home/neovim: highlight non-ascii characters

home/neovim.nix

@@ -130,6 +130,27 @@ in {
       highlight ExtraWhitespace ctermbg=red guibg=red
       match ExtraWhitespace /\s\+$/
 
+      " Show non-ascii characters (except norwegian æøå)
+      highlight nonascii ctermbg=214 guibg=#FFA500 " orange
+      function! HighlightNonAscii()
+        " delete the old match if it exists
+        let s:matchid = get(s:, 'matchid', -1)
+        if s:matchid != -1
+          try
+            call matchdelete(s:matchid)
+          catch /E803/
+            " matchid does not exist, pass
+          endtry
+        endif
+        " Skip popups like telescope
+        if &buftype ==# ""
+          let s:matchid = matchadd('nonascii', '[^\x00-\x7FæøåÆØÅ]', 100)
+        else
+          let s:matchid = -1
+        endif
+      endfunction
+      autocmd BufEnter * call HighlightNonAscii()
+
       " Disable search highlights
       map <Leader><Space> :noh<CR>