summaryrefslogtreecommitdiff
path: root/src/Language/GraphQL/Trans.hs
diff options
context:
space:
mode:
Diffstat (limited to 'src/Language/GraphQL/Trans.hs')
-rw-r--r--src/Language/GraphQL/Trans.hs2
1 files changed, 1 insertions, 1 deletions
diff --git a/src/Language/GraphQL/Trans.hs b/src/Language/GraphQL/Trans.hs
index 24752a2..09c012b 100644
--- a/src/Language/GraphQL/Trans.hs
+++ b/src/Language/GraphQL/Trans.hs
@@ -56,7 +56,7 @@ instance Monad m => MonadPlus (ActionT m) where
-- | Retrieves an argument by its name. If the argument with this name couldn't
-- be found, returns 'Value.Null' (i.e. the argument is assumed to
-- be optional then).
-argument :: MonadIO m => Name -> ActionT m Value
+argument :: Monad m => Name -> ActionT m Value
argument argumentName = do
argumentValue <- ActionT $ lift $ asks $ lookup . arguments
pure $ fromMaybe Null argumentValue