How to provide explicit type declarations for functions when using GHCi?

Question

How to I define the equivalent of this function (taken from learnyouahaskell) inside GHCi?

import Data.List  

numUniques :: (Eq a) => [a] -> Int  
num         


        

Answer 1

Is there a way provide type declarations in GHCi?

let numUniques' :: (Eq a) => [a] -> Int; numUniques' = length . nub

Or is there another way to define functions like these which doesn't require type declarations?

If you turn off the monomorphism restriction with -XNoMonomorphismRestriction, it will infer the right type.