SpaceAge.hs

module SpaceAge (Planet(..), ageOn) where
import Data.List
--Given an age in seconds, calculate how old someone would be on:

--Mercury: orbital period 0.2408467 Earth years
--Venus: orbital period 0.61519726 Earth years
--Earth: orbital period 1.0 Earth years, 365.25 Earth days, or 31557600 seconds
--Mars: orbital period 1.8808158 Earth years
--Jupiter: orbital period 11.862615 Earth years
--Saturn: orbital period 29.447498 Earth years
--Uranus: orbital period 84.016846 Earth years
--Neptune: orbital period 164.79132 Earth years
--So if you were told someone were 1,000,000,000 seconds old, you should be able to say that they're 31.69 Earth-years old.
data Planet = Mercury
            | Venus
            | Earth
            | Mars
            | Jupiter 
            | Saturn
            | Uranus
            | Neptune

type Planets = [(Planet, Float)]

orbPers :: Planets
orbPers = [(Mercury, 0.2408467), (Venus, 0.61519726), (Earth, 1), (Mars, 1.8808158)]

ageOn :: Planet -> Float -> Float
ageOn p a = snd (head ((filter (p == fst) orbPers))) 

--orbPer :: Planet -> Float
--orbPer
--    | Mercury = 0.2408467

--ageOn Mercury seconds = ageOn Earth seconds / 0.2408467
--ageOn Venus seconds = ageOn Earth seconds / 0.61519726
--ageOn Earth seconds= seconds / 31557600
--ageOn Mars seconds = ageOn Earth seconds / 1.8808158
--ageOn Jupiter seconds = ageOn Earth seconds / 11.862615
--ageOn Saturn seconds = ageOn Earth seconds / 29.447498
--ageOn Uranus seconds = ageOn Earth seconds / 84.016846
--ageOn Neptune seconds = ageOn Earth seconds / 164.79132