Use data-default to provide fafault parsers; remove proxies.

[time-http.git] / Data / Time / Format / C.hs

diff --git a/Data/Time/Format/C.hs b/Data/Time/Format/C.hs
index 0c204d5d387177c01e51023dca6e5723e4f48441..ba9fee881198afd04aba614238ec38da983daf61 100644 (file)
--- a/Data/Time/Format/C.hs
+++ b/Data/Time/Format/C.hs
@@ -3,6 +3,7 @@
   , MultiParamTypeClasses
   , OverloadedStrings
   , TemplateHaskell
+  , TypeSynonymInstances
   , UnicodeSyntax
   #-}
 -- |This module provides functions for ANSI C's date and time strings.
@@ -24,17 +25,14 @@
 -- > year      ::= 4DIGIT
 module Data.Time.Format.C
     ( C
-    , c
-    , cDateAndTime
     )
     where
-import Control.Applicative
 import Data.Ascii (Ascii, AsciiBuilder)
 import qualified Data.Ascii as A
 import Data.Attoparsec.Char8
 import Data.Convertible.Base
+import Data.Default
 import Data.Monoid.Unicode
-import Data.Proxy
 import Data.Tagged
 import Data.Time
 import Data.Time.Calendar.WeekDate
@@ -44,50 +42,44 @@ import Prelude.Unicode
 -- |The phantom type for conversions between ANSI C's date and time
 -- strings and 'LocalTime'.
 --
--- >>> convertSuccess (LocalTime (ModifiedJulianDay 49662) (TimeOfDay 8 49 37))
--- Tagged "Sun Nov  6 08:49:37 1994"
+-- >>> convertSuccess (Tagged (LocalTime (ModifiedJulianDay 49662) (TimeOfDay 8 49 37)) :: Tagged C LocalTime)
+-- "Sun Nov  6 08:49:37 1994"
 data C
 
--- |The proxy for conversions between ANSI C's date and time strings
--- and 'LocalTime'.
-c ∷ Proxy C
-{-# INLINE CONLIKE c #-}
-c = Proxy
-
-instance ConvertSuccess LocalTime (Tagged C Ascii) where
+instance ConvertSuccess (Tagged C LocalTime) Ascii where
     {-# INLINE convertSuccess #-}
-    convertSuccess = (A.fromAsciiBuilder <$>) ∘ cs
+    convertSuccess = A.fromAsciiBuilder ∘ cs
 
-instance ConvertSuccess LocalTime (Tagged C AsciiBuilder) where
+instance ConvertSuccess (Tagged C LocalTime) AsciiBuilder where
     {-# INLINE convertSuccess #-}
-    convertSuccess = Tagged ∘ toAsciiBuilder
+    convertSuccess = toAsciiBuilder ∘ untag
 
-instance ConvertAttempt (Tagged C Ascii) LocalTime where
+instance ConvertAttempt Ascii (Tagged C LocalTime) where
     {-# INLINE convertAttempt #-}
-    convertAttempt = parseAttempt' cDateAndTime ∘ untag
+    convertAttempt = parseAttempt' def
 
 -- |Parse an ANSI C's date and time string.
-cDateAndTime ∷ Parser LocalTime
-cDateAndTime
-    = do weekDay ← shortWeekDayNameP
-         _       ← char ' '
-         month   ← shortMonthNameP
-         _       ← char ' '
-         day     ← read2'
-         _       ← char ' '
-         hour    ← read2
-         _       ← char ':'
-         minute  ← read2
-         _       ← char ':'
-         second  ← read2
-         _       ← char ' '
-         year    ← read4
+instance Default (Parser (Tagged C LocalTime)) where
+    {-# INLINEABLE def #-}
+    def = do weekDay ← shortWeekDayNameP
+             _       ← char ' '
+             month   ← shortMonthNameP
+             _       ← char ' '
+             day     ← read2'
+             _       ← char ' '
+             hour    ← read2
+             _       ← char ':'
+             minute  ← read2
+             _       ← char ':'
+             second  ← read2
+             _       ← char ' '
+             year    ← read4
 
-         gregDay ← assertGregorianDateIsGood year month day
-         _       ← assertWeekDayIsGood weekDay gregDay
-         tod     ← assertTimeOfDayIsGood hour minute second
+             gregDay ← assertGregorianDateIsGood year month day
+             _       ← assertWeekDayIsGood weekDay gregDay
+             tod     ← assertTimeOfDayIsGood hour minute second
 
-         return (LocalTime gregDay tod)
+             return ∘ Tagged $ LocalTime gregDay tod
 
 toAsciiBuilder ∷ LocalTime → AsciiBuilder
 toAsciiBuilder localTime
@@ -109,6 +101,6 @@ toAsciiBuilder localTime
         ⊕ A.toAsciiBuilder " "
         ⊕ show4 year
 
-deriveAttempts [ ([t| LocalTime |], [t| Tagged C Ascii        |])
-               , ([t| LocalTime |], [t| Tagged C AsciiBuilder |])
+deriveAttempts [ ([t| Tagged C LocalTime |], [t| Ascii        |])
+               , ([t| Tagged C LocalTime |], [t| AsciiBuilder |])
                ]