Erlang 基础入门

函数

mirror(Anything) -> Anything.

number(one) -> 1;
number(two) -> 2;
number(three) -> 3;
number(_) -> default.

another_factorial(0) -> 1;
another_factorial(N) -> N * another_factorial(N-1).

another_fib(0) -> 1;
another_fib(1) -> 1;
another_fib(N) -> another_fib(N-1) + another_fib(N-2).

模式匹配

animal_case(Animal) ->
    case Animal of
        "dog" -> underdog;
        "cat" -> thundercat;
        _ -> unknown
    end.

my_abs(N) ->
    if 
        N > 0 -> positive;
        N < 0 -> negative;
        true -> zero
    end.

actor并发

loop() ->
    receive
        {From, "casa"} ->
            From ! "house",
            loop();
        {From, "blanca"} ->
            From ! "white",
            loop();
        3 -> 
            io:format("bang~n"), exit({basic, dir, at, erlang:time()});
        {From, _} ->
            From ! "I don't understand.",
            loop()
end.

translate(To, Word) ->
    To ! {self(), Word},
    receive
        Translate -> Translate
    end.

输出结果

1> Pid = spawn(fun translate:loop/0).
<0.21.0>

2> Pid ! "casa"
"house"
"casa"