Generalize getTimeUTC, chronological, recentFirst

2 files changed, 8 insertions, 6 deletions

diff --git a/src/Hakyll/Web/Template/Context.hs b/src/Hakyll/Web/Template/Context.hs
index 8aab989..1a9aba3 100644
--- a/src/Hakyll/Web/Template/Context.hs
+++ b/src/Hakyll/Web/Template/Context.hs
@@ -167,9 +167,10 @@ dateFieldWith locale key format = field key $ \i -> do
 -- | Parser to try to extract and parse the time from the @published@
 -- field or from the filename. See 'renderDateField' for more information.
 -- Exported for user convenience.
-getItemUTC :: TimeLocale        -- ^ Output time locale
+getItemUTC :: MonadMetadata m
+           => TimeLocale        -- ^ Output time locale
            -> Identifier        -- ^ Input page
-           -> Compiler UTCTime  -- ^ Parsed UTCTime
+           -> m UTCTime         -- ^ Parsed UTCTime
 getItemUTC locale id' = do
     metadata <- getMetadata id'
     let tryField k fmt = M.lookup k metadata >>= parseTime' fmt
@@ -180,7 +181,7 @@ getItemUTC locale id' = do
         [tryField "date"      fmt | fmt <- formats] ++
         [parseTime' "%Y-%m-%d" $ intercalate "-" $ take 3 $ splitAll "-" fn]
   where
-    empty'     = compilerThrow $ "Hakyll.Web.Template.Context.getItemUTC: " ++
+    empty'     = fail $ "Hakyll.Web.Template.Context.getItemUTC: " ++
         "could not parse time for " ++ show id'
     parseTime' = parseTime locale
     formats    =
diff --git a/src/Hakyll/Web/Template/List.hs b/src/Hakyll/Web/Template/List.hs
index 5f94369..1401119 100644
--- a/src/Hakyll/Web/Template/List.hs
+++ b/src/Hakyll/Web/Template/List.hs
@@ -28,6 +28,7 @@ import           System.Locale               (defaultTimeLocale)
 import           Hakyll.Core.Compiler
 import           Hakyll.Core.Identifier
 import           Hakyll.Core.Item
+import           Hakyll.Core.Metadata
 import           Hakyll.Web.Template
 import           Hakyll.Web.Template.Context
 
@@ -59,7 +60,7 @@ applyJoinTemplateList delimiter tpl context items = do
 -- | Sort pages chronologically. This function assumes that the pages have a
 -- @year-month-day-title.extension@ naming scheme -- as is the convention in
 -- Hakyll.
-chronological :: [Item a] -> Compiler [Item a]
+chronological :: MonadMetadata m => [Item a] -> m [Item a]
 chronological = sortByM $ getItemUTC defaultTimeLocale . itemIdentifier
                 where sortByM :: (Monad m, Ord k) => (a -> m k) -> [a] -> m [a]
                       sortByM f xs = liftM (map fst . sortBy (comparing snd)) $
@@ -67,5 +68,5 @@ chronological = sortByM $ getItemUTC defaultTimeLocale . itemIdentifier
 
 --------------------------------------------------------------------------------
 -- | The reverse of 'chronological'
-recentFirst :: [Item a] -> Compiler [Item a]
-recentFirst i = return . reverse =<< chronological i
+recentFirst :: (MonadMetadata m, Functor m) => [Item a] -> m [Item a]
+recentFirst = fmap reverse . chronological