How do you hide an operator when importing?

Question

Here's my code, trying to redefine *. It could be achieved only when * previously hided:

import Prelude hiding (*)

(*) :: Int -> Int -> Int
x * 0 = 0
x * y = x + x*(y-1)

But it doesn't work:

$ ghci test.hs

GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help

test.hs:1:24: error: parse error on input ‘*’

Failed, modules loaded: none.

Prelude>

I could hide other function as:

import Prelude hiding (read)

import Prelude hiding (show)

while it doesn't work for operator like *, +, -.

How do I hide them?

Answer 1

Recall how you query ghci for type of a function:

:t read
:t show

About operator:

Do you type :t +?

No, you would receive a parse error then.

You do :t (+).

As for your case, you hide it with additional brackets: ((*))

import Prelude hiding ((*))

(*) :: Int -> Int -> Int
x * 0 = 0
x * y = x + x*(y-1)