From 50a37a0b36af70046b57472d314195bd8d99fed8 Mon Sep 17 00:00:00 2001
From: PHO <pho@cielonegro.org>
Date: Sun, 31 Jul 2011 13:29:27 +0900
Subject: [PATCH] ETag

Ditz-issue: 8959dadc07db1bd363283dee401073f6e48dc7fa
---
 Network/HTTP/Lucu/ETag.hs | 60 ++++++++++++++++++++++++---------------
 1 file changed, 37 insertions(+), 23 deletions(-)

diff --git a/Network/HTTP/Lucu/ETag.hs b/Network/HTTP/Lucu/ETag.hs
index 41e99f8..056f14f 100644
--- a/Network/HTTP/Lucu/ETag.hs
+++ b/Network/HTTP/Lucu/ETag.hs
@@ -1,8 +1,15 @@
+{-# LANGUAGE
+    OverloadedStrings
+  , UnicodeSyntax
+  #-}
 {-# OPTIONS_HADDOCK prune #-}
 
 -- |Manipulation of entity tags.
 module Network.HTTP.Lucu.ETag
     ( ETag(..)
+
+    , printETag
+
     , strongETag
     , weakETag
     , eTagP
@@ -10,6 +17,11 @@ module Network.HTTP.Lucu.ETag
     )
     where
 import Control.Monad
+import Control.Monad.Unicode
+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
 
@@ -17,40 +29,42 @@ import Network.HTTP.Lucu.Utils
 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)
+    , etagToken  ∷ !Ascii
+    } deriving (Eq, Show)
 
-instance Show ETag where
-    show (ETag isWeak token) = (if isWeak then
-                                    "W/"
-                                else
-                                    "")
-                               ++
-                               quoteStr token
+-- |Convert an 'ETag' to 'Ascii'.
+printETag ∷ ETag → Ascii
+printETag et
+    = A.fromAsciiBuilder $
+      ( ( if etagIsWeak et then
+              A.toAsciiBuilder "W/"
+          else
+              (∅)
+        )
+        ⊕
+        quoteStr (etagToken et) )
 
 -- |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 equivalent to @'ETag' 'Prelude.True'@.
-weakETag :: String -> ETag
+weakETag ∷ Ascii → ETag
 weakETag = ETag True
 
-
-eTagP :: Parser ETag
-eTagP = do isWeak <- option False (string "W/" >> return True)
-           str    <- quotedStr
+eTagP ∷ Parser ETag
+eTagP = try $
+        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
-- 
2.40.0