gistfile1.txt

23.hs:23:3: error:
    • Couldn't match type ‘a’ with ‘a0’
      ‘a’ is a rigid type variable bound by
        the type signature for:
          rnd_select :: forall a. [a] -> Int -> IO [a]
        at 23.hs:18:1-34
      Expected type: IO [a]
        Actual type: IO [a0]
    • In a stmt of a 'do' block: return choice
      In the expression:
        do gen <- getStdGen
           let (gen', choice) = (chooseN gen n xs)
           setStdGen gen'
           return choice
      In an equation for ‘rnd_select’:
          rnd_select xs n
            = do gen <- getStdGen
                 let (gen', choice) = ...
                 setStdGen gen'
                 ....
    • Relevant bindings include
        choice :: [a0] (bound at 23.hs:21:14)
        xs :: [a] (bound at 23.hs:19:12)
        rnd_select :: [a] -> Int -> IO [a] (bound at 23.hs:19:1)
   |
23 |   return choice
   |   ^^^^^^^^^^^^^
Failed, one module loaded.