diff --git a/ethereum-analyzer.cabal b/ethereum-analyzer.cabal
--- a/ethereum-analyzer.cabal
+++ b/ethereum-analyzer.cabal
@@ -1,5 +1,5 @@
 name:                ethereum-analyzer
-version:             3.1.0
+version:             3.2.0
 synopsis:            A Ethereum contract analyzer.
 homepage:            https://github.com/zchn/ethereum-analyzer
 license:             Apache-2.0
@@ -21,7 +21,7 @@
 source-repository this
   type:     git
   location: https://github.com/zchn/ethereum-analyzer
-  tag:      v3.1.0
+  tag:      v3.2.0
   subdir:   ethereum-analyzer
 
 library
diff --git a/src/Ethereum/Analyzer/Debug.hs b/src/Ethereum/Analyzer/Debug.hs
--- a/src/Ethereum/Analyzer/Debug.hs
+++ b/src/Ethereum/Analyzer/Debug.hs
@@ -1,6 +1,7 @@
 module Ethereum.Analyzer.Debug
   ( pprintContracts
   , pprintSimpleSol
+  , prettyContracts
   , dbgGetSimpleSol
   ) where
 
@@ -17,3 +18,6 @@
 
 pprintContracts :: [Contract] -> IO ()
 pprintContracts = GP.pp
+
+prettyContracts :: [Contract] -> Text
+prettyContracts = toS . GP.pretty
diff --git a/src/Ethereum/Analyzer/EVM/IR.hs b/src/Ethereum/Analyzer/EVM/IR.hs
--- a/src/Ethereum/Analyzer/EVM/IR.hs
+++ b/src/Ethereum/Analyzer/EVM/IR.hs
@@ -62,11 +62,6 @@
   show HpEnd {} = "OC: HpEnd"
   show (HpCodeCopy offset) = "HpCodeCopy " <> show offset
 
-instance Show (Block HplOp C C) where
-  show (a :: Block HplOp C C) =
-    let (h, m, t) = blockSplit a
-    in DL.unlines $ [show h] <> DL.map show (blockToList m) <> [show t]
-
 instance Eq (HplOp C O) where
   (==) (CoOp a) (CoOp b) = a == b
 
diff --git a/src/Ethereum/Analyzer/Solidity/Hoople.hs b/src/Ethereum/Analyzer/Solidity/Hoople.hs
--- a/src/Ethereum/Analyzer/Solidity/Hoople.hs
+++ b/src/Ethereum/Analyzer/Solidity/Hoople.hs
@@ -6,9 +6,10 @@
   , HFunDefinition(..)
   ) where
 
-import Protolude hiding ((<*>))
+import Protolude hiding ((<*>), show)
 
 import Compiler.Hoopl
+import GHC.Show (Show(..))
 import Ethereum.Analyzer.Solidity.Simple
 
 data HContract = HContract
@@ -33,6 +34,14 @@
         OoSt :: Statement -> HStatement O O
         OcSt :: Statement -> [Label] -> HStatement O C
         OcJump :: Label -> HStatement O C
+
+instance Show (HStatement e x) where
+  show (CoSt l) = show l
+  show (OoSt st) = show st
+  show (OcSt (StIf lval _ _) ll) = "if " <> show lval <> " -> " <> show ll
+  show (OcSt (StLoop _) ll) = "loop -> " <> show ll
+  show (OcSt st ll) = show st <> " -> " <> show ll
+  show (OcJump l) = "jump -> " <> show l
 
 instance NonLocal HStatement where
   entryLabel (CoSt lbl) = lbl
diff --git a/src/Ethereum/Analyzer/Solidity/Simple.hs b/src/Ethereum/Analyzer/Solidity/Simple.hs
--- a/src/Ethereum/Analyzer/Solidity/Simple.hs
+++ b/src/Ethereum/Analyzer/Solidity/Simple.hs
@@ -43,7 +43,7 @@
   } deriving (Eq, Generic, Show, GP.Out)
 
 newtype Idfr =
-  Idfr Text
+  Idfr { unIdfr :: Text }
   deriving (Eq, Generic, Show, GP.Out)
 
 data LValue
diff --git a/src/Ethereum/Analyzer/Util.hs b/src/Ethereum/Analyzer/Util.hs
--- a/src/Ethereum/Analyzer/Util.hs
+++ b/src/Ethereum/Analyzer/Util.hs
@@ -14,8 +14,16 @@
 import Data.GraphViz
 import Data.GraphViz.Printing hiding ((<>))
 import qualified Data.Text.Lazy as DTL
+import qualified Data.List as DL
 import GHC.Show
 import Text.Read (read)
+
+instance ( Show (n C O)
+         , Show (n O O)
+         , Show (n O C)) => Show (Block n C C) where
+  show a =
+    let (h, m, t) = blockSplit a
+    in DL.unlines $ [show h] <> map show (blockToList m) <> [show t]
 
 toDotText
   :: (NonLocal n, Show (Block n C C))
diff --git a/test/Ethereum/Analyzer/Solidity/HoopleSpec.hs b/test/Ethereum/Analyzer/Solidity/HoopleSpec.hs
--- a/test/Ethereum/Analyzer/Solidity/HoopleSpec.hs
+++ b/test/Ethereum/Analyzer/Solidity/HoopleSpec.hs
@@ -8,7 +8,6 @@
 
 import Ethereum.Analyzer.Solidity
 import Ethereum.Analyzer.TestData.Asts
-import GHC.Show (Show(..))
 
 import Test.Hspec