• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Finally, you can manage your Google Docs, uploads, and email attachments (plus Dropbox and Slack files) in one convenient place. Claim a free account, and in less than 2 minutes, Dokkio (from the makers of PBworks) can automatically organize your content for you.


Fizz Buzz Kata In Erlang

Page history last edited by Milano eXtreme Programming User Group 10 years, 8 months ago

Il Fizz Buzz รจ un semplice gioco per bambini, usato spesso come primissimo test per l'assunzione di programmatori.

Ieri Gabriele Lana ci ha guidato nello svolgimento collettivo di un kata in Erlang su questo argomento. Ecco il codice prodotto.


In primo luogo i test (file fizzbuzz_tests.erl):







fizzbuzz_of_zero_should_be_zero_test() ->

  ?assertEqual(0, fizzbuzz:number(0)).


fizzbuzz_of_one_should_be_one_test() ->

  ?assertEqual(1, fizzbuzz:number(1)).



on_multiple_of_three_should_be_fizz_test_() -> [

  ?_assertEqual(fizz, fizzbuzz:number(3)),

  ?_assertEqual(fizz, fizzbuzz:number(6))




fizzbuzz_of_five_should_be_buzz_test_() -> [

  ?_assertEqual(buzz, fizzbuzz:number(5)),

  ?_assertEqual(buzz, fizzbuzz:number(10))



returns_fizzbuzz_for_multiples_of_fifteen_test_() -> [

  ?_assertEqual(fizzbuzz, fizzbuzz:number(15)),

  ?_assertEqual(fizzbuzz, fizzbuzz:number(30))



returns_list_of_fizzbuzzed_numbers_test_() -> [

  ?_assertEqual([], fizzbuzz:list([])),

  ?_assertEqual([0], fizzbuzz:list([0])),

  ?_assertEqual([0, 1, fizz], fizzbuzz:list([0, 1, 6]))



Ed ora il codice di "produzione" ;-) (file fizzbuzz.erl)



-export([ number/1, list/1 ]).


list(List) -> 

  Parent = self(),

  FizzBuzzers= lists:map(fun(X) -> 

    TimeToSleep = random:uniform(50000),

    spawn(fun() ->


               Parent ! {self(), fizzbuzz:number(X)} 


  end, List),



receive_result(FizzBuzzers) -> 

  receive_result(FizzBuzzers, []).


receive_result([], Results) ->


receive_result([FizzBuzzer|Tail], Results) -> 


    {FizzBuzzer, Result} -> receive_result(Tail, Results ++ [Result])



number (0) -> 0;

number(Number) when Number rem 15 =:= 0 -> fizzbuzz;

number(Number) when Number rem 5 =:= 0 -> buzz;

number(Number) when Number rem 3 =:= 0 -> fizz;

number(Number) -> Number.



Comments (0)

You don't have permission to comment on this page.