From 0c4ded0fd1b9dfc9a617141daed74d636bde69ec Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Sun, 25 Nov 2012 21:45:08 +0200
Subject: [PATCH] Slightly more efficient header construction

---
 yesod-core/Yesod/Handler.hs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/yesod-core/Yesod/Handler.hs b/yesod-core/Yesod/Handler.hs
index 9a952752..569f5c8d 100644
--- a/yesod-core/Yesod/Handler.hs
+++ b/yesod-core/Yesod/Handler.hs
@@ -522,12 +522,12 @@ runHandler handler mrender sroute tomr master sub upload log' =
                 Right c' -> return $ YARPlain status (appEndo headers []) ct c' finalSession
         HCError e -> handleError e
         HCRedirect status loc -> do
-            let disable_caching =
-                    [ Header "Cache-Control" "no-cache, must-revalidate"
-                    , Header "Expires" "Thu, 01 Jan 1970 05:05:05 GMT"
-                    ]
-                hs = (if status /= H.movedPermanently301 then disable_caching else [])
-                      ++ Header "Location" (encodeUtf8 loc) : appEndo headers []
+            let disable_caching x =
+                      Header "Cache-Control" "no-cache, must-revalidate"
+                    : Header "Expires" "Thu, 01 Jan 1970 05:05:05 GMT"
+                    : x
+                hs = (if status /= H.movedPermanently301 then disable_caching else id)
+                      $ Header "Location" (encodeUtf8 loc) : appEndo headers []
             return $ YARPlain
                 status hs typePlain emptyContent
                 finalSession