Haskell generate subsets

Question

I have a function \'subsets\' which generate all the subsets of a given set:

subsets :: [Int] -> [[Int]]
subsets []  = [[]]
subsets (x:xs) = subsets xs ++         


        

Answer 1

The idea is that you want to take all subsets and then only keep the ones that sum 0

subsetsSum0 ls = filter (\ss -> (sum ss) == 0) (subsets ls)

let's make this code point-free

subsetsSum0 = filter ((==0) . sum) . subsets