How can I configure vim to display hidden characters like tabs or spaces ONLY while those characters are typed? I do not want tabs and/or space replaced with special characters like ">" or "_" when the file is written.
You can use the commands
to show all characters that aren't whitespace. So spaces are the only thing that doesn't show up.
If you absolutely need spaces to be marked as well, you'll need to try something less nice. Something like
Will replace all spaces with a block character. Then you'd need to undo it before writing. You could remap your write command do
Just a suggestion. I haven't tried that though.