Use Data.Map.foldlWithKey' when possible

diff --git a/Network/HTTP/Lucu/MIMEParams.hs b/Network/HTTP/Lucu/MIMEParams.hs
index bfde1c932e3156e4db53456994c15943f3b8e9e4..9c39236679feea13cabaaa94edd346684be9a810 100644 (file)
--- a/Network/HTTP/Lucu/MIMEParams.hs
+++ b/Network/HTTP/Lucu/MIMEParams.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE
-    DeriveDataTypeable
+    CPP
+  , DeriveDataTypeable
   , DoAndIfThenElse
   , GeneralizedNewtypeDeriving
   , OverloadedStrings
@@ -61,8 +62,11 @@ instance Lift MIMEParams where
 -- |Convert MIME parameter values to an 'AsciiBuilder'.
 printMIMEParams ∷ MIMEParams → AsciiBuilder
 {-# INLINEABLE printMIMEParams #-}
+#if MIN_VERSION_containers(0, 4, 1)
+printMIMEParams (MIMEParams m) = M.foldlWithKey' f (∅) m
+#else
 printMIMEParams (MIMEParams m) = M.foldlWithKey f (∅) m
-    -- THINKME: Use foldlWithKey' for newer Data.Map
+#endif
     where
       f ∷ AsciiBuilder → CIAscii → Text → AsciiBuilder
       {-# INLINE f #-}