class GA a where
    initGA :: t -> StdGen -> (a, StdGen)
    mutateGA :: a -> StdGen -> (a, StdGen)
    crossGA :: a -> a -> StdGen -> (a, StdGen)

instance GA Float where
    initGA _ r = randomR (-1.0, 1.0) r
    mutateGA _ r = randomR (-1.0, 1.0) r
    crossGA p1 p2 r = (if choose then p1 else p2, r') where
        (choose, r') = randomR (False, True) r

instance (Ix i, GA e) => GA (Array i e) where
    initGA t r = (array t [], r) {-where
        (arr, r') = initArrayList init (range bounds) r-}