4 files changed, 20 insertions, 0 deletions

diff --git a/packages/base/src/Numeric/LinearAlgebra.hs b/packages/base/src/Numeric/LinearAlgebra.hs
index fd100e0..73d4a13 100644
--- a/packages/base/src/Numeric/LinearAlgebra.hs
+++ b/packages/base/src/Numeric/LinearAlgebra.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE FlexibleContexts #-}
 
 -----------------------------------------------------------------------------
@@ -190,6 +191,9 @@ import Internal.Random
 import Internal.Sparse((!#>))
 import Internal.CG
 import Internal.Conversion
+#if MIN_VERSION_base(4,11,0)
+import Prelude hiding ((<>))
+#endif
 
 {- | dense matrix product
 
diff --git a/packages/base/src/Numeric/LinearAlgebra/HMatrix.hs b/packages/base/src/Numeric/LinearAlgebra/HMatrix.hs
index 5ce529c..3a84645 100644
--- a/packages/base/src/Numeric/LinearAlgebra/HMatrix.hs
+++ b/packages/base/src/Numeric/LinearAlgebra/HMatrix.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 --------------------------------------------------------------------------------
 {- |
 Module      :  Numeric.LinearAlgebra.HMatrix
@@ -19,6 +20,9 @@ module Numeric.LinearAlgebra.HMatrix (
 import Numeric.LinearAlgebra
 import Internal.Util
 import Internal.Algorithms(cholSH, mbCholSH, eigSH', eigenvaluesSH', geigSH')
+#if MIN_VERSION_base(4,11,0)
+import Prelude hiding ((<>))
+#endif
 
 infixr 8 <·>
 (<·>) :: Numeric t => Vector t -> Vector t -> t
diff --git a/packages/base/src/Numeric/LinearAlgebra/Static.hs b/packages/base/src/Numeric/LinearAlgebra/Static.hs
index 3000dcb..e328904 100644
--- a/packages/base/src/Numeric/LinearAlgebra/Static.hs
+++ b/packages/base/src/Numeric/LinearAlgebra/Static.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE KindSignatures #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
@@ -80,6 +81,9 @@ import Control.Arrow((***))
 import Text.Printf
 import Data.Type.Equality ((:~:)(Refl))
 import qualified Data.Bifunctor as BF (first)
+#if MIN_VERSION_base(4,11,0)
+import Prelude hiding ((<>))
+#endif
 
 ud1 :: R n -> Vector ℝ
 ud1 (R (Dim v)) = v
diff --git a/packages/base/src/Numeric/Matrix.hs b/packages/base/src/Numeric/Matrix.hs
index 5400f26..06da150 100644
--- a/packages/base/src/Numeric/Matrix.hs
+++ b/packages/base/src/Numeric/Matrix.hs
@@ -32,8 +32,11 @@ import Internal.Element
 import Internal.Numeric
 import qualified Data.Monoid as M
 import Data.List(partition)
+import qualified Data.Foldable as F
+import qualified Data.Semigroup as S
 import Internal.Chain
 
+
 -------------------------------------------------------------------
 
 instance Container Matrix a => Eq (Matrix a) where
@@ -84,6 +87,11 @@ adaptScalarM f1 f2 f3 x y
     | isScalar y = f3 x (y @@>(0,0) )
     | otherwise = f2 x y
 
+instance (Container Vector t, Eq t, Num (Vector t), Product t) => S.Semigroup (Matrix t)
+  where
+    (<>) = mappend
+    sconcat = mconcat . F.toList
+
 instance (Container Vector t, Eq t, Num (Vector t), Product t) => M.Monoid (Matrix t)
   where
     mempty = 1