[scaffold] refactor uses of CPP into pure Haskell

yesod/scaffold/Application.hs.cg

@@ -10,13 +10,8 @@ import Yesod.Auth
 import Yesod.Default.Config
 import Yesod.Default.Main
 import Yesod.Default.Handlers
-#if DEVELOPMENT
-import Yesod.Logger (Logger, logBS)
-import Network.Wai.Middleware.RequestLogger (logCallbackDev)
-#else
 import Yesod.Logger (Logger, logBS, toProduction)
-import Network.Wai.Middleware.RequestLogger (logCallback)
-#endif
+import Network.Wai.Middleware.RequestLogger (logCallback, logCallbackDev)
 import qualified Database.Persist.Store~importMigration~
 import Network.HTTP.Conduit (newManager, def)
 
@@ -38,13 +33,8 @@ makeApplication conf logger = do
     app <- toWaiAppPlain foundation
     return $ logWare app
   where
-#ifdef DEVELOPMENT
-    logWare = logCallbackDev (logBS setLogger)
-    setLogger = logger
-#else
-    setLogger = toProduction logger -- by default the logger is set for development
-    logWare = logCallback (logBS setLogger)
-#endif
+    logWare = dev logCallbackDev logCallback (logBS setLogger)
+    setLogger = dev id toProduction logger
 
 makeFoundation :: AppConfig DefaultEnv Extra -> Logger -> IO ~sitearg~
 makeFoundation conf setLogger = do

yesod/scaffold/Import.hs.cg

@@ -18,6 +18,7 @@ import Data.Monoid (Monoid (mappend, mempty, mconcat))
 import Control.Applicative ((<$>), (<*>), pure)
 import Data.Text (Text)
 import Settings.StaticFiles
+import Settings.Development
 
 #if __GLASGOW_HASKELL__ < 704
 infixr 5 <>

yesod/scaffold/Settings.hs.cg

@@ -21,6 +21,7 @@ import qualified Yesod.Default.Util
 import Data.Text (Text)
 import Data.Yaml
 import Control.Applicative
+import Settings.Development
 
 -- | Which Persistent backend this site is using.
 type PersistConfig = ~configPersist~
@@ -53,11 +54,8 @@ staticRoot conf = [st|#{appRoot conf}/static|]
 -- user.
 
 widgetFile :: String -> Q Exp
-#if DEVELOPMENT
-widgetFile = Yesod.Default.Util.widgetFileReload
-#else
-widgetFile = Yesod.Default.Util.widgetFileNoReload
-#endif
+widgetFile = dev Yesod.Default.Util.widgetFileReload
+                 Yesod.Default.Util.widgetFileNoReload
 
 data Extra = Extra
     { extraCopyright :: Text

yesod/scaffold/Settings/Development.hs.cg

@@ -0,0 +1,12 @@
+module Settings.Development where
+
+development :: Bool
+development =
+#if DEVELOPMENT
+  True
+#else
+  False
+#endif
+
+dev :: a -> a -> a
+dev a b = if development then a else b

yesod/scaffold/Settings/StaticFiles.hs.cg

@@ -4,15 +4,11 @@ import Prelude (IO)
 import Yesod.Static
 import qualified Yesod.Static as Static
 import Settings (staticDir)
+import Settings.Development
 
 -- | use this to create your static file serving site
 staticSite :: IO Static.Static
-staticSite =
-#ifdef DEVELOPMENT
-  Static.staticDevel staticDir
-#else
-  Static.static staticDir
-#endif
+staticSite = dev Static.staticDevel Static.static staticDir
 
 -- | This generates easy references to files in the static directory at compile time,
 --   giving you compile-time verification that referenced files exist.