Display number of matches while searching

Nobody has claimed this yet.

I'd be interested in finding a way to display the number of matches while searching. Currently I use vim-anzu (vim-indexed-search also exists, but I don't use it) together with oblique, but that only shows me the number of matches / which match number I'm on after I've finished searching and am going through the matches.

Do you have a gut sense of how complex this addition would be, as well as if it's even possible? My two thoughts would be to somehow display the number of matches (with a couple characters of padding to prevent the screen area the user is actually typing into from moving) to the left of the `/` search prompt, e.g.:

`[6 of 21] /searchin`

The other option I can see, although I don't know if it's possible, is to update the statusline as the user types. I think that would be preferable if it can be done.

Start by tracing how vim-oblique handles the search prompt and whether it updates the statusline while typing. Compare the proposed prompt-side display with statusline updates, then verify that the match count and current match are accurate without moving the area where the user types.

Written by the indexing model from the issue text.