Include file name in error messages

src/Hakyll/Web/Feed.hs

@@ -33,6 +33,7 @@ import           Hakyll.Core.Compiler.Internal
 import           Hakyll.Core.Item
 import           Hakyll.Web.Template
 import           Hakyll.Web.Template.Context
+import           Hakyll.Web.Template.Internal
 import           Hakyll.Web.Template.List
 
 
@@ -72,7 +73,10 @@ renderFeed feedPath itemPath config itemContext items = do
     applyTemplate feedTpl feedContext body
   where
     -- Auxiliary: load a template from a datafile
-    loadTemplate = fmap readTemplate . readFile <=< getDataFileName
+    loadTemplate path = do
+        file <- getDataFileName path
+        templ <- readFile file
+        return $ readTemplateFile file templ
 
     itemContext' = mconcat
         [ itemContext

src/Hakyll/Web/Template.hs

@@ -147,14 +147,16 @@ import           Hakyll.Web.Template.Internal
 templateBodyCompiler :: Compiler (Item Template)
 templateBodyCompiler = cached "Hakyll.Web.Template.templateBodyCompiler" $ do
     item <- getResourceBody
-    return $ fmap readTemplate item
+    file <- getResourceFilePath
+    return $ fmap (readTemplateFile file) item
 
 --------------------------------------------------------------------------------
 -- | Read complete file contents as a template
 templateCompiler :: Compiler (Item Template)
 templateCompiler = cached "Hakyll.Web.Template.templateCompiler" $ do
     item <- getResourceString
-    return $ fmap readTemplate item
+    file <- getResourceFilePath
+    return $ fmap (readTemplateFile file) item
 
 
 --------------------------------------------------------------------------------
@@ -259,5 +261,6 @@ applyAsTemplate :: Context String          -- ^ Context
                 -> Item String             -- ^ Item and template
                 -> Compiler (Item String)  -- ^ Resulting item
 applyAsTemplate context item =
-    let tpl = readTemplate $ itemBody item
+    let tpl = readTemplateFile file (itemBody item)
+        file = toFilePath $ itemIdentifier item
     in applyTemplate tpl context item

src/Hakyll/Web/Template/Internal.hs

@@ -8,6 +8,7 @@ module Hakyll.Web.Template.Internal
     , TemplateExpr (..)
     , TemplateElement (..)
     , readTemplate
+    , readTemplateFile
     ) where
 
 
@@ -120,10 +121,16 @@ instance Binary TemplateExpr where
 
 --------------------------------------------------------------------------------
 readTemplate :: String -> Template
-readTemplate input = case P.parse topLevelTemplate "" input of
+readTemplate = readTemplateFile "{literal}"
+
+
+--------------------------------------------------------------------------------
+readTemplateFile :: FilePath -> String -> Template
+readTemplateFile file input = case P.parse topLevelTemplate file input of
     Left err -> error $ "Cannot parse template: " ++ show err
     Right t  -> t
 
+
 --------------------------------------------------------------------------------
 topLevelTemplate :: P.Parser Template
 topLevelTemplate = Template <$>