module Data.Time.RFC733.Parsec
( rfc733DateAndTime
)
where
import Control.Monad
import Data.Fixed
import Data.Time
import Data.Time.Calendar.WeekDate
import Data.Time.HTTP.Common
import Text.Parsec
rfc733DateAndTime :: Stream s m Char => ParsecT s u m ZonedTime
rfc733DateAndTime = dateTime
dateTime :: Stream s m Char => ParsecT s u m ZonedTime
dateTime = do weekDay <- optionMaybe $
do w <- try longWeekDayNameP
<|>
shortWeekDayNameP
_ <- string ", "
return w
gregDay <- date
case weekDay of
Nothing
-> return ()
Just givenWD
-> assertWeekDayIsGood givenWD gregDay
(tod, timeZone) <- time
let lt = LocalTime gregDay tod
zt = ZonedTime lt timeZone
return zt
date :: Stream s m Char => ParsecT s u m Day
date = do day <- read2
_ <- char '-' <|> char ' '
month <- try longMonthNameP
<|>
shortMonthNameP
_ <- char '-' <|> char ' '
year <- try read4
<|>
liftM (+ 1900) read2
_ <- char ' '
assertGregorianDateIsGood year month day
time :: Stream s m Char => ParsecT s u m (TimeOfDay, TimeZone)
time = do tod <- hour
_ <- char '-' <|> char ' '
tz <- zone
return (tod, tz)
hour :: Stream s m Char => ParsecT s u m TimeOfDay
hour = do hour <- read2
_ <- optional (char ':')
minute <- read2
second <- option 0 $
do _ <- optional (char ':')
read2
assertTimeOfDayIsGood hour minute second
zone :: Stream s m Char => ParsecT s u m TimeZone
zone = choice [ string "GMT" >> return (TimeZone 0 False "GMT")
, char 'N'
>> choice [ string "ST" >> return (TimeZone ((3) * 60 30) False "NST")
, return (TimeZone (1 * 60) False "N")
]
, char 'A'
>> choice [ string "ST" >> return (TimeZone ((4) * 60) False "AST")
, string "DT" >> return (TimeZone ((3) * 60) False "AST")
, return (TimeZone ((1) * 60) False "A")
]
, 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 'Y'
>> choice [ string "ST" >> return (TimeZone ((9) * 60) False "YST")
, string "DT" >> return (TimeZone ((8) * 60) True "YDT")
, return (TimeZone ( 12 * 60) False "Y")
]
, char 'H'
>> choice [ string "ST" >> return (TimeZone ((10) * 60) False "HST")
, string "DT" >> return (TimeZone (( 9) * 60) True "HDT")
]
, char 'B'
>> choice [ string "ST" >> return (TimeZone ((11) * 60) False "BST")
, string "DT" >> return (TimeZone ((10) * 60) True "BDT")
]
, char 'Z' >> return (TimeZone 0 False "Z")
, read4digitsTZ
]