diff --git a/Database/QDBM/Cabin/List.hsc b/Database/QDBM/Cabin/List.hsc
--- a/Database/QDBM/Cabin/List.hsc
+++ b/Database/QDBM/Cabin/List.hsc
@@ -50,7 +50,7 @@
 
 
 wrapList :: Ptr CBLIST -> IO List
-wrapList listPtr = newForeignPtr _close listPtr >>= return . List
+wrapList listPtr = fmap List (newForeignPtr _close listPtr)
 
 
 withListPtr :: List -> (Ptr CBLIST -> IO a) -> IO a
@@ -71,7 +71,7 @@
 length :: List -> IO Int
 length list
     = withListPtr list $ \ listPtr ->
-      _num listPtr >>= return . fromIntegral
+      fmap fromIntegral (_num listPtr)
 
 
 (!!) :: List -> Int -> IO (Maybe Strict.ByteString)
@@ -90,7 +90,7 @@
 toList :: List -> IO [Strict.ByteString]
 toList list
     = do len <- length list
-         mapM (list !!) [0..len] >>= return . catMaybes
+         fmap catMaybes (mapM (list !!) [0..len])
 
 
 fromList :: [Strict.ByteString] -> IO List
diff --git a/Database/QDBM/Cabin/Map.hsc b/Database/QDBM/Cabin/Map.hsc
--- a/Database/QDBM/Cabin/Map.hsc
+++ b/Database/QDBM/Cabin/Map.hsc
@@ -52,11 +52,11 @@
 
 
 wrapMap :: Ptr CBMAP -> IO Map
-wrapMap mapPtr = newForeignPtr _close mapPtr >>= return . Map
+wrapMap = fmap Map . newForeignPtr _close
 
 
 unsafePeekMap :: Ptr CBMAP -> IO Map
-unsafePeekMap mapPtr = newForeignPtr_ mapPtr >>= return . Map
+unsafePeekMap = fmap Map . newForeignPtr_
 
 
 withMapPtr :: Map -> (Ptr CBMAP -> IO a) -> IO a
@@ -72,11 +72,10 @@
     = withMapPtr         m     $ \ mapPtr               ->
       C8.useAsCStringLen key   $ \ (keyPtr  , keyLen  ) ->
       C8.useAsCStringLen value $ \ (valuePtr, valueLen) ->
-      _put mapPtr
-           keyPtr   (fromIntegral keyLen  )
-           valuePtr (fromIntegral valueLen)
-           (fromIntegral $ fromEnum overwrite)
-           >>= return . (/= 0)
+      fmap (/= 0) (_put mapPtr
+                        keyPtr   (fromIntegral keyLen  )
+                        valuePtr (fromIntegral valueLen)
+                        (fromIntegral $ fromEnum overwrite))
 
 
 get :: Map -> Strict.ByteString -> IO (Maybe Strict.ByteString)
@@ -95,9 +94,7 @@
 
 initIterator :: Map -> IO ()
 initIterator m
-    = withMapPtr m $ \ mapPtr ->
-      _iterinit mapPtr
-
+    = withMapPtr m _iterinit
 
 iterateNext :: Map -> IO (Maybe (Strict.ByteString, Strict.ByteString))
 iterateNext m
@@ -110,16 +107,13 @@
            else
              do keyLen <- peek keyLenPtr
                 key    <- C8.packCStringLen (keyPtr, fromIntegral keyLen)
-                -- QDBM のソースを見たら、keyPtr そのものの値からアドレ
-                -- スを計算してゐた…。良くそんな無茶をやるなあと思ふ。
                 valPtr <- _iterval keyPtr valLenPtr
                 valLen <- peek valLenPtr
                 value  <- C8.packCStringLen (valPtr, fromIntegral valLen)
                 return $ Just (key, value)
 
-
--- iterator の状態は Map 内部に格納されるので、thread-safe でない。だか
--- ら list にするなら正格にしなければならない。
+-- Internal state of the iterator is stored in the Map itself. That's
+-- not thread-safe. So we can't iterate it lazily.
 toList :: Map -> IO [(Strict.ByteString, Strict.ByteString)]
 toList m = initIterator m >> loop
     where
@@ -127,7 +121,9 @@
       loop = do next <- iterateNext m
                 case next of
                   Nothing   -> return []
-                  Just pair -> do rest <- loop -- ここで unsafeInterleaveIO したいが出來ない。
+                  Just pair -> do -- We want to do unsafeInterleaveIO
+                                  -- here, but we can't.
+                                  rest <- loop
                                   return $ pair : rest
 
 
diff --git a/HsHyperEstraier.cabal b/HsHyperEstraier.cabal
--- a/HsHyperEstraier.cabal
+++ b/HsHyperEstraier.cabal
@@ -5,7 +5,7 @@
     Haskell. HyperEstraier is an embeddable full text search engine
     which is supposed to be independent to any particular natural
     languages.
-Version:       0.3.1
+Version:       0.3.2
 License:       PublicDomain
 License-File:  COPYING
 Author:        PHO <pho at cielonegro dot org>
@@ -27,7 +27,7 @@
 
 Library
     Build-Depends:
-        base >= 4, bytestring, network, utf8-string
+        base >= 4 && < 5, bytestring, network, utf8-string
     PkgConfig-Depends:
         hyperestraier >= 1.4.9, qdbm >= 1.8.74
     Exposed-Modules:
diff --git a/NEWS b/NEWS
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,8 @@
+Changes from 0.3.1 to 0.3.2
+---------------------------
+* Fixed breakage on GHC 6.12.1
+
+
 Changes from 0.3 to 0.3.1
 -------------------------
 * Fixed incorrect dependency declaration in HsHyperEstraier.cabal. No
diff --git a/Text/HyperEstraier/Condition.hsc b/Text/HyperEstraier/Condition.hsc
--- a/Text/HyperEstraier/Condition.hsc
+++ b/Text/HyperEstraier/Condition.hsc
@@ -72,15 +72,15 @@
     deriving (Eq, Show)
 
 marshalCondOption :: CondOption -> Int
-marshalCondOption (Speed Slow         ) = (#const ESTCONDSURE  )
-marshalCondOption (Speed Normal       ) = (#const ESTCONDUSUAL )
-marshalCondOption (Speed Fast         ) = (#const ESTCONDFAST  )
-marshalCondOption (Speed EvenFaster   ) = (#const ESTCONDAGITO )
-marshalCondOption OmitTFIDF             = (#const ESTCONDNOIDF )
-marshalCondOption (Syntax Simplified  ) = (#const ESTCONDSIMPLE)
-marshalCondOption (Syntax Rough       ) = (#const ESTCONDROUGH )
-marshalCondOption (Syntax Union       ) = (#const ESTCONDUNION )
-marshalCondOption (Syntax Intersection) = (#const ESTCONDISECT )
+marshalCondOption (Speed Slow         ) = #const ESTCONDSURE
+marshalCondOption (Speed Normal       ) = #const ESTCONDUSUAL
+marshalCondOption (Speed Fast         ) = #const ESTCONDFAST
+marshalCondOption (Speed EvenFaster   ) = #const ESTCONDAGITO
+marshalCondOption OmitTFIDF             = #const ESTCONDNOIDF
+marshalCondOption (Syntax Simplified  ) = #const ESTCONDSIMPLE
+marshalCondOption (Syntax Rough       ) = #const ESTCONDROUGH
+marshalCondOption (Syntax Union       ) = #const ESTCONDUNION
+marshalCondOption (Syntax Intersection) = #const ESTCONDISECT
 
 -- |'Eclipse' represents how to hide documents from the search
 -- result by their similarity.
@@ -103,10 +103,10 @@
 
 marshalEclipse :: Eclipse -> Double
 marshalEclipse (Threshold thr)        = assertThreshold thr
-marshalEclipse (ThresholdWithURL thr) = assertThreshold thr + (#const ESTECLSIMURL)
-marshalEclipse SameServer             = (#const ESTECLSERV)
-marshalEclipse SameDirectory          = (#const ESTECLDIR )
-marshalEclipse SameFile               = (#const ESTECLFILE)
+marshalEclipse (ThresholdWithURL thr) = assertThreshold thr + #const ESTECLSIMURL
+marshalEclipse SameServer             = #const ESTECLSERV
+marshalEclipse SameDirectory          = #const ESTECLDIR
+marshalEclipse SameFile               = #const ESTECLFILE
 
 assertThreshold :: Double -> Double
 assertThreshold thr = assert (thr >= 0.0 && thr <= 1.0) thr
@@ -150,7 +150,7 @@
 
 
 wrapCond :: Ptr ESTCOND -> IO Condition
-wrapCond condPtr = newForeignPtr _delete condPtr >>= return . Condition
+wrapCond = fmap Condition . newForeignPtr _delete
 
 
 withCondPtr :: Condition -> (Ptr ESTCOND -> IO a) -> IO a
@@ -167,8 +167,8 @@
 setPhrase :: Condition -> String -> IO ()
 setPhrase cond phrase
     = withCondPtr     cond   $ \ condPtr   ->
-      withUTF8CString phrase $ \ phrasePtr ->
-      _set_phrase condPtr phrasePtr
+      withUTF8CString phrase $
+      _set_phrase condPtr
 
 -- |@'addAttrCond' cond expr@ appends an attribute search condition to
 -- @cond@. See the user's guide for explanation about the attribute
@@ -176,8 +176,8 @@
 addAttrCond :: Condition -> String -> IO ()
 addAttrCond cond attr
     = withCondPtr     cond $ \ condPtr ->
-      withUTF8CString attr $ \ attrPtr ->
-      _add_attr condPtr attrPtr
+      withUTF8CString attr $
+      _add_attr condPtr
 
 -- |@'setOrder' cond expr@ stores an ordering expression into
 -- @cond@. See the user's guide for explanation about the ordering
@@ -186,51 +186,47 @@
 setOrder :: Condition -> String -> IO ()
 setOrder cond order
     = withCondPtr     cond  $ \ condPtr  ->
-      withUTF8CString order $ \ orderPtr ->
-      _set_order condPtr orderPtr
+      withUTF8CString order $
+      _set_order condPtr
 
 -- |@'setMax' cond n@ specifies the maximum number of results. By
 -- default, the number of results is unlimited.
 setMax :: Condition -> Int -> IO ()
 setMax cond n
-    = withCondPtr cond $ \ condPtr ->
-      _set_max condPtr n
+    = withCondPtr cond $ flip _set_max n
 
 -- |@'setSkip' cond n@ specifies how many documents should be skipped
 -- from the beginning of result.
 setSkip :: Condition -> Int -> IO ()
 setSkip cond n
-    = withCondPtr cond $ \ condPtr ->
-      _set_skip condPtr n
+    = withCondPtr cond $ flip _set_skip n
 
 -- |@'setOptions' cond opts@ specifies options to the search
 -- condition.
 setOptions :: Condition -> [CondOption] -> IO ()
 setOptions cond options
-    = withCondPtr cond $ \ condPtr ->
-      _set_options condPtr (marshalOpts marshalCondOption options)
+    = withCondPtr cond $
+      flip _set_options (marshalOpts marshalCondOption options)
 
 -- |@'setAuxiliary' cond min@ specifies how many documents should be
 -- in the result to avoid using the auxiliary index to pad the result.
 setAuxiliary :: Condition -> Int -> IO ()
 setAuxiliary cond n
-    = withCondPtr cond $ \ condPtr ->
-      _set_auxiliary condPtr n
+    = withCondPtr cond $ flip _set_auxiliary n
 
 -- |@'setEclipse' cond ecl@ specifies how to hide documents from the
 -- search result by their similarity.
 setEclipse :: Condition -> Eclipse -> IO ()
 setEclipse cond ecl
-    = withCondPtr cond $ \ condPtr ->
-      _set_eclipse condPtr (marshalEclipse ecl)
+    = withCondPtr cond $ flip _set_eclipse (marshalEclipse ecl)
 
 -- |@'setDistinct' cond attr@ specifies an attribute which must be
 -- unique to the search result.
 setDistinct :: Condition -> String -> IO ()
 setDistinct cond attr
     = withCondPtr     cond $ \ condPtr ->
-      withUTF8CString attr $ \ attrPtr ->
-      _set_distinct condPtr attrPtr
+      withUTF8CString attr $
+      _set_distinct condPtr
 
 -- |@'setMetaSearchMask' cond xs@ specifies that, in
 -- 'Text.HyperEstraier.Database.metaSearch', some databases must be
@@ -249,8 +245,7 @@
 --
 setMetaSearchMask :: Condition -> [Int] -> IO ()
 setMetaSearchMask cond xs
-    = withCondPtr cond $ \ condPtr ->
-      _set_max condPtr (calculateMask xs)
+    = withCondPtr cond $ flip _set_max (calculateMask xs)
     where
       calculateMask :: [Int] -> Int
       calculateMask []     = 0
diff --git a/Text/HyperEstraier/Database.hsc b/Text/HyperEstraier/Database.hsc
--- a/Text/HyperEstraier/Database.hsc
+++ b/Text/HyperEstraier/Database.hsc
@@ -200,8 +200,8 @@
 marshalWriterOption (WriteLock mode) = marshalLockingMode mode
 
 marshalLockingMode :: LockingMode -> Int
-marshalLockingMode NoLock          = (#const ESTDBNOLCK)
-marshalLockingMode NonblockingLock = (#const ESTDBLCKNB)
+marshalLockingMode NoLock          = #const ESTDBNOLCK
+marshalLockingMode NonblockingLock = #const ESTDBLCKNB
 
 marshalCreateOption :: CreateOption -> Int
 marshalCreateOption (Analysis opt   ) = marshalAnalysisOption opt
@@ -209,20 +209,20 @@
 marshalCreateOption (Score    opts  ) = marshalOpts marshalScoreOption opts
 
 marshalAnalysisOption :: AnalysisOption -> Int
-marshalAnalysisOption PerfectNGram = (#const ESTDBPERFNG)
-marshalAnalysisOption CharCategory = (#const ESTDBCHRCAT)
+marshalAnalysisOption PerfectNGram = #const ESTDBPERFNG
+marshalAnalysisOption CharCategory = #const ESTDBCHRCAT
 
 marshalIndexTuning :: IndexTuning -> Int
-marshalIndexTuning Small = (#const ESTDBSMALL)
-marshalIndexTuning Large = (#const ESTDBLARGE)
-marshalIndexTuning Huge  = (#const ESTDBHUGE )
-marshalIndexTuning Huge2 = (#const ESTDBHUGE2)
-marshalIndexTuning Huge3 = (#const ESTDBHUGE3)
+marshalIndexTuning Small = #const ESTDBSMALL
+marshalIndexTuning Large = #const ESTDBLARGE
+marshalIndexTuning Huge  = #const ESTDBHUGE
+marshalIndexTuning Huge2 = #const ESTDBHUGE2
+marshalIndexTuning Huge3 = #const ESTDBHUGE3
 
 marshalScoreOption :: ScoreOption -> Int
-marshalScoreOption Nullified      = (#const ESTDBSCVOID)
-marshalScoreOption StoredAsInt    = (#const ESTDBSCINT )
-marshalScoreOption OnlyToBeStored = (#const ESTDBSCASIS)
+marshalScoreOption Nullified      = #const ESTDBSCVOID
+marshalScoreOption StoredAsInt    = #const ESTDBSCINT
+marshalScoreOption OnlyToBeStored = #const ESTDBSCASIS
 
 -- |'AttrIndexType' represents an index type for an attribute.
 data AttrIndexType
@@ -238,9 +238,9 @@
 
 
 marshalAttrIndexType :: AttrIndexType -> Int
-marshalAttrIndexType SeqIndex = (#const ESTIDXATTRSEQ)
-marshalAttrIndexType StrIndex = (#const ESTIDXATTRSTR)
-marshalAttrIndexType NumIndex = (#const ESTIDXATTRNUM)
+marshalAttrIndexType SeqIndex = #const ESTIDXATTRSEQ
+marshalAttrIndexType StrIndex = #const ESTIDXATTRSTR
+marshalAttrIndexType NumIndex = #const ESTIDXATTRNUM
 
 -- |'OptimizeOption' is an option for the 'optimizeDatabase' action.
 data OptimizeOption
@@ -252,8 +252,8 @@
 
 
 marshalOptimizeOption :: OptimizeOption -> Int
-marshalOptimizeOption NoPurge      = (#const ESTOPTNOPURGE)
-marshalOptimizeOption NoDBOptimize = (#const ESTOPTNODBOPT)
+marshalOptimizeOption NoPurge      = #const ESTOPTNOPURGE
+marshalOptimizeOption NoDBOptimize = #const ESTOPTNODBOPT
 
 -- |'RemoveOption' is an option for the 'mergeDatabase' action and the
 -- 'removeDocument' action.
@@ -264,7 +264,7 @@
 
 
 marshalRemoveOption :: RemoveOption -> Int
-marshalRemoveOption CleaningRemove = (#const ESTODCLEAN)
+marshalRemoveOption CleaningRemove = #const ESTODCLEAN
 
 -- |'PutOption' is an option for the 'putDocument' action.
 data PutOption
@@ -277,8 +277,8 @@
 
 
 marshalPutOption :: PutOption -> Int
-marshalPutOption CleaningPut      = (#const ESTPDCLEAN)
-marshalPutOption WeightStatically = (#const ESTPDWEIGHT)
+marshalPutOption CleaningPut      = #const ESTPDCLEAN
+marshalPutOption WeightStatically = #const ESTPDWEIGHT
 
 -- |'GetOption' is an option for the 'getDocument' action.
 data GetOption
@@ -288,9 +288,9 @@
     deriving (Eq, Show)
 
 marshalGetOption :: GetOption -> Int
-marshalGetOption NoAttributes = (#const ESTGDNOATTR)
-marshalGetOption NoText       = (#const ESTGDNOTEXT)
-marshalGetOption NoKeywords   = (#const ESTGDNOKWD)
+marshalGetOption NoAttributes = #const ESTGDNOATTR
+marshalGetOption NoText       = #const ESTGDNOTEXT
+marshalGetOption NoKeywords   = #const ESTGDNOKWD
 
 -- |@'Database'@ is an opaque object representing a HyperEstraier
 -- database.
@@ -369,7 +369,7 @@
 
 
 wrapDB :: Ptr ESTMTDB -> IO Database
-wrapDB dbPtr = newIORef dbPtr >>= return . Database
+wrapDB dbPtr = fmap Database (newIORef dbPtr)
 
 
 withDBPtr :: Database -> (Ptr ESTMTDB -> IO a) -> IO a
@@ -408,9 +408,9 @@
       alloca                $ \ errPtr   ->
       do dbPtr <- _open fpathPtr (marshalOpenMode opts) errPtr
          if dbPtr == nullPtr then
-             peek errPtr >>= return . Left . unmarshalError
+             fmap (Left . unmarshalError) (peek errPtr)
            else
-             wrapDB dbPtr >>= return . Right
+             fmap Right (wrapDB dbPtr)
 
 -- |@'closeDatabase' db@ closes the database @db@. If the @db@ has
 -- already been closed, this operation causes nothing.
@@ -442,7 +442,7 @@
 hasFatalError :: Database -> IO Bool
 hasFatalError db
     = withDBPtr db $ \ dbPtr ->
-      _fatal dbPtr >>= return . (/= 0)
+      fmap (/= 0) (_fatal dbPtr)
 
 -- |@'addAttrIndex' db attr idxType@ creates an index of type
 -- @idxType@ for attribute @attr@ into the database @db@.
@@ -536,12 +536,12 @@
          if valuePtr == nullPtr then
              return Nothing
            else
-             packMallocUTF8CString valuePtr >>= return . Just
+             fmap Just (packMallocUTF8CString valuePtr)
 
 -- |Get the URI of a document in a database.
 getDocURI :: Database -> DocumentID -> IO URI
 getDocURI db docId
-    = getDocAttr db docId "@uri" >>= return . fromJust . parseURI . fromJust
+    = fmap (fromJust . parseURI . fromJust) (getDocAttr db docId "@uri")
 
 -- |Find a document in a database by an URI and return its ID.
 getDocIdByURI :: Database -> URI -> IO (Maybe DocumentID)
@@ -563,23 +563,20 @@
 -- |Get the number of documents in a database.
 getNumOfDocs :: Database -> IO Int
 getNumOfDocs db
-    = withDBPtr db $ \ dbPtr ->
-      _doc_num dbPtr
+    = withDBPtr db _doc_num
 
 -- |Get the number of words in a database.
 getNumOfWords :: Database -> IO Int
 getNumOfWords db
-    = withDBPtr db $ \ dbPtr ->
-      _word_num dbPtr
+    = withDBPtr db _word_num
 
 -- |Get the size of a database.
 getDatabaseSize :: Database -> IO Integer
 getDatabaseSize db
     = withDBPtr db $ \ dbPtr ->
-      -- なんで est_db_size() の戻り値が double なの。なんで size_t と
-      -- か long long int とかぢゃないの。H.E. のやってる事は大雜把には
-      -- 凄いのに、細かい部分が實に好い加減だなあ…
-      _size dbPtr >>= return . floor
+      -- Why est_db_size() returns double? Why not size_t or long long
+      -- int? Crazy.
+      fmap floor (_size dbPtr)
 
 -- |Search for documents in a database by a condition.
 searchDatabase :: Database -> Condition -> IO [DocumentID]
@@ -670,8 +667,7 @@
     = withDBPtr   db   $ \ dbPtr   ->
       withDocPtr  doc  $ \ docPtr  ->
       withCondPtr cond $ \ condPtr ->
-      _scan_doc dbPtr docPtr condPtr
-           >>= return . (/= 0)
+      fmap (/= 0) (_scan_doc dbPtr docPtr condPtr)
 
 -- |Change the size of various caches of a database. Passing negative
 -- values leaves the old values unchanged.
diff --git a/Text/HyperEstraier/Document.hsc b/Text/HyperEstraier/Document.hsc
--- a/Text/HyperEstraier/Document.hsc
+++ b/Text/HyperEstraier/Document.hsc
@@ -112,7 +112,7 @@
 
 
 wrapDoc :: Ptr ESTDOC -> IO Document
-wrapDoc docPtr = newForeignPtr _delete docPtr >>= return . Document
+wrapDoc = fmap Document . newForeignPtr _delete
 
 
 withDocPtr :: Document -> (Ptr ESTDOC -> IO a) -> IO a
@@ -138,29 +138,29 @@
 setAttribute doc name value
     = withDocPtr       doc   $ \ docPtr   ->
       withUTF8CString  name  $ \ namePtr  ->
-      withUTF8CString' value $ \ valuePtr ->
-      _add_attr docPtr namePtr valuePtr
+      withUTF8CString' value $
+      _add_attr docPtr namePtr
 
 -- |Add a block of text to a document.
 addText :: Document -> String -> IO ()
 addText doc text
     = withDocPtr      doc  $ \ docPtr  ->
-      withUTF8CString text $ \ textPtr ->
-      _add_text docPtr textPtr
+      withUTF8CString text $
+      _add_text docPtr
 
 -- |Add a block of hidden text to a document.
 addHiddenText :: Document -> String -> IO ()
 addHiddenText doc text
     = withDocPtr      doc  $ \ docPtr  ->
-      withUTF8CString text $ \ textPtr ->
-      _add_hidden_text docPtr textPtr
+      withUTF8CString text $
+      _add_hidden_text docPtr
 
 -- |Set an URI of a document. This is a special case of
 -- 'setAttribute'.
 setURI :: Document -> Maybe URI -> IO ()
 setURI doc uri = setAttribute doc "@uri" (fmap uri2str uri)
     where
-      uri2str u = uriToString id u ""
+      uri2str = flip (uriToString id) ""
 
 -- |Set keywords of a document.
 setKeywords :: Document            -- ^ The document.
@@ -168,8 +168,8 @@
             -> IO ()
 setKeywords doc keywords
     = withDocPtr doc    $ \ docPtr ->
-      withKeywordMapPtr $ \ mapPtr ->
-      _set_keywords docPtr mapPtr
+      withKeywordMapPtr $
+      _set_keywords docPtr
     where
       withKeywordMapPtr :: (Ptr CM.CBMAP -> IO a) -> IO a
       withKeywordMapPtr f = do m <- CM.fromList $ map encodeKeyword keywords
@@ -180,14 +180,12 @@
 -- |Set an alternative score of a document.
 setScore :: Document -> Maybe Int -> IO ()
 setScore doc score
-    = withDocPtr doc $ \ docPtr ->
-      _set_score docPtr (fromMaybe (-1) score)
+    = withDocPtr doc $ flip _set_score (fromMaybe (-1) score)
 
 -- |Get the ID of document.
 getId :: Document -> IO DocumentID
 getId doc
-    = withDocPtr doc $ \ docPtr ->
-      _id docPtr
+    = withDocPtr doc _id
 
 -- |Get a list of all attribute names in a document.
 getAttrNames :: Document -> IO [String]
@@ -207,7 +205,7 @@
          if valuePtr == nullPtr then
              return Nothing
            else
-             peekUTF8CString valuePtr >>= return . Just
+             fmap Just (peekUTF8CString valuePtr)
 
 -- |Get the text in a document.
 getText :: Document -> IO String
@@ -218,7 +216,7 @@
 
 -- |Get the URI of a document.
 getURI :: Document -> IO (Maybe URI)
-getURI doc = getAttribute doc "@uri" >>= return . fmap parse
+getURI doc = fmap (fmap parse) (getAttribute doc "@uri")
     where
       parse :: String -> URI
       parse = fromJust . parseURIReference
@@ -230,7 +228,6 @@
       _keywords docPtr
            >>= CM.unsafePeekMap
            >>= CM.toList
-           -- ここまで正格。次の行は遲延される。
            >>= return . map decodeKeyword
     where
       decodeKeyword (word, score) = (decodeString $ C8.unpack word, read $ C8.unpack score)
diff --git a/Text/HyperEstraier/Utils.hsc b/Text/HyperEstraier/Utils.hsc
--- a/Text/HyperEstraier/Utils.hsc
+++ b/Text/HyperEstraier/Utils.hsc
@@ -36,20 +36,9 @@
 
 
 peekUTF8CString :: CString -> IO String
-peekUTF8CString cstr = peekCString cstr >>= return . decodeString
+peekUTF8CString = fmap decodeString . peekCString
 
--- (.) の型は (b -> c) -> (a -> b) -> a -> c である。(.) は同じ arity
--- の函數を繋げる。map は二引數函數なので、それと繋げる方も二引數にしな
--- ければならない。所で foldl (.|.) 0 の型は Bits a => [a] -> a で一引
--- 數である。これを (foldl (.|.) 0 .) にすると、その型は Bits b => (a
--- -> [b]) -> a -> b になり、單純に Bits a のリストを取ってゐた函數が
--- 「何かの値を取って Bits b のリストを返す函數」と「その何かの値」を取
--- る函數に變化する。それを (.) の左邊に置くと、((foldl (.|.) 0 .) .)
--- の型は Bits c => (a -> b -> [c]) -> a -> b -> c になる。この函數に
--- map を適用すると、map の型は (a -> b) -> [a] -> [b] なので、結果は
--- Bits b => (a -> b) -> [a] -> b になる。
---
--- point-free って難しいね。
+
 marshalOpts :: Bits b => (a -> b) -> [a] -> b
 marshalOpts = (foldl (.|.) 0 .) . map
 
@@ -59,8 +48,7 @@
                 -> (Ptr (Ptr b) -> IO c)
                 -> IO c
 withArrayOfPtrs withXPtr xs f
-    = withXPtrList xs [] $ \ xPtrs ->
-      withArray xPtrs f
+    = withXPtrList xs [] $ flip withArray f
     where
       -- withXPtrList :: [a] -> [Ptr b] -> ([Ptr b] -> IO c) -> IO c
       withXPtrList []     acc g = g acc