In this exercise we are going to model a shopping cart. You can put items inside it (an item is just a tuple {ItemName, Price}) and ask it for the total cost of all the items.
So, using a gen_server, write the following functions:
-
shopping_cart:start_link/0: Start an empty shopping cart. -
shopping_cart:put_item/2: Takes a PID and an item (a tuple) and saves it into the shopping cart. -
shopping_cart:cost_so_far/1: Calculates the cost of all the items inside the shopping cart. -
finish/1: Print the total price and finishes the shopping cart. -
All the functions required by the behaviour.
Example:
{ok, Pid} = shopping_cart:start_link().
shopping_cart:put_item(Pid, {orange, 2}).
%% [{orange, 2}]
shopping_cart:put_item(Pid, {apple, 1}).
%% [{apple, 1}, {orange, 2}]
shopping_cart:cost_so_far(Pid).
%% 3