+{-# LANGUAGE
+ 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
+ ( -- * Formatting
+ toAscii
+ , toAsciiBuilder
+
+ -- * Parsing
+ , fromAscii
+ , rfc822DateAndTime
)
where
-
-import qualified Text.Parsec as P
-
+import Data.Ascii (Ascii)
+import qualified Data.Ascii as A
+import qualified Data.Attoparsec.Char8 as P
import Data.Time
-import Data.Time.Calendar.WeekDate
-import Data.Time.HTTP.Common
-import Data.Time.RFC822.Parsec
-
-
-{-
- date-time = [ day "," ] date time ; dd mm yy
- ; hh:mm:ss zzz
-
- day = "Mon" / "Tue" / "Wed" / "Thu"
- / "Fri" / "Sat" / "Sun"
-
- date = 1*2DIGIT month 2DIGIT ; day month year
- ; e.g. 20 Jun 82
+import Data.Time.RFC822.Internal
+import Prelude.Unicode
- month = "Jan" / "Feb" / "Mar" / "Apr"
- / "May" / "Jun" / "Jul" / "Aug"
- / "Sep" / "Oct" / "Nov" / "Dec"
-
- time = hour zone ; ANSI and Military
-
- hour = 2DIGIT ":" 2DIGIT [":" 2DIGIT]
- ; 00:00:00 - 23:59:59
-
- 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)
--}
-
-format :: ZonedTime -> String
-format 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]
+-- |Convert a 'ZonedTime' to RFC 822 date and time string.
+toAscii ∷ ZonedTime → Ascii
+toAscii = A.fromAsciiBuilder ∘ toAsciiBuilder
-parse :: String -> Maybe ZonedTime
-parse src = case P.parse p "" src of
- Right zt -> Just zt
- Left _ -> Nothing
+-- |Parse an RFC 822 date and time string. When the string can't be
+-- parsed, it returns @'Left' err@.
+fromAscii ∷ Ascii → Either String ZonedTime
+fromAscii = P.parseOnly p ∘ A.toByteString
where
- p = do zt <- parser
- _ <- P.eof
+ p = do zt ← rfc822DateAndTime
+ P.endOfInput
return zt