Re: [Haskell-cafe] nub vs. find + (:) Is this abysmal code?

On Sun, 10 Feb 2008, Michael Feathers wrote:

How bad is this:

addProduct :: [Product] -> Product -> [Product] addProduct inventory product = nub (product : inventory)

compared to this:

addProduct :: [Product] -> Product -> [Product] addProduct inventory p | isNothing (find (==p) inventory) = p : inventory | otherwise = inventory

Data.Set is first choice, 'elem' is second choice, but still better than 'isNothing (find ...)'.