Is it possible to write a Haskell function with type Int -> Float

Question

I can write

double :: Int -> Float
double i = 2.0

but that isn't in any way a function of its argument. Casting is apparently forbidden, mixed-mode arithmetic isn't supported, so I can't do anything like

double :: Int -> Float
double i = 2.0 * i

I'm actually trying to figure out how to define

series :: (Int -> Float) -> Int -> [Float]

to return the infinite series [f(i), f(i+1), f(i+2),...] but I'm stuck at computing f(i).

If this is really impossible, what type must I use?

Thanks!

Answer 1

I think you're looking for the fromIntegral function.