Use the new infix synonym for mappend (<>)

Define it in Compat to support base < 4.5

Also, tweak Compat's doc comment, as we no longer use regex (see a2a04b3).

src/Database/PostgreSQL/Simple.hs

@@ -133,10 +133,10 @@ import           Data.ByteString (ByteString)
 import           Data.Int (Int64)
 import qualified Data.IntMap as IntMap
 import           Data.List (intersperse)
-import           Data.Monoid (mappend, mconcat)
+import           Data.Monoid (mconcat)
 import           Data.Typeable (Typeable)
 import           Database.PostgreSQL.Simple.BuiltinTypes ( oid2typname )
-import           Database.PostgreSQL.Simple.Compat ( mask )
+import           Database.PostgreSQL.Simple.Compat ( mask, (<>) )
 import           Database.PostgreSQL.Simple.FromField (ResultError(..))
 import           Database.PostgreSQL.Simple.FromRow (FromRow(..))
 import           Database.PostgreSQL.Simple.Ok
@@ -325,7 +325,7 @@ buildQuery conn q template xs = zipParams (split template) <$> mapM sub xs
         sub (Many  ys)      = mconcat <$> mapM sub ys
         split s = fromByteString h : if B.null t then [] else split (B.tail t)
             where (h,t) = B.break (=='?') s
-        zipParams (t:ts) (p:ps) = t `mappend` p `mappend` zipParams ts ps
+        zipParams (t:ts) (p:ps) = t <> p <> zipParams ts ps
         zipParams [t] []        = t
         zipParams _ _ = fmtError (show (B.count '?' template) ++
                                   " '?' characters, but " ++
@@ -499,8 +499,7 @@ doFold FoldOptions{..} conn _template q a f = do
   where
     go = do
        -- FIXME:  what about name clashes with already-declared cursors?
-       _ <- execute_ conn ("DECLARE fold NO SCROLL CURSOR FOR "
-                           `mappend` q)
+       _ <- execute_ conn ("DECLARE fold NO SCROLL CURSOR FOR " <> q)
        loop a `finally` execute_ conn "CLOSE fold"
 
 -- FIXME: choose the Automatic chunkSize more intelligently

src/Database/PostgreSQL/Simple/Compat.hs

@@ -1,11 +1,13 @@
 {-# LANGUAGE CPP #-}
--- | This is a module of its own, because it uses the CPP extension, which
--- doesn't play well with the regex string literal in Simple.hs .
+-- | This is a module of its own, partly because it uses the CPP extension,
+-- which doesn't play well with backslash-broken string literals.
 module Database.PostgreSQL.Simple.Compat
     ( mask
+    , (<>)
     ) where
 
 import qualified Control.Exception as E
+import Data.Monoid
 
 -- | Like 'E.mask', but backported to base before version 4.3.0.
 --
@@ -23,3 +25,11 @@ mask io = do
     E.block $ io $ \m -> if b then m else E.unblock m
 #endif
 {-# INLINE mask #-}
+
+#if !MIN_VERSION_base(4,5,0)
+infixr 6 <>
+
+(<>) :: Monoid m => m -> m -> m
+(<>) = mappend
+{-# INLINE (<>) #-}
+#endif