Function string_difference 

pub fn string_difference<'a>(
    new_string: &'a str,
    old_string: &str,
) -> (usize, &'a str)

Finds different string between two strings

Example usage

use reedline::menu_functions::string_difference;

let new_string = "this is a new string";
let old_string = "this is a string";

let res = string_difference(new_string, old_string);
assert_eq!(res, (10, "new "));