- In addition to decorated symbols, it will also keep special marks, such as `thatMark`, `sourceMark`, the previous location stack (#190), and bookmarks (#46) - If an action returns undefined for a mark, don't overwrite - keep marks up to date - should all marks be stacks? - Also include previous edit ranges? How to avoid really large stack here?
thatMark,sourceMark, the previous location stack (Add proper "jump back" command #190), and bookmarks (Add "mark" action to bookmark a target #46)