a bit of refactoring and clearer naming

fcore/player.sml

@@ -440,6 +440,60 @@ struct
       PlayerPatch.withPatches (player, patches)
     end
 
+  fun concatAttackedEnemies (player: player, enemyCollisions) =
+    let
+      val newDefeated = Vector.map (fn id => {angle = 360}) enemyCollisions
+      val oldDefeated = #enemies player
+      val allDefeated = Vector.concat [oldDefeated, newDefeated]
+    in
+      PlayerPatch.withPatch (player, W_ENEMIES allDefeated)
+    end
+
+  fun getEnemyRecoilPatches (player, playerOnRight, acc) =
+    if playerOnRight then
+      let
+        val newRecoil = RECOIL_RIGHT 0
+        val newAttacked = ATTACKED 0
+      in
+        W_RECOIL newRecoil :: W_ATTACKED newAttacked :: W_FACING FACING_LEFT
+        :: W_Y_AXIS FALLING :: W_X_AXIS STAY_STILL :: acc
+      end
+    else
+      let
+        val newRecoil = RECOIL_LEFT 0
+        val newAttacked = ATTACKED 0
+      in
+        W_RECOIL newRecoil :: W_ATTACKED newAttacked :: W_FACING FACING_RIGHT
+        :: W_Y_AXIS FALLING :: W_X_AXIS STAY_STILL :: acc
+      end
+
+  fun enemyCollisionReaction (player: player, enemies: enemy vector, lst, acc) =
+    case lst of
+      id :: tl =>
+        let
+          val playerOnRight =
+            (* check if collision is closer to left side of enemy or right
+             * and then chose appropriate direction to recoil in *)
+            let
+              val {x, ...} = player
+              val pFinishX = x + Constants.playerSize
+              val pHalfW = Constants.playerSize div 2
+              val pCentreX = x + pHalfW
+
+              val {x = ex, y = ey, ...} = Enemy.find (id, enemies)
+              val eFinishX = ex + Constants.enemySize
+              val eHalfW = Constants.enemySize div 2
+              val eCentreX = ex + eHalfW
+            in
+              eCentreX < pCentreX
+            end
+
+          val acc = getEnemyRecoilPatches (player, playerOnRight, acc)
+        in
+          enemyCollisionReaction (player, enemies, tl, acc)
+        end
+    | [] => PlayerPatch.withPatches (player, acc)
+
   (* block is placeholder asset *)
   fun helpGetDrawVec (x, y, size, width, height, attacked, mainAttack) =
     case mainAttack of