pub fn edits(old: &Scene, new: &Scene) -> Vec<Edit>Expand description
The operations from old to new. Each node of new that old has is
kept — moved if it has another parent or falls out of the longest run of
siblings still in their order, and changed if its own attributes did;
each one old hasn’t is inserted, whole where nothing under it is kept,
alone where something is, which is then moved into it. Last, what old
has and new doesn’t goes: by then nothing kept is under it.