import "JavaBuiltin" as Java

infixl 6  (+), (-)

class Num a where 
    (+) :: a -> a -> a
    (-) :: a -> a -> a
    isZero :: a -> Boolean
    one :: a     
    
instance Num Integer where
    x + y = Java.iadd x y
    x - y = Java.isub x y
    isZero x = Java.icmpeq Java.iconst_0 x
    one = Java.iconst_1
  
even x = if isZero x then True else odd (x - one)
odd x = if isZero x then False else even (x - one)   
    
main = odd (8 :: Integer)
--
false