Split Dodge.Base

src/Dodge/Base/Arithmetic.hs

@@ -0,0 +1,10 @@
+module Dodge.Base.Arithmetic where
+import MaybeHelp
+
+decreaseToZero :: Int -> Int
+decreaseToZero = max 0 . subtract 1
+
+decreaseToNothing' :: (Num a, Ord a) => Maybe' a -> Maybe' a
+decreaseToNothing' ma = case ma of
+    Just' x | x > 0 -> Just' (x - 1)
+    _ -> Nothing'