Mirko Rahn
Jon Fairbairn wrote:
Trees with all the elements of a list in that order:
the_trees [x] = [Leaf x] the_trees l = zipWith Branch (concat (map the_trees (tail $ inits l))) (concat (map the_trees (tail $ tails l)))
Sorry, but this problem seems to trigger incorrect codes, somehow.
I don't think it's the problem in this case -- it's writing code when half asleep. The network connexion had been down for hours, so it was past my bedtime when I started...
splits xs = zip (tail . inits $ xs) (tail . tails $ xs)
I should have defined this (though I might have called it partitions), probably like this:
partitions l = inits l `zip` tails l
and used (with appropriate discarding) it in both the_trees and combinations, and I should have written a proper combinations rather than writing "nonempty_combinations" and calling it "combinations". -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk