Function difft::diff::sliders::slide_to_next_node

fn slide_to_next_node<'a>(
    nodes: &[&'a Syntax<'a>],
    change_map: &mut ChangeMap<'a>,
    start_idx: usize,
    end_idx: usize
)

If the next node is unchanged, matches the beginning of the region, and has a smaller text distance, mark it as novel.

x NOVEL <- start_idx

y NOVEL <- end_idx
x UNCHANGED

After this function:

x UNCHANGED

y NOVEL
x NOVEL