Add version guards for Monoid imports

src/Arguments.hs

@@ -1,9 +1,12 @@
+{-# LANGUAGE CPP #-}
 module Arguments (
       Arguments(..)
     , get
   ) where
 
+#if !MIN_VERSION_base(4,11,0)
 import Data.Monoid ((<>))
+#endif
 import Data.Version (showVersion)
 import Control.Applicative ((<|>), (<**>), optional)
 import Options.Applicative (

src/Blog/Path.hs

@@ -1,6 +1,7 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
 module Blog.Path (
       Path(..)
     , build
@@ -11,7 +12,9 @@ import qualified Arguments as Arguments (Arguments(..))
 import Control.Monad (join)
 import Control.Monad.Except (MonadError(..), ExceptT(..), runExceptT)
 import Data.Aeson (ToJSON(..), (.=), pairs)
+#if !MIN_VERSION_base(4,11,0)
 import Data.Monoid ((<>))
+#endif
 import Files (File(..), filePath)
 import GHC.Generics (Generic)
 

src/Blog/Skin.hs

@@ -1,6 +1,7 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE CPP #-}
 module Blog.Skin (
       Skin(..)
     , build
@@ -11,7 +12,9 @@ import qualified Arguments (bannerPath, favicon, cardImage, headPath, previewArt
 import Control.Monad (filterM)
 import Data.Aeson (ToJSON(..), (.=), pairs)
 import Data.Maybe (listToMaybe)
+#if !MIN_VERSION_base(4,11,0)
 import Data.Monoid ((<>))
+#endif
 import Files (absoluteLink)
 import GHC.Generics (Generic)
 import Prelude hiding (head)