4 -- |This module provides functions to parse and format RFC 822 date
7 -- The syntax is as follows:
9 -- > date-time ::= [ day-of-week ", " ] date SP time SP zone
10 -- > day-of-week ::= "Mon" | "Tue" | "Wed" | "Thu"
11 -- > | "Fri" | "Sat" | "Sun"
12 -- > date ::= day SP month SP year
14 -- > year ::= 2DIGIT ; Yes, only 2 digits.
15 -- > month ::= "Jan" | "Feb" | "Mar" | "Apr"
16 -- > | "May" | "Jun" | "Jul" | "Aug"
17 -- > | "Sep" | "Oct" | "Nov" | "Dec"
18 -- > time ::= hour ":" minute [ ":" second ]
20 -- > minute ::= 2DIGIT
21 -- > second ::= 2DIGIT
22 -- > zone ::= "UT" | "GMT" ; Universal Time
23 -- > | "EST" | "EDT" ; Eastern : -5 / -4
24 -- > | "CST" | "CDT" ; Central : -6 / -5
25 -- > | "MST" | "MDT" ; Mountain: -7 / -6
26 -- > | "PST" | "PDT" ; Pacific : -8 / -7
32 -- > | ("+" | "-") 4DIGIT ; Local diff: HHMM
33 module Data.Time.RFC822
43 import Data.Ascii (Ascii)
44 import qualified Data.Ascii as A
45 import qualified Data.Attoparsec.Char8 as P
47 import Data.Time.RFC822.Internal
48 import Prelude.Unicode
50 -- |Convert a 'ZonedTime' to RFC 822 date and time string.
51 toAscii ∷ ZonedTime → Ascii
52 toAscii = A.fromAsciiBuilder ∘ toAsciiBuilder
54 -- |Parse an RFC 822 date and time string. When the string can't be
55 -- parsed, it returns @'Left' err@.
56 fromAscii ∷ Ascii → Either String ZonedTime
57 fromAscii = P.parseOnly p ∘ A.toByteString
59 p = do zt ← rfc822DateAndTime