Week-1: Shapes

.gitignore

*.beam

shapes.erl

%% Future Learn: Week 1

-module(shapes).
-export([perimeter/1, sum/1, area/1, area/2]).
-include_lib("eunit/include/eunit.hrl").

sum(L) -> sum(L, 0).

sum([H|T], A) ->
  sum(T, H + A);
sum([], A) ->
  A.

perimeter({triangle, L}) ->
  shapes:sum(L);
perimeter(L) ->
  shapes:sum(L).

area(W, L) ->
  W * L.

area({triangle, B, H}) ->
  (B * H) / 2;
area({circle, R}) ->
  math:pi() * 2 * R;
area({rectangle, W, H}) ->
  area(W, H).

perimeter_test_() ->
  [
    ?_assertEqual(6, shapes:sum([1, 2, 3])),
    ?_assertEqual(14, shapes:perimeter([2, 3, 4, 5])),
    ?_assertEqual(9, shapes:perimeter({triangle, [2, 3, 4]})),
    ?_assertEqual(27, shapes:perimeter([2, 3, 4, 5, 6, 7])),
    ?_assertEqual(60, shapes:area(10, 6)),
    ?_assertEqual(30.0, shapes:area({triangle, 15, 4})),
    ?_assertEqual(22, round(shapes:area({circle, 3.5}))),
    ?_assertEqual(30, shapes:area({rectangle, 5, 6}))
  ].