Clean up code a little

cabal-install/tests/UnitTests/Distribution/Solver/Modular/QuickCheck/Utils.hs

@@ -43,6 +43,8 @@ instance IsTest QCWithSeed where
     notice normal $ "Using --quickcheck-replay=" ++ show replay
     run (setOption (QuickCheckReplayLegacy replay) options) test progress
 
+-- | Typeclass for doing arbitrary (but law-abiding) comparisons.  See also
+-- 'ArbitraryOrd', this is the version that works with 'GHC.Generics'.
 class GArbitraryOrd f where
   garbitraryCompare :: QC.Gen (f p -> f p -> Ordering)
 
@@ -83,20 +85,19 @@ instance GArbitraryOrd f => GArbitraryOrd (M1 i t f) where
 instance ArbitraryOrd c => GArbitraryOrd (K1 i c) where
   garbitraryCompare = (\c (K1 l) (K1 r) -> c l r) <$> arbitraryCompare
 
+-- | Typeclass for doing arbitrary (but law-abiding) comparisons.
 class ArbitraryOrd a where
   arbitraryCompare :: QC.Gen (a -> a -> Ordering)
   default arbitraryCompare
     :: (Generic a, GArbitraryOrd (Rep a)) => QC.Gen (a -> a -> Ordering)
   arbitraryCompare = (\c l r -> c (from l) (from r)) <$> garbitraryCompare
 
-instance ArbitraryOrd Int where
-  arbitraryCompare = do
-    bias <- QC.arbitrary
-    pure $ \l r -> if bias then compare l r else compare r l
-
 instance ArbitraryOrd Char where
   arbitraryCompare = arbitraryCompareReverseSection
 
+-- | Construct an arbitrary comparison by (conceptually) laying out all values
+-- in a list, picking two values (since we are using arbitrary these should
+-- be "good" values), and then reversing the section between these two values.
 arbitraryCompareReverseSection
   :: (QC.Arbitrary a, Ord a) => QC.Gen (a -> a -> Ordering)
 arbitraryCompareReverseSection = do