Function adjust_number 

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

Vim Ctrl-a / Ctrl-x — find the next number at or after the cursor on the current line, add delta, leave the cursor on the last digit of the result. Recognises 0x/0X hex literals (incremented in hex, width and digit case preserved) as well as signed decimals. No-op if the line has no number to the right.