X-Git-Url: http://git.cielonegro.org/gitweb.cgi?p=Lucu.git;a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FResource.hs;h=2672399bf7a249102d2368d387bc529dcfdae017;hp=3bc75246cca62f8e9ba6b8be59d8a01d53aefd70;hb=db4b61223e0d8b34079d3b190fb3e3644b0b4866;hpb=054e36027618944ea45f85ae349e51b76a139270

diff --git a/Network/HTTP/Lucu/Resource.hs b/Network/HTTP/Lucu/Resource.hs
index 3bc7524..2672399 100644
--- a/Network/HTTP/Lucu/Resource.hs
+++ b/Network/HTTP/Lucu/Resource.hs
@@ -1,5 +1,9 @@
 {-# LANGUAGE
-    UnboxedTuples
+    BangPatterns
+  , GeneralizedNewtypeDeriving
+  , DoAndIfThenElse
+  , OverloadedStrings
+  , RecordWildCards
   , UnicodeSyntax
   #-}
 {-# OPTIONS_HADDOCK prune #-}
@@ -110,8 +114,6 @@ module Network.HTTP.Lucu.Resource
     -- Body/.
     , input
     , inputChunk
-    , inputLBS
-    , inputChunkLBS
     , inputForm
     , defaultLimit
 
@@ -133,96 +135,90 @@ module Network.HTTP.Lucu.Resource
     -- Body/.
     , output
     , outputChunk
-    , outputLBS
-    , outputChunkLBS
 
-    , driftTo
+    , driftTo -- private
     )
     where
-import           Control.Concurrent.STM
-import           Control.Monad.Reader
-import qualified Data.ByteString as Strict (ByteString)
-import qualified Data.ByteString.Lazy as Lazy (ByteString)
-import qualified Data.ByteString.Char8 as C8 hiding (ByteString)
-import qualified Data.ByteString.Lazy.Char8 as L8 hiding (ByteString)
-import           Data.Char
-import           Data.List
-import           Data.Maybe
-import           Data.Time
+import Control.Applicative
+import Control.Concurrent.STM
+import Control.Monad.Reader
+import Control.Monad.Unicode
+import Data.Ascii (Ascii, CIAscii)
+import qualified Data.Ascii as A
+import qualified Data.Attoparsec.Char8 as P
+import qualified Data.Attoparsec.Lazy  as LP
+import Data.ByteString (ByteString)
+import qualified Data.ByteString.Char8 as C8
+import qualified Data.ByteString.Lazy  as Lazy
+import qualified Data.ByteString.Lazy.Char8 as L8
+import Data.List
+import qualified Data.Map as M
+import Data.Maybe
+import Data.Monoid.Unicode
+import qualified Data.Sequence as S
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as T
+import qualified Data.Text.Encoding.Error as T
+import Data.Time
 import qualified Data.Time.HTTP as HTTP
-import           Network.HTTP.Lucu.Abortion
-import           Network.HTTP.Lucu.Authorization
-import           Network.HTTP.Lucu.Config
-import           Network.HTTP.Lucu.ContentCoding
-import           Network.HTTP.Lucu.DefaultPage
-import           Network.HTTP.Lucu.ETag
+import Network.HTTP.Lucu.Abortion
+import Network.HTTP.Lucu.Authorization
+import Network.HTTP.Lucu.Config
+import Network.HTTP.Lucu.ContentCoding
+import Network.HTTP.Lucu.DefaultPage
+import Network.HTTP.Lucu.ETag
 import qualified Network.HTTP.Lucu.Headers as H
-import           Network.HTTP.Lucu.HttpVersion
-import           Network.HTTP.Lucu.Interaction
-import           Network.HTTP.Lucu.MultipartForm
-import           Network.HTTP.Lucu.Postprocess
-import           Network.HTTP.Lucu.Request
-import           Network.HTTP.Lucu.Response
-import           Network.HTTP.Lucu.MIMEType
-import           Network.HTTP.Lucu.Utils
-import           Network.Socket hiding (accept)
-import           Network.URI hiding (path)
-import           OpenSSL.X509
-
--- |The 'Resource' monad. This monad implements
--- 'Control.Monad.Trans.MonadIO' so it can do any 'Prelude.IO'
--- actions.
-newtype Resource a = Resource { unRes :: ReaderT Interaction IO a }
-
-instance Functor Resource where
-    fmap f c = Resource (fmap f (unRes c))
-
-instance Monad Resource where
-    c >>= f = Resource (unRes c >>= unRes . f)
-    return  = Resource . return
-    fail    = Resource . fail
-
-instance MonadIO Resource where
-    liftIO = Resource . liftIO
-
-
-runRes :: Resource a -> Interaction -> IO a
+import Network.HTTP.Lucu.HttpVersion
+import Network.HTTP.Lucu.Interaction
+import Network.HTTP.Lucu.MultipartForm
+import Network.HTTP.Lucu.Postprocess
+import Network.HTTP.Lucu.Request
+import Network.HTTP.Lucu.Response
+import Network.HTTP.Lucu.MIMEType
+import Network.HTTP.Lucu.Utils
+import Network.Socket hiding (accept)
+import Network.URI hiding (path)
+import OpenSSL.X509
+import Prelude.Unicode
+
+-- |The 'Resource' monad. This monad implements 'MonadIO' so it can do
+-- any 'IO' actions.
+newtype Resource a
+    = Resource {
+        unRes ∷ ReaderT Interaction IO a
+      }
+    deriving (Applicative, Functor, Monad, MonadIO)
+
+runRes ∷ Resource a → Interaction → IO a
 runRes r itr
     = runReaderT (unRes r) itr
 
-
-getInteraction :: Resource Interaction
+getInteraction ∷ Resource Interaction
 getInteraction = Resource ask
 
+-- |Get the 'Config' value which is used for the httpd.
+getConfig ∷ Resource Config
+getConfig = itrConfig <$> getInteraction
 
--- |Get the 'Network.HTTP.Lucu.Config.Config' value which is used for
--- the httpd.
-getConfig :: Resource Config
-getConfig = do itr <- getInteraction
-               return $! itrConfig itr
-
-
--- |Get the 'Network.Socket.SockAddr' of the remote host. If you want
--- a string representation instead of 'Network.Socket.SockAddr', use
--- 'getRemoteAddr''.
-getRemoteAddr :: Resource SockAddr
-getRemoteAddr = do itr <- getInteraction
-                   return $! itrRemoteAddr itr
-
+-- |Get the 'SockAddr' of the remote host. If you want a string
+-- representation instead of 'SockAddr', use 'getRemoteAddr''.
+getRemoteAddr ∷ Resource SockAddr
+getRemoteAddr = itrRemoteAddr <$> getInteraction
 
 -- |Get the string representation of the address of remote host. If
--- you want a 'Network.Socket.SockAddr' instead of 'Prelude.String',
--- use 'getRemoteAddr'.
-getRemoteAddr' :: Resource String
-getRemoteAddr' = do addr          <- getRemoteAddr
-                    (Just str, _) <- liftIO $! getNameInfo [NI_NUMERICHOST] True False addr
-                    return str
+-- you want a 'SockAddr' instead of 'String', use 'getRemoteAddr'.
+getRemoteAddr' ∷ Resource HostName
+getRemoteAddr'
+    = do sa          ← getRemoteAddr
+         (Just a, _) ← liftIO $ getNameInfo [NI_NUMERICHOST] False False sa
+         return a
 
 -- |Resolve an address to the remote host.
-getRemoteHost :: Resource String
-getRemoteHost = do addr          <- getRemoteAddr
-                   (Just str, _) <- liftIO $! getNameInfo [] True False addr
-                   return str
+getRemoteHost ∷ Resource (Maybe HostName)
+getRemoteHost
+    = do sa ← getRemoteAddr
+         fst <$> (liftIO $ getNameInfo [] True False sa)
 
 -- | Return the X.509 certificate of the client, or 'Nothing' if:
 --
@@ -231,34 +227,29 @@ getRemoteHost = do addr          <- getRemoteAddr
 --   * The client didn't send us its certificate.
 --
 --   * The 'OpenSSL.Session.VerificationMode' of
---     'OpenSSL.Session.SSLContext' in
---     'Network.HTTP.Lucu.Config.SSLConfig' has not been set to
---     'OpenSSL.Session.VerifyPeer'.
-getRemoteCertificate :: Resource (Maybe X509)
-getRemoteCertificate = do itr <- getInteraction
-                          return $! itrRemoteCert itr
-
--- |Get the 'Network.HTTP.Lucu.Request.Request' value which represents
--- the request header. In general you don't have to use this action.
-getRequest :: Resource Request
-getRequest = do itr <- getInteraction
-                req <- liftIO $! atomically $! readItr itr itrRequest fromJust
-                return req
-
--- |Get the 'Network.HTTP.Lucu.Request.Method' value of the request.
-getMethod :: Resource Method
-getMethod = do req <- getRequest
-               return $! reqMethod req
+--   'OpenSSL.Session.SSLContext' in 'SSLConfig' has not been set to
+--   'OpenSSL.Session.VerifyPeer'.
+getRemoteCertificate ∷ Resource (Maybe X509)
+getRemoteCertificate = itrRemoteCert <$> getInteraction
+
+-- |Get the 'Request' value which represents the request header. In
+-- general you don't have to use this action.
+getRequest ∷ Resource Request
+getRequest
+    = do itr ← getInteraction
+         liftIO $ atomically $ readItr itrRequest fromJust itr
+
+-- |Get the 'Method' value of the request.
+getMethod ∷ Resource Method
+getMethod = reqMethod <$> getRequest
 
 -- |Get the URI of the request.
-getRequestURI :: Resource URI
-getRequestURI = do req <- getRequest
-                   return $! reqURI req
+getRequestURI ∷ Resource URI
+getRequestURI = reqURI <$> getRequest
 
 -- |Get the HTTP version of the request.
-getRequestVersion :: Resource HttpVersion
-getRequestVersion = do req <- getRequest
-                       return $! reqVersion req
+getRequestVersion ∷ Resource HttpVersion
+getRequestVersion = reqVersion <$> getRequest
 
 -- |Get the path of this 'Resource' (to be exact,
 -- 'Network.HTTP.Lucu.Resource.Tree.ResourceDef') in the
@@ -273,141 +264,155 @@ getRequestVersion = do req <- getRequest
 -- >
 -- > resFoo = ResourceDef {
 -- >     resIsGreedy = True
--- >   , resGet = Just $ do requestURI   <- getRequestURI
--- >                        resourcePath <- getResourcePath
--- >                        pathInfo     <- getPathInfo
+-- >   , resGet = Just $ do requestURI   ← getRequestURI
+-- >                        resourcePath ← getResourcePath
+-- >                        pathInfo     ← getPathInfo
 -- >                        -- uriPath requestURI == "/foo/bar/baz"
 -- >                        -- resourcePath       == ["foo"]
 -- >                        -- pathInfo           == ["bar", "baz"]
 -- >                        ...
 -- >   , ...
 -- >   }
-getResourcePath :: Resource [String]
-getResourcePath = do itr <- getInteraction
-                     return $! fromJust $! itrResourcePath itr
-
+getResourcePath ∷ Resource [Ascii]
+getResourcePath = (fromJust ∘ itrResourcePath) <$> getInteraction
 
 -- |This is an analogy of CGI PATH_INFO. The result is
 -- URI-unescaped. It is always @[]@ if the
 -- 'Network.HTTP.Lucu.Resource.Tree.ResourceDef' is not greedy. See
 -- 'getResourcePath'.
-getPathInfo :: Resource [String]
-getPathInfo = do rsrcPath <- getResourcePath
-                 uri      <- getRequestURI
+getPathInfo ∷ Resource [ByteString]
+getPathInfo = do rsrcPath ← getResourcePath
+                 uri      ← getRequestURI
                  let reqPathStr = uriPath uri
-                     reqPath    = [unEscapeString x | x <- splitBy (== '/') reqPathStr, x /= ""]
+                     reqPath    = [unEscapeString x | x ← splitBy (≡ '/') reqPathStr, (¬) (null x)]
                  -- rsrcPath と reqPath の共通する先頭部分を reqPath か
                  -- ら全部取り除くと、それは PATH_INFO のやうなものにな
                  -- る。rsrcPath は全部一致してゐるに決まってゐる（でな
                  -- ければこの Resource が撰ばれた筈が無い）ので、
                  -- rsrcPath の長さの分だけ削除すれば良い。
-                 return $! drop (length rsrcPath) reqPath
+                 return $ map C8.pack $ drop (length rsrcPath) reqPath
 
 -- |Assume the query part of request URI as
 -- application\/x-www-form-urlencoded, and parse it to pairs of
 -- @(name, formData)@. This action doesn't parse the request body. See
--- 'inputForm'.
-getQueryForm :: Resource [(String, FormData)]
-getQueryForm = liftM parse' getRequestURI
+-- 'inputForm'. Field names are decoded in UTF-8.
+getQueryForm ∷ Resource [(Text, FormData)]
+getQueryForm = parse' <$> getRequestURI
     where
-      parse' = map toPairWithFormData .
-               parseWWWFormURLEncoded .
-               snd .
-               splitAt 1 .
+      parse' = map toPairWithFormData ∘
+               parseWWWFormURLEncoded ∘
+               fromJust ∘
+               A.fromChars ∘
+               drop 1 ∘
                uriQuery
 
-toPairWithFormData :: (String, String) -> (String, FormData)
+toPairWithFormData ∷ (ByteString, ByteString) → (Text, FormData)
 toPairWithFormData (name, value)
     = let fd = FormData {
                  fdFileName = Nothing
-               , fdContent  = L8.pack value
+               , fdContent  = L8.fromChunks [value]
                }
-      in (name, fd)
+      in (T.decodeUtf8With T.lenientDecode name, fd)
 
 -- |Get a value of given request header. Comparison of header name is
 -- case-insensitive. Note that this action is not intended to be used
 -- so frequently: there should be actions like 'getContentType' for
 -- every common headers.
-getHeader :: Strict.ByteString -> Resource (Maybe Strict.ByteString)
-getHeader name = name `seq`
-                 do req <- getRequest
-                    return $! H.getHeader name req
-
--- |Get a list of 'Network.HTTP.Lucu.MIMEType.MIMEType' enumerated on
--- header \"Accept\".
-getAccept :: Resource [MIMEType]
-getAccept = do acceptM <- getHeader (C8.pack "Accept")
-               case acceptM of
-                 Nothing 
-                     -> return []
-                 Just accept
-                     -> case parse mimeTypeListP (L8.fromChunks [accept]) of
-                          (# Success xs, _ #) -> return xs
-                          (# _         , _ #) -> abort BadRequest []
-                                                 (Just $ "Unparsable Accept: " ++ C8.unpack accept)
+getHeader ∷ CIAscii → Resource (Maybe Ascii)
+getHeader name
+    = H.getHeader name <$> getRequest
+
+-- |Get a list of 'MIMEType' enumerated on header \"Accept\".
+getAccept ∷ Resource [MIMEType]
+getAccept
+    = do acceptM ← getHeader "Accept"
+         case acceptM of
+           Nothing
+               → return []
+           Just accept
+               → case P.parseOnly p (A.toByteString accept) of
+                    Right xs → return xs
+                    Left  _  → abort BadRequest []
+                               (Just $ "Unparsable Accept: " ⊕ A.toText accept)
+    where
+      p = do xs ← mimeTypeListP
+             P.endOfInput
+             return xs
 
 -- |Get a list of @(contentCoding, qvalue)@ enumerated on header
 -- \"Accept-Encoding\". The list is sorted in descending order by
 -- qvalue.
-getAcceptEncoding :: Resource [(String, Maybe Double)]
+getAcceptEncoding ∷ Resource [(CIAscii, Maybe Double)]
 getAcceptEncoding
-    = do accEncM <- getHeader (C8.pack "Accept-Encoding")
+    = do accEncM ← getHeader "Accept-Encoding"
          case accEncM of
            Nothing
                -- HTTP/1.0 には Accept-Encoding が無い場合の規定が無い
                -- ので安全の爲 identity が指定された事にする。HTTP/1.1
                -- の場合は何でも受け入れて良い事になってゐるので "*" が
                -- 指定された事にする。
-               -> do ver <- getRequestVersion
-                     case ver of
-                       HttpVersion 1 0 -> return [("identity", Nothing)]
-                       HttpVersion 1 1 -> return [("*"       , Nothing)]
-                       _               -> undefined
-           Just value
-               -> if C8.null value then
+               → do ver ← getRequestVersion
+                    case ver of
+                      HttpVersion 1 0 → return [("identity", Nothing)]
+                      HttpVersion 1 1 → return [("*"       , Nothing)]
+                      _               → abort InternalServerError []
+                                        (Just "getAcceptEncoding: unknown HTTP version")
+           Just ae
+               → if ae ≡ "" then
                       -- identity のみが許される。
                       return [("identity", Nothing)]
                   else
-                      case parse acceptEncodingListP (L8.fromChunks [value]) of
-                        (# Success x, _ #) -> return $ reverse $ sortBy orderAcceptEncodings x
-                        (# _        , _ #) -> abort BadRequest []
-                                              (Just $ "Unparsable Accept-Encoding: " ++ C8.unpack value)
+                      case P.parseOnly p (A.toByteString ae) of
+                        Right xs → return $ map toTuple $ reverse $ sort xs
+                        Left  _  → abort BadRequest []
+                                   (Just $ "Unparsable Accept-Encoding: " ⊕ A.toText ae)
+    where
+      p = do xs ← acceptEncodingListP
+             P.endOfInput
+             return xs
 
--- |Check whether a given content-coding is acceptable.
-isEncodingAcceptable :: String -> Resource Bool
-isEncodingAcceptable coding
-    = do accList <- getAcceptEncoding
-         return (flip any accList $ \ (c, q) ->
-                     (c == "*" || C8.pack c `H.noCaseEq` C8.pack coding) && q /= Just 0)
+      toTuple (AcceptEncoding {..})
+          = (aeEncoding, aeQValue)
 
+-- |Check whether a given content-coding is acceptable.
+isEncodingAcceptable ∷ CIAscii → Resource Bool
+isEncodingAcceptable encoding = any f <$> getAcceptEncoding
+    where
+      f (e, q)
+          = (e ≡ "*" ∨ e ≡ encoding) ∧ q ≢ Just 0
 
--- |Get the header \"Content-Type\" as
--- 'Network.HTTP.Lucu.MIMEType.MIMEType'.
-getContentType :: Resource (Maybe MIMEType)
+-- |Get the header \"Content-Type\" as 'MIMEType'.
+getContentType ∷ Resource (Maybe MIMEType)
 getContentType
-    = do cTypeM <- getHeader (C8.pack "Content-Type")
+    = do cTypeM ← getHeader "Content-Type"
          case cTypeM of
            Nothing
-               -> return Nothing
+               → return Nothing
            Just cType
-               -> case parse mimeTypeP (L8.fromChunks [cType]) of
-                    (# Success t, _ #) -> return $ Just t
-                    (# _        , _ #) -> abort BadRequest []
-                                          (Just $ "Unparsable Content-Type: " ++ C8.unpack cType)
-
+               → case P.parseOnly p (A.toByteString cType) of
+                    Right t → return $ Just t
+                    Left  _ → abort BadRequest []
+                              (Just $ "Unparsable Content-Type: " ⊕ A.toText cType)
+    where
+      p = do t ← mimeTypeP
+             P.endOfInput
+             return t
 
--- |Get the header \"Authorization\" as
--- 'Network.HTTP.Lucu.Authorization.AuthCredential'.
-getAuthorization :: Resource (Maybe AuthCredential)
+-- |Get the header \"Authorization\" as 'AuthCredential'.
+getAuthorization ∷ Resource (Maybe AuthCredential)
 getAuthorization
-    = do authM <- getHeader (C8.pack "Authorization")
+    = do authM ← getHeader "Authorization"
          case authM of
            Nothing
-               -> return Nothing
+               → return Nothing
            Just auth
-               -> case parse authCredentialP (L8.fromChunks [auth]) of
-                    (# Success a, _ #) -> return $ Just a
-                    (# _        , _ #) -> return Nothing
+               → case P.parseOnly p (A.toByteString auth) of
+                    Right ac → return $ Just ac
+                    Left  _  → return Nothing
+    where
+      p = do ac ← authCredentialP
+             P.endOfInput
+             return ac
 
 
 {- ExaminingRequest 時に使用するアクション群 -}
@@ -426,17 +431,16 @@ getAuthorization
 --
 -- If this is a GET or HEAD request, 'foundEntity' automatically puts
 -- \"ETag\" and \"Last-Modified\" headers into the response.
-foundEntity :: ETag -> UTCTime -> Resource ()
-foundEntity tag timeStamp
-    = tag `seq` timeStamp `seq`
-      do driftTo ExaminingRequest
-
-         method <- getMethod
-         when (method == GET || method == HEAD)
-                  $ setHeader' (C8.pack "Last-Modified") (C8.pack $ HTTP.format timeStamp)
-         when (method == POST)
-                  $ abort InternalServerError []
-                        (Just "Illegal computation of foundEntity for a POST request.")
+foundEntity ∷ ETag → UTCTime → Resource ()
+foundEntity !tag !timeStamp
+    = do driftTo ExaminingRequest
+
+         method ← getMethod
+         when (method ≡ GET ∨ method ≡ HEAD)
+             $ setHeader' "Last-Modified" (HTTP.toAscii timeStamp)
+         when (method ≡ POST)
+             $ abort InternalServerError []
+               (Just "Illegal computation of foundEntity for a POST request.")
          foundETag tag
 
          driftTo GettingBody
@@ -448,55 +452,61 @@ foundEntity tag timeStamp
 --
 -- This action is not preferred. You should use 'foundEntity' whenever
 -- possible.
-foundETag :: ETag -> Resource ()
-foundETag tag
-    = tag `seq`
-      do driftTo ExaminingRequest
+foundETag ∷ ETag → Resource ()
+foundETag !tag
+    = do driftTo ExaminingRequest
       
-         method <- getMethod
-         when (method == GET || method == HEAD)
-                  $ setHeader' (C8.pack "ETag") (C8.pack $ show tag)
-         when (method == POST)
-                  $ abort InternalServerError []
-                        (Just "Illegal computation of foundETag for POST request.")
+         method ← getMethod
+         when (method ≡ GET ∨ method ≡ HEAD)
+              $ setHeader' "ETag" (printETag tag)
+         when (method ≡ POST)
+              $ abort InternalServerError []
+                (Just "Illegal computation of foundETag for POST request.")
 
          -- If-Match があればそれを見る。
-         ifMatch <- getHeader (C8.pack "If-Match")
+         ifMatch ← getHeader "If-Match"
          case ifMatch of
-           Nothing    -> return ()
-           Just value -> if value == C8.pack "*" then
-                             return ()
-                         else
-                             case parse eTagListP (L8.fromChunks [value]) of
-                               (# Success tags, _ #)
+           Nothing    → return ()
+           Just value → if value ≡ "*" then
+                            return ()
+                        else
+                            case P.parseOnly p (A.toByteString value) of
+                              Right tags
                                  -- tags の中に一致するものが無ければ
                                  -- PreconditionFailed で終了。
-                                 -> when (not $ any (== tag) tags)
-                                    $ abort PreconditionFailed []
-                                          $! Just ("The entity tag doesn't match: " ++ C8.unpack value)
-                               (# _, _ #)
-                                   -> abort BadRequest [] $! Just ("Unparsable If-Match: " ++ C8.unpack value)
-
-         let statusForNoneMatch = if method == GET || method == HEAD then
-                                      NotModified
-                                  else
-                                      PreconditionFailed
+                                 → when ((¬) (any (≡ tag) tags))
+                                       $ abort PreconditionFailed []
+                                         (Just $ "The entity tag doesn't match: " ⊕ A.toText value)
+                              Left _
+                                   → abort BadRequest [] (Just $ "Unparsable If-Match: " ⊕ A.toText value)
+
+         let statusForNoneMatch
+                 = if method ≡ GET ∨ method ≡ HEAD then
+                       NotModified
+                   else
+                       PreconditionFailed
 
          -- If-None-Match があればそれを見る。
-         ifNoneMatch <- getHeader (C8.pack "If-None-Match")
+         ifNoneMatch ← getHeader "If-None-Match"
          case ifNoneMatch of
-           Nothing    -> return ()
-           Just value -> if value == C8.pack "*" then
-                             abort statusForNoneMatch [] $! Just ("The entity tag matches: *")
+           Nothing    → return ()
+           Just value → if value ≡ "*" then
+                             abort statusForNoneMatch [] (Just "The entity tag matches: *")
                          else
-                             case parse eTagListP (L8.fromChunks [value]) of
-                               (# Success tags, _ #)
-                                   -> when (any (== tag) tags)
-                                      $ abort statusForNoneMatch [] $! Just ("The entity tag matches: " ++ C8.unpack value)
-                               (# _, _ #)
-                                   -> abort BadRequest [] $! Just ("Unparsable If-None-Match: " ++ C8.unpack value)
+                             case P.parseOnly p (A.toByteString value) of
+                               Right tags
+                                   → when (any (≡ tag) tags)
+                                         $ abort statusForNoneMatch []
+                                           (Just $ "The entity tag matches: " ⊕ A.toText value)
+                               Left _
+                                   → abort BadRequest []
+                                     (Just $ "Unparsable If-None-Match: " ⊕ A.toText value)
 
          driftTo GettingBody
+    where
+      p = do xs ← eTagListP
+             P.endOfInput
+             return xs
 
 -- |Tell the system that the 'Resource' found an entity for the
 -- request URI. The only difference from 'foundEntity' is that
@@ -508,46 +518,46 @@ foundETag tag
 --
 -- This action is not preferred. You should use 'foundEntity' whenever
 -- possible.
-foundTimeStamp :: UTCTime -> Resource ()
+foundTimeStamp ∷ UTCTime → Resource ()
 foundTimeStamp timeStamp
-    = timeStamp `seq`
-      do driftTo ExaminingRequest
+    = do driftTo ExaminingRequest
 
-         method <- getMethod
-         when (method == GET || method == HEAD)
-                  $ setHeader' (C8.pack "Last-Modified") (C8.pack $ HTTP.format timeStamp)
-         when (method == POST)
-                  $ abort InternalServerError []
-                        (Just "Illegal computation of foundTimeStamp for POST request.")
+         method ← getMethod
+         when (method ≡ GET ∨ method ≡ HEAD)
+             $ setHeader' "Last-Modified" (HTTP.toAscii timeStamp)
+         when (method ≡ POST)
+             $ abort InternalServerError []
+               (Just "Illegal computation of foundTimeStamp for POST request.")
 
-         let statusForIfModSince = if method == GET || method == HEAD then
-                                       NotModified
-                                   else
-                                       PreconditionFailed
+         let statusForIfModSince
+                 = if method ≡ GET ∨ method ≡ HEAD then
+                       NotModified
+                   else
+                       PreconditionFailed
 
          -- If-Modified-Since があればそれを見る。
-         ifModSince <- getHeader (C8.pack "If-Modified-Since")
+         ifModSince ← getHeader "If-Modified-Since"
          case ifModSince of
-           Just str -> case HTTP.parse (C8.unpack str) of
-                         Just lastTime
-                             -> when (timeStamp <= lastTime)
-                                $ abort statusForIfModSince []
-                                      $! Just ("The entity has not been modified since " ++ C8.unpack str)
-                         Nothing
-                             -> return () -- 不正な時刻は無視
-           Nothing  -> return ()
+           Just str → case HTTP.fromAscii str of
+                         Right lastTime
+                             → when (timeStamp ≤ lastTime)
+                               $ abort statusForIfModSince []
+                                 (Just $ "The entity has not been modified since " ⊕ A.toText str)
+                         Left _
+                             → return () -- 不正な時刻は無視
+           Nothing  → return ()
 
          -- If-Unmodified-Since があればそれを見る。
-         ifUnmodSince <- getHeader (C8.pack "If-Unmodified-Since")
+         ifUnmodSince ← getHeader "If-Unmodified-Since"
          case ifUnmodSince of
-           Just str -> case HTTP.parse (C8.unpack str) of
-                         Just lastTime
-                             -> when (timeStamp > lastTime)
-                                $ abort PreconditionFailed []
-                                      $! Just  ("The entity has not been modified since " ++ C8.unpack str)
-                         Nothing
-                             -> return () -- 不正な時刻は無視
-           Nothing  -> return ()
+           Just str → case HTTP.fromAscii str of
+                         Right lastTime
+                             → when (timeStamp > lastTime)
+                               $ abort PreconditionFailed []
+                                 (Just $ "The entity has not been modified since " ⊕ A.toText str)
+                         Left _
+                             → return () -- 不正な時刻は無視
+           Nothing  → return ()
 
          driftTo GettingBody
 
@@ -559,20 +569,19 @@ foundTimeStamp timeStamp
 -- test and aborts with status \"412 Precondition Failed\" when it
 -- failed. If this is a GET, HEAD, POST or DELETE request,
 -- 'foundNoEntity' always aborts with status \"404 Not Found\".
-foundNoEntity :: Maybe String -> Resource ()
+foundNoEntity ∷ Maybe Text → Resource ()
 foundNoEntity msgM
-    = msgM `seq`
-      do driftTo ExaminingRequest
+    = do driftTo ExaminingRequest
 
-         method <- getMethod
-         when (method /= PUT)
-                  $ abort NotFound [] msgM
+         method ← getMethod
+         when (method ≢ PUT)
+             $ abort NotFound [] msgM
 
          -- エンティティが存在しないと云ふ事は、"*" も含めたどのやうな
          -- If-Match: 條件も滿たさない。
-         ifMatch <- getHeader (C8.pack "If-Match")
-         when (ifMatch /= Nothing)
-                  $ abort PreconditionFailed [] msgM
+         ifMatch ← getHeader "If-Match"
+         when (ifMatch ≢ Nothing)
+             $ abort PreconditionFailed [] msgM
 
          driftTo GettingBody
 
@@ -587,82 +596,68 @@ foundNoEntity msgM
 -- no body, 'input' returns an empty string.
 --
 -- @limit@ may be less than or equal to zero. In this case, the
--- default limitation value
--- ('Network.HTTP.Lucu.Config.cnfMaxEntityLength') is used. See
+-- default limitation value ('cnfMaxEntityLength') is used. See
 -- 'defaultLimit'.
 --
--- Note that 'inputLBS' is more efficient than 'input' so you should
--- use it whenever possible.
-input :: Int -> Resource String
-input limit = limit `seq`
-              inputLBS limit >>= return . L8.unpack
-
-
--- | This is mostly the same as 'input' but is more
--- efficient. 'inputLBS' returns a 'Data.ByteString.Lazy.ByteString'
--- but it's not really lazy: reading from the socket just happens at
--- the computation of 'inputLBS', not at the evaluation of the
--- 'Data.ByteString.Lazy.ByteString'. The same goes for
--- 'inputChunkLBS'.
-inputLBS :: Int -> Resource Lazy.ByteString
-inputLBS limit
-    = limit `seq`
-      do driftTo GettingBody
-         itr     <- getInteraction
-         hasBody <- liftIO $! atomically $! readItr itr itrRequestHasBody id
-         chunk   <- if hasBody then
-                        askForInput itr
-                    else
-                        do driftTo DecidingHeader
-                           return L8.empty
+-- 'input' returns a 'Lazy.ByteString' but it's not really lazy:
+-- reading from the socket just happens at the computation of 'input',
+-- not at the evaluation of the 'Lazy.ByteString'. The same goes for
+-- 'inputChunk'.
+input ∷ Int → Resource Lazy.ByteString
+input limit
+    = do driftTo GettingBody
+         itr     ← getInteraction
+         hasBody ← liftIO $ atomically $ readItr itrRequestHasBody id itr
+         chunk   ← if hasBody then
+                       askForInput itr
+                   else
+                       do driftTo DecidingHeader
+                          return L8.empty
          return chunk
     where
-      askForInput :: Interaction -> Resource Lazy.ByteString
+      askForInput ∷ Interaction → Resource Lazy.ByteString
       askForInput itr
-          = itr `seq`
-            do let confLimit   = cnfMaxEntityLength $ itrConfig itr
-                   actualLimit = if limit <= 0 then
+          = do let confLimit   = cnfMaxEntityLength $ itrConfig itr
+                   actualLimit = if limit ≤ 0 then
                                      confLimit
                                  else
                                      limit
-               when (actualLimit <= 0)
-                        $ fail ("inputLBS: limit must be positive: " ++ show actualLimit)
+               when (actualLimit ≤ 0)
+                        $ fail ("inputLBS: limit must be positive: " ⧺ show actualLimit)
                -- Reader にリクエスト
-               liftIO $! atomically
-                          $! do chunkLen <- readItr itr itrReqChunkLength id
-                                writeItr itr itrWillReceiveBody True
-                                if fmap (> actualLimit) chunkLen == Just True then
-                                    -- 受信前から多過ぎる事が分かってゐる
-                                    tooLarge actualLimit
-                                  else
-                                    writeItr itr itrReqBodyWanted $ Just actualLimit
-               -- 應答を待つ。トランザクションを分けなければ當然デッドロック。
-               chunk <- liftIO $! atomically
-                        $! do chunk       <- readItr itr itrReceivedBody id
-                              chunkIsOver <- readItr itr itrReqChunkIsOver id
-                              if L8.length chunk < fromIntegral actualLimit then
-                                  -- 要求された量に滿たなくて、まだ殘り
-                                  -- があるなら再試行。
-                                  unless chunkIsOver
-                                             $ retry
-                                else
-                                  -- 制限値一杯まで讀むやうに指示したの
-                                  -- にまだ殘ってゐるなら、それは多過ぎ
-                                  -- る。
-                                  unless chunkIsOver
-                                             $ tooLarge actualLimit
-                              -- 成功。itr 内にチャンクを置いたままにす
-                              -- るとメモリの無駄になるので除去。
-                              writeItr itr itrReceivedBody L8.empty
-                              return chunk
+               liftIO $ atomically
+                      $ do chunkLen ← readItr itrReqChunkLength id itr
+                           writeItr itrWillReceiveBody True itr
+                           if fmap (> actualLimit) chunkLen ≡ Just True then
+                               -- 受信前から多過ぎる事が分かってゐる
+                               tooLarge actualLimit
+                           else
+                               writeItr itrReqBodyWanted (Just actualLimit) itr
+               -- 應答を待つ。トランザクションを分けなければ當然デッドロックする。
+               chunk ← liftIO $ atomically
+                       $ do chunk       ← readItr itrReceivedBody chunksToLBS itr
+                            chunkIsOver ← readItr itrReqChunkIsOver id itr
+                            if L8.length chunk < fromIntegral actualLimit then
+                                -- 要求された量に滿たなくて、まだ殘りが
+                                -- あるなら再試行。
+                                unless chunkIsOver
+                                    $ retry
+                            else
+                                -- 制限値一杯まで讀むやうに指示したのに
+                                -- まだ殘ってゐるなら、それは多過ぎる。
+                                unless chunkIsOver
+                                    $ tooLarge actualLimit
+                            -- 成功。itr 内にチャンクを置いたままにする
+                            -- とメモリの無駄になるので除去。
+                            writeItr itrReceivedBody (∅) itr
+                            return chunk
                driftTo DecidingHeader
                return chunk
 
-      tooLarge :: Int -> STM ()
-      tooLarge lim = lim `seq`
-                     abortSTM RequestEntityTooLarge []
-                     $! Just ("Request body must be smaller than "
-                              ++ show lim ++ " bytes.")
+      tooLarge ∷ Int → STM ()
+      tooLarge lim = abortSTM RequestEntityTooLarge []
+                     (Just $ "Request body must be smaller than "
+                             ⊕ T.pack (show lim) ⊕ " bytes.")
          
 -- | Computation of @'inputChunk' limit@ attempts to read a part of
 -- request body up to @limit@ bytes. You can read any large request by
@@ -671,36 +666,26 @@ inputLBS limit
 -- the 'Resource' transit to /Deciding Header/ state.
 --
 -- @limit@ may be less than or equal to zero. In this case, the
--- default limitation value
--- ('Network.HTTP.Lucu.Config.cnfMaxEntityLength') is used. See
+-- default limitation value ('cnfMaxEntityLength') is used. See
 -- 'defaultLimit'.
 --
 -- Note that 'inputChunkLBS' is more efficient than 'inputChunk' so you
 -- should use it whenever possible.
-inputChunk :: Int -> Resource String
-inputChunk limit = limit `seq`
-                   inputChunkLBS limit >>= return . L8.unpack
-
-
--- | This is mostly the same as 'inputChunk' but is more
--- efficient. See 'inputLBS'.
-inputChunkLBS :: Int -> Resource Lazy.ByteString
-inputChunkLBS limit
-    = limit `seq`
-      do driftTo GettingBody
-         itr     <- getInteraction
-         hasBody <- liftIO $ atomically $ readItr itr itrRequestHasBody id
-         chunk   <- if hasBody then
+inputChunk ∷ Int → Resource Lazy.ByteString
+inputChunk limit
+    = do driftTo GettingBody
+         itr     ← getInteraction
+         hasBody ← liftIO $ atomically $ readItr itrRequestHasBody id itr
+         chunk   ← if hasBody then
                         askForInput itr
                     else
                         do driftTo DecidingHeader
                            return L8.empty
          return chunk
     where
-      askForInput :: Interaction -> Resource Lazy.ByteString
+      askForInput ∷ Interaction → Resource Lazy.ByteString
       askForInput itr
-          = itr `seq`
-            do let confLimit   = cnfMaxEntityLength $! itrConfig itr
+          = do let confLimit   = cnfMaxEntityLength $ itrConfig itr
                    actualLimit = if limit < 0 then
                                       confLimit
                                   else
@@ -708,23 +693,23 @@ inputChunkLBS limit
                when (actualLimit <= 0)
                         $ fail ("inputChunkLBS: limit must be positive: " ++ show actualLimit)
                -- Reader にリクエスト
-               liftIO $! atomically
-                          $! do writeItr itr itrReqBodyWanted $! Just actualLimit
-                                writeItr itr itrWillReceiveBody True
+               liftIO $ atomically
+                          $ do writeItr itrReqBodyWanted (Just actualLimit) itr
+                               writeItr itrWillReceiveBody True itr
                -- 應答を待つ。トランザクションを分けなければ當然デッドロック。
-               chunk <- liftIO $! atomically
-                        $ do chunk <- readItr itr itrReceivedBody id
+               chunk ← liftIO $ atomically
+                        $ do chunk ← readItr itrReceivedBody chunksToLBS itr
                              -- 要求された量に滿たなくて、まだ殘りがあ
                              -- るなら再試行。
                              when (L8.length chunk < fromIntegral actualLimit)
-                                      $ do chunkIsOver <- readItr itr itrReqChunkIsOver id
+                                      $ do chunkIsOver ← readItr itrReqChunkIsOver id itr
                                            unless chunkIsOver
-                                                      $ retry
+                                               $ retry
                              -- 成功
-                             writeItr itr itrReceivedBody L8.empty
+                             writeItr itrReceivedBody (∅) itr
                              return chunk
                when (L8.null chunk)
-                        $ driftTo DecidingHeader
+                   $ driftTo DecidingHeader
                return chunk
 
 -- | Computation of @'inputForm' limit@ attempts to read the request
@@ -734,57 +719,69 @@ inputChunkLBS limit
 -- makes 'Resource' abort with status \"415 Unsupported Media
 -- Type\". If the request has no \"Content-Type\", it aborts with
 -- \"400 Bad Request\".
-inputForm :: Int -> Resource [(String, FormData)]
+inputForm ∷ Int → Resource [(Text, FormData)]
 inputForm limit
-    = limit `seq` 
-      do cTypeM <- getContentType
+    = do cTypeM ← getContentType
          case cTypeM of
            Nothing
-               -> abort BadRequest [] (Just "Missing Content-Type")
+               → abort BadRequest [] (Just "Missing Content-Type")
            Just (MIMEType "application" "x-www-form-urlencoded" _)
-               -> readWWWFormURLEncoded
+               → readWWWFormURLEncoded
            Just (MIMEType "multipart" "form-data" params)
-               -> readMultipartFormData params
+               → readMultipartFormData params
            Just cType
-               -> abort UnsupportedMediaType [] (Just $! "Unsupported media type: "
-                                                          ++ show cType)
+               → abort UnsupportedMediaType []
+                 (Just $ "Unsupported media type: " ⊕ A.toText (printMIMEType cType))
     where
       readWWWFormURLEncoded
-          = liftM (map toPairWithFormData . parseWWWFormURLEncoded) (input limit)
+          = (map toPairWithFormData ∘ parseWWWFormURLEncoded)
+            <$>
+            (bsToAscii =≪ input limit)
+
+      bsToAscii bs
+          = case A.fromByteString (C8.concat (L8.toChunks bs)) of
+              Just a  → return a
+              Nothing → abort BadRequest [] (Just "Malformed x-www-form-urlencoded")
 
       readMultipartFormData params
-          = do case find ((== "boundary") . map toLower . fst) params of
+          = do case M.lookup "boundary" params of
                  Nothing
-                     -> abort BadRequest [] (Just "Missing boundary of multipart/form-data")
-                 Just (_, boundary)
-                     -> do src <- inputLBS limit
-                           case parse (multipartFormP boundary) src of
-                             (# Success formList, _ #)
-                                 -> return formList
-                             (# _, _ #)
-                                 -> abort BadRequest [] (Just "Unparsable multipart/form-data")
+                     → abort BadRequest [] (Just "Missing boundary of multipart/form-data")
+                 Just boundary
+                     → do src ← input limit
+                          b   ← case A.fromText boundary of
+                                   Just b  → return b
+                                   Nothing → abort BadRequest []
+                                             (Just $ "Malformed boundary: " ⊕ boundary)
+                          case LP.parse (p b) src of
+                            LP.Done _ formList
+                                → return formList
+                            _   → abort BadRequest [] (Just "Unparsable multipart/form-data")
+          where
+            p b = do xs ← multipartFormP b
+                     P.endOfInput
+                     return xs
 
 -- | This is just a constant @-1@. It's better to say @'input'
 -- 'defaultLimit'@ than to say @'input' (-1)@ but these are exactly
 -- the same.
-defaultLimit :: Int
+defaultLimit ∷ Int
 defaultLimit = (-1)
 
 
-
 {- DecidingHeader 時に使用するアクション群 -}
 
 -- | Set the response status code. If you omit to compute this action,
 -- the status code will be defaulted to \"200 OK\".
-setStatus :: StatusCode -> Resource ()
+setStatus ∷ StatusCode → Resource ()
 setStatus code
-    = code `seq`
-      do driftTo DecidingHeader
-         itr <- getInteraction
-         liftIO $! atomically $! updateItr itr itrResponse
-                    $! \ res -> res {
-                                  resStatus = code
-                                }
+    = do driftTo DecidingHeader
+         itr ← getInteraction
+         liftIO $ atomically $ updateItr itrResponse f itr
+    where
+      f res = res {
+                resStatus = code
+              }
 
 -- | Set a value of given resource header. Comparison of header name
 -- is case-insensitive. Note that this action is not intended to be
@@ -800,62 +797,64 @@ setStatus code
 -- 20 bytes long. In this case the client shall only accept the first
 -- 10 bytes of response body and thinks that the residual 10 bytes is
 -- a part of header of the next response.
-setHeader :: Strict.ByteString -> Strict.ByteString -> Resource ()
+setHeader ∷ CIAscii → Ascii → Resource ()
 setHeader name value
-    = name `seq` value `seq`
-      driftTo DecidingHeader >> setHeader' name value
-         
+    = driftTo DecidingHeader ≫ setHeader' name value
 
-setHeader' :: Strict.ByteString -> Strict.ByteString -> Resource ()
+setHeader' ∷ CIAscii → Ascii → Resource ()
 setHeader' name value
-    = name `seq` value `seq`
-      do itr <- getInteraction
+    = do itr ← getInteraction
          liftIO $ atomically
-                    $ updateItr itr itrResponse
-                          $ H.setHeader name value
+                $ updateItr itrResponse (H.setHeader name value) itr
 
 -- | Computation of @'redirect' code uri@ sets the response status to
 -- @code@ and \"Location\" header to @uri@. The @code@ must satisfy
--- 'Network.HTTP.Lucu.Response.isRedirection' or it causes an error.
-redirect :: StatusCode -> URI -> Resource ()
+-- 'isRedirection' or it causes an error.
+redirect ∷ StatusCode → URI → Resource ()
 redirect code uri
-    = code `seq` uri `seq`
-      do when (code == NotModified || not (isRedirection code))
-                  $ abort InternalServerError []
-                        $! Just ("Attempted to redirect with status " ++ show code)
+    = do when (code ≡ NotModified ∨ not (isRedirection code))
+             $ abort InternalServerError []
+               (Just $ "Attempted to redirect with status " ⊕ A.toText (printStatusCode code))
          setStatus code
          setLocation uri
-{-# INLINE redirect #-}
-
 
 -- | Computation of @'setContentType' mType@ sets the response header
 -- \"Content-Type\" to @mType@.
-setContentType :: MIMEType -> Resource ()
+setContentType ∷ MIMEType → Resource ()
 setContentType mType
-    = setHeader (C8.pack "Content-Type") (C8.pack $ show mType)
+    = setHeader "Content-Type" (printMIMEType mType)
 
 -- | Computation of @'setLocation' uri@ sets the response header
 -- \"Location\" to @uri@.
-setLocation :: URI -> Resource ()
+setLocation ∷ URI → Resource ()
 setLocation uri
-    = setHeader (C8.pack "Location") (C8.pack $ uriToString id uri $ "")
+    = case A.fromChars uriStr of
+        Just a  → setHeader "Location" a
+        Nothing → abort InternalServerError []
+                  (Just $ "Malformed URI: " ⊕ T.pack uriStr)
+    where
+      uriStr = uriToString id uri ""
 
 -- |Computation of @'setContentEncoding' codings@ sets the response
 -- header \"Content-Encoding\" to @codings@.
-setContentEncoding :: [String] -> Resource ()
+setContentEncoding ∷ [CIAscii] → Resource ()
 setContentEncoding codings
-    = do ver <- getRequestVersion
-         let tr = case ver of
-                    HttpVersion 1 0 -> unnormalizeCoding
-                    HttpVersion 1 1 -> id
-                    _               -> undefined
-         setHeader (C8.pack "Content-Encoding") (C8.pack $ joinWith ", " $ map tr codings)
+    = do ver ← getRequestVersion
+         tr  ← case ver of
+                  HttpVersion 1 0 → return (toAB ∘ unnormalizeCoding)
+                  HttpVersion 1 1 → return toAB
+                  _               → abort InternalServerError []
+                                    (Just "setContentEncoding: Unknown HTTP version")
+         setHeader "Content-Encoding"
+                   (A.fromAsciiBuilder $ joinWith ", " $ map tr codings)
+    where
+      toAB = A.toAsciiBuilder ∘ A.fromCIAscii
 
 -- |Computation of @'setWWWAuthenticate' challenge@ sets the response
 -- header \"WWW-Authenticate\" to @challenge@.
-setWWWAuthenticate :: AuthChallenge -> Resource ()
+setWWWAuthenticate ∷ AuthChallenge → Resource ()
 setWWWAuthenticate challenge
-    = setHeader (C8.pack "WWW-Authenticate") (C8.pack $ show challenge)
+    = setHeader "WWW-Authenticate" (printAuthChallenge challenge)
 
 
 {- DecidingBody 時に使用するアクション群 -}
@@ -864,70 +863,53 @@ setWWWAuthenticate challenge
 -- and then make the 'Resource' transit to /Done/ state. It is safe to
 -- apply 'output' to an infinite string, such as a lazy stream of
 -- \/dev\/random.
---
--- Note that 'outputLBS' is more efficient than 'output' so you should
--- use it whenever possible.
-output :: String -> Resource ()
-output str = outputLBS $! L8.pack str
+output ∷ Lazy.ByteString → Resource ()
 {-# INLINE output #-}
-
--- | This is mostly the same as 'output' but is more efficient.
-outputLBS :: Lazy.ByteString -> Resource ()
-outputLBS str = do outputChunkLBS str
-                   driftTo Done
-{-# INLINE outputLBS #-}
+output str = do outputChunk str
+                driftTo Done
 
 -- | Computation of @'outputChunk' str@ writes @str@ as a part of
 -- response body. You can compute this action multiple times to write
 -- a body little at a time. It is safe to apply 'outputChunk' to an
 -- infinite string.
---
--- Note that 'outputChunkLBS' is more efficient than 'outputChunk' so
--- you should use it whenever possible.
-outputChunk :: String -> Resource ()
-outputChunk str = outputChunkLBS $! L8.pack str
-{-# INLINE outputChunk #-}
-
--- | This is mostly the same as 'outputChunk' but is more efficient.
-outputChunkLBS :: Lazy.ByteString -> Resource ()
-outputChunkLBS wholeChunk
-    = wholeChunk `seq`
-      do driftTo DecidingBody
-         itr <- getInteraction
+outputChunk ∷ Lazy.ByteString → Resource ()
+outputChunk wholeChunk
+    = do driftTo DecidingBody
+         itr ← getInteraction
          
          let limit = cnfMaxOutputChunkLength $ itrConfig itr
-         when (limit <= 0)
-                  $ fail ("cnfMaxOutputChunkLength must be positive: "
-                          ++ show limit)
+         when (limit ≤ 0)
+             $ abort InternalServerError []
+               (Just $ "cnfMaxOutputChunkLength must be positive: " ⊕ T.pack (show limit))
 
-         discardBody <- liftIO $ atomically $
-                        readItr itr itrWillDiscardBody id
+         discardBody ← liftIO $ atomically $
+                       readItr itrWillDiscardBody id itr
 
          unless (discardBody)
-                    $ sendChunks wholeChunk limit
+             $ sendChunks wholeChunk limit
 
          unless (L8.null wholeChunk)
-                    $ liftIO $ atomically $
-                      writeItr itr itrBodyIsNull False
+             $ liftIO $ atomically $
+               writeItr itrBodyIsNull False itr
     where
       -- チャンクの大きさは Config で制限されてゐる。もし例へば
       -- "/dev/zero" を L8.readFile して作った Lazy.ByteString をそのまま
       -- ResponseWriter に渡したりすると大變な事が起こる。何故なら
       -- ResponseWriter は Transfer-Encoding: chunked の時、ヘッダを書
-      -- く爲にチャンクの大きさを測る。
-      sendChunks :: Lazy.ByteString -> Int -> Resource ()
+      -- く爲にチャンクの大きさを測るからだ。
+      sendChunks ∷ Lazy.ByteString → Int → Resource ()
       sendChunks str limit
           | L8.null str = return ()
           | otherwise   = do let (chunk, remaining) = L8.splitAt (fromIntegral limit) str
-                             itr <- getInteraction
+                             itr ← getInteraction
                              liftIO $ atomically $ 
-                                    do buf <- readItr itr itrBodyToSend id
-                                       if L8.null buf then
-                                           -- バッファが消化された
-                                           writeItr itr itrBodyToSend chunk
-                                         else
-                                           -- 消化されるのを待つ
-                                           retry
+                                 do buf ← readItr itrBodyToSend id itr
+                                    if S.null buf then
+                                        -- バッファが消化された
+                                        writeItr itrBodyToSend (chunksFromLBS chunk) itr
+                                    else
+                                        -- 消化されるのを待つ
+                                        retry
                              -- 殘りのチャンクについて繰り返す
                              sendChunks remaining limit
 
@@ -950,11 +932,10 @@ outputChunkLBS wholeChunk
 
 -}
 
-driftTo :: InteractionState -> Resource ()
+driftTo ∷ InteractionState → Resource ()
 driftTo newState
-    = newState `seq`
-      do itr <- getInteraction
-         liftIO $ atomically $ do oldState <- readItr itr itrState id
+    = do itr ← getInteraction
+         liftIO $ atomically $ do oldState ← readItr itrState id itr
                                   if newState < oldState then
                                       throwStateError oldState newState
                                     else
@@ -962,27 +943,27 @@ driftTo newState
                                              b = tail a
                                              c = zip a b
                                          mapM_ (uncurry $ drift itr) c
-                                         writeItr itr itrState newState
+                                         writeItr itrState newState itr
     where
-      throwStateError :: Monad m => InteractionState -> InteractionState -> m a
+      throwStateError ∷ Monad m => InteractionState → InteractionState → m a
 
       throwStateError Done DecidingBody
           = fail "It makes no sense to output something after finishing to output."
 
       throwStateError old new
-          = fail ("state error: " ++ show old ++ " ==> " ++ show new)
+          = fail ("state error: " ⧺ show old ⧺ " ==> " ⧺ show new)
 
 
-      drift :: Interaction -> InteractionState -> InteractionState -> STM ()
+      drift ∷ Interaction → InteractionState → InteractionState → STM ()
 
       drift itr GettingBody _
-          = writeItr itr itrReqBodyWasteAll True
+          = writeItr itrReqBodyWasteAll True itr
 
       drift itr DecidingHeader _
           = postprocess itr
 
       drift itr _ Done
-          = do bodyIsNull <- readItr itr itrBodyIsNull id
+          = do bodyIsNull ← readItr itrBodyIsNull id itr
                when bodyIsNull
                         $ writeDefaultPage itr