From 292385b7e5eb265032983f0669e5050b4fa89557 Mon Sep 17 00:00:00 2001
From: Jasper Van der Jeugt <m@jaspervdj.be>
Date: Wed, 6 Apr 2016 15:03:54 +0200
Subject: Hint for weird yaml error

---
 src/Hakyll/Core/Provider/Metadata.hs | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

(limited to 'src/Hakyll')

diff --git a/src/Hakyll/Core/Provider/Metadata.hs b/src/Hakyll/Core/Provider/Metadata.hs
index 97dbc9e..ca1cc6c 100644
--- a/src/Hakyll/Core/Provider/Metadata.hs
+++ b/src/Hakyll/Core/Provider/Metadata.hs
@@ -1,6 +1,7 @@
 --------------------------------------------------------------------------------
 -- | Internal module to parse metadata
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE BangPatterns    #-}
+{-# LANGUAGE RecordWildCards #-}
 module Hakyll.Core.Provider.Metadata
     ( loadMetadata
     , parsePage
@@ -140,4 +141,14 @@ instance Exception MetadataException
 --------------------------------------------------------------------------------
 instance Show MetadataException where
     show (MetadataException fp err) =
-        fp ++ ": " ++ Yaml.prettyPrintParseException err
+        fp ++ ": " ++ Yaml.prettyPrintParseException err ++ hint
+
+      where
+        hint = case err of
+            Yaml.InvalidYaml (Just (Yaml.YamlParseException {..}))
+                | yamlProblem == problem -> "\n" ++
+                    "Hint: if the metadata value contains characters such\n" ++
+                    "as ':' or '-', try enclosing it in quotes."
+            _ -> ""
+
+        problem = "mapping values are not allowed in this context"
-- 
cgit v1.2.3