Added exception handling with Alternative constraint according to spec.

1 files changed, 5 insertions, 2 deletions

diff --git a/Data/GraphQL.hs b/Data/GraphQL.hs
index 2da8a46..a2796ae 100644
--- a/Data/GraphQL.hs
+++ b/Data/GraphQL.hs
@@ -1,6 +1,6 @@
 module Data.GraphQL where
 
-import Control.Applicative (Alternative, empty)
+import Control.Applicative (Alternative)
 
 import Data.Text (Text)
 
@@ -11,10 +11,13 @@ import Data.GraphQL.Execute
 import Data.GraphQL.Parser
 import Data.GraphQL.Schema
 
+import Data.GraphQL.Error
+
 graphql :: (Alternative m, Monad m) => Schema m -> Text -> m Aeson.Value
 graphql = flip graphqlSubs $ const Nothing
 
+
 graphqlSubs :: (Alternative m, Monad m) => Schema m -> Subs -> Text -> m Aeson.Value
 graphqlSubs schema f =
-    either (const empty) (execute schema f)
+    either parseError (execute schema f)
   . Attoparsec.parseOnly document