Add creature statistics, speed depends on strength and equip weight

src/Dodge/Creature/Statistics.hs

@@ -0,0 +1,25 @@
+module Dodge.Creature.Statistics 
+    ( getCrStrength
+    ) where
+import Dodge.Data
+import qualified IntMapHelp as IM
+
+import Data.IntMap.Merge.Strict
+
+getCrStrength :: Creature -> Int
+getCrStrength cr = strFromEquipment cr + _crStrength (_crStatistics cr)
+
+strFromEquipment :: Creature -> Int
+strFromEquipment = sum . fmap equipmentStrValue . crCurrentEquipment
+
+equipmentStrValue :: Item -> Int
+equipmentStrValue itm = case _itType itm of
+    FRONTARMOUR -> negate 2
+    POWERLEGS   -> 3
+    _ -> 0
+
+crCurrentEquipment :: Creature -> IM.IntMap Item
+crCurrentEquipment cr =  merge dropMissing dropMissing (zipWithMatched (\_ _ itm -> itm))
+    (_crInvEquipped cr)
+    (_crInv cr)
+