35. More harvesting challenges

Reeborg’s aunt is a fruit farmer. In her fields, many types of fruits can be found. On a given day, only a certain kind of fruit needs to be harvested. Have a look at worlds Harvest 5a, Harvest 5b, Harvest 5c and Harvest 5d. As he enters the field, Reeborg sees the type of fruit that needs to be harvested as his aunt put a sample there. He picks it up and proceed to harvest all fruits of the similar type.

Reeborg uses the function object_here() which return one of "star", "triangle", "square" or "token" depending if one these objects is found, or return zero otherwise.

There is also a function token_here() that returns either the number of tokens found at the current location. Using these, you can complete the following outline of a solution that will work for each of these four worlds.

Warning

There are two new things in the code below which makes is a bit difficult to understand when you read it for the first time. First, we define a new function that takes an argument, in this case fruit. Second, we test to see if two quantities are equal by using two consecutive equal signs: ==.

var selection;
think(0);  // optional; so it does not take too long...

function harvest_one_row (fruit) {
    while (front_is_clear()) {
        if (object_here() === fruit) {
            take(fruit);
        }
        move();
    }
}

function go_back_to_beginning_of_row() {
    ...
}

function move_to_next_row() {
    ...
}

function go_to_first_row() {
    ...
}

function complete_one_row() {
    harvest_one_row(selection);
    go_back_to_beginning_of_row();
    move_to_next_row();
}

move();
selection = object_here();
take(selection);
go_to_first_row();
repeat(complete_one_row, 6);

Try it!

Complete the above program so that it works in all four worlds: Harvest 5a, Harvest 5b, Harvest 5c and Harvest 5d.