{-# OPTIONS -Wall -Werror #-} -- #hide module Data.Time.Clock.Scale ( -- * Universal Time -- | Time as measured by the earth. UniversalTime(..), -- * Absolute intervals DiffTime, secondsToDiffTime, picosecondsToDiffTime ) where import Data.Ratio ((%)) import Data.Fixed -- | The Modified Julian Date is the day with the fraction of the day, measured from UT midnight. -- It's used to represent UT1, which is time as measured by the earth's rotation, adjusted for various wobbles. newtype UniversalTime = ModJulianDate {getModJulianDate :: Rational} deriving (Eq,Ord) -- | This is a length of time, as measured by a clock. -- Conversion functions will treat it as seconds. -- It has a precision of 10^-12 s. newtype DiffTime = MkDiffTime Pico deriving (Eq,Ord) -- necessary because H98 doesn't have "cunning newtype" derivation instance Enum DiffTime where succ (MkDiffTime a) = MkDiffTime (succ a) pred (MkDiffTime a) = MkDiffTime (pred a) toEnum = MkDiffTime . toEnum fromEnum (MkDiffTime a) = fromEnum a enumFrom (MkDiffTime a) = fmap MkDiffTime (enumFrom a) enumFromThen (MkDiffTime a) (MkDiffTime b) = fmap MkDiffTime (enumFromThen a b) enumFromTo (MkDiffTime a) (MkDiffTime b) = fmap MkDiffTime (enumFromTo a b) enumFromThenTo (MkDiffTime a) (MkDiffTime b) (MkDiffTime c) = fmap MkDiffTime (enumFromThenTo a b c) instance Show DiffTime where show (MkDiffTime t) = (showFixed True t) ++ "s" -- necessary because H98 doesn't have "cunning newtype" derivation instance Num DiffTime where (MkDiffTime a) + (MkDiffTime b) = MkDiffTime (a + b) (MkDiffTime a) - (MkDiffTime b) = MkDiffTime (a - b) (MkDiffTime a) * (MkDiffTime b) = MkDiffTime (a * b) negate (MkDiffTime a) = MkDiffTime (negate a) abs (MkDiffTime a) = MkDiffTime (abs a) signum (MkDiffTime a) = MkDiffTime (signum a) fromInteger i = MkDiffTime (fromInteger i) -- necessary because H98 doesn't have "cunning newtype" derivation instance Real DiffTime where toRational (MkDiffTime a) = toRational a -- necessary because H98 doesn't have "cunning newtype" derivation instance Fractional DiffTime where (MkDiffTime a) / (MkDiffTime b) = MkDiffTime (a / b) recip (MkDiffTime a) = MkDiffTime (recip a) fromRational r = MkDiffTime (fromRational r) -- | Create a 'DiffTime' which represents an integral number of seconds. secondsToDiffTime :: Integer -> DiffTime secondsToDiffTime = fromInteger -- | Create a 'DiffTime' from a number of picoseconds. picosecondsToDiffTime :: Integer -> DiffTime picosecondsToDiffTime x = fromRational (x % 1000000000000)