Function adjust_number_visual 

pub fn adjust_number_visual<H: Host>(
    ed: &mut Editor<View, H>,
    delta: i64,
    sequential: bool,
)

Visual-mode <C-a> / <C-x> and g<C-a> / g<C-x>. Adds delta to the first number on each selected line. When sequential is true the increment grows by delta for each successive number found (vim’s g<C-a>): the first gets delta, the second 2*delta, and so on.