Thomas Hartman wrote:
could someone explain sharing?
A good tool for visualising the difference between shared and non-shared results would be vacuum, using one of its front ends, vacuum-cairo or vacuum-ubigraph. http://hackage.haskell.org/package/vacuum http://hackage.haskell.org/package/vacuum-cairo http://hackage.haskell.org/package/vacuum-ubigraph To see sharing, you will need to view a set of outputs (not just one string). To keep the graph to a manageable size, use a smaller alphabet: digits = "01" -- All words of length n, with shared substrings shared :: Int -> [String] shared n = sss !! n where sss = [""] : [ [ c:s | c <- digits, s <- ss ] | ss <- sss ] -- All words of length n, with unshared substrings unshared :: Int -> [String] unshared 0 = [""] unshared n = [ c:s | c <- digits, s <- unshared (n-1) ] And then in GHCi: Vacuum.Cairo> shared 3 == unshared 3 True Vacuum.Cairo> view $ shared 3 Vacuum.Cairo> view $ unshared 3 I'd send some PNGs, except my vacuum installation is currently broken. Perhaps someone else can? Regards, Matthew