Sirs/Mesdames: We are considering a course using Haskell. We have "Hugs 98: Based on the haskell 98 standard Copyright 1994-2001," downloaded just a few months ago. (This is under Windows NT.) The following puzzles us --

From the prelude: take 1 [ ] -- expected to return the empty list [ ], instead gives error message: ERROR - Cannot find "show" function for: *** Expression : take 1 [ ] *** Of type : [a]

From a module of ours with definition: -- select nth item from a list select :: Eq a => Int -> [a] -> [a] select n lis | n <= 0 || n > length lis = error "Invalid position!" | n == 1 = [head lis] | otherwise = select (n-1) (tail lis) when called thus: select 0 [ ] Hugs gives the error message: ERROR - Unresolved overloading *** Type : Eq a => [a] *** Expression : select 0 [ ]

Surely Haskell should be able to just return [ ] in both cases. Thanks ahead for your response. Prof Ernest Paquet Walsh University 2020 Easton St. N.W. Canton, OH, 44720 (USA) Phone voice: 330-490-7229 fax: 330-490-7165