X-Git-Url: http://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Network%2FHTTP%2FLucu%2FETag.hs;h=7e618782c45e17e75ec16ef8667510447c518a20;hb=ea2b7838f1b3d9d4923a220a601be2e04cc559d7;hp=bdb1473786a001fa016f9e4b8440892c5220060f;hpb=175e14b3b144537644e65ca76f1fca5c56fd44e9;p=Lucu.git

diff --git a/Network/HTTP/Lucu/ETag.hs b/Network/HTTP/Lucu/ETag.hs
index bdb1473..7e61878 100644
--- a/Network/HTTP/Lucu/ETag.hs
+++ b/Network/HTTP/Lucu/ETag.hs
@@ -1,58 +1,81 @@
--- #prune
-
+{-# LANGUAGE
+    OverloadedStrings
+  , UnicodeSyntax
+  #-}
 -- |Manipulation of entity tags.
 module Network.HTTP.Lucu.ETag
     ( ETag(..)
+    , parseETag
+    , printETag
+
     , strongETag
     , weakETag
     , eTagP
     , eTagListP
     )
     where
-
-import           Control.Monad
-import           Network.HTTP.Lucu.Parser
-import           Network.HTTP.Lucu.Parser.Http
-import           Network.HTTP.Lucu.Utils
+import Control.Applicative
+import Control.Monad
+import Data.Ascii (Ascii)
+import qualified Data.Ascii as A
+import Data.Attoparsec.Char8
+import Data.Monoid.Unicode
+import Network.HTTP.Lucu.Parser.Http hiding (token)
+import Network.HTTP.Lucu.Utils
+import Prelude.Unicode
 
 -- |An entity tag is made of a weakness flag and a opaque string.
 data ETag = ETag {
       -- |The weakness flag. Weak tags looks like W\/\"blahblah\" and
       -- strong tags are like \"blahblah\".
-      etagIsWeak :: Bool
+      etagIsWeak ∷ !Bool
       -- |An opaque string. Only characters from 0x20 (sp) to 0x7e (~)
       -- are allowed.
-    , etagToken  :: String
-    } deriving (Eq)
-
-instance Show ETag where
-    show (ETag isWeak token) = (if isWeak then
-                                    "W/"
-                                else
-                                    "")
-                               ++
-                               quoteStr token
-
--- |This is an equivalent to @'ETag' False@. If you want to generate
--- an ETag from a file, try using
+    , etagToken  ∷ !Ascii
+    } deriving (Eq, Show)
+
+-- |Convert an 'ETag' to 'Ascii'.
+printETag ∷ ETag → Ascii
+printETag et
+    = A.fromAsciiBuilder $
+      ( ( if etagIsWeak et then
+              A.toAsciiBuilder "W/"
+          else
+              (∅)
+        )
+        ⊕
+        quoteStr (etagToken et) )
+
+-- |Parse 'Etag' from an 'Ascii'. This functions throws an exception
+-- for parse error.
+parseETag ∷ Ascii → ETag
+parseETag str
+    = let p  = do et ← eTagP
+                  endOfInput
+                  return et
+          bs = A.toByteString str
+      in
+        case parseOnly p bs of
+          Right et → et
+          Left err → error ("unparsable ETag: " ⧺ A.toString str ⧺ ": " ⧺ err)
+
+-- |This is equivalent to @'ETag' 'Prelude.False'@. If you want to
+-- generate an ETag from a file, try using
 -- 'Network.HTTP.Lucu.StaticFile.generateETagFromFile'.
-strongETag :: String -> ETag
+strongETag ∷ Ascii → ETag
 strongETag = ETag False
 
--- |This is an equivalent to @'ETag' True@.
-weakETag :: String -> ETag
+-- |This is equivalent to @'ETag' 'Prelude.True'@.
+weakETag ∷ Ascii → ETag
 weakETag = ETag True
 
-
-eTagP :: Parser ETag
-eTagP = do isWeak <- option False (string "W/" >> return True)
-           str    <- quotedStr
+eTagP ∷ Parser ETag
+eTagP = do isWeak ← option False (string "W/" *> return True)
+           str    ← quotedStr
            return $ ETag isWeak str
 
-
-eTagListP :: Parser [ETag]
-eTagListP = allowEOF
-            $ do xs <- listOf eTagP
-                 when (null xs)
-                          $ fail ""
-                 return xs
+eTagListP ∷ Parser [ETag]
+eTagListP = do xs ← listOf eTagP
+               when (null xs) $
+                   fail "empty list of ETags"
+               return xs