Store past damages in vector form

src/Dodge/Creature/State.hs

@@ -31,6 +31,8 @@ import System.Random
 --import qualified Data.Set as S
 --import qualified Data.Map as M
 import Data.Monoid
+import qualified Data.Vector as V
+import qualified Data.Vector.Mutable as MV
 
 dummyUpdate :: CRUpdate
 dummyUpdate cr _ = (Endo id, Just cr)
@@ -80,10 +82,18 @@ crFriction _ _ = V2 0 0
 
 doDamage :: Creature -> Creature
 doDamage cr = set (crState . crDamage) [] 
-    $ over (crState . crPastDamage) (forceFoldable . take 10 . (dams :) ) damagedCr
+    . over (crState . crPastDamage) (advancePastDamages dams)
+    $ snd $ _crApplyDamage cr dams cr
   where 
     dams = _crDamage $ _crState cr
-    damagedCr = snd $ _crApplyDamage cr dams cr
+
+advancePastDamages :: [DamageType] -> V.Vector [DamageType] -> V.Vector [DamageType]
+advancePastDamages newDs v = f $ V.backpermute v bpVector
+  where
+    f = V.modify $ \v' -> MV.write v' 0 newDs
+
+bpVector :: V.Vector Int
+bpVector = V.fromList $ 0 : [0 .. 18]
 
 movementSideEff :: Creature -> World -> World
 movementSideEff cr w