*grin* its so obvious once you know the answer :-) Thx ----Original Message Follows---- On Tue, 20 Jul 2004, Crypt Master wrote:

Exmaple:

<CODE> type Fitness = Integer data Population a = Population [(Fitness, a)] deriving (Show)

data GAParams = GAParams { randomNums :: [Integer] , someFunc :: (Int->Int->(Population a))} </CODE>

Like for 'Population a' you have to specify a type parameter for 'GAParams', i.e. | v data GAParams a = GAParams { randomNums :: [Integer] , someFunc :: (Int->Int->(Population a))} _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963