+-- | (Un)pickle a UTCTime from a weather forecast's gamedate. Example
+-- input looks like,
+--
+-- When unpickling we get rid of the suffixes \"st\", \"nd\", \"rd\", and
+-- \"th\". During pickling, we add them back based on the last digit
+-- of the date.
+--
+-- Examples:
+--
+-- >>> let tn = text_node "Monday, December 30th"
+-- >>> let (Just gd) = unpickleDoc xp_gamedate tn
+-- >>> gd
+-- 1970-12-30 00:00:00 UTC
+-- >>> pickleDoc xp_gamedate gd
+-- NTree (XTag "/" []) [NTree (XText "Wednesday, December 30th") []]
+--
+xp_gamedate :: PU UTCTime
+xp_gamedate =
+ (to_gamedate, from_gamedate) `xpWrapMaybe` xpText
+ where
+ format = "%A, %B %-d"
+
+ to_gamedate :: String -> Maybe UTCTime
+ to_gamedate s =
+ parseTime defaultTimeLocale format s'
+ where
+ s' = case (reverse s) of
+ (c2:c1:cs) -> let suffix = [c1,c2]
+ in
+ case suffix of
+ "st" -> reverse cs
+ "nd" -> reverse cs
+ "rd" -> reverse cs
+ "th" -> reverse cs
+ _ -> s -- Unknown suffix, leave it alone.
+ _ -> s -- The String is less than two characters long,
+ -- leave it alone.
+
+
+ from_gamedate :: UTCTime -> String
+ from_gamedate d = s ++ (suffix s)
+ where
+ s = formatTime defaultTimeLocale format d
+
+ suffix :: String -> String
+ suffix cs =
+ case (reverse cs) of
+ [] -> []
+ ('1':_) -> "st"
+ ('2':_) -> "nd"
+ ('3':_) -> "rd"
+ _ -> "th"
+
+
+
+
+
+
+-- | (Un)pickle a UTCTime without the date portion. Doesn't work if
+-- the fields aren't zero-padded to two characters.
+--
+-- /Examples/:
+--
+-- Padded, should work:
+--
+-- >>> let tn = text_node "04:35 PM"
+-- >>> unpickleDoc xp_time tn
+-- Just 1970-01-01 16:35:00 UTC
+--
+-- Unpadded, should fail:
+--
+-- >>> let tn = text_node "4:35 PM"
+-- >>> unpickleDoc xp_time tn
+-- Nothing
+--
+xp_time :: PU UTCTime
+xp_time =
+ (to_time, from_time) `xpWrapMaybe` xpText
+ where
+ to_time :: String -> Maybe UTCTime
+ to_time = parseTime defaultTimeLocale time_format
+
+ from_time :: UTCTime -> String
+ from_time = formatTime defaultTimeLocale time_format
+
+
+-- | (Un)pickle a UTCTime without the date portion. This differs from
+-- 'xp_time' in that it uses periods in the AM/PM part, i.e. \"A.M.\"
+-- and \"P.M.\" It also doesn't use padding for the \"hours\" part.
+--
+-- /Examples/:
+--
+-- A standard example of the correct form:
+--
+-- >>> let tn = text_node "11:30 A.M."
+-- >>> let (Just result) = unpickleDoc xp_time_dots tn
+-- >>> result
+-- 1970-01-01 11:30:00 UTC
+-- >>> pickleDoc xp_time_dots result
+-- NTree (XTag "/" []) [NTree (XText "11:30 A.M.") []]
+--
+-- Another miracle, it still parses with a leading zero!
+--
+-- >>> let tn = text_node "01:30 A.M."
+-- >>> unpickleDoc xp_time_dots tn
+-- Just 1970-01-01 01:30:00 UTC
+--
+xp_time_dots :: PU UTCTime
+xp_time_dots =
+ (to_time, from_time) `xpWrapMaybe` xpText
+ where
+ -- | The hours arent padded with zeros.
+ nopad_time_format :: String
+ nopad_time_format = "%-I:%M %p"
+
+ to_time :: String -> Maybe UTCTime
+ to_time = (parseTime defaultTimeLocale nopad_time_format) . (replace "." "")
+
+ from_time :: UTCTime -> String
+ from_time t =
+ replace "AM" "A.M." (replace "PM" "P.M." s)
+ where
+ s = formatTime defaultTimeLocale nopad_time_format t
+
+
+-- | (Un)pickle a UTCTime without the date portion, allowing for a
+-- value of \"TBA\" (which gets translated to 'Nothing').
+--
+-- /Examples/:
+--
+-- A failed parse will return 'Nothing':
+--
+-- >>> let tn = text_node "YO"
+-- >>> unpickleDoc xp_tba_time tn
+-- Just Nothing
+--
+-- And so will parsing a \"TBA\":
+--
+-- >>> let tn = text_node "TBA"
+-- >>> unpickleDoc xp_tba_time tn
+-- Just Nothing
+--
+-- But re-pickling 'Nothing' gives only \"TBA\":
+--
+-- >>> pickleDoc xp_tba_time Nothing
+-- NTree (XTag "/" []) [NTree (XText "TBA") []]
+--
+-- A normal time is also parsed successfully, of course:
+--
+-- >>> let tn = text_node "08:10 PM"
+-- >>> unpickleDoc xp_tba_time tn
+-- Just (Just 1970-01-01 20:10:00 UTC)
+--
+xp_tba_time :: PU (Maybe UTCTime)
+xp_tba_time =
+ (to_time, from_time) `xpWrap` xpText
+ where
+ to_time :: String -> Maybe UTCTime
+ to_time s
+ | s == "TBA" = Nothing
+ | otherwise = parseTime defaultTimeLocale time_format s
+
+ from_time :: Maybe UTCTime -> String
+ from_time Nothing = "TBA"
+ from_time (Just t) = formatTime defaultTimeLocale time_format t
+
+
+
+-- | (Un)pickle the \<time_stamp\> element format to/from a 'UTCTime'.
+-- The time_stamp elements look something like,
+--
+-- \<time_stamp\> January 6, 2014, at 10:11 PM ET \</time_stamp\>
+--
+-- TSN doesn't provide a proper time zone name, so we assume that
+-- it's always Eastern Standard Time. EST is UTC-5, so we
+-- add/subtract 5 hours to convert to/from UTC.
+--
+-- Examples:
+--
+-- >>> let tn = text_node " January 6, 2014, at 10:11 PM ET "
+-- >>> unpickleDoc xp_time_stamp tn
+-- Just 2014-01-07 03:11:00 UTC
+--
+xp_time_stamp :: PU UTCTime
+xp_time_stamp =
+ (parse_time_stamp, from_time_stamp) `xpWrapMaybe` xpText
+ where
+ five_hours :: NominalDiffTime
+ five_hours = 5 * 60 * 60
+
+ subtract_five :: UTCTime -> UTCTime
+ subtract_five = addUTCTime (-1 * five_hours)
+
+ from_time_stamp :: UTCTime -> String
+ from_time_stamp =
+ formatTime defaultTimeLocale time_stamp_format . subtract_five
+
+
+-- | (Un)pickle an ambiguous 12-hour AM/PM time, which is ambiguous
+-- because it's missing the AM/PM part.
+--
+-- Examples:
+--
+-- >>> let tn = text_node "8:00"
+-- >>> unpickleDoc xp_ambiguous_time tn
+-- Just 1970-01-01 08:00:00 UTC
+--
+xp_ambiguous_time :: PU UTCTime
+xp_ambiguous_time =
+ (to_time, from_time) `xpWrapMaybe` xpText
+ where
+ ambiguous_time_format :: String
+ ambiguous_time_format = "%-I:%M"
+
+ to_time :: String -> Maybe UTCTime
+ to_time = parseTime defaultTimeLocale ambiguous_time_format
+
+ from_time :: UTCTime -> String
+ from_time =
+ formatTime defaultTimeLocale ambiguous_time_format
+
+
+-- | Create an 'XmlTree' containing only the given text. This is
+-- useful for testing (un)picklers, where we don't want to have to
+-- bother to create a dummy XML document.
+--
+-- Examples:
+--
+-- >>> text_node "8:00"
+-- NTree (XText "8:00") []
+--
+text_node :: String -> XmlTree
+text_node s = NTree (XText s) []
+
+
+
+--
+-- * Tasty Tests
+--
+
+-- | A list of all tests for this module. This primary exists to
+-- eliminate the unused import/export warnings for 'unpickleDoc' and
+-- 'text_node' which are otherwise only used in the doctests.
+--
+pickler_tests :: TestTree
+pickler_tests =
+ testGroup
+ "Pickler tests"
+ [ test_pickle_of_unpickle_is_identity ]
+
+
+-- | If we unpickle something and then pickle it, we should wind up
+-- with the same thing we started with (plus an additional root
+-- element).
+--
+test_pickle_of_unpickle_is_identity :: TestTree
+test_pickle_of_unpickle_is_identity =
+ testCase "pickle composed with unpickle is (almost) the identity" $ do
+ let tn = text_node "8:00"
+ let (Just utctime) = unpickleDoc xp_ambiguous_time tn
+ let actual = pickleDoc xp_ambiguous_time utctime
+ let expected = NTree (XTag (mkName "/") []) [tn]
+ actual @?= expected