diff --git a/digestive-functors.cabal b/digestive-functors.cabal
--- a/digestive-functors.cabal
+++ b/digestive-functors.cabal
@@ -1,5 +1,5 @@
 Name:     digestive-functors
-Version:  0.3.0.0
+Version:  0.3.0.1
 Synopsis: A practical formlet library
 
 Description:
diff --git a/src/Text/Digestive/View.hs b/src/Text/Digestive/View.hs
--- a/src/Text/Digestive/View.hs
+++ b/src/Text/Digestive/View.hs
@@ -13,6 +13,7 @@
       -- * Querying a view
       -- ** Low-level
     , absolutePath
+    , absoluteRef
 
       -- ** Form encoding
     , viewEncType
@@ -33,6 +34,7 @@
 import Data.Maybe (fromMaybe)
 
 import Data.Text (Text)
+import qualified Data.Text as T
 
 import Text.Digestive.Field
 import Text.Digestive.Form.Encoding
@@ -77,6 +79,11 @@
 absolutePath :: Text -> View v -> Path
 absolutePath ref view@(View name _ _ _ _ _) = name : viewPath ref view
 
+-- | Determine an absolute path and call 'fromPath' on it. Useful if you're
+-- writing a view library...
+absoluteRef :: Text -> View v -> Text
+absoluteRef ref view = fromPath $ absolutePath ref view
+
 -- | Internal version of 'absolutePath' which does not take the form name into
 -- account
 viewPath :: Text -> View v -> Path
@@ -98,7 +105,8 @@
     eval' :: Field v b -> Text
     eval' field = case field of
         Text t -> evalField method givenInput (Text t)
-        _      -> ""  -- TODO: perhaps throw error?
+        f      -> error $ T.unpack ref ++ ": expected (Text _), " ++
+            "but got: (" ++ show f ++ ")"
 
 fieldInputChoice :: forall v. Text -> View v -> ([v], Int)
 fieldInputChoice ref view@(View _ _ form input _ method) =
@@ -113,7 +121,8 @@
             let x   = evalField method givenInput (Choice xs i)
                 idx = fromMaybe 0 $ findIndex (== x) (map fst xs)
             in (map snd xs, idx)
-        _           -> ([], 0)  -- TODO: perhaps throw error?
+        f           -> error $ T.unpack ref ++ ": expected (Choice _ _), " ++
+            "but got: (" ++ show f ++ ")"
 
 fieldInputBool :: forall v. Text -> View v -> Bool
 fieldInputBool ref view@(View _ _ form input _ method) =
@@ -125,7 +134,8 @@
     eval' :: Field v b -> Bool
     eval' field = case field of
         Bool x -> evalField method givenInput (Bool x)
-        _      -> False  -- TODO: perhaps throw error?
+        f      -> error $ T.unpack ref ++ ": expected (Bool _), " ++
+            "but got: (" ++ show f ++ ")"
 
 fieldInputFile :: forall v. Text -> View v -> Maybe FilePath
 fieldInputFile ref view@(View _ _ form input _ method) =
@@ -137,7 +147,8 @@
     eval' :: Field v b -> Maybe FilePath
     eval' field = case field of
         File -> evalField method givenInput File
-        _    -> Nothing  -- TODO: perhaps throw error?
+        f    -> error $ T.unpack ref ++ ": expected (File), " ++
+            "but got: (" ++ show f ++ ")"
 
 errors :: Text -> View v -> [v]
 errors ref view = map snd $ filter ((== viewPath ref view) . fst) $