neatvi (210B)
1 " q t : toggle between todo/done 2 rs \t 3 s/todo/__SWAP__/ 4 s/done/todo/ 5 s/__SWAP__/done/ 6 . 7 8 " q i : set as todo 9 rs \i 10 s/^/todo: / 11 . 12 13 " q o : set as done 14 rs \o 15 s/^/done: / 16 . 17 18 " q n : go to next todo 19 rs \n 20 /todo/ 21 .