+{-# LANGUAGE
+ FlexibleInstances
+ , MultiParamTypeClasses
+ , OverloadedStrings
+ , TemplateHaskell
+ , UnicodeSyntax
+ #-}
+-- |This module provides functions to parse and format RFC 822 date
+-- and time formats.
+--
+-- The syntax is as follows:
+--
+-- > date-time ::= [ day-of-week ", " ] date SP time SP zone
+-- > day-of-week ::= "Mon" | "Tue" | "Wed" | "Thu"
+-- > | "Fri" | "Sat" | "Sun"
+-- > date ::= day SP month SP year
+-- > day ::= 2DIGIT
+-- > year ::= 2DIGIT ; Yes, only 2 digits.
+-- > month ::= "Jan" | "Feb" | "Mar" | "Apr"
+-- > | "May" | "Jun" | "Jul" | "Aug"
+-- > | "Sep" | "Oct" | "Nov" | "Dec"
+-- > time ::= hour ":" minute [ ":" second ]
+-- > hour ::= 2DIGIT
+-- > minute ::= 2DIGIT
+-- > second ::= 2DIGIT
+-- > zone ::= "UT" | "GMT" ; Universal Time
+-- > | "EST" | "EDT" ; Eastern : -5 / -4
+-- > | "CST" | "CDT" ; Central : -6 / -5
+-- > | "MST" | "MDT" ; Mountain: -7 / -6
+-- > | "PST" | "PDT" ; Pacific : -8 / -7
+-- > | "Z" ; UT
+-- > | "A" ; -1
+-- > | "M" ; -12
+-- > | "N" ; +1
+-- > | "Y" ; +12
+-- > | ("+" | "-") 4DIGIT ; Local diff: HHMM
module Data.Time.RFC822
- ( format
- , parse
+ ( RFC822
+ , rfc822DateAndTime
+ , rfc822Time
)
where
-
-import qualified Text.Parsec as P
-
+import Control.Applicative
+import Data.Ascii (Ascii, AsciiBuilder)
+import qualified Data.Ascii as A
+import Data.Attoparsec.Char8
+import Data.Convertible.Base
+import Data.Monoid.Unicode
+import Data.Tagged
import Data.Time
import Data.Time.Calendar.WeekDate
import Data.Time.HTTP.Common
-import Data.Time.RFC822.Parsec
+import Prelude.Unicode
+
+-- |FIXME: docs
+data RFC822
+
+instance ConvertSuccess ZonedTime (Tagged RFC822 Ascii) where
+ {-# INLINE convertSuccess #-}
+ convertSuccess = (A.fromAsciiBuilder <$>) ∘ cs
+
+instance ConvertSuccess ZonedTime (Tagged RFC822 AsciiBuilder) where
+ {-# INLINE convertSuccess #-}
+ convertSuccess = Tagged ∘ toAsciiBuilder
+
+instance ConvertSuccess TimeZone (Tagged RFC822 Ascii) where
+ {-# INLINE convertSuccess #-}
+ convertSuccess = (A.fromAsciiBuilder <$>) ∘ cs
+instance ConvertSuccess TimeZone (Tagged RFC822 AsciiBuilder) where
+ {-# INLINE convertSuccess #-}
+ convertSuccess tz
+ | timeZoneMinutes tz ≡ 0 = Tagged $ A.toAsciiBuilder "GMT"
+ | otherwise = Tagged $ show4digitsTZ tz
-{-
- date-time = [ day "," ] date time ; dd mm yy
- ; hh:mm:ss zzz
+instance ConvertAttempt (Tagged RFC822 Ascii) ZonedTime where
+ {-# INLINE convertAttempt #-}
+ convertAttempt = parseAttempt' rfc822DateAndTime ∘ untag
- day = "Mon" / "Tue" / "Wed" / "Thu"
- / "Fri" / "Sat" / "Sun"
+-- |Parse an RFC 822 date and time string.
+rfc822DateAndTime ∷ Parser ZonedTime
+rfc822DateAndTime = dateTime
- date = 1*2DIGIT month 2DIGIT ; day month year
- ; e.g. 20 Jun 82
+dateTime ∷ Parser ZonedTime
+dateTime = do weekDay ← optionMaybe $
+ do w ← shortWeekDayNameP
+ _ ← string ", "
+ return w
+ gregDay ← date
+ case weekDay of
+ Nothing
+ -> return ()
+ Just givenWD
+ -> assertWeekDayIsGood givenWD gregDay
+ (tod, timeZone) ← rfc822Time
+ let lt = LocalTime gregDay tod
+ zt = ZonedTime lt timeZone
+ return zt
- month = "Jan" / "Feb" / "Mar" / "Apr"
- / "May" / "Jun" / "Jul" / "Aug"
- / "Sep" / "Oct" / "Nov" / "Dec"
+date ∷ Parser Day
+date = do day ← read2
+ _ ← char ' '
+ month ← shortMonthNameP
+ _ ← char ' '
+ year ← (+ 1900) <$> read2
+ _ ← char ' '
+ assertGregorianDateIsGood year month day
- time = hour zone ; ANSI and Military
+-- |Parse the time and time zone of an RFC 822 date and time string.
+rfc822Time ∷ Parser (TimeOfDay, TimeZone)
+rfc822Time = do tod ← hms
+ _ ← char ' '
+ tz ← zone
+ return (tod, tz)
- hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
- ; 00:00:00 - 23:59:59
+hms ∷ Parser TimeOfDay
+hms = do hour ← read2
+ minute ← char ':' *> read2
+ second ← option 0 (char ':' *> read2)
+ assertTimeOfDayIsGood hour minute second
- zone = "UT" / "GMT" ; Universal Time
- ; North American : UT
- / "EST" / "EDT" ; Eastern: - 5/ - 4
- / "CST" / "CDT" ; Central: - 6/ - 5
- / "MST" / "MDT" ; Mountain: - 7/ - 6
- / "PST" / "PDT" ; Pacific: - 8/ - 7
- / 1ALPHA ; Military: Z = UT;
- ; A:-1; (J not used)
- ; M:-12; N:+1; Y:+12
- / ( ("+" / "-") 4DIGIT ) ; Local differential
- ; hours+min. (HHMM)
--}
+zone ∷ Parser TimeZone
+zone = choice [ string "UT" *> return (TimeZone 0 False "UT" )
+ , string "GMT" *> return (TimeZone 0 False "GMT")
+ , char 'E'
+ *> choice [ string "ST" *> return (TimeZone ((-5) * 60) False "EST")
+ , string "DT" *> return (TimeZone ((-4) * 60) True "EDT")
+ ]
+ , char 'C'
+ *> choice [ string "ST" *> return (TimeZone ((-6) * 60) False "CST")
+ , string "DT" *> return (TimeZone ((-5) * 60) True "CDT")
+ ]
+ , char 'M'
+ *> choice [ string "ST" *> return (TimeZone ((-7) * 60) False "MST")
+ , string "DT" *> return (TimeZone ((-6) * 60) True "MDT")
+ , return (TimeZone ((-12) * 60) False "M")
+ ]
+ , char 'P'
+ *> choice [ string "ST" *> return (TimeZone ((-8) * 60) False "PST")
+ , string "DT" *> return (TimeZone ((-7) * 60) True "PDT")
+ ]
+ , char 'Z' *> return (TimeZone 0 False "Z")
+ , char 'A' *> return (TimeZone ((-1) * 60) False "A")
+ , char 'N' *> return (TimeZone ( 1 * 60) False "N")
+ , char 'Y' *> return (TimeZone ( 12 * 60) False "Y")
+ , read4digitsTZ
+ ]
-format :: ZonedTime -> String
-format zonedTime
+toAsciiBuilder ∷ ZonedTime → AsciiBuilder
+toAsciiBuilder zonedTime
= let localTime = zonedTimeToLocalTime zonedTime
timeZone = zonedTimeZone zonedTime
(year, month, day) = toGregorian (localDay localTime)
(_, _, week) = toWeekDate (localDay localTime)
timeOfDay = localTimeOfDay localTime
in
- concat [ shortWeekDayName week
- , ", "
- , show2 day
- , " "
- , shortMonthName month
- , " "
- , show2 (year `mod` 100)
- , " "
- , show2 (todHour timeOfDay)
- , ":"
- , show2 (todMin timeOfDay)
- , ":"
- , show2 (floor (todSec timeOfDay))
- , " "
- , showTZ timeZone
- ]
-
-showTZ :: TimeZone -> String
-showTZ tz
- = case timeZoneMinutes tz of
- offset | offset < 0 -> '-' : showTZ' (negate offset)
- | otherwise -> '+' : showTZ' offset
- where
- showTZ' offset
- = let h = offset `div` 60
- m = offset - h * 60
- in
- concat [show2 h, show2 m]
+ shortWeekDayName week
+ ⊕ A.toAsciiBuilder ", "
+ ⊕ show2 day
+ ⊕ A.toAsciiBuilder " "
+ ⊕ shortMonthName month
+ ⊕ A.toAsciiBuilder " "
+ ⊕ show2 (year `mod` 100)
+ ⊕ A.toAsciiBuilder " "
+ ⊕ show2 (todHour timeOfDay)
+ ⊕ A.toAsciiBuilder ":"
+ ⊕ show2 (todMin timeOfDay)
+ ⊕ A.toAsciiBuilder ":"
+ ⊕ show2 (floor (todSec timeOfDay) ∷ Int)
+ ⊕ A.toAsciiBuilder " "
+ ⊕ untag (cs timeZone ∷ Tagged RFC822 AsciiBuilder)
-parse :: String -> Maybe ZonedTime
-parse src = case P.parse p "" src of
- Right zt -> Just zt
- Left _ -> Nothing
- where
- p = do zt <- parser
- _ <- P.eof
- return zt
+deriveAttempts [ ([t| ZonedTime |], [t| Tagged RFC822 Ascii |])
+ , ([t| ZonedTime |], [t| Tagged RFC822 AsciiBuilder |])
+ , ([t| TimeZone |], [t| Tagged RFC822 Ascii |])
+ , ([t| TimeZone |], [t| Tagged RFC822 AsciiBuilder |])
+ ]