+ 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