Daniel Fischer
So we must make sure that the list of composites that primes' consumes is not the same as that which primes'' consumes.
yes that is what I had done too. Duplicated everything. Turns out, it works exactly as you told it would when using the compiler switch, -fno-cse, thanks!
I used the switch; it didn't help at all. The only thing I can see is
wrong. I didn't. When I did, it worked.
Unfortunately it grows, as you've said - 23MB for 2 mln. :|
And I've found out why. Change the definition of tfold to
tfold f (a: ~(b: ~(c:xs))) = (a `f` (b `f` c)) `f` tfold f xs
and memory stays low (things are going much slower, though).
(forced by gmane poster to delete unusually many of your comments today...) Interesting... As for the structure, I chose it trying to minimize the estimated average cost of a composite production, Sum (1/p)*depth.
You can make a compromise by using the above tfold (which is no longer a tree-fold) and grouping (and merging) the multiples in a slower-growing manner, .......
memory still grows, but much slower, in my tests, due to the much smaller GC time, it's a bit faster than the version with the original tfold.
Great! :)