diff --git a/src/parserlib/CommonParserUtil.hs b/src/parserlib/CommonParserUtil.hs
--- a/src/parserlib/CommonParserUtil.hs
+++ b/src/parserlib/CommonParserUtil.hs
@@ -50,6 +50,10 @@
 import Control.Exception
 import System.IO.Error hiding (catch)
 
+import System.TimeIt (timeItT)
+import Control.Monad.IO.Class(MonadIO(liftIO))
+import Text.Printf
+
 -- | Common parser utilities:
 -- |
 -- |  1. A parser(and lexer) specification interface to the parser generator
@@ -874,7 +878,7 @@
           Nothing -> \s -> "..."
           Just fn -> fn
   in
-  do (candidateListList, emacsDisplay) <- compCandidatesFn ccOption 0 [] state stk
+  do (candidateListList, emacsDisplay) <- timeItShow (compCandidatesFn ccOption 0 [] state stk)
      let colorListList_symbols =
           [ filterCandidates candidateList terminalListAfterCursor
           | candidateList <- candidateListList ]
@@ -995,3 +999,10 @@
 -- debug :: Bool -> String -> a -> a
 -- debug flag msg x = if flag then trace msg x else x
 
+--
+timeItShow :: (MonadIO m, Show a) => m a -> m a
+timeItShow ioa =
+  do (t,a) <- timeItT ioa
+     liftIO $ printf ("Time: %6.2f\n") t
+     return a
+     
diff --git a/yapb.cabal b/yapb.cabal
--- a/yapb.cabal
+++ b/yapb.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: d0b9a77c0d67fbcf2f0f940bd558e929e1fa2e0e1ca4d08e171c07c0244e03ad
+-- hash: f77819b422fe4bf504a61917dc5fbf6875bc35d76c7f3ea16707505b9f6134ed
 
 name:           yapb
-version:        0.2.2
+version:        0.2.3
 synopsis:       Yet Another Parser Builder (YAPB)
 description:    A programmable LALR(1) parser builder system. Please see the README on GitHub at <https://github.com/kwanghoon/yapb#readme>
 category:       parser builder
@@ -73,6 +73,7 @@
     , network >=3.1.1 && <3.2
     , process >=1.6.5 && <1.7
     , regex-tdfa >=1.3.1 && <1.4
+    , timeit >=2.0
     , transformers
   default-language: Haskell2010
 
@@ -96,6 +97,7 @@
     , hspec
     , mtl
     , regex-tdfa
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -112,6 +114,7 @@
     , deepseq >=1.4.4.0
     , hspec
     , mtl
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -136,6 +139,7 @@
     , hspec
     , mtl
     , regex-tdfa
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -160,6 +164,7 @@
     , hspec
     , mtl
     , regex-tdfa
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -184,6 +189,7 @@
     , hspec
     , mtl
     , regex-tdfa
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -200,6 +206,7 @@
     , deepseq >=1.4.4.0
     , hspec
     , mtl
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010
@@ -218,6 +225,7 @@
     , hspec
     , mtl
     , process
+    , timeit >=2.0
     , transformers
     , yapb
   default-language: Haskell2010