+-- |This module parses and prints RFC 1123 Date and Time string.
+--
+-- In general you don't have to use this module directly.
module Network.HTTP.Lucu.RFC1123DateTime
( formatRFC1123DateTime
, formatHTTPDateTime
where
import Control.Monad
-import qualified Data.ByteString.Lazy.Char8 as B
-import Data.ByteString.Lazy.Char8 (ByteString)
+import Network.HTTP.Lucu.Format
import Network.HTTP.Lucu.Parser
import System.Time
-import System.Locale
-import Text.Printf
-month = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
-week = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]
+month :: [String]
+month = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
+week :: [String]
+week = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]
+
+-- |Format a @CalendarTime@ to RFC 1123 Date and Time string.
formatRFC1123DateTime :: CalendarTime -> String
formatRFC1123DateTime time
- = printf "%s, %02d %s %04d %02d:%02d:%02d %s"
- (week !! fromEnum (ctWDay time))
- (ctDay time)
- (month !! fromEnum (ctMonth time))
- (ctYear time)
- (ctHour time)
- (ctMin time)
- (ctSec time)
- (ctTZName time)
+ = time `seq`
+ id (week !! fromEnum (ctWDay time))
+ ++ ", " ++
+ fmtDec 2 (ctDay time)
+ ++ " " ++
+ id (month !! fromEnum (ctMonth time))
+ ++ " " ++
+ fmtDec 4 (ctYear time)
+ ++ " " ++
+ fmtDec 2 (ctHour time)
+ ++ ":" ++
+ fmtDec 2 (ctMin time)
+ ++ ":" ++
+ fmtDec 2 (ctSec time)
+ ++ ":" ++
+ id (ctTZName time)
+
+-- |Format a @ClockTime@ to HTTP Date and Time. Time zone will be
+-- always UTC but prints as GMT.
formatHTTPDateTime :: ClockTime -> String
-formatHTTPDateTime = formatRFC1123DateTime . (\cal -> cal { ctTZName = "GMT" }) . toUTCTime
-
+formatHTTPDateTime time
+ = time `seq`
+ formatRFC1123DateTime $! (\cal -> cal { ctTZName = "GMT" }) $! toUTCTime time
+-- |Parse an HTTP Date and Time.
+--
+-- Limitation: RFC 2616 (HTTP\/1.1) says we must accept these three
+-- formats:
+--
+-- * @Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123@
+--
+-- * @Sunday, 06-Nov-94 08:49:37 GMT ; RFC 850, obsoleted by RFC 1036@
+--
+-- * @Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format@
+--
+-- ...but currently this function only supports the RFC 1123
+-- format. This is a violation of RFC 2616 so this should be fixed
+-- later. What a bother!
parseHTTPDateTime :: String -> Maybe ClockTime
parseHTTPDateTime src
= case parseStr httpDateTime src of