21. Newspaper delivery revisited again

Let’s go back to our newspaper delivery example. Below is an outline of a solution that will work both Ms. Lovelace’s world Newspaper 1, and Mr. Babbage’s Newspaper 2:

function climb_up_one_floor() {
    turn_left();
    move();
    turn_right();
    move();
    move();
}

function climb_down_one_floor() {
    move();
    move();
    turn_left();
    move();
    turn_right();
}

function get_money() {
    while ( ... ) {
      // single line of code
    }
}

// === End of definitions ===

take("star");
while ( !token_here() ){
    // single line of code
}
get_money();
put("star"); // leave paper
turn_around();
while ( ! ... ){
    // single line of code
}

It is up to you to fill up the missing tests and other lines of code. Once you are done, you might want to go back to Newspaper delivery revisited and see how much shorter this new version, which works in both worlds, is as compared with the old one which only worked in one of the two worlds.