Merge pull request #5 from typeable/ville/add-opm-holidays

src/Holidays/EDay.hs

@@ -0,0 +1,28 @@
+{-# OPTIONS -Wno-orphans #-}
+{-# LANGUAGE DeriveLift #-}
+
+module Holidays.EDay (EDay, eDayToDay) where
+
+import Data.ByteString.Char8
+import Data.Csv
+import Data.Time
+import Data.Time.Calendar.OrdinalDate
+import Data.Vector qualified as V
+import Language.Haskell.TH.Lift
+
+data EDay = EDay {edYear :: Integer, edDay :: Int}
+  deriving stock (Eq,Ord,Show,Lift)
+
+eDayToDay :: EDay -> Day
+eDayToDay (EDay y d) = fromOrdinalDate y  d
+
+instance FromField EDay where
+  parseField f = mkEDay <$> parseTimeM False defaultTimeLocale (iso8601DateFormat Nothing) (unpack f)
+    where mkEDay d = let (theYear,theDay) = toOrdinalDate d in EDay theYear theDay
+
+instance FromRecord EDay where
+  parseRecord v
+      | n == 1 = unsafeIndex v 0
+      | otherwise = fail "Expected single field for a day"
+        where
+          n = V.length v