added error if field not indexed

Data/TCache/IndexQuery.hs

@@ -165,7 +165,11 @@ getIndexr :: (Queriable reg a)
 getIndexr rindex val= do
    mindex <- readDBRef rindex
 
-   let index = case mindex of Just (Index index) ->  index; _ -> M.empty
+   let index = case mindex of 
+        Just (Index index) ->  index
+        _ -> do
+             let fields= show $ typeOf  rindex
+             error $ "the index for "++ fields ++" do not exist. At main, use \"Data.TCache.IdexQuery.index\" to start indexing this field"
 
    let dbrefs= case M.lookup  val index of
         Just  dbrefs -> dbrefs

TCache.cabal

@@ -1,5 +1,5 @@
 name: TCache
-version: 0.12.0
+version: 0.12.2
 cabal-version: >= 1.6
 build-type: Simple
 license: BSD3

dist/build/autogen/Paths_TCache.hs

@@ -0,0 +1,50 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE NoRebindableSyntax #-}
+{-# OPTIONS_GHC -fno-warn-missing-import-lists #-}
+module Paths_TCache (
+    version,
+    getBinDir, getLibDir, getDynLibDir, getDataDir, getLibexecDir,
+    getDataFileName, getSysconfDir
+  ) where
+
+import qualified Control.Exception as Exception
+import Data.Version (Version(..))
+import System.Environment (getEnv)
+import Prelude
+
+#if defined(VERSION_base)
+
+#if MIN_VERSION_base(4,0,0)
+catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a
+#else
+catchIO :: IO a -> (Exception.Exception -> IO a) -> IO a
+#endif
+
+#else
+catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a
+#endif
+catchIO = Exception.catch
+
+version :: Version
+version = Version [0,12,2] []
+bindir, libdir, dynlibdir, datadir, libexecdir, sysconfdir :: FilePath
+
+bindir     = "/root/.cabal/bin"
+libdir     = "/root/.cabal/lib/x86_64-linux-ghc-8.4.2/TCache-0.12.2-BMoMHGzpnmeC7ODwXjoyvu"
+dynlibdir  = "/root/.cabal/lib/x86_64-linux-ghc-8.4.2"
+datadir    = "/root/.cabal/share/x86_64-linux-ghc-8.4.2/TCache-0.12.2"
+libexecdir = "/root/.cabal/libexec/x86_64-linux-ghc-8.4.2/TCache-0.12.2"
+sysconfdir = "/root/.cabal/etc"
+
+getBinDir, getLibDir, getDynLibDir, getDataDir, getLibexecDir, getSysconfDir :: IO FilePath
+getBinDir = catchIO (getEnv "TCache_bindir") (\_ -> return bindir)
+getLibDir = catchIO (getEnv "TCache_libdir") (\_ -> return libdir)
+getDynLibDir = catchIO (getEnv "TCache_dynlibdir") (\_ -> return dynlibdir)
+getDataDir = catchIO (getEnv "TCache_datadir") (\_ -> return datadir)
+getLibexecDir = catchIO (getEnv "TCache_libexecdir") (\_ -> return libexecdir)
+getSysconfDir = catchIO (getEnv "TCache_sysconfdir") (\_ -> return sysconfdir)
+
+getDataFileName :: FilePath -> IO FilePath
+getDataFileName name = do
+  dir <- getDataDir
+  return (dir ++ "/" ++ name)