Simple example for Erlang memoization

Question

Suppose you have a simple function, which can get quite expensive for large values:

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

Where can I

Answer 1

Depending on your case, you can also use the process dictionary for memoization:

fact(0) -> 1;
fact(N) ->
    case erlang:get({'fact', N}) of
        F when is_integer(F) ->
            F;
        'undefined' ->
            F = N * fact(N-1),
            erlang:put({'fact', N}, F),
            F
    end.