Split off StreamingHelp module

src/Dodge/WorldEvent/SpawnParticle.hs

@@ -25,6 +25,7 @@ import LensHelp
 
 import Data.Foldable
 import Data.Tuple
+import StreamingHelp
 import qualified Streaming.Prelude as S
 aFlameParticle 
     :: Int      -- ^ Timer
@@ -240,14 +241,13 @@ makeGasCloud pos vel w = w
     (col, g) = runState (takeOne [green,yellow]) $ _randGen w
 {- Attach poison cloud damage to creatures near cloud.  -}
 cloudPoisonDamage :: Cloud -> World -> World
-cloudPoisonDamage c w = w & creatures 
-    %~ dodamagesto damagedCrs
+cloudPoisonDamage c w = w & dodamagesto (S.filter f $ crsNearPoint clpos w)
   where 
-    dodamagesto :: StreamOf Creature -> IM.IntMap Creature -> IM.IntMap Creature
-    dodamagesto = undefined
-    damagedCrs = S.filter f $ crsNearPoint clpos w
+    dodamagesto :: StreamOf Creature -> World -> World
+    dodamagesto scrs mcrs = runIdentity $ S.fold_ (flip doDam) mcrs id scrs
+    doDam cr = creatures . ix (_crID cr) . crState . csDamage 
+        .:~ Damage POISONDAM 1 clpos clpos clpos NoDamageEffect
     f cr = dist3 (addZ 20 $ _crPos cr) (_clPos c) < _crRad cr + _clRad c + 10
-    doDam cr = cr & crState . csDamage .:~ Damage POISONDAM 1 clpos clpos clpos NoDamageEffect
     clpos = stripZ $ _clPos c
 
 incBall :: RandomGen g => Point2 -> State g Particle