2 -behaviour(gen_server).
20 -define(INTERVAL, 100). % In milliseconds
22 -define(CHAR_DEAD, 32). % Space
23 -define(CHAR_ALIVE, 111). % o
24 -define(CHAR_BAR, 45). % -
27 -record(state, {x :: integer()
28 ,cells :: list(atom())
29 ,num_cells :: integer()
30 ,state_pairs :: list(tuple(integer(), integer())) | []
31 ,replies_pending :: integer()
32 ,gen_count = 0 :: integer()
36 %% ============================================================================
38 %% ============================================================================
40 start_link(X, Cells) ->
41 ServerName = {local, ?MODULE},
44 gen_server:start_link(ServerName, ?MODULE, Args, Opts).
47 tock(CellID, CellState) ->
48 gen_server:cast(?MODULE, {tock, {CellID, CellState}}).
51 %% ============================================================================
53 %% ============================================================================
58 ,num_cells=length(Cells)
66 terminate(_Reason, State) ->
70 code_change(_Old, State, _Other) ->
74 handle_call(_Msg, _From, State) ->
78 handle_cast(next_tick,
84 ok = cast_all(Cells, tick),
85 {noreply, State#state{replies_pending=NumCells}};
87 handle_cast({tock, {ID, CellState}},
89 ,state_pairs=StatePairs
90 ,replies_pending=RepliesPending
95 NewStatePairs = [{ID, CellState} | StatePairs],
96 NewRepliesPending = RepliesPending - 1,
97 NewState = State#state{replies_pending=NewRepliesPending},
99 case NewRepliesPending of
101 NewGenCount = GenCount + 1,
102 SortedStatePairs = lists:sort(
103 fun({A, _}, {B, _}) -> A < B end,
106 StateChars = [state_to_char(S) || {_, S} <- SortedStatePairs],
109 "CELLS: ~b GENERATIONS: ~b~n",
110 [NumCells, NewGenCount]
112 ok = do_print_bar(X),
114 ok = do_print_state_chars(X, StateChars),
116 ok = timer:sleep(?INTERVAL),
117 schedule_next_tick(),
118 {noreply, NewState#state{state_pairs=[], gen_count=NewGenCount}};
121 {noreply, NewState#state{state_pairs=NewStatePairs}}
124 handle_cast(_Msg, State) ->
128 handle_info(_Msg, State) ->
132 %% ============================================================================
134 %% ============================================================================
136 schedule_next_tick() ->
137 gen_server:cast(?MODULE, next_tick).
140 cast_all([], _) -> ok;
141 cast_all([Server | Servers], Msg) ->
142 ok = gen_server:cast(Server, Msg),
143 cast_all(Servers, Msg).
146 state_to_char(0) -> ?CHAR_DEAD;
147 state_to_char(1) -> ?CHAR_ALIVE.
150 do_print_state_chars(_, []) -> ok;
151 do_print_state_chars(X, Chars) ->
152 {XChars, RestChars} = lists:split(X, Chars),
153 ok = io:format([XChars, $\n]),
154 do_print_state_chars(X, RestChars).
158 io:format("~s~n", [[?CHAR_BAR || _ <- lists:seq(1, X - 1)]]).