module Data.Time.Calendar.Days
(
Day(..)
, addDays
, diffDays
) where
import Control.DeepSeq
import Data.Data
import Data.Ix
newtype Day = ModifiedJulianDay
{ toModifiedJulianDay :: Integer
} deriving (Eq, Ord, Data, Typeable)
instance NFData Day where
rnf (ModifiedJulianDay a) = rnf a
instance Enum Day where
succ (ModifiedJulianDay a) = ModifiedJulianDay (succ a)
pred (ModifiedJulianDay a) = ModifiedJulianDay (pred a)
toEnum = ModifiedJulianDay . toEnum
fromEnum (ModifiedJulianDay a) = fromEnum a
enumFrom (ModifiedJulianDay a) = fmap ModifiedJulianDay (enumFrom a)
enumFromThen (ModifiedJulianDay a) (ModifiedJulianDay b) = fmap ModifiedJulianDay (enumFromThen a b)
enumFromTo (ModifiedJulianDay a) (ModifiedJulianDay b) = fmap ModifiedJulianDay (enumFromTo a b)
enumFromThenTo (ModifiedJulianDay a) (ModifiedJulianDay b) (ModifiedJulianDay c) =
fmap ModifiedJulianDay (enumFromThenTo a b c)
instance Ix Day where
range (ModifiedJulianDay a, ModifiedJulianDay b) = fmap ModifiedJulianDay (range (a, b))
index (ModifiedJulianDay a, ModifiedJulianDay b) (ModifiedJulianDay c) = index (a, b) c
inRange (ModifiedJulianDay a, ModifiedJulianDay b) (ModifiedJulianDay c) = inRange (a, b) c
rangeSize (ModifiedJulianDay a, ModifiedJulianDay b) = rangeSize (a, b)
addDays :: Integer -> Day -> Day
addDays n (ModifiedJulianDay a) = ModifiedJulianDay (a + n)
diffDays :: Day -> Day -> Integer
diffDays (ModifiedJulianDay a) (ModifiedJulianDay b) = a b