Add a pickler for the <time_stamp> elements.

diff --git a/src/TSN/Picklers.hs b/src/TSN/Picklers.hs
index 72ab4553a9dac895d6b0c77698c0c4a89f6da79b..f80b085efb1dd06507b0735cff9b2d5ba217bc6d 100644 (file)
--- a/src/TSN/Picklers.hs
+++ b/src/TSN/Picklers.hs
@@ -4,11 +4,12 @@
 module TSN.Picklers (
   xp_date,
   xp_gamedate,
-  xp_time )
+  xp_time,
+  xp_time_stamp )
 where
 
 -- System imports.
-import Data.Time.Clock ( UTCTime )
+import Data.Time.Clock ( NominalDiffTime, UTCTime, addUTCTime )
 import Data.Time.Format ( formatTime, parseTime )
 import System.Locale ( defaultTimeLocale )
 import Text.XML.HXT.Arrow.Pickle (
@@ -79,17 +80,53 @@ xp_gamedate =
             _        -> "th"
 
 
+
+-- | The time format string used in 'xp_time' and 'xp_time_stamp'.
+--
+xp_time_format :: String
+xp_time_format = "%I:%M %p"
+
+
 -- | (Un)pickle a UTCTime without the date portion.
 --
 xp_time :: PU UTCTime
 xp_time =
   (to_time, from_time) `xpWrapMaybe` xpText
   where
-    format = "%I:%M %p"
-
     to_time :: String -> Maybe UTCTime
-    to_time = parseTime defaultTimeLocale format
+    to_time = parseTime defaultTimeLocale xp_time_format
 
     from_time :: UTCTime -> String
-    from_time = formatTime defaultTimeLocale format
+    from_time = formatTime defaultTimeLocale xp_time_format
+
+
+
+-- | (Un)pickle the \<time_stamp\> element format to/from a 'UTCTime'.
+--
+--   Example:  \<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.
+--
+xp_time_stamp :: PU UTCTime
+xp_time_stamp =
+  (to_time_stamp, from_time_stamp) `xpWrapMaybe` xpText
+  where
+    -- This omits the timezone and trailing space.
+    format = " %B %-d, %Y, at " ++ xp_time_format ++ " ET "
+
+    five_hours :: NominalDiffTime
+    five_hours = 5 * 60 * 60
+
+    add_five :: UTCTime -> UTCTime
+    add_five = addUTCTime five_hours
+
+    subtract_five :: UTCTime -> UTCTime
+    subtract_five = addUTCTime (-1 * five_hours)
+
+    to_time_stamp :: String -> Maybe UTCTime
+    to_time_stamp = fmap add_five . parseTime defaultTimeLocale format
 
+    from_time_stamp :: UTCTime -> String
+    from_time_stamp = formatTime defaultTimeLocale format . subtract_five