[iagno] Use PossibleMove more.

[Arnaud B. <arnaudb src gnome org>]

commit 153910c4518ef359bfc6cb412aa85af517980ff9
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Fri May 10 12:53:14 2019 +0200

    Use PossibleMove more.

 src/computer-player.vala  | 18 ++++++++++--------
 src/computer-reversi.vala | 30 +++++++++++++-----------------
 2 files changed, 23 insertions(+), 25 deletions(-)
---
diff --git a/src/computer-player.vala b/src/computer-player.vala
index dc16d86..8e22c0c 100644
--- a/src/computer-player.vala
+++ b/src/computer-player.vala
@@ -50,9 +50,12 @@ private abstract class ComputerPlayer : Object
     internal void move_sync (out uint8 x, out uint8 y)      // for tests
     {
         move_pending = true;
-        run_search (out x, out y);
+        PossibleMove best_move;
+        run_search (out best_move);
         move_pending = false;
-        complete_move (x, y);
+        complete_move (best_move);
+        x = best_move.x;
+        y = best_move.y;
     }
 
     internal void move (double delay_seconds = 0.0)
@@ -62,8 +65,7 @@ private abstract class ComputerPlayer : Object
     private async void move_async (double delay_seconds)
     {
         Timer timer = new Timer ();
-        uint8 x = 0; // garbage, should not be needed
-        uint8 y = 0; // idem
+        PossibleMove best_move = PossibleMove (0, 0, 0); // garbage
 
         while (move_pending)
         {
@@ -76,7 +78,7 @@ private abstract class ComputerPlayer : Object
         timer.start ();
         new Thread<void *> ("AI thread", () => {
             move_pending = true;
-            run_search (out x, out y);
+            run_search (out best_move);
             move_async.callback ();
             return null;
         });
@@ -98,7 +100,7 @@ private abstract class ComputerPlayer : Object
 
         /* complete_move() needs to be called on the UI thread. */
         Idle.add (() => {
-            complete_move (x, y);
+            complete_move (best_move);
             return Source.REMOVE;
         });
     }
@@ -120,6 +122,6 @@ private abstract class ComputerPlayer : Object
         move_pending = false;
     }
 
-    protected abstract void run_search (out uint8 x, out uint8 y);
-    protected abstract void complete_move (uint8 x, uint8 y);
+    protected abstract void run_search (out PossibleMove chosen_move);
+    protected abstract void complete_move (PossibleMove chosen_move);
 }
diff --git a/src/computer-reversi.vala b/src/computer-reversi.vala
index f1ff6df..7d35702 100644
--- a/src/computer-reversi.vala
+++ b/src/computer-reversi.vala
@@ -230,25 +230,24 @@ private abstract class ComputerReversi : ComputerPlayer
     * * common methods
     \*/
 
-    protected override void complete_move (uint8 x, uint8 y)
+    protected override void complete_move (PossibleMove chosen_move)
     {
-        if (!game.place_tile (x, y))
+        if (!game.place_tile (chosen_move.x, chosen_move.y))
         {
-            critical (@"Computer chose an invalid move: $x,$y\n$game");
+            critical (@"Computer chose an invalid move: $(chosen_move.x),$(chosen_move.y)\n$game");
 
             /* Has been reached, once. So let's have a fallback. */
-            uint8 new_x;
-            uint8 new_y;
-            random_select (game.current_state, out new_x, out new_y);
-            if (!game.place_tile (new_x, new_y))
+            PossibleMove random_move;
+            random_select (game.current_state, out random_move);
+            if (!game.place_tile (random_move.x, random_move.y))
             {
-                critical (@"Computer chose an invalid move for the second time: $new_x,$new_y\n$game");
+                critical (@"Computer chose an invalid move for the second time: 
$(random_move.x),$(random_move.y)\n$game");
                 assert_not_reached ();
             }
         }
     }
 
-    private static void random_select (GameState g, out uint8 move_x, out uint8 move_y)
+    private static void random_select (GameState g, out PossibleMove random_move)
     {
         SList<PossibleMove?> moves;
         g.get_possible_moves (out moves);
@@ -262,26 +261,24 @@ private abstract class ComputerReversi : ComputerPlayer
 
         if (move == null)
             assert_not_reached ();
-        move_x = ((!) move).x;
-        move_y = ((!) move).y;
+        random_move = (!) move;
     }
 
     /*\
     * * minimax / negamax / alpha-beta pruning
     \*/
 
-    protected override void run_search (out uint8 x, out uint8 y)
+    protected override void run_search (out PossibleMove best_move)
         requires (game.current_player_can_move)
     {
         /* For the first/first two moves play randomly so the game is not always the same */
         if (game.current_state.n_tiles < game.initial_number_of_tiles + (game.size < 6 ? 2 : 4))
         {
-            random_select (game.current_state, out x, out y);
+            random_select (game.current_state, out best_move);
             return;
         }
 
-        x = 0;  // garbage
-        y = 0;  // idem
+        best_move = PossibleMove (0, 0, 0); // garbage
 
         /* Choose a location to place by building the tree of possible moves and
          * using the minimax algorithm to pick the best branch with the chosen
@@ -306,8 +303,7 @@ private abstract class ComputerReversi : ComputerPlayer
             if (a_new > a)
             {
                 a = a_new;
-                x = ((!) move).x;
-                y = ((!) move).y;
+                best_move = (!) move;
             }
 
             /* Checking move_pending here is optional. It helps avoid a long unnecessary search