Age.hs

{-# LANGUAGE GeneralizedNewtypeDeriving #-}

module Age where

main :: IO ()
main = do
    print "Hello, world."
    print $ show $ ageOn Mecury (earthYearInSeconds * 38)

data Planet =
    Mecury
    | Venus
    | Earth
    | Mars
    | Jupiter
    | Saturn
    | Uranus
    | Neptune

newtype Seconds = MkSeconds Float deriving (Show, Num, Fractional)

earthYearInSeconds :: Seconds
earthYearInSeconds = MkSeconds 31557600

planetFactor :: Planet -> Seconds
planetFactor p = MkSeconds $ 
    case p of
        Mecury -> 0.2408467
        Venus -> 0.61519726
        Earth -> 1
        Mars -> 1.8808158
        Jupiter -> 11.862615
        Saturn -> 29.447498
        Uranus -> 84.016846
        Neptune -> 164.79132

ageOn :: Planet -> Seconds -> Seconds
ageOn p s = (s / earthYearInSeconds / (planetFactor p))