On Thu, 2008-01-10 at 20:37 -0800, Jonathan Cast wrote:
It might be faster; laziness usually has higher constants than direct implementations. But I doubt the difference is critical in this case, and I would definitely time a re-writing and throw it away unless it was significantly faster. But I don't think this is a case where laziness actually alters either the time or the space asymptotics of the algorithm (you end up creating an ~ O(n) tree anyway, so I'd figure O(n) space was OK for the loop, too).
I was wondering if laziness would make it run as if it was a single O(n) operation (get one directory entry "on demand", pass it to filter and then to insertInTree), because only one entry is used at a time, so that only the "current" entry needs to be evaluated. I still find it hard to evaluate the effects of laziness on the complexity of programs... Andre