Version bump and fix for old versions of TH.

yesod-core/ChangeLog.md

@@ -1,3 +1,8 @@
+## 1.4.34
+
+* Contexts can be included in generated TH instances. [1365](https://github.com/yesodweb/yesod/issues/1365)
+* Type variables can be included in routes.
+
 ## 1.4.32
 
 * Fix warnings

yesod-core/Yesod/Core/Internal/TH.hs

@@ -16,7 +16,11 @@ import Language.Haskell.TH.Syntax
 import qualified Network.Wai as W
 
 import Data.ByteString.Lazy.Char8 ()
+#if MIN_VERSION_base(4,8,0)
 import Data.List (foldl', uncons)
+#else
+import Data.List (foldl')
+#endif
 #if __GLASGOW_HASKELL__ < 710
 import Control.Applicative ((<$>))
 #endif
@@ -125,7 +129,13 @@ mkYesodGeneral' :: [[String]]               -- ^ Appliction context. Used in Ren
                -> [ResourceTree String]
                -> Q([Dec],[Dec])
 mkYesodGeneral' appCxt' namestr args isSub f resS = do
-    let appCxt = fmap (\(c:rest) -> foldl' (\acc v -> acc `AppT` nameToType v) (ConT $ mkName c) rest) appCxt'
+    let appCxt = fmap (\(c:rest) -> 
+#if MIN_VERSION_template_haskell(2,10,0)
+            foldl' (\acc v -> acc `AppT` nameToType v) (ConT $ mkName c) rest
+#else
+            ClassP (mkName c) $ fmap nameToType rest
+#endif
+          ) appCxt'
     mname <- lookupTypeName namestr
     arity <- case mname of
                Just name -> do
@@ -186,6 +196,12 @@ mkYesodGeneral' appCxt' namestr args isSub f resS = do
             ]
     return (dataDec, dispatchDec)
 
+#if !MIN_VERSION_base(4,8,0)
+    where
+        uncons (h:t) = Just (h,t)
+        uncons _ = Nothing
+#endif
+
 mkMDS :: (Exp -> Q Exp) -> Q Exp -> MkDispatchSettings a site b
 mkMDS f rh = MkDispatchSettings
     { mdsRunHandler = rh

yesod-core/Yesod/Routes/TH/RenderRoute.hs

@@ -12,7 +12,9 @@ import Yesod.Routes.TH.Types
 import Language.Haskell.TH (conT)
 #endif
 import Language.Haskell.TH.Syntax
+#if MIN_VERSION_template_haskell(2,11,0)
 import Data.Bits (xor)
+#endif
 import Data.Maybe (maybeToList)
 import Control.Monad (replicateM)
 import Data.Text (pack)
@@ -158,22 +160,27 @@ mkRenderRouteInstance' cxt typ ress = do
     (cons, decs) <- mkRouteCons ress
 #if MIN_VERSION_template_haskell(2,12,0)
     did <- DataInstD [] ''Route [typ] Nothing cons <$> fmap (pure . DerivClause Nothing) (mapM conT (clazzes False))
+    let sds = fmap (\t -> StandaloneDerivD cxt $ ConT t `AppT` ( ConT ''Route `AppT` typ)) (clazzes True)
 #elif MIN_VERSION_template_haskell(2,11,0)
     did <- DataInstD [] ''Route [typ] Nothing cons <$> mapM conT (clazzes False)
-#else
-    let did = DataInstD [] ''Route [typ] cons (clazzes False)
-#endif
     let sds = fmap (\t -> StandaloneDerivD cxt $ ConT t `AppT` ( ConT ''Route `AppT` typ)) (clazzes True)
+#else
+    let did = DataInstD [] ''Route [typ] cons clazzes'
+    let sds = []
+#endif
     return $ instanceD cxt (ConT ''RenderRoute `AppT` typ)
         [ did
         , FunD (mkName "renderRoute") cls
         ]
         : sds ++ decs
   where
+#if MIN_VERSION_template_haskell(2,11,0)
     clazzes standalone = if standalone `xor` null cxt then
-          [''Show, ''Eq, ''Read]
+          clazzes'
         else
           []
+#endif
+    clazzes' = [''Show, ''Eq, ''Read]
 
 #if MIN_VERSION_template_haskell(2,11,0)
 notStrict :: Bang

yesod-core/yesod-core.cabal

@@ -1,5 +1,5 @@
 name:            yesod-core
-version:         1.4.32
+version:         1.4.34
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>