Add :Syntack command to view syntax group stack

plugin/functions.vim

@@ -28,6 +28,17 @@ function! CloneHighlightGroupWithAttributes(group, new_group, attributes)
         \' term='.a:attributes.' cterm='.a:attributes.' gui='.a:attributes
 endfunction
 
+function! <SID>Synstack()
+  for id in synstack(line('.'), col('.'))
+    let attributes = synIDattr(id, 'name')
+    let attr = synIDattr(id, 'fg')
+    if attr != ''
+      let attributes = attributes.' fg='.attr
+    endif
+  endfor
+endfunction
+command Synstack :call <SID>Synstack()
+
 " Strip trailing whitespace
 function! <SID>StripWhitespace()
   let l = line(".")