp .= ',~/.vim/bundle/vimtex/after'
+filetype plugin indent on
+syntax enable
+
+" let g:vimtex_indent_delims_type = 'complex'
+
+silent edit test.tex
+profile start test.log
+profile func *
+profile file *
+silent! normal! gg=G
+profile pause
+quit!