Prefix form of unary operator in Haskell

Question

In GHCi:

1. Prelude> (+3) 2
   5
2. Prelude> (*3) 2
   6
3. Prelude> (/3) 2
   0.6666666666666666
4. Prelude> (-3) 2
   No instance for (Num (t -> t1))
   arising from the literal 3' at <interactive>:1:2
Possible fix: add an instance declaration for (Num (t -> t1))
In the expression: 3
In the expression: (- 3) 2
In the definition ofit': it = (- 3) 2

How can I correct the last one to make it return -1?

Answer 1

Haskell's grammar doesn't allow you to use - like that. Use the subtract function instead:

(subtract 3) 2