On Sat, 2009-01-17 at 10:44 -0800, Max Rabkin wrote: > This traverses the list three times (reverse, init and last are each > linear time): > fromListEnd xs = Zipper (reverse $ init xs) (last xs) [] > > But we only need to do it once: > fromListEnd xs = let x:xs' = reverse xs in Zipper xs' x [] > > I don't *think* this has an effect on strictness/laziness, since both > versions are strict in the spine of the list.
Excellent suggestion; your solution is much more readable and faster. I've made the change here: http://hpaste.org/14030#a1 Thanks, Jeff Wheeler _______________________________________________ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
