partial refactoring so we use EnemyMap.t for collection of enemies

fcore/game-update.sml

@@ -13,32 +13,38 @@ struct
         , fallingEnemies
         } = game
 
-      val enemyTree = Enemy.generateTree enemies
+      val enemyTree = MakeEnemyTree.foldUnordered
+        ( enemies
+        , ()
+        , QuadTree.create (Constants.worldWidth, Constants.worldHeight)
+        )
       val player = Player.runPhysicsAndInput (game, input, enemyTree)
 
       val projectiles = #projectiles player
       val projectileTree = Projectile.generateTree projectiles
 
-      (* update state of falling enemies and possibly filter *)
-      val fallingEnemies = FallingEnemies.updateList
-        (Vector.length fallingEnemies - 1, fallingEnemies, player, [])
-
-      val (enemies, fallingEnemies) = Enemy.updateEnemyList
-        ( Vector.length enemies - 1
-        , enemies
-        , projectiles
-        , projectileTree
-        , walls
-        , wallTree
-        , platforms
-        , platformTree
-        , player
-        , graph
-        , []
-        , fallingEnemies
-        )
-
-      val fallingEnemies = Vector.fromList fallingEnemies
+    (* update state of falling enemies and possibly filter *)
+    (* todo: use enemy map
+    val fallingEnemies = FallingEnemies.updateList
+      (Vector.length fallingEnemies - 1, fallingEnemies, player, [])
+    
+    val (enemies, fallingEnemies) = Enemy.updateEnemyList
+      ( Vector.length enemies - 1
+      , enemies
+      , projectiles
+      , projectileTree
+      , walls
+      , wallTree
+      , platforms
+      , platformTree
+      , player
+      , graph
+      , []
+      , fallingEnemies
+      )
+    
+    val fallingEnemies = Vector.fromList fallingEnemies
+      *)
     in
       { player = player
       , walls = walls