Moved Life implementations into 'life' directory.

[cellular-automata.git] / life / 002 / src / life.ml

diff --git a/life/002/src/life.ml b/life/002/src/life.ml
new file mode 100644 (file)
index 0000000..f7bf55e
--- /dev/null
+++ b/life/002/src/life.ml
@@ -0,0 +1,115 @@
+type direction =
+  N | NE | E | SE | S | SW | W | NW
+
+
+let directions =
+  [N; NE; E; SE; S; SW; W; NW]
+
+
+let (|>) x f = f x
+
+
+let char_dead  = ' '
+let char_alive = 'o'
+
+
+let char_of_state = function
+  | 0 -> char_dead
+  | 1 -> char_alive
+  | _ -> assert false
+
+
+let offset = function
+  (* direction -> x, y *)
+  | N  ->  0, -1
+  | NE ->  1, -1
+  | E  ->  1,  0
+  | SE ->  1,  1
+  | S  ->  0,  1
+  | SW -> -1,  1
+  | W  -> -1,  0
+  | NW -> -1, -1
+
+
+(* Hack to sleep less than 1 sec *)
+let minisleep subsec =
+  ignore (Unix.select [] [] [] subsec)
+
+
+let init_board x y =
+  Array.map (Array.map (fun _ -> Random.int 2)) (Array.make_matrix y x 0)
+
+
+let print_board board =
+  Array.iter
+  (
+    fun row ->
+      Array.iter
+      (fun state -> print_char (char_of_state state))
+      row;
+      print_newline ()
+  )
+  board
+
+
+let new_state = function
+  | 1, live_neighbors when live_neighbors < 2 -> 0
+  | 1, live_neighbors when live_neighbors < 4 -> 1
+  | 1, live_neighbors when live_neighbors > 3 -> 0
+  | 0, live_neighbors when live_neighbors = 3 -> 1
+  | state, _ -> state
+
+
+let filter_offsides width height neighbors =
+  List.filter
+  (fun (x, y) -> x >= 0 && y >= 0 && x < width && y < height)
+  neighbors
+
+
+let neighbors x y =
+  List.map
+  (
+    fun d ->
+      let off_x, off_y = offset d in
+      (x + off_x), (y + off_y)
+  )
+  directions
+
+
+let new_generation board =
+  let h = Array.length board
+  and w = Array.length board.(0) in
+  Array.mapi
+  (
+    fun y row ->
+      Array.mapi
+      (
+        fun x state->
+          let neighbors = neighbors x y |> filter_offsides w h in
+          let states = List.map (fun (x, y) -> board.(y).(x)) neighbors in
+          let live_neighbors = List.fold_left (+) 0 states in
+          new_state (state, live_neighbors)
+      )
+      row
+  )
+  board
+
+
+let rec life_loop board =
+  print_board board;
+  print_newline ();
+  minisleep 0.1;
+  life_loop (new_generation board)
+
+
+let main argv =
+  let x = int_of_string argv.(1)
+  and y = int_of_string argv.(2)
+  in
+
+  Random.init (int_of_float (Unix.time ()));
+
+  life_loop (init_board x y)
+
+
+let () = main Sys.argv