-{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE
+ OverloadedStrings
+ , UnicodeSyntax
+ #-}
module Data.Time.RFC822.Internal
( rfc822DateAndTime
-
- -- private
, rfc822time
)
where
-import Control.Monad
-import Data.Fixed
+import Control.Applicative
+import Data.Attoparsec.Char8
import Data.Time
-import Data.Time.Calendar.WeekDate
import Data.Time.HTTP.Common
--- |This is a parsec parser for RFC 822 date and time strings.
-rfc822DateAndTime :: Stream s m Char => ParsecT s u m ZonedTime
+-- |Parse an RFC 822 date and time string.
+rfc822DateAndTime ∷ Parser ZonedTime
rfc822DateAndTime = dateTime
-dateTime :: Stream s m Char => ParsecT s u m ZonedTime
-dateTime = do weekDay <- optionMaybe $
- do w <- shortWeekDayNameP
- _ <- string ", "
- return w
- gregDay <- date
+dateTime ∷ Parser ZonedTime
+dateTime = do weekDay ← optionMaybe $
+ do w ← shortWeekDayNameP
+ _ ← string ", "
+ return w
+ gregDay ← date
case weekDay of
Nothing
- -> return () -- No day in week exists.
+ -> return ()
Just givenWD
-> assertWeekDayIsGood givenWD gregDay
- (tod, timeZone) <- rfc822time
+ (tod, timeZone) ← rfc822time
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 ' '
- month <- shortMonthNameP
- _ <- char ' '
- year <- liftM (+ 1900) read2
- _ <- char ' '
+date ∷ Parser Day
+date = do day ← read2
+ _ ← char ' '
+ month ← shortMonthNameP
+ _ ← char ' '
+ year ← (+ 1900) <$> read2
+ _ ← char ' '
assertGregorianDateIsGood year month day
-rfc822time :: Stream s m Char => ParsecT s u m (TimeOfDay, TimeZone)
-rfc822time = do tod <- hour
- _ <- char ' '
- tz <- zone
+-- |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 :: Stream s m Char => ParsecT s u m TimeOfDay
-hour = do hour <- read2
- minute <- char ':' >> read2
- second <- option 0 (char ':' >> read2)
- assertTimeOfDayIsGood hour minute second
+hms ∷ Parser TimeOfDay
+hms = do hour ← read2
+ minute ← char ':' *> read2
+ second ← option 0 (char ':' *> read2)
+ assertTimeOfDayIsGood hour minute second
-zone :: Stream s m Char => ParsecT s u m TimeZone
-zone = choice [ string "UT" >> return (TimeZone 0 False "UT" )
- , string "GMT" >> return (TimeZone 0 False "GMT")
+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")
+ *> 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")
+ *> 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")
+ *> 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")
+ *> 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")
+ , 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
]