Simplify creature update

src/Dodge/Creature/Impulse.hs

@@ -1,8 +1,10 @@
 {-# LANGUAGE TupleSections #-}
 module Dodge.Creature.Impulse
     ( impulsiveAI
+    , impulsiveAI'
     , followImpulses
     , followThenClearImpulses
+    , followThenClearImpulses'
     ) where
 import Dodge.Data
 import Dodge.Creature.Vocalization
@@ -17,6 +19,12 @@ import System.Random
 import Data.Bifunctor
 --import Data.Maybe
 
+impulsiveAI' :: (World -> Creature -> Creature)
+    -> Creature -> World -> World
+impulsiveAI' f cr w = g w & creatures . ix (_crID cr) .~ cr'
+  where
+    (g,cr') = impulsiveAI f cr w
+
 impulsiveAI 
     :: (World -> Creature -> Creature) -- | internal creature update
     -> Creature
@@ -24,6 +32,11 @@ impulsiveAI
     -> (World -> World , Creature)
 impulsiveAI f cr w = followImpulses w $ f w cr
 
+followThenClearImpulses' :: Creature -> World -> World
+followThenClearImpulses' cr w = f w & creatures . ix (_crID cr) .~ cr'
+  where
+    (f,cr') = followThenClearImpulses w cr
+
 followThenClearImpulses :: World -> Creature -> (World -> World, Creature)
 followThenClearImpulses w = second f . followImpulses w
   where