Gist for the FeatureLearn Erlang course (1.15)

pattern_matching.erl

% @doc Pattern Mathing module for the 1.15 step of the FutureLearn Erlang Course.
-module(pattern_matching).

-export([
  xOr/2,
  xOr1/2,
  xOr2/2,
  xOr3/2,
  xOr4/2,
  max_three/3,
  how_many_equal/3
]).

% Exclusive Or from lesson

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

% Exclusive Or implementations

xOr1(true,true) -> false;
xOr1(false,false) -> false;
xOr1(_,_) -> true.

xOr2(true, false) -> true;
xOr2(false, true) -> true;
xOr2(_,_) -> false.

xOr3(X,Y) -> X =/= Y.

xOr4(X,Y) -> not X == Y.

% @doc Given three integers returns the maximum
max_three(X,Y,Z) -> max(X, max(Y,Z)).

% @doc Given three integers returns a number representing the equivalent ones
how_many_equal(X,X,X) -> 3;
how_many_equal(X,X,_) -> 2;
how_many_equal(X,_,X) -> 2;
how_many_equal(_,X,X) -> 2;
how_many_equal(_,_,_) -> 0.

test_pattern_matching.erl

-module(test_pattern_matching).

-export([
    test_max_three/0,
    test_how_many_equal/0
]).

test_max_three() ->
  4 = pattern_matching:max_three(4, 2, 0),
  4 = pattern_matching:max_three(2, 4, 0),
  4 = pattern_matching:max_three(0, 2, 4),
  ':: max_three tests passed succesfully'.

test_how_many_equal() ->
  3 = pattern_matching:how_many_equal(4,4,4),
  2 = pattern_matching:how_many_equal(4,4,0),
  2 = pattern_matching:how_many_equal(4,0,4),
  2 = pattern_matching:how_many_equal(0,4,4),
  0 = pattern_matching:how_many_equal(4,2,0),
  ':: how_many_equal tests passed succesfully'.

It looks nice! If you want to comply with common_test conventions (which might be useful for you in the future) your tests should return something like…

{comment, ""}.

But since you're not using CT yet… it doesn't matter.

What does CT stand for?

What does CT stand for?

Common Test ;)

What does CT stand for?

Common Test ;)

Thanks @elbrujohalcon 👍 !