Add syntax for reasonml config from javascript so that it can support jsx tag

after/ftplugin/reason.vim

@@ -0,0 +1,68 @@
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+" Vim ftplugin file
+"
+" Language: javascript.jsx
+" Maintainer: MaxMEllon <maxmellon1994@gmail.com>
+"
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+" modified from html.vim
+" For matchit plugin
+if exists("loaded_matchit")
+  let b:match_ignorecase = 0
+  let b:match_words = '(:),\[:\],{:},<:>,' .
+        \ '<\@<=\([^/][^ \t>]*\)[^>]*\%(>\|$\):<\@<=/\1>'
+endif
+
+" For andymass/vim-matchup plugin
+if exists("loaded_matchup")
+  setlocal matchpairs=(:),{:},[:],<:>
+  let b:match_words = '<\@<=\([^/][^ \t>]*\)\g{hlend}[^>]*\%(/\@<!>\|$\):<\@<=/\1>'
+  let b:match_skip = 's:comment\|string'
+endif
+
+let b:jsx_pretty_old_cms = &l:commentstring
+
+function! s:update_commentstring(original)
+  let line = getline(".")
+  let col = col('.')
+  if line !~# '^\s*$' && line[: col - 1] =~# '^\s*$'    " skip indent
+    let col = indent('.') + 1
+  endif
+  let syn_start = s:syn_name(line('.'), col)
+  let save_cursor = getcurpos()
+
+  if syn_start =~? '^jsx'
+    if line =~ '^\s*//'
+      let &l:commentstring = '// %s'
+    elseif s:syn_contains(line('.'), col, 'jsxTaggedRegion')
+      let &l:commentstring = '<!-- %s -->'
+    elseif syn_start =~? '^jsxAttrib'
+      let &l:commentstring = '// %s'
+    else
+      let &l:commentstring = '{/* %s */}'
+    endif
+  else
+    let &l:commentstring = a:original
+  endif
+
+  " Restore the cursor position
+  call setpos('.', save_cursor)
+endfunction
+
+function! s:syn_name(lnum, cnum)
+  let syn_id = get(synstack(a:lnum, a:cnum), -1)
+  return synIDattr(syn_id, "name")
+endfunction
+
+function! s:syn_contains(lnum, cnum, syn_name)
+  let stack = synstack(a:lnum, a:cnum)
+  let syn_names = map(stack, 'synIDattr(v:val, "name")')
+  return index(syn_names, a:syn_name) >= 0
+endfunction
+augroup jsx_comment
+  autocmd! CursorMoved <buffer>
+  autocmd CursorMoved <buffer> call s:update_commentstring(b:jsx_pretty_old_cms)
+augroup end
+
+setlocal suffixesadd+=.jsx