Updating PE.

pe/geometry1.erl

@@ -0,0 +1,15 @@
+-module(geometry1).
+-export([test/0, area/1]).
+
+test() ->
+    12 = area({rectangle, 3, 4}),
+    144 = area({square, 12}),
+    tests_worked.
+area({rectangle, Width, Height}) ->
+    Width * Height;
+area({circle, Radius}) ->
+    3.14159 * Radius * Radius;
+area({square, Side}) ->
+    Side * Side.
+
+

pe/shop.erl

@@ -1,4 +1,14 @@
 -module(shop).
--export([cost/1]).
+-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).