[Haskell-cafe] Function that put elements in Left or Right side of Either depending on type

[Richard A. O'Keefe]

On 4/03/16 4:04 am, Kristoffer Føllesdal wrote:
> I want a function fun :: q -> Either a b where q is of type a or b.  fun shall work in the following way
>
> fun x    gives    Left x     if x :: a
> fun x    gives    Right x   if x :: b

What does "fun 0 :: Either Int Int" do?