Question

I am trying to use the Data.Unique in Haskell.
The newUnique can generate an object, but I want to see what it is. How can I do that?

Answer 1

It generates an opaque, unique object different from all others in your program. You cannot look at it. You are allowed to hash it to an Int though:

import Data.Unique

main = do
    u <- newUnique
    print (hashUnique u)

Like so:

*Main> main
1
*Main> main
2
*Main> main
3
*Main> main
4