pattern_matching_trontz.erl

-module(pattern_matching_practice).
-export([test/0]).


xOr(X,X) ->
  false;
xOr(_,_) ->
  true.

exclusive_or(X, Y) when X =/= Y -> true;
exclusive_or(_,_) -> false.

ex_or(X,Y) when not(X == Y) -> true;
ex_or(_,_) -> false.

maxThree(A, A, A) -> A;
maxThree(A, B, C) when A > B, A > C -> A;
maxThree(A, B, C) when B > A, B > C -> B;
maxThree(A, B, C) when C > A, C > B -> C.

howManyEqual(A, A, A) when is_integer(A) -> 3;
howManyEqual(A, A, B) when is_integer(A), is_integer(B) -> 2;
howManyEqual(A, B, A) when is_integer(A), is_integer(B) -> 2;
howManyEqual(B, A, A) when is_integer(A), is_integer(B) -> 2;
howManyEqual(_, _, _) -> 0.

test() ->
  false = xOr(5, 5),
  true = xOr(4, 5),
  false = exclusive_or(5, 5),
  true = exclusive_or(4, 5),
  false = ex_or(5, 5),
  true = ex_or(4, 5),
  5 = maxThree(5, 5, 5),
  8 = maxThree(8, 5, 6),
  8 = maxThree(5, 6, 8),
  8 = maxThree(5, 8, 6),
  3 = howManyEqual(10, 10, 10),
  2 = howManyEqual(5, 8, 8),
  2 = howManyEqual(5, 5, 8),
  2 = howManyEqual(5, 8, 5),
  0 = howManyEqual(5, 6, 8),
  ok.