grouplens/lenskit — pull request #571 by elehack (2014-04-14 17:27:55+00:00)
Title: Compact more data structures

This introduces the `CompactableLongArrayList`, a long array list that uses an int list if everything fits. I also use the compactable list to reduce packed scored ID list memory use, and the memory use of Top-N accumulation.

Also includes a bump on FunkSVD code in response to getting mikera/vectorz#26 fixed.