[erlang-questions] learning Erlang: factoring primes

Martin Ankerl martin.ankerl@REDACTED
Fri May 4 09:20:01 CEST 2007

Hello everybody, I have just started learning Erlang and wrote one of
my first programs. It is a very simple prime factoring program, but it
works. I would appreciate comments about the programming style, is
this how Erlang code should be written? Any way to make it simpler?

Here is the code:


% c('factor').
% factor:fact(123456723456789).
fact(1) ->
fact(N) ->
        % io:format("~w\n", [N]),
        M = next_factor(N, 2, N rem 2),
        [ M | fact(N div M) ].

% find the next factor
next_factor(_, M, 0) ->
next_factor(N, N, _) ->
next_factor(N, M, _) ->
        next_factor(N, M+1, N rem (M+1)).

Martin Ankerl | http://martin.ankerl.com

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