-module(shop).
-export([cost/1, total/1]).

%% ShoppingList = [{oranges,4},{newspaper,1},{apples,10},{pears,6},{milk,3}]
cost (oranges) -> 5;
cost (newspaper) -> 8;
cost (apples) -> 2;
cost (pears) -> 9;
cost (milk) -> 7.

total([]) ->
    0;
total([{Item, Count}|Rest]) ->
    cost(Item) * Count + total(Rest).