[Haskell-beginners] `coarbitrary' is not a (visible) method of class `Arbitrary'

[Amy de Buitléir]

Thank you Daniel, that solved it. In case anyone else is struggling
with this, here's a revised version of Test.hs which works fine for
me.

import Char
import List
import Test.QuickCheck
import Text.Printf

main  = mapM_ (\(s,a) -> printf "%-25s: " s >> a) tests

-- reversing twice a finite list, is the same as identity
prop_reversereverse s = (reverse . reverse) s == id s
    where _ = s :: [Int]

-- and add this to the tests list
tests  = [("reverse.reverse/id", quickCheck prop_reversereverse)]