@@ -0,0 +1,39 @@
1+{-# LANGUAGE OverloadedStrings #-}
2+module RFC2616 where
3+
4+import Data.ParserCombinators.Attoparsec.Incremental.Char8
5+import Data.ByteString.Lazy.Char8 (ByteString)
6+import qualified Data.ByteString.Lazy.Char8 as L
7+import Data.ByteString.Char8 ()
8+import Control.Applicative
9+import Data.Char
10+import Control.Monad
11+import Prelude hiding (takeWhile)
12+
13+date = rfc1123Date -- <|> rfc850Date <|> asctimeDate
14+
15+oneOf :: Alternative f => [f a] -> f a
16+oneOf = foldr (<|>) empty
17+
18+rfc1123Date =
19+ liftA3 (,,) (wkday <* string ", ") (date <* char ' ') (time <* string " GMT") <?> "RFC1123 date"
20+ where wkday = oneWord "Mon Tue Wed Thu Fri Sat Sun"
21+ oneWord = oneOf . map string . L.words
22+ date = liftA3 (,,) (d2 <* char ' ') (month <* char ' ') d4
23+ month = oneWord "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec"
24+ d2 = replicateM 2 (satisfy isDigit)
25+ d4 = replicateM 4 (satisfy isDigit)
26+
27+time = liftA3 (,,) (d <* c) (d <* c) d <?> "time"
28+ where d = replicateM 2 (satisfy isDigit)
29+ c = char ':'
30+
31+eol = (char '\n' *> pure Nothing) <|> (string "\r\n" *> pure Nothing)
32+
33+header =
34+ (,) <$> (takeWhile fieldChar <* char ':' <* skipWhile space)
35+ <*> ((:) <$> tillEOL <*> many cont)
36+ where tillEOL = takeTill (\c -> c == '\r' || c == '\n') <* eol
37+ fieldChar c = c /= ':' && c >= '!' && c <= '~'
38+ cont = some (satisfy space) *> tillEOL
39+ space c = c == ' ' || c == '\t'