2016 Update

Task/Discordian-date/Haskell/discordian-date-1.hs

@@ -0,0 +1,44 @@
+import Data.Time (isLeapYear)
+import Data.Time.Calendar.MonthDay (monthAndDayToDayOfYear)
+import Text.Printf (printf)
+
+type Year = Integer
+type Day = Int
+type Month = Int
+
+data DDate = DDate Weekday Season Day Year
+           | StTibsDay Year deriving (Eq, Ord)
+
+data Season = Chaos
+            | Discord
+            | Confusion
+            | Bureaucracy
+            | TheAftermath
+            deriving (Show, Enum, Eq, Ord, Bounded)
+
+data Weekday = Sweetmorn
+             | Boomtime
+             | Pungenday
+             | PricklePrickle
+             | SettingOrange
+             deriving (Show, Enum, Eq, Ord, Bounded)
+
+instance Show DDate where
+  show (StTibsDay y) = printf "St. Tib's Day, %d YOLD" y
+  show (DDate w s d y) = printf "%s, %s %d, %d YOLD" (show w) (show s) d y
+
+fromYMD :: (Year, Month, Day) -> DDate
+fromYMD (y, m, d)
+  | leap && dayOfYear == 59 = StTibsDay yold
+  | leap && dayOfYear >= 60 = mkDDate $ dayOfYear - 1
+  | otherwise               = mkDDate dayOfYear
+  where
+    yold = y + 1166
+    dayOfYear = monthAndDayToDayOfYear leap m d - 1
+    leap = isLeapYear y
+
+    mkDDate dayOfYear = DDate weekday season dayOfSeason yold
+      where
+        weekday = toEnum $ dayOfYear `mod` 5
+        season = toEnum $ dayOfYear `div` 73
+        dayOfSeason = 1 + dayOfYear `mod` 73

Task/Discordian-date/Haskell/discordian-date-2.hs

@@ -0,0 +1,11 @@
+test = mapM_ display dates
+  where
+    display d = putStr (show d ++ " -> ") >> print (fromYMD d)
+    dates = [(2012,2,28)
+            ,(2012,2,29)
+            ,(2012,3,1)
+            ,(2012,3,14)
+            ,(2012,3,15)
+            ,(2010,9,2)
+            ,(2010,12,31)
+            ,(2011,1,1)]

Task/Discordian-date/Haskell/discordian-date.hs

@@ -1,14 +0,0 @@
-import Data.List
-import Data.Time
-import Data.Time.Calendar.MonthDay
-
-seasons = words "Chaos Discord Confusion Bureaucracy The_Aftermath"
-
-discordianDate (y,m,d) = do
-  let doy = monthAndDayToDayOfYear (isLeapYear y) m d
-      (season, dday) = divMod doy 73
-      dos = dday - fromEnum (isLeapYear y && m >2)
-      dDate
-	| isLeapYear y && m==2 && d==29 = "St. Tib's Day, " ++ show (y+1166) ++ " YOLD"
-	| otherwise = seasons!!season ++ " " ++ show dos ++ ", " ++ show (y+1166) ++ " YOLD"
-  putStrLn dDate