Implement sconcat for Intersection (#1080)

Author: meooow25

containers/src/Data/IntSet/Internal.hs

@@ -196,11 +196,7 @@ import Data.Bits
 import qualified Data.List as List
 import Data.List.NonEmpty (NonEmpty(..))
 import Data.Maybe (fromMaybe)
-import Data.Semigroup
-  (Semigroup(stimes), stimesIdempotent, stimesIdempotentMonoid)
-#if !(MIN_VERSION_base(4,11,0))
-import Data.Semigroup (Semigroup((<>)))
-#endif
+import Data.Semigroup (Semigroup(..), stimesIdempotent, stimesIdempotentMonoid)
 import Utils.Containers.Internal.Prelude hiding
   (filter, foldr, foldl, foldl', foldMap, null, map)
 import Prelude ()
@@ -224,6 +220,7 @@ import Data.IntSet.Internal.IntTreeCommons
 import Data.Data (Data(..), Constr, mkConstr, constrIndex, DataType, mkDataType)
 import qualified Data.Data
 import Text.Read
+import Data.Coerce (coerce)
 #endif
 
 #if __GLASGOW_HASKELL__
@@ -687,6 +684,13 @@ instance Semigroup Intersection where
   stimes = stimesIdempotent
   {-# INLINABLE stimes #-}
 
+  sconcat =
+#ifdef __GLASGOW_HASKELL__
+    coerce intersections
+#else
+    Intersection . intersections . fmap getIntersection
+#endif
+
 {--------------------------------------------------------------------
   Symmetric difference
 --------------------------------------------------------------------}

containers/src/Data/Set/Internal.hs

@@ -239,11 +239,7 @@ import Prelude ()
 import Control.Applicative (Const(..))
 import qualified Data.List as List
 import Data.Bits (shiftL, shiftR)
-import Data.Semigroup (Semigroup(stimes))
-#if !(MIN_VERSION_base(4,11,0))
-import Data.Semigroup (Semigroup((<>)))
-#endif
-import Data.Semigroup (stimesIdempotentMonoid, stimesIdempotent)
+import Data.Semigroup (Semigroup(..), stimesIdempotentMonoid, stimesIdempotent)
 import Data.Functor.Classes
 import Data.Functor.Identity (Identity)
 import qualified Data.Foldable as Foldable
@@ -265,6 +261,7 @@ import Data.Data
 import Language.Haskell.TH.Syntax (Lift)
 -- See Note [ Template Haskell Dependencies ]
 import Language.Haskell.TH ()
+import Data.Coerce (coerce)
 #endif
 
 
@@ -928,6 +925,14 @@ instance (Ord a) => Semigroup (Intersection a) where
     stimes = stimesIdempotent
     {-# INLINABLE stimes #-}
 
+    sconcat =
+#ifdef __GLASGOW_HASKELL__
+      coerce intersections
+#else
+      Intersection . intersections . fmap getIntersection
+#endif
+    {-# INLINABLE sconcat #-}
+
 {--------------------------------------------------------------------
   Symmetric difference
 --------------------------------------------------------------------}