-{-# LANGUAGE
- OverloadedStrings
- , UnicodeSyntax
- #-}
--- |Internal functions for "Data.Time.RFC822".
-module Data.Time.RFC822.Internal
- ( rfc822DateAndTime
- , rfc822time
- , showRFC822TimeZone
- , toAsciiBuilder
- )
- where
-import Control.Applicative
-import Data.Ascii (AsciiBuilder)
-import qualified Data.Ascii as A
-import Data.Attoparsec.Char8
-import Data.Monoid.Unicode
-import Data.Time
-import Data.Time.Calendar.WeekDate
-import Data.Time.HTTP.Common
-import Prelude.Unicode
-
--- |Parse an RFC 822 date and time string.
-rfc822DateAndTime ∷ Parser ZonedTime
-rfc822DateAndTime = dateTime
-
-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
-
-date ∷ Parser Day
-date = do day ← read2
- _ ← char ' '
- month ← shortMonthNameP
- _ ← char ' '
- year ← (+ 1900) <$> read2
- _ ← char ' '
- assertGregorianDateIsGood year month day
-
--- |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)
-
-hms ∷ Parser TimeOfDay
-hms = do hour ← read2
- minute ← char ':' *> read2
- second ← option 0 (char ':' *> read2)
- assertTimeOfDayIsGood hour minute second
-
-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
- ]
-
--- |No need to explain.
-showRFC822TimeZone ∷ TimeZone → AsciiBuilder
-showRFC822TimeZone tz
- | timeZoneMinutes tz ≡ 0 = A.toAsciiBuilder "GMT"
- | otherwise = show4digitsTZ tz
-
--- |Convert a 'ZonedTime' to RFC 822 date and time string.
-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
- 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 " "
- ⊕ showRFC822TimeZone timeZone