From cae124f201e52ae37f7ffbcb936e34a34ad95429 Mon Sep 17 00:00:00 2001
From: Maximilian Algehed <m.algehed@gmail.com>
Date: Thu, 21 Mar 2024 12:03:05 +0100
Subject: [PATCH] Min and Max from Semigroup

---
 src/Test/QuickCheck/Arbitrary.hs | 22 ++++++++++++++++++++++
 src/Test/QuickCheck/Function.hs  | 11 ++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/Test/QuickCheck/Arbitrary.hs b/src/Test/QuickCheck/Arbitrary.hs
index 2ddfb7f7..3f649f56 100644
--- a/src/Test/QuickCheck/Arbitrary.hs
+++ b/src/Test/QuickCheck/Arbitrary.hs
@@ -150,6 +150,7 @@ import System.IO
 #if defined(MIN_VERSION_base)
 #if MIN_VERSION_base(4,9,0)
 import Data.List.NonEmpty (NonEmpty(..))
+import qualified Data.Semigroup as Semigroup
 #endif
 #endif
 
@@ -1014,6 +1015,18 @@ instance Arbitrary a => Arbitrary (Monoid.Last a) where
   shrink = map Monoid.Last . shrink . Monoid.getLast
 #endif
 
+#if defined(MIN_VERSION_base)
+#if MIN_VERSION_base(4,9,0)
+instance Arbitrary a => Arbitrary (Semigroup.Min a) where
+  arbitrary = fmap Semigroup.Min arbitrary
+  shrink = map Semigroup.Min . shrink . Semigroup.getMin
+
+instance Arbitrary a => Arbitrary (Semigroup.Max a) where
+  arbitrary = fmap Semigroup.Max arbitrary
+  shrink = map Semigroup.Max . shrink . Semigroup.getMax
+#endif
+#endif
+
 #if MIN_VERSION_base(4,8,0)
 instance Arbitrary (f a) => Arbitrary (Monoid.Alt f a) where
   arbitrary = fmap Monoid.Alt arbitrary
@@ -1584,6 +1597,15 @@ instance CoArbitrary a => CoArbitrary (Monoid.Last a) where
   coarbitrary = coarbitrary . Monoid.getLast
 #endif
 
+#if MIN_VERSION_base(4,9,0)
+instance CoArbitrary a => CoArbitrary (Semigroup.Min a) where
+  coarbitrary = coarbitrary . Semigroup.getMin
+
+instance CoArbitrary a => CoArbitrary (Semigroup.Max a) where
+  coarbitrary = coarbitrary . Semigroup.getMax
+#endif
+
+
 #if MIN_VERSION_base(4,8,0)
 instance CoArbitrary (f a) => CoArbitrary (Monoid.Alt f a) where
   coarbitrary = coarbitrary . Monoid.getAlt
diff --git a/src/Test/QuickCheck/Function.hs b/src/Test/QuickCheck/Function.hs
index f2ef5f89..6fa2cc61 100644
--- a/src/Test/QuickCheck/Function.hs
+++ b/src/Test/QuickCheck/Function.hs
@@ -105,6 +105,7 @@ import GHC.Generics hiding (C)
 #if defined(MIN_VERSION_base)
 #if MIN_VERSION_base(4,9,0)
 import Data.List.NonEmpty (NonEmpty(..))
+import qualified Data.Semigroup as Semigroup
 #endif
 #endif
 
@@ -442,13 +443,21 @@ instance Function a => Function (Monoid.Last a) where
 instance Function a => Function (Down a) where
   function = functionMap (\(Down a) -> a) Down
 #endif
-#endif
 
 #if MIN_VERSION_base(4,8,0)
 instance Function (f a) => Function (Monoid.Alt f a) where
   function = functionMap Monoid.getAlt Monoid.Alt
 #endif
 
+#if MIN_VERSION_base(4,9,0)
+instance Function a => Function (Semigroup.Min a) where
+  function = functionMap Semigroup.getMin Semigroup.Min
+
+instance Function a => Function (Semigroup.Max a) where
+  function = functionMap Semigroup.getMax Semigroup.Max
+#endif
+#endif
+
 -- poly instances
 
 instance Function A where