issue #2

Data/TCache/IndexQuery.hs

@@ -185,11 +185,14 @@ selectorIndex selector rindex pobject mobj = do
 index
   :: (Queriable reg a) =>
      (reg -> a) -> IO ()
-index sel=
+index sel= do
    let [one, two]= typeRepArgs $! typeOf sel
        rindex= getDBRef $! keyIndex one two
-   in  addTrigger $ selectorIndex sel rindex
-
+   addTrigger $ selectorIndex sel rindex
+   withResources [] $ const  [ (Index M.empty  `asTypeOf` indexsel sel )]
+   where
+   indexsel :: (reg-> a)  -> Index reg a
+   indexsel= undefined
 -- | implement the relational-like operators, operating on record fields
 class RelationOps field1 field2 res | field1 field2 -> res  where
     (.==.) :: field1 -> field2 -> STM  res
@@ -289,7 +292,11 @@ indexOf selector= do
    let [one, two]= typeRepArgs $! typeOf selector
    let rindex= getDBRef $! keyIndex one two
    mindex <- readDBRef rindex
-   case mindex of Just (Index index) -> return $ M.toList index; _ -> return []
+   case mindex of
+     Just (Index index) -> return $ M.toList index;
+     _ -> do
+        let fields= show $ typeOf  selector
+        error $ "the index for "++ fields ++" do not exist. At main, use \"Data.TCache.IdexQuery.index\" to start indexing this field"
 
 retrieve :: Queriable reg a => (reg -> a) -> a -> (a -> a -> Bool) -> STM[DBRef reg]
 retrieve field value op= do

Data/TCache/IndexText.hs

@@ -141,15 +141,24 @@ indexText
      => (a -> b)      -- ^ field to index
      -> (b -> T.Text) -- ^ method to convert the field content to lazy Text (for example `pack` in case of String fields). This permits to index non Textual fields
      -> IO ()
-indexText sel convert= addTrigger (indext sel  (words1 . convert))
+indexText sel convert= do
+  addTrigger (indext sel  (words1 . convert))
+  let [t1,t2]=  typeRepArgs $! typeOf sel
+      t=  show t1 ++ show t2
+  withResources [] $ const [IndexText t 0 M.empty M.empty M.empty]
 
 -- | trigger the indexation of list fields with elements convertible to Text
 indexList
   :: (IResource a, Typeable a, Typeable b)
      => (a -> b)      -- ^ field to index
      -> (b -> [T.Text]) -- ^ method to convert a field element to Text (for example `pack . show` in case of elemets with Show instances)
      -> IO ()
-indexList sel convert= addTrigger (indext sel  convert)
+indexList sel convert= do
+  addTrigger (indext sel  convert)
+  let [t1,t2]=  typeRepArgs $! typeOf sel
+      t=  show t1 ++ show t2
+  withResources [] $ const [IndexText t 0 M.empty M.empty M.empty]
+
 
 
 indext :: (IResource a, Typeable a,Typeable b)
@@ -191,7 +200,9 @@ containsElem  sel wstr = do
     mr <- withSTMResources [IndexText t u u u u]
        $ \[r] -> resources{toReturn= r}
     case mr of
-      Nothing -> return []
+      Nothing -> do
+        let fields= show $ typeOf  sel
+        error $ "the index for "++ fields ++" do not exist. At main, use \"Data.TCache.IdexQuery.index\" to start indexing this field"
       Just (IndexText t n _ mmapIntString map1) ->
        case M.lookup w map1 of
         Nothing ->  return []